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Renewable Energy as an Airport Revenue Source (2015)

Chapter: Chapter 1 - Introduction to Renewable Energy in the Airport Environment

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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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Suggested Citation:"Chapter 1 - Introduction to Renewable Energy in the Airport Environment." National Academies of Sciences, Engineering, and Medicine. 2015. Renewable Energy as an Airport Revenue Source. Washington, DC: The National Academies Press. doi: 10.17226/22139.
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4Airports are operating today in an ever changing environment influenced by an inter­ connected world economy. With the effects of the great recession lingering and air travel in the post­911 world more costly, airports are striving to provide services more efficiently and identify a competitive advantage. In particular, airports see an opportunity to more fully utilize their land and facility assets to diversify their revenue streams (1). Yet, airports come in many forms from the large international metropolis to the rural transpor­ tation terminus and each has different needs and assets available. According to a recent Report to Congress on the National Plan of Integrated Airport Systems (NPIAS), there are 3,331 operating public use airports in the United States (65% of all airports in the country), that are eligible to receive funding under the FAA’s Airport Improvement Program (AIP) (2). Given the wide differ­ ences in their character, individual airports will deploy their assets in strategic and diverse ways. What these airports have in common is their function as distinct government units. (Ninety­ eight percent of airports in the NPIAS are owned by public entities: 38% city, 25% regional, 17% county, and 9% multi­jurisdictional. Of those, state ownership accounts for 5% and unified port authorities account for 3%). (3) They all provide aviation services to customers and are subject to federal regulatory oversight from the FAA (4). As a result, they must operate like a business provid­ ing services and collecting fees, while implementing public policy objectives in their government jurisdiction. This guidebook focuses on a topic area that can potentially fulfill both responsibilities: renewable energy as a potential revenue source. 1.1 Problem Statement The ACRP issued a problem statement in 2012 titled, “Renewable Energy as an Alternative Revenue Source.” The research objective was predicated on two fundamental points: (1) Airports need to diversify potential fee and rental structures including non­traditional revenue sources that will make them as financially self­sustaining as possible. (2) Renewable energy markets are growing and diversifying, fueled by requirements that utilities purchase renewable energy to meet state, regional, and federal environmental and energy goals. Given that airports have underutilized property that could host renewable energy facilities and many consume significant quantities of power that could be provided more cheaply through on­site renewable generation, opportunities exist for airports to gain financial benefits from renewable energy. Kramer in ACRP Synthesis 19 describes how airports can use ancillary land uses, such as mineral extraction and renewable resources (5). Airport renewable energy projects can be complex, requiring an understanding of emerging technologies, financing mechanisms, regulatory frameworks, and operational factors. The ACRP Introduction to Renewable Energy in the Airport Environment C H A P T E R 1

Introduction to Renewable Energy in the Airport Environment 5 determined that guidance is needed to help airports understand the feasibility, opportunities, and challenges of renewable energy projects for financial benefit. 1.1.1 The Opportunity Federal, state, and local governments have enacted renewable energy public policy to: • Mitigate potential impacts of climate change; • Increase the amount of domestic energy consumption; • Diversify sources of energy; • Invest in long­term savings associated with free renewable fuels; • Decentralize power generation; and • Stimulate job growth. National investments in renewable energy have driven down solar panel production and instal­ lation costs, making solar electricity cost competitive with conventional sources. Similarly, utility­ scale wind power constructed in large farms across the country represents more than a third of all new electricity generation over the past three years. New renewable­based fuels, like biogas and wood waste, are being produced in sufficient quantities to provide cost­effective fuel to fire conventional engines for electricity, heat, and mobile transportation. Newer technologies, like geothermal and fuel cells, are being successfully piloted through demonstration projects to show their commercial potential. Figure 1­1 shows the annual generation in renewable energy capacity over the past 8 years including the forecast out to 2016 as reported by the U.S. Energy Information Administration (EIA) (6). Policy incentive programs are envisioned to be temporary measures with sunset periods necessary to increase production and reduce costs to the point where renew­ able energy can be cost competitive with traditional sources. Solar and wind have approached a cost competitive level in some markets with solar power’s federal investment tax credit (ITC) scaling back from 30% to 10% of project costs at the end of 2016 and wind power’s production tax credit (PTC) having expired at the end of 2014. The figure illustrates in particular the growth in wind power since 2009. Solar power has also shown a large increase over the past 5 years though the total amount of electricity being produced by solar still remains small compared to wind, liquid biofuels, wood biomass, and hydropower. The other renewable energy sources have remained relatively constant over the past 8 years with hydropower still the largest source of renewable energy. The EIA also forecasts that solar and wind will continue to increase in the future due to decreasing costs and available resources. Figure 1-1. Renewable energy generation in the United States. Source: Short-Term Energy Outlook, March 2015.

6 Renewable Energy as an Airport Revenue Source Airports have particular characteristics that enhance the potential financial viability of on­site renewable energy. Land and buildings can provide cost­effective physical locations for renewable energy facilities. The open landscape and geographic position of airports necessary for managing air traffic arrivals and departures also facilitates the capture of natural resources from the sun, wind, water, and earth that fuel renewable energy. Small rural airports may have surplus land available to site such facilities. Larger airports often have a level of electricity demand to support power consumption that positively affects project financials by avoiding the need to use the elec­ trical grid. All of these attributes combined with improved renewable energy market conditions make airport renewable energy financially viable. 1.1.2 Guidebook Organization The purpose of this guidebook is to provide airport readers with tangible information show­ ing where renewable energy has produced a financial benefit in the form of an alternative rev­ enue source or cost savings by limiting the need to purchase power from the grid. Through the examples, the reader can understand the factors that are considered by the airport in evaluating the renewable energy opportunity along with some of the financial benchmarks. While not all the cases are applicable to every airport, the types of information needed and the form that it comes in will be directly applicable. The airport case summaries are supported by additional guidance that will help airport decision­making of its own renewable energy opportunities, including which renewable energy resource is most appropriate given a particular airport’s location, and what information is needed to begin an assessment of financial viability. Chapter 1 provides an introduction to renewable energy at airports including description of technologies, the key participants in the airport renewable energy project, and the essential base­ line information that the airport needs to consider renewable energy. Technologies summarized include solar PV and thermal, geothermal, wind, biomass, hydro, and fuel cells. Chapter 2 presents the important evaluation factors that the airport should consider when assessing the renewable energy opportunity. These include setting of the project, airport char­ acteristics, existing energy costs, relevant public policy programs, airport ownership options, regulatory requirements, and operational and safety considerations. Chapter 3 examines in detail the financial factors that should be considered when evaluating whether or not a renewable energy project is anticipated to provide a financial benefit whether it be for revenue generation or cost savings. These include projected capital and maintenance costs, funding sources available to the airport, government incentive programs, preparing a cost­benefit analysis, and applying appropriate financial metrics such as the project return on investment or total cost of ownership. Chapter 4 identifies the steps associated with implementing a project. These include coordi­ nating with internal and external stakeholders, procuring and contracting with private partners, obtaining regulatory approvals, and publicizing the project milestones and accomplishments. Chapter 5 presents case summaries of specific airport renewable energy projects to illustrate some of the concepts described above. These include a variety of airport sizes, regions of the coun­ try with a few international examples, renewable energy technologies, ownership models, and key participants. There are also a number of appendices and available resources. Appendix D is a summary of state renewable energy policies in North Carolina and airport solar projects that have been devel­ oped there to illustrate the importance of state policy incentives in project feasibility. Appendix E is a feasibility assessment for solar PV at Monterey Regional Airport (MRY) in California that

