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22 CHAPTER FIVE ENERGY EFFICIENCY PRACTICES: ENERGY USE AND SYSTEMS This chapter of the report will discuss practices for improv- Multiple Fuel Sources ing energy efficiency at airports as they relate to energy use, including potential impacts on and ideas about energy sources, As mentioned previously, fuel costs will fluctuate based on mechanical systems, lighting, and other energy loads. national and global events, and in extreme cases large energy users can be dramatically impacted when tied to a single source At an in-depth level the source discussion will high- of fuel. Having the option to utilize additional fuel sources pro- light practices regarding both carbon-based and renewable tects the airport from dramatic fluctuations. energy, techniques for documenting and managing energy use with metering systems, and practices for improving By agreement with their primary fuel provider, one survey energy rate structure and minimizing peak loads with util- respondent is able to switch to more economical boiler fuel ity providers. during transition seasons, resulting in a substantially lower energy rate and the elimination of winter use charges. Another airport noted that jet fuel, a readily available energy source Following sources, improvements to mechanical sys- at airports, could be used by facilities on a limited basis for tems in relation to both new and retrofit projects will be peak load shedding. broken down into tactics addressing major heating and heat recovery components and strategies affecting cooling components. Renewable Energy Topics related to lighting will address lamp and fixture As an update to findings in ACRP Research Results Digest 2, retrofit and replacement options as well as extensive discus- this synthesis found limited utilization of on-site renewable sion of sensor and control improvements used by respondent power at the airports surveyed. airports. Finally, additional major equipment energy loads that are somewhat unique to airports will be discussed. These include changes to visual information displays and efficiency Solar Photovoltaic $ - $$$ - techniques for conveyance systems. Large-scale solar PV systems have found limited applicabil- ity at airports seeking low-cost energy efficiency improve- SOURCES ments with a few exceptions noted here. The technology is still largely unable to compete with nonrenewable power Natural gas was the predominant fuel type at most airports in most regions. Because of rapidly changing technology, surveyed. This fuel is vulnerable to cost increases such as materials, and installation costs, solar PV technology is men- all carbon-based sources--sometimes to dramatic effect at tioned both as a viable, low-cost improvement here and as a a large consumer such as an airport. This was dramatically future technology in chapter eight. demonstrated in 2000 at SeattleTacoma International Air- port (SeaTac) when natural gas prices increased 8,000% Two airport respondents noted the installation of grid-tied, and the annual energy bill climbed from $5 million dollars to on-site PV arrays. Both airports, Phoenix Sky Harbor Inter- more than $17 million in one year (CAP 2004). Future energy national (PHX) and Fresno Yosemite International (FAT), sources that will reduce energy costs are largely based on are located in regions with higher solar resources as identi- solar power, although in some parts of the country where bio- fied by the DOE. mass is available cogeneration plants may also serve to meet airport energy needs. Cost/Payback/Savings: Payback time for solar PV systems at airport terminals depends largely on where the airport is For the near future, carbon-based, nonrenewable fuels will located and what rebates or incentives are provided by local continue to be used at airports to generate electricity, hot water, utilities, and state and federal governments. An average pay- and steam. As resources are depleted and greater carbon con- back time of greater than ten years is expected; however, FAT trols put in place, airport terminals and other large commercial noted a 1-year payback on its recently installed system. This buildings will be affected by rising energy costs. 2.4-mW project was estimated to supply 42% of electrical

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23 Box 13 Fresno Yosemite International, California, Photovoltaic Field One Year Later The initial cost of installing photovoltaic (PV) or wind generation systems, although less costly than in the past, is still prohibitively expensive, especially for medium- sized and smaller airports with limited budgets. One notable exception to this situation is Fresno Yosemite International, where a combination of incentives from the State Public Utilities Commission and a third-party con- tractor were utilized to install a 2.4 mW PV field (see Fig- ures 7 and 8). Selected through a Request for Proposal process, the third- FIGURE 8 Photovoltaic panels and supports at Fresno Yosemite party contractor designed and constructed as well as owns International. (Courtesy: FresnoYosemite International Airport.) and operates the installation on airport property. The agree- ment provides the operator use of airport land and the air- port with electricity at a fixed rate for 20 years (at slightly higher than the current market rate). needs and save the facility $13 million in energy costs over After one year of operations, the PV field actually pro- 20 years (Schwartz 2009). vides 58% of the airports power, exceeding projections. The fixed electrical rate is now expected to save the air- Metering Energy Use port more than $19 million in utility charges over the 20-year period. One of the keys to these savings is that the Energy use data are extremely valuable to airports seeking peak production of the PV field coincides with the air- to reduce energy costs. Improvements in energy use meter- ports peak energy use, substantially reducing its peak ing in recent years have made it possible to obtain pre- demand. This installation also has the ability to sell excess cision data. With these data, airport energy managers and power to the grid. operations staff are able to verify utility bills, benchmark systems, and determine where improvements are needed to save money. Metering technologies allow airport operators to initiate best management practices, monitor trends in energy use, and improve building operations (Sullivan et al. 2007, p. 2.1). In the future, if federal, state, or local mandates demand greater accounting of energy use, advance metering will allow airports to comply with legislation such as the Energy Policy Act of 2005 ("H.R. 6109th Congress: Energy Policy Act of 2005," 2005; Sullivan et al. 2007, p. 2.2), which updated fed- eral building performance standards and required all new fed- eral facilities to implement advanced metering. Benchmarking with Meters Utilizing energy use data from meters to develop building- wide energy benchmarks is essential to assessing performance, setting goals, and evaluating change. Benchmarking supports retrofit or upgrade projects, because it identifies