Introduction to Renewable Energy in the Airport Environment 7 provides readers with an up­to­date look at a current project example for California. Appendix F includes sample RFPs. 1.2 Renewable Energy Options for Airports According to the EIA, renewable energy represents sources that are regenerative, inexhaustible, and can be sustained indefinitely. They are fueled either by energy resources that constantly occur in the environment, or by organic materials that are fast growing and potentially byproducts of other human processes. In comparison, conventional energy is customarily produced by burning fossil fuels such as coal and gas, which were formed deep in the earth over thousands of years and cannot be grown or manufactured. For centuries, renewable energy was the primary power source where wind was used to move ships and water to process grains. Burning fossil fuels was identified as a very efficient source of energy that helped drive the industrial revolution and has provided the energy needed for modern life. Centralized electricity plants fueled by fossil fuels were constructed to generate electricity and some incorporated co­generation technology to capture and use the waste heat (see Figure 1­2). Advances in new technologies to capture renewable energy ever more efficiently in the context of a planet warmed by extensive carbon emissions have triggered the recent trend back to renewable sources. The amount of renewable electricity as a percentage of the country’s total electricity genera­ tion has increased from 7.7% in 2000 to 12.87% in 2013 (7). Public policy incentives for renew­ able energy have opened up new opportunities for airports to obtain financial value. Airports are always looking for opportunities to increase revenue to support their aviation businesses and improve their competitive position relative to each other. New energy develop­ ment provides opportunity for both new revenue and cost savings. On the revenue side, air­ ports may be able to lease land that is not useful for other aviation or non­aviation commercial What is energy? Energy can be supplied in the form of electricity or heating/cooling. Renewable electricity generating technologies include solar PV, wind, and hydro. Heating/ cooling can be fueled by electricity but may be more economical through thermal and combustion processes, which in the renewable sector is provided by solar thermal, geothermal, and biomass. Fuel cells generate electricity and heat. Co-generation systems produce both electricity and heating by capturing and utilizing waste heat. Combustion systems including biomass are best suited for co-generation. Source: US EPA, http://www.epa.gov/chp/basic/index.html Figure 1-2. Co-generation: electricity and heat.

8 Renewable Energy as an Airport Revenue Source business development, due to proximity and access to valuable airport infrastructure, earning potential revenue from those leases. For some airports, that means learning about the business and observing whether energy prices are high enough to justify investments based on revenue potential. Other airports may be interested in leasing land for solar PV installations. In terms of cost savings, airports may also consider developing solar or even wind energy if the production price is lower than existing electricity obligations to local utilities. About three dozen solar projects have been developed at airports and business plans for their development have generally been of two types. First, airports can capitalize, own, and construct the facilities themselves, relying on low­interest bonds or federal government grants. The risk is held entirely by the airport but the benefits of free electricity will also be realized more imme­ diately. The second option has been to lease land to a private developer of solar energy that can take advantage of federal and state tax credits (which are unavailable to public airports), the private developer then passes the financial benefits to the airport in the form of lease payments or discounted electricity. The sophistication and diversity in structuring energy projects has also increased the number of economically viable opportunities. Units of Measure: Electricity is measured in watts. Electricity consumed is measured in watts per hour. Heat energy is expressed in Btus (British Thermal Units). To compare heat and electricity, watts can be converted to Btus (1 kilowatt hour = 3,412 Btus [as of 2013]) (see Figure 1-1). (8) The following section provides a brief introduction to renewable energy technologies that may be viable options for airports and includes airport participation in these markets to date. 1.2.1 Solar The sun’s energy can be converted into useful forms of electricity and heat. PV technology turns light into electricity (9). The heat of the sun can also be concentrated on water and other fluids to produce steam generated electricity and provide direct heating (known as solar ther­ mal). Most applications of solar have been to generate on­site power to homes and businesses. However, technology advances and recent market demands have led to an increase in utility scale electricity generation from large PV farms and concentrating solar power (CSP) plants which produce steam to drive a turbine. The solar energy industry has expanded in recent years due primarily to reduced module production costs that have made solar technologies more affordable for utilities and consum­ ers alike. In addition, the widespread deployment of solar technologies has been recognized by homeowners, businesses, and government agencies as a rational economic investment to mini­ mize the risk from volatile energy prices in the future. For example, when a homeowner installs a system on his roof, he has a high level of certainty (usually warranted by manufacturers) about how much electricity the system will produce over a 25­year period. These factors have led to widespread adoption of solar and market confidence to sustain the industry into the future, irrespective of any future breakthroughs in efficiency gains that may be achieved. Airports have also been an active participant in utilizing solar power primarily driven by the opportunities associated with decreasing installation prices. In most cases, the power generated by solar, primarily through PV along with a few solar thermal applications, is consumed at the

Introduction to Renewable Energy in the Airport Environment 9 airport. CSP is not practical for airport applications due to the need for large areas to locate mirrors and the incompatibility of the 400­foot plus tall power tower which collects the heat. The partnership between airports and solar energy is a logical one given their open landscapes, the availability of large surfaces on buildings and open land to site projects, and the proximity to high­load electricity transmission infrastructure that airports provide. Airport managers have also recognized the business advantages of solar power as a source of alternative revenue and long­term cost savings. In addition, public policy benefits to the state, county, and municipal government agencies that manage public airports offer a purposeful basis for these projects, including the opportunity to achieve goals related to greenhouse gas reduction. 1.2.1.1 Photovoltaic Solar PV is the direct conversion of sunlight into electricity. PV technology is constructed on flat panels that are located to optimize exposure to the sun (see Figure 1­3). The electricity produced is delivered in direct current (DC) form to an inverter which converts it to alternating current (AC) so that it can be compatible with the electrical grid and utilized by end users. The amount of electricity generated by the PV panel will vary with geography and the amount and intensity of sunlight available. A strong advantage of solar PV is its flexibility in siting. The panels can be located on rooftops thereby avoiding the need to set aside land that may be valuable for other uses. Or the panels can be mounted on poles driven into the ground to form larger solar farms. Many roof and ground mounted panels are held in a fixed position but in other cases tracking mechanisms may be employed for ground­mounted systems to increase the efficiency of electricity generation. The low profile of solar panels either mounted on buildings or on the ground makes them less visible and may expand the areas where they can be located. DC vs. AC: DC is the form of electricity produced by electrochemical and photo- voltaic cells and batteries. The electricity delivered to homes and business by the utility is in the form of AC. An inverter converts power from a solar system from DC to AC. The conversion results in a loss of a small percentage of the power. Figure 1-3. Schematic of a solar photovoltaic string.

10 Renewable Energy as an Airport Revenue Source The deployment of solar power has expanded throughout the United States over the past 5 years. Annual solar installations in 2013 were 15 times greater than installations in 2008 (see Figure 1­4). Decreasing costs of solar electricity have driven this growth with the installed cost of solar installations falling from $7.50/watt in 2009 to $2.89/watt in 2013 (10). The cost of solar panels fell by 60% from 2010 to 2012. In addition to lower solar costs, a variety of incentives are also creating a burgeoning solar market, including tax credits, purchasing mandates by federal agencies, and state level renewable energy portfolio standards. The amount of electricity pro­ duced by solar in the United States is now enough to power 1.3 million homes. There has been widespread adoption of solar PV by airports throughout the world. This activ­ ity has been driven by the expanding solar PV market and associated financial benefits to airports from lease payments and electricity price stabilization over the term of a long­term contract. In Source: Solar Energy Industries Association Figure 1-4. Solar installations and system price over time. System Size: The size of solar, wind, and other electricity generating systems is expressed as a nameplate capacity. For solar PV, each solar panel has a nameplate of between 250 and 300 watts. Multiply the panel rating by the number of pan- els and you get the nameplate capacity of the facility. For wind power, there are varying turbine models with different generating capacities from 1 kW to 3 MW. The nameplate capacity, if not otherwise specified, typically reflects the DC rating. Actual power available is the AC rating which is about 10% less. Also, the name- plate value is the maximum amount of electricity that will be generated at any single time when conditions are optimal. A capacity factor must also be applied to calculate the actual amount of electricity that will be generated by the system in kilowatt hours on average over the course of a year. For solar, capacity factor varies based on geography and technology, but is typically between 10 and 20%. For wind, it also varies by location but projects typically need a minimum of a 25% capacity factor. Offshore wind projects can have capacity factors of 50% or more.

Introduction to Renewable Energy in the Airport Environment 11 addition, airports are regularly seeking to make their operations more sustainable, which has been an important but supplementary benefit. Furthermore, the flexible options in siting solar have provided airports with various options to consider a solar project that meets the scale and needs of an individual facility. Figure 1­5 shows airports in the United States that host a 100­kilowatt (kW) or greater solar PV system. A list of solar projects at airports is provided in Appendix A. Chapter 5 provides case summaries of solar PV projects exhibiting a variety of airport types and locations at Barnstable, Boston­Logan, Denver, Indianapolis, Lakeland, Redding, Rockford, San Diego, and Tucson including details on siting, ownership and financing. Several solar PV projects at airports are also described in the context of state renewable energy policy (see Appendix D for an example from North Carolina). 1.2.1.2 Thermal Solar thermal technology stores and concentrates the heat of the sun for space heating (and cooling) and uses requiring hot water (see Figure 1­6). The energy from the sun is collected, stored, and distributed in liquid (usually water) or gas (air) form. There are low (less than 110°F) and medium (110° to 180°) temperature systems that can be used for on­site uses. High tem­ perature systems are primarily used for utility­scale electricity generation. The number of low Figure 1-5. Solar PV facilities at airports in the United States.

12 Renewable Energy as an Airport Revenue Source temperature collectors increased in the 2000s but by 2009 had dropped back to year 2000 levels (11). Medium size collectors have increased three­fold over the past 5 years but are only a fifth of what they were in the early 1980s. In 2009, three quarters of all collectors were low temperature models with 85% for residential use and 70% of all collectors were used for pool heating. The EIA projects solar thermal production to have an annual growth rate of about 2% over the next several decades compared to a 7% rate for solar PV (12). Solar thermal collectors applicable to on­site heating and cooling have similar siting advan­ tages as those described for PV. Thermal collectors are generally co­located with buildings, either on the roof or on south facing walls, to provide heating and cooling for internal operations. They have been particularly useful where low temperature hot water is used for heating and domestic uses as illustrated by the EIA statistics. Solar thermal has had a more limited applicability for airports for a few reasons. One of the primary public policy incentives—the requirement that utilities purchase renewable electricity through a renewable portfolio standard (RPS)—is typically not applicable to renewable thermal energy. In addition, it can be difficult to retrofit existing heating and cooling systems with solar thermal and other forms of renewable thermal technologies (see geothermal). The best applica­ tions can be included in the design of new construction and particularly for designs seeking a Figure 1-6. Schematic of a solar thermal system.

Introduction to Renewable Energy in the Airport Environment 13 zero carbon result whereby solar thermal can provide a benefit to reduce carbon emissions from heating and cooling. Despite these barriers, there are examples of solar thermal applications at airports that can illustrate the path forward for a successful project. Case summaries for solar thermal at Brainerd Lakes Airport in Minnesota and Toronto­Pearson Airport are provided in Chapter 5. 1.2.2 Geothermal Geothermal technologies utilize heat from the earth. There are two primary methods for extracting geothermal energy: conventional or “true” geothermal which taps heat originating from the earth’s core, and shallow geothermal or ground source heat pumps which utilize the constant temperatures below ground for heating and cooling (13). Geothermal is considered to be an important baseline renewable energy source because it is the primary resource with the potential of providing carbon­free heating and cooling. 1.2.2.1 Conventional Geothermal Conventional geothermal technologies extract energy from water heated underground by the earth’s core. While there are a number of different types of systems and technologies, the most fundamental technology, referred to as hydrothermal, extracts hot groundwater occurring near underground heated fissures. New methods, referred to as Enhanced Geothermal Systems (EGS), pump fluids underground where existing water and soil permeability does not exist, allowing for the isolated heat energy underground to be unlocked. The heated water can be used to provide power for heating and cooling, or it can be used to power a steam turbine and generate electricity. Conventional geothermal can be used as a local power source to meet on­site energy needs or act as a regional power source supplying a grid or district energy network. Costs associated with generating conventional geothermal energy are directly associated with the depth of drilling and infrastructure installation necessary to tap into these hot underground resources. Therefore, the most economical sites for developing geothermal projects are in areas where the molten core occurs close to the earth’s surface. Conventional geothermal is typically more economical in a utility­scale application as larger electricity generating plants provide power to the utility grid (14, 15). The potential of specific areas in the American west to provide power from geothermal resources has been investigated since the earliest days of the development of the national electrical grid. A site in Northern California known as The Geysers, which first generated electricity in the 1920s, was the site of the first United States modern geothermal plant completed in 1960, and today is the largest complex of geothermal power plants in the world (16). The site has shown that underground water reservoirs become depleted overtime and major investments have been made to pipe treated wastewater from urban centers to The Geysers to replenish the reservoirs. The growth of geothermal power production has been modest in the United States compared with development overseas. Geothermal production at the end of 2013 was 3,442 megawatts (MW) with 85 MW or about 16% of global installations (17) added during 2013. This level is rela­ tively small when compared to 4,751 MW of solar and 1,084 MW of wind generated in the United States. The Department of Energy’s Geothermal Technology Office operates an active research and development program that is supporting geothermal technology development including demonstration projects with the intention of developing a sustainable and cost­effective geo­ thermal power industry (18). Airports have not been a viable source for conventional geothermal projects due to the specific geographic requirements of conventional geothermal and the focus on utility­scale electricity generation development due to its potential to be more cost effective.

14 Renewable Energy as an Airport Revenue Source 1.2.2.2 Geothermal Heat Pumps Geothermal heat pumps, also called ground source heat pumps (GSHP), utilize the constant temperature in the ground and its capacity to store energy to provide heating and cooling. At about 10 feet below the earth’s surface, the temperature remains constant between 50°F and 60°F, depending on latitude. The geothermal heat pump facility circulates a fluid through a closed­loop system which is cooled to say 50°F in summer (when above ground temperatures are 80°F or more) and warmed to 50°F in winter (when above ground temperatures are 30°F and less) (see Figure 1­7). The heat pump is a mechanical device that transfers heat from the fluid to conditioning interior spaces. In winter, heat is extracted from the fluid and the colder liquid is returned to ground. In summer, the colder fluid is utilized for cooling and heated fluid returned underground and stored for winter use (19). One of the advantages of geothermal heat pumps is that there are no particular geographic limitations or specific geologic requirements for installing such systems. Furthermore, the loops are installed under the ground and above ground facilities are typically located inside buildings providing enhanced flexibility in locating systems within existing site conditions. Ground loops can be installed vertically where above ground construction access is limited or can be built horizontally, potentially limiting installation costs. However, different engineering strategies may need to be employed based on site­specific geophysical characteristics and costs can vary based on the relative difficulty of system installation. The primary benefit of installing a GSHP system is a reduction in energy consumption and a resultant decrease in utility expenses (20). In terms of heating, GSHP systems have a coefficient of performance of 3.0 or higher. This means that for every unit of energy consumed, three units are generated (i.e., GSHP systems are 300% or more efficient). In comparison, the efficiencies of most boiler­based heating systems are 80% or less. For space cooling, GSHP systems have an energy­efficiency ratio in excess of 14.5 (27 is the market best), which is approximately twice the energy­efficiency ratio of conventional air­conditioning. Energy savings of 70% can be achieved; 50% is the norm (21). Other GSHP system benefits include: • Increased conditioned space comfort: Heat pumps run almost constantly, ramping heating and cooling up and down as needed (i.e., there are no on­off fluctuations); provide superior humidity regulation; and are quiet. Figure 1-7. Schematic of geothermal heat pump.

Introduction to Renewable Energy in the Airport Environment 15 • Safe operation: Heat pumps are electric and do not combust fuel, which also results in signifi­ cantly reduced greenhouse gas emissions. • Free to low­cost domestic hot water: This can be achieved by adding a de­superheater or an additional heat pump or by installing a three­phase heat pump. • Low operations and maintenance costs: Annual costs are typically 50% to 70% less than con­ ventional systems. • Long warranty periods: Typically, warranties are 25 years for the interior components and 50 years for the loop­field piping. GSHP systems work optimally in climate regimes where heating and cooling are relatively bal­ anced. However, they are versatile, and with minor system adaptation, modification, or hybrid­ ization, GSHP systems can be deployed effectively in heating­dominated or cooling­dominated climates. Additionally, GSHP systems can be used to supply hot water for domestic purposes and/or commercial or industrial applications (e.g., snow melting, brewing). System performance and cost­effectiveness of projects may vary by geographic region and each individual project site requires an assessment to determine cost­effectiveness. All systems must be balanced to accommodate heating and cooling needs of the particular climate (e.g., more heating in the north, more cooling in the south). Thus, it may not be economical to size a system to fulfill the entire heating or cooling capacity of a particular season if there is a dramatic disparity in power demand between summer and winter. Cost­effectiveness will also be influ­ enced considerably by not only specific elements of a project site’s design, but also the availability of financial incentives from state policies and the local cost of power that the geothermal will be replacing (i.e., displacing high cost energy is more economical than low cost energy) (22). A number of airports have installed GSHP largely associated with new terminal construction projects. These projects have primarily received supplemental funding from the FAA’s Volun­ tary Airport Low Emissions (VALE) Program allocated to reducing on­airport emissions at facil­ ities located in U.S. EPA designated areas not meeting ambient air quality standards of the Clean Air Act. These projects are compatible with existing airport activities as all of the facilities are located underground or inside buildings avoiding conflicts with airspace protection. Chapter 5 presents case summaries on two GSHP projects at Juneau Airport and Portland Jetport in Maine. Table 1­1 provides a list of GSHP projects that have been installed at airports around the world. 1.2.3 Biomass Biomass (also referred to as bioenergy and can include biofuels) is organic material that comes from plants and animals. Plants store the sun’s energy which is then consumed by ani­ mals and is released slowly through decomposition. Biomass energy can be released at higher rates through combustion, which also accelerates the release of carbon dioxide stored in the plant material. Biomass is considered renewable because it comes from natural processes that can be produced and consumed through a relatively short and sustainable time period as illus­ trated in Figure 1­8 (23, 24). Biomass can provide potential revenue and cost savings in two ways: either by growing crops on airport land as a feedstock of bioenergy; or by burning the feedstock to produce energy through combustion. It is important to note that bioenergy, while renewable, is not emissions free. However, through its life cycle, it is considered to release and capture equal amounts of carbon and therefore can be classified as carbon neutral. 1.2.3.1 Feedstock Propagation A variety of organic materials can be used to produce bioenergy. These include materials that are a waste product from other activities, such as wood waste from logging and the manufac­ turing of forest products, and domestic wastes that would otherwise be disposed of in landfills.

16 Renewable Energy as an Airport Revenue Source g g p y g y y g p ( ) p y Austin-Straubel WI Snow Airport CapacityLocationCountry/State Removal Buildin n/a Bin hamton NY A ron Snow Melt n/a Central Wisconsin WI Terminal n/a Dane Count WI Airfield Maintenance Buildin n/a Dickinson ND Terminal 10 wells Duluth MN New Terminal 80 wells Juneau AK Refurbished Terminal 108 wells Knox Count ME New Terminal 12 wells Nantucket MA New Terminal 3 wells Olso-Gardermoen Norwa Terminal 18 wells Outa amie WI Fixed-base O erator FBO 20 wells Paris-Orly France Terminal 2 arallel shafts Portland ME New Terminal 120 wells South Bend IN Concourse A n/a Stockholm-Arlanda Sweden Terminal n/a Universit Park PA Refurbished Terminal 33 wells Zurich Switzerland Terminal 440 wells n/a: information not available Table 1-1. GSHP projects at airports around the world. Figure 1-8. Life cycle of biomass power generation.

Introduction to Renewable Energy in the Airport Environment 17 Other feedstock can be deliberately grown to meet the demand for a bioenergy feedstock with the most common example being farming of corn to produce ethanol as an additive to gasoline. In current practice, most biomass energy plants that utilize organic material to produce heat or electricity are typically fueled by wood waste or trash. Many are located close to regions with a forestry industry, which limits transportation costs, and also provides some compensation for the wood waste that is produced and offsets costs necessary for disposal. Likewise, waste­to­ energy power plants provide an alternative means for disposal of domestic wastes and potentially construction and demolition debris where landfill capacity is limited, and costs for shipping waste long distance are not economically or environmentally preferable. However, the aviation industry is investing a considerable amount of resources developing potential alternative jet fuels, some of which may be developed by organic materials including specific crops that may be grown domestically (25, 26). Some of the crops identified as being a feedstock for alternative jet fuels are oil seed plants including Camelina and Jatropha. The U.S. Department of Agriculture’s (USDA) National Wildlife Research Center is currently conduct­ ing field studies on the suitability of growing oilseeds on airport land from a wildlife hazard perspective. The research is not expected to be completed until 2016 (T. DeVault, personal communications, January 5, 2015). In 2012, Wayne County Airport Authority (WCAA), opera­ tor of Detroit Metropolitan (DTW) and Willow Run airports, partnered with Michigan State University (MSU) Extension to assess the potential to grow biofuel crops on airport property. These initiatives associated with assessing the potential compatibility of growing biofuel crops and generating revenue are described in Appendix B. While not an immediate example of poten­ tial revenue, feedstock propagation represents a potential future opportunity for certain airports that might become part of the alternative jet fuel supply chain and should be considered when conducting long­term master planning activities. 1.2.3.2 Combustion Biomass combustion, unlike biofuel production, utilizes organic matter that has not been overly processed to produce electricity or heat. Some examples of biomass fuels are wood, crops, animal manure, and human sewage. Biogas, produced from the decomposition of organic mat­ ter, can also be combusted to produce heat or electricity. The most utilized forms of biogas come from methane released from old landfills and produced by anaerobic digestion facilities fueled by food wastes. Biomass is burned to produce electricity and heat in the same manner that traditional fossil fuels such as coal, oil, and gas are used. To produce electricity, the biomass is burned to boil water, which produces steam to drive a steam turbine and generate electricity. The waste heat can be stored in water to provide hot water heating as a form of co­generation. Biomass power facilities are most often found close to low cost sources of fuel which is typi­ cally produced from wood waste, and are more concentrated in areas where there is a commer­ cial forest products industry. Logging operations produce wood scraps that cannot be used in the forestry products. These scraps can be sold as is or processed into wood pellets for residential and commercial heating fuels. Large utility­scale plants often utilize unprocessed biomass whereas small facilities require a more uniform product that can be delivered, stored, and accessed. In some locations, waste­to­energy power plants have been approved to receive and incinerate domestic trash as a fuel for power generation (27). A challenge with waste­to­energy is ensuring that the trash does not include harmful chemicals that could become airborne after incineration. Some energy is being produced by landfill gas facilities that release and burn methane trapped in the landfill to produce electricity. This methane would otherwise remain trapped or released to the atmosphere slowly over time. Anaerobic digestion is an old technology given new life in

18 Renewable Energy as an Airport Revenue Source areas that are restricting the landfilling of food wastes particularly produced in large quantities by large food producers. Anaerobic digesters accelerate the decomposition of the food wastes producing gas that can be burned to generate electricity. There are a few examples of biomass power plants at airports including one at Grant County Regional Airport in John Day, Oregon, which is included in the case summaries in Chapter 5. There may be other opportunities to retrofit an airport’s heating system to accept biomass in the form of wood pellets as has been accomplished at Grant County. However, the challenges of deploying biomass at airports include proximity to the biomass fuel source, additional traffic generated by delivering the biomass to the airport, and space constraints associated with storing wood pellets and other biomass fuels on­site. 1.2.4 Wind Wind power is responsible for much of the significant progress in large scale renewable energy generation throughout the world. No other renewable energy power generation can match the capacity of a traditional power plant (when the wind is blowing). These successes have been achieved by building taller wind turbines comprised of lighter and stronger materials to reach higher into the sky and extract a more consistent wind resource (28). While these taller turbines have improved the efficiency of wind energy generation, they also can create safety hazards for air navigation. As shown in Figure 1­9, wind generation capacity in the United States has increased from 4 gigawatts (GW) in 2001 to 65 GW in 2014, and wind could supply 20% of the nation’s electricity by 2030, equating to 300 GW (including 54 GW of offshore wind) (29, 30). A variety of incentives have catalyzed wind power growth, including tax credits, purchasing mandates by federal agencies, and state level RPS (31). Examples of renewable energy purchasing goals include the U.S. Department of Energy’s (DOE) goal of 20% by the year 2030, the Depart­ ment of Defense (DOD) goal of 25% by 2025 (32), and the 2004 Colorado Renewable Energy Requirement Initiative whereby Colorado became the first state to pass an RPS. Approximately half of all states have followed suit with RPS development, ensuring a growing role for wind energy production (33). The following section briefly describes the two types of wind energy projects—utility­scale and building­integrated—and their applicability to airports. The basic components of a wind turbine generator referred to in the sections below are identified in Figure 1­10. 1.2.4.1 Utility-Scale Wind The American Wind Energy Association (AWEA) defines a utility­scale wind turbine as one that has a nameplate capacity of 100 kW or larger (34). Today, wind turbines on land have a nameplate capacity of 3 MW (or 30 times the generation capacity of a 100 kW unit), and offshore wind turbines can be 6 MW and larger in capacity. These larger generators are viable because they can be placed on taller poles to capture more consistent wind; 100 kW generators may be placed on tubular towers that are 100 feet above ground level whereas the 3 MW generators are placed on 500 foot tall towers. Regardless of individual wind turbine size, single units may be placed at a load center to supply on­site electricity and limit the amount required to be drawn from the grid. Multiple wind turbines (typically in larger size categories) are grouped together in a wind farm to generate large amounts of electricity to supply the electric grid. The greatest amount of wind energy development has occurred in the Midwest where the wind blows at higher consis­ tent velocities across relatively flat terrain, unobstructed by mountain ranges and forests, and wind turbines can be located in the existing agrarian landscape providing supplemental income for farming families without disturbing their daily operations. Wind has also been developed in

Introduction to Renewable Energy in the Airport Environment 19 Source: American Wind Energy Association Figure 1-9. Annual and cumulative installed wind power capacity in the United States. Figure 1-10. Components of a utility-scale wind turbine.

20 Renewable Energy as an Airport Revenue Source other parts of the country on plateaus, mountain passes, ridgetops, and some coastal areas where wind is favorable and local acceptance has been gained. As very large structures on the landscape, wind turbines are typically incompatible with aviation, and the FAA and military have often expressed concern about airspace impacts either directly from the structure or through impacts on radar facilities. This issue is described in greater detail in Section 2.6.4. Despite the size of the structures and their potential to impact airspace, a handful of utility­ scale wind turbines have been constructed on airport property to provide on­site electricity generation. Projects at Burlington International Airport (BTV) in Vermont and East Midlands Airport in the United Kingdom (UK) are provided as case summaries in Chapter 5. 1.2.4.2 Small Wind Small wind comes in two forms: stand­alone wind turbines with a generation capacity of less than 100 kW similar in design to a utility­scale turbine and built­environment designs. A picture of a built­environment wind turbine from the Wind Turbine Lab at the Museum of Science in Boston is shown in Figure 1­11. Stand­alone wind turbines are typically less than 100 feet tall and provide on­site power for smaller electricity loads from commercial buildings to farms to single residences. Their design components are typically similar to those of utility­scale wind turbines shown in Figure 1­11, though other designs like a two­bladed turbine and an egg­beater design are also utilized. Stand­ alone wind turbines less than 100 kW have not been installed at airports most likely because of the increasing cost of electricity produced with the decreasing size of the unit. Built­environment wind turbines (also referred to as architectural wind) are wind turbines that are mounted on the roof of building structures. They are much smaller than utility­scale wind turbines primarily because the structure that they are mounted on is not designed to accommodate the load the wind causes. They have smaller blades and a smaller area to capture the wind. The capacity of each wind turbine is usually between 1 and 10 kW and it is common that multiple structures are deployed to increase the overall electricity generating capacity. As with stand­alone wind turbines, experience has shown that the smaller the generator is, the more expensive the electricity or cost of electricity produced. Small wind has been constructed at a handful of airports. Table 1­2 provides a listing of iden­ tified projects. The project at Boston Logan is described in more detail as a case summary in Source: Museum of Science, Boston Figure 1-11. Example of built-environment wind turbines.

Introduction to Renewable Energy in the Airport Environment 21 Chapter 5. Experience suggests that these wind turbines are more of an architectural treatment and symbol of a renewable energy future than a substantive producer of cost­effective renewable energy. 1.2.5 Hydropower Hydropower is produced by moving water and has a long history of providing power for human uses. Currently, it is the largest source of electricity generation from renewable sources in the United States. In 2013, hydropower contributed 6% of all electricity in the United States and 52% of all renewable electricity sources in the country (35). However, the amount of elec­ tricity generated from other sources such as solar and wind has increased substantially over the past years, while hydropower generation has been relatively constant as shown in Figure 1­12. Boston-Logan Administrative Building Aeroenvironment 20 units, 20 kW Honolulu DOT building Aeroenvironment 16 units, 16 kW Martha’s Vineyard Airfield Eastern Wind 1 unit, 50 kW Minneapolis-St. Paul Airport Fire Station Aeroenvironment 10 units, 10 kW Oakland County - Michigan Ground WindSpire 3 units, 7.2 kW Wayne County - Detroit Ground WindSpire 6 units, 7.2 kW Airport CapacityLocation Wind Turbine Table 1-2. Small wind installed at airports. Source: U.S. Energy Information Administration, Electric Power Monthly (February 2014). Figure 1-12. Hydropower and other renewable sources of electricity: 1995–2013.

22 Renewable Energy as an Airport Revenue Source Traditional hydropower sources are generated by damming rivers and passing the detained water over the dam. Due to the significant environmental consequences associated with dams, new applications are focused on capturing energy from free flowing waters both in river and ocean settings (36). Some public policies have been enacted to promote small scale hydropower including the Hydropower Regulatory Efficiency Act of 2013 (37). While its applicability to airports is limited to those adjacent to flowing rivers and ocean sites, a brief summary of the dif­ ferent types of hydropower and their potential application to airports is provided. 1.2.5.1 Riverine Hydro Power Most of the hydropower production in the world comes from turbines located in dams fed by flowing rivers (e.g., riverine). Water is detained behind dams and the impounded water is passed over the dam with the gravity of the falling water turning a hydro turbine. As dams retain a sig­ nificant amount of water, electricity can be generated in an uninterrupted fashion as upstream water flow constantly replenishes the reservoir above the dam. Historic dams provided on­site power for industry. Modern dams have been constructed to generate utility­scale electricity directly into the electric grid. Hydropower constitutes a large share of the regional power market in particular areas of the country such as the Pacific Northwest where there are large rivers with limited commercial and residential development nearby. As part of the movement to decentralize power generation and minimize the environmental impacts of utility­scale hydropower generation, new riverine power technologies and projects have been proposed and demonstrated in recent years. In some cases, old dams that are not being used for power generation are being retrofitted with low­impact devices that pass water through the dam without impact to aquatic life (see Figure 1­13). In other cases, new technologies are being located in flowing rivers to capture electricity without impounding the river using so­called run­of­the­river technologies. These technologies are not utility­scale in nature and are most appropriate to supply electricity for an energy source operating adjacent to the river. When siting such facilities, it is important that they not obstruct the rights of navigation. Airports in certain areas of the country may obtain their electricity from large scale legacy hydropower plants that are feeding electricity to the grid. However because the hydropower is mixed with many other regional electricity generating sources including those from fossil fuel power plants, airports and other retail customers make a direct claim to using renewable energy. New hydropower projects, while less benign on the environment, are difficult to develop due to the highly regulated environment associated with work in wetlands and waterways. Figure 1-13. Existing dam retrofitted with advanced hydropower technology.

Introduction to Renewable Energy in the Airport Environment 23 Opportunities may exist for pilot projects to connect individual projects and direct the power to an airport, though no such projects are known at this time. 1.2.5.2 Wave Power Wave energy can be generated in coastal environments subject to wave action (38). One of the advantages of wave power is that it can be predicted in a matter of days allowing electric system operators to forecast its contribution to the grid mix and make adjustments to other sources as necessary. A disadvantage of wave power is the difficulty in installing, operating, and maintain­ ing facilities in the ocean. In the United States, wave resources are strongest on the west coast due to the long fetch of wind moving across the Pacific Ocean. Wave energy generation technology remains in an early stage of development. Technologies are being tested in the water at the European Marine Energy Centre (EMEC) in the United Kingdom (UK). There have been a few wave test installations in the United States including in Hawaii, Massachusetts, North Carolina, and Oregon. Figure 1­14 shows a device being devel­ oped by a Massachusetts­based company. While wave energy is not seen as being a major contributor to the world’s electricity genera­ tion in the near­term, the volume of the stored energy in the ocean is massive and it will remain of interest to countries to investigate cost­effective ways to extract wave and other ocean energies to generate electricity. Therefore, it is possible that pilot projects could be located near coastal airports to demonstrate the potential for wave energy to provide on­site electricity generation. 1.2.5.3 Tidal Power and Ocean Current Energy Tidal and ocean current energy is extracted from ocean areas in a manner similar to run­ of­the­river or riverine hydropower discussed above. With tidal power, turbines are located in coastal inlets where strong currents are created by the ebbing and flooding of the tides (39). Because the tides flow in two directions, the turbines must be designed to accommodate the bi­directional nature of the flow. Conversely, ocean current power occurs where there are major currents in the ocean that always flow in one direction. The best known current in the United States is the Gulf Stream that flows north from Florida along the east coast up to Cape Cod and across the Atlantic Ocean. Tidal and ocean current energy technologies, like that of wave power, are in an early stage of development. A few technologies are being tested at EMEC in the UK and there is a commercial Source: Resolute Marine Energy Figure 1-14. Wave energy converter.

24 Renewable Energy as an Airport Revenue Source scale installation that has been operating since 2011 in a coastal inlet in Northern Ireland. Several technologies have been demonstrated in the United States in Maine, New York, and Washington State. Figure 1­15 shows a device that was deployed in Lubec, Maine in the fall of 2013. There have been no demonstrations at ocean current sites, though studies have been undertaken in the Gulf Stream off the east coast of Florida. Opportunities for demonstrating tidal energy technologies at airport sites are possible but generally unlikely with a few exceptions. Pilot sites would need to match up airports near strong tidal resource areas. Such a condition could exist at Anchorage International Airport (ANC) but the challenges of developing a tidal energy project at an airport location are significant. 1.2.6 Fuel Cells Fuel cells generate electricity through a chemical reaction that is catalyzed by an outside fuel source. Once the chemical reaction commences, the splitting atoms create a flow of electricity. The by­products are heat and emissions depending on the initial fuel source. Most contempo­ rary fuel cells have a source of natural gas that catalyzes the chemical reaction that will result in some limited amount of air emissions. However, because the fuel use is limited to sustaining the reaction but not producing the electricity, emission levels are relatively low. Future fuel cells could be powered by hydrogen, which once cycled through the fuel cell catalytic process, would have as a byproduct water and oxygen (see Figure 1­16) (40). Fuel cells can generate both electricity and heat. Like solar, they are a modular technology that can be sized to the appropriate use. Fuel cells to power transportation are sized to fit in a car. Larger fuel cells look like a storage shed providing a stationary electricity source to nearby loads. One of the most valuable aspects of a fuel cell is as an emergency electricity generation source that is not connected to the electrical grid and can supply on­site power when the electric grid goes down. Many technology firms with data centers have installed fuel cells to provide reli­ able backup power in the event of a potential brown or black­out condition. Utilities have also installed large stationary fuel cells as part of demonstration projects to improve the reliability of the grid in advance of a potential system­wide power disruption. The DOE is partnering with Federal Express (FedEx) and Plug Power, a fuel cell manufacturer, to provide FedEx with 15 hydrogen powered fuel cell ground support equipment (GSE) units. Source: Ocean Renewable Power Company Figure 1-15. Tidal energy device deployed in Maine.

Introduction to Renewable Energy in the Airport Environment 25 The units were expected to be delivered by the end of 2014 for use at FedEx’s hub at Memphis International Airport (MEM) after it demonstrated the technology earlier in the year. Accord­ ing to Bloom Energy, a major fuel cell manufacturer in California, airports that are interested in shoring up backup power as part of a microgrid have also been exploring the option of install­ ing stationary fuel cells. While fuel cells remain relatively expensive, they could provide value as a reliable backup source necessary to power critical infrastructure similar to that of hospitals, in that airports also need to improve their operational reliability during emergency situations. 1.3 Project Participants and Interested Parties The implementation of a successful renewable energy project on airport property requires leadership from the airport and oversight from the FAA. However, the role of key internal air­ port department personnel in concept development and the interests of external stakeholders through the review process may not be obvious. This section introduces the reader to the central project participants both internal to the airport organization and externally, which are shown in Figure 1­17, and highlights their roles and interests. 1.3.1 Internal Participants Internal participants are responsible for developing the project concept, assessing its techni­ cal and financial feasibility, developing a defensible plan for locating and financing the project, and building support from decision makers at the airport prior to engaging other interested parties. Key elements of this process are ensuring that the projects are compatible with airport activities and avoiding impacts to sensitive airport receptors including glare impacts from solar PV or radar interference from wind power. These topics are discussed in more detail below in Section 2.6. In addition, a strategy for ownership structure needs to be evaluated early on in the decision­making process to help determine the key financing options. These options are addressed in greater detail in Section 2.5. Figure 1-16. Schematic of a fuel cell.

26 Renewable Energy as an Airport Revenue Source 1.3.1.1 Planning The project concept will initially require input from planning professionals internal to the airport. They will want to review the type of technology proposed, alternatives for siting relative to the master plan, and consistency with existing and future infrastructure. The planning group will be familiar with other projects that have been undertaken and issues that have arisen in project planning and construction. Their input can be used to verify potential fatal flaws such as conflicts with the airport layout plan (ALP), potential sensitivity to navigational aid (NAVAID) interference or glare impacts, and environmental impacts. 1.3.1.2 Financial As soon as a feasible concept plan and site has been identified, the internal project lead should engage the airport’s financial planners to evaluate financial structures that could be used to fund the project. The financial evaluation will consider the Airports Capital Improvement Program (ACIP) to identify whether there are leveraging opportunities or barriers associated with the current plan. It will also evaluate unconventional sources of FAA funds (such as VALE or the Section 512 Program), as well as viability of a public­private partnership. Based on this coordi­ nation, the internal team should have identified if the project is viable and the information needs identified along with what the options may be for financing it with preferred and alternative funding mechanisms. 1.3.1.3 Facilities While the facilities group may be initially engaged during the planning process to confirm existing and near­term electrical infrastructure requirements, once a financing plan is devel­ oped, it should be engaged in evaluating integrated design of a renewable energy system and the practical considerations associated with long­term operations and maintenance. The facilities group can help improve project design by evaluating how the system installation would physi­ cally interconnect with the existing electrical network. It will have a strong understanding of the affected system components and their capacity to accommodate the proposed project concept. Facilities staff will also be familiar with the operations and maintenance of electrical facilities and can begin to engage key contacts with the utility company about the project, its design and interconnection approval process. Figure 1-17. Stakeholder engagement.

Introduction to Renewable Energy in the Airport Environment 27 1.3.1.4 Management Key members of management should be consulted during the early stages of developing the project concept to make sure the airport is receptive to pursuing a renewable energy project. However, once the project concept has been vetted through the different areas of internal exper­ tise, the airport management should be engaged to affirm its commitment. At this stage, man­ agement will want to understand all of the planning, facilities, regulatory and financial aspects of the project. Based on the project manager’s communication of the problem and solutions provided by the renewable energy project, management will evaluate all aspects of the project before proceeding to the governing authority for a formal decision to proceed. 1.3.1.5 Governing Authority The airport governing authority varies among airport organizations, though many are advised by a board of advisers that conducts business at public meetings. It is often prudent to advise the board early about different project activities, including pursuing new projects such as developing renewable energy. The board will want to have answers to many of the same questions that the management will have addressed during the internal review. Several board meetings are typically necessary to answer questions from the board and the public before proceeding with a formal vote on the project. Authorization may include funding, transfer of property rights, or pursuing a strategy that might be followed up by future board actions. 1.3.2 External Stakeholders 1.3.2.1 FAA The FAA has a significant oversight role at all federally obligated airports to ensure safe and efficient air transportation and to protect the long­term viability of the air transportation system. This responsibility includes evaluating decision­making that may have an effect on the long­ term productivity of the airport business. For renewable energy projects, the FAA’s involvement will focus primarily on preservation of airspace, protection of aeronautical uses, oversight of property rights and value, and authorization of federal funding. Airports should initially contact their FAA representative at the airport district office. The discussion should start with appropriate staff that they work with on planning issues to ensure that the project is consistent with the Master Planning and ALP and does not obstruct the future development of aeronautical uses. At the same time, the air traffic division should be consulted about the location of navigational aids and the proximity of the project to FAR Part 77 surfaces to determine that the project will not negatively impact airspace safety. If a lease is being con­ sidered, the FAA property division should be engaged about the lease approval process and pro­ cedures for documenting fair market value for any lease. For FAA funding through the Airport Improvement Program (AIP) or VALE, the airport will need to discuss its ACIP and include the renewable energy project in its ACIP when filed annually with the FAA regional office. 1.3.2.2 Airlines/Tenants For commercial service airports, airlines should be consulted on any projects that may affect their rates and fees. Airlines evaluate the short­term financial benefits of such investments and look to see cost savings that will be provided. Other tenants, both aeronautical and non­ aeronautical, should be informed about a proposed renewable energy project as part of the regular tenant communication programs implemented by the airport. These tenants will be interested in proposed airport improvements and how they may affect their business as well as the potential for any rate increases in future lease agreements. Tenants may also be interested in partnering with the airport on a renewable energy project if such a project can provide a mutual benefit.

28 Renewable Energy as an Airport Revenue Source 1.3.2.3 Electrical Utility The electrical utility is a key stakeholder for planning and implementing any power infrastruc­ ture project. The utility has unique expertise on the technical considerations for interconnect­ ing a power generation project to the existing electric network. It will also advise the airport on the interconnection application process and timeframe. The utility should be seen as a partner throughout the process engaged with the airport and its technical consultants. 1.3.2.4 Government Agencies A number of different government agencies may be interested in the proposed project depending on the airport’s location and political geography. Most airports are a division of municipal, county, or state government or are a separate regional or state authority. Irrespective of the specific governing structure, the sister agencies of the airport will be most affected by the activity as they likely participate in intergovernmental coordination including implementation of master planning and shared public policy goals. Those that are most relevant to a renewable energy project include sustainability, renewable energy generation, and greenhouse gas emission policies. Other government agencies may be part of the approval process. These include natural resource agencies authorized to review and approve development projects and their potential effects on wetlands and historic resources, as two examples. Meeting with agency representa­ tives early in project planning will help avoid any permitting fatal flaws and build support where alignment with government policy goals can be demonstrated. 1.3.2.5 Community Renewable energy projects generally have a broad public appeal particularly in urban areas where air quality degradation is of concern. In rural areas, a renewable energy project on airport property may be seen as having potential economic development benefits. Other renewable energy projects could be seen as having a negative aesthetic impact depending on the visibility of the technology. In all cases, engaging the community is an important part of building general support for the project. Informing the community of the project through existing communica­ tion processes, including newsletters, websites, information kiosks, and public meetings, will help the airport avoid misinformation and misunderstanding about the project. 1.4 Essential Baseline Information Before proceeding with the investigation of the renewable energy project, the airport should become acquainted with some essential information focused on energy that it can readily get access to but may not be familiar with. These include utility bills, electrical meters, and state incentive programs. 1.4.1 Utility Bills Utility bills can be complex and difficult to understand. Spending some time reviewing the utility bill and consulting with facility staff and utility representatives is essential for planning a renewable energy project. The following description of the utility bill generally applies to both electricity and natural gas, if it is used as a fuel for heating. Utility bills are typically segregated by individual meter with large airports having multiple electrical meters. The rate (or tariff) paid for the electricity at each meter will depend on the type of customer (e.g., residential, commercial) and amount of electricity consumed at the meter. The total rate for the electricity is determined on a kilowatt­hour (kWh) basis. The total rate is subdivided into the generation rate (i.e., the cost to make the electricity) and the distribu­ tion rate (i.e., the cost to deliver the electricity). There may be other add­ons to the bill that are

Introduction to Renewable Energy in the Airport Environment 29 deposited into accounts to fund energy efficiency and renewable energy incentive programs. Figure 1­18 provides an example of a utility bill and calls out some of the specific components and charges. Utilities have been more regularly implementing time­of­day charge programs as well as demand charges to encourage users to limit their electricity consumption. Demand charges apply a higher usage rate when overall monthly electricity use exceeds an identified threshold. All electrical usage above the threshold rate is charged at a premium. Time­of­day rates apply elevated charges to high demand or consumption times of the day as well as on a seasonal basis to limit use during peak consumption hours such as hot summer afternoons. These programs encourage customer cost savings and reduced demand based on usage but also limit the need for the utility to invest in infrastructure upgrades necessary to provide power at peak usage times. These upgrades are ultimately funded by all customers through rate increases. Figure 1­19 shows an example of a utility bill with time of day and seasonal pricing. 1.4.2 Electrical Meters Electrical meters are located at various places on an airport to track the amount of electricity consumed for a building or an area and are used to monitor net metering where the excess elec­ tricity is produced and sent back into the grid system. Gas meters generally do the same though they are only affiliated with occupied spaces and central heating plants. Meters are particularly important for installing renewable energy generation projects that will provide on­site power as the size of the generating system will need to be sized with the amount of power consumed either on an average or peak use basis. Electrical meters will also provide information on the downstream wire capacity though that information should also be readily available to airport facility personnel and the local utility representatives. As the renewable energy project will need to be connected to the existing power network, the location of meters is a critical element for project siting. Figure 1-18. Utility bill example showing different rates and charges.

30 Renewable Energy as an Airport Revenue Source 1.4.3 State Incentive Programs While federal incentives for renewable energy are available regardless of geographic location in the country, many states have also passed legislation to encourage the consumption of renew­ able energy sources and build a renewable energy industry. This is particularly true for solar power because the federal investment tax credit is typically not sufficient alone to generate a cost competitive source of electricity. States have incentivized local renewable energy development projects by requiring utilities to purchase a certain annual percentage of the electricity it sells to customers in the form of renewable energy thereby creating a separate market for renewable energy. These programs are referred to as a RPS and are discussed in Section 2.4.2. Under these programs, the utility buys the renewable energy at a premium or pays a penalty. The airport should obtain information on their state’s renewable energy incentive programs to understand the potential for a private market for renewable energy, which could lead the air­ port to select a third party project as the model to pursue. If the state incentives are limited, the airport may want to pursue FAA grant funding. State incentive programs are very dynamic and their status should be evaluated regularly. Pro­ grams apply variably to different utility service providers depending on whether they are public, private, or non­profit organizations. However, state programs applicable to all utility customers are described in the Database of State Incentives for Renewables and Efficiency (DSIRE) website (www.dsireusa.org). The airport could also benefit from contacting its state energy office or a local renewable non­profit organization to learn more about relevant incentive programs. More information on relevant public policy is described in Section 2.4. Figure 1-19. Utility bill showing seasonal and time-of-day (based on peak use) charges.

Next: Chapter 2 - Applying Evaluation Factors to Airport Renewable Energy »
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TRB’s Airport Cooperative Research Program (ACRP) Report 141: Renewable Energy as an Airport Revenue Source explores challenges airports may anticipate when considering renewable energy as a revenue source. These considerations include the airport’s geography and terrain, infrastructure, real estate, energy costs, public policy, regulatory and compliance requirements, tax credits, sponsor assurances, ownership, impacts to navigation and safety, security, staffing issues, and many others. The guidebook also includes detailed financial information on the cost and performance of projects that have been implemented by airports.

The guidebook also includes an appendix available online that provides sample a request for proposals.

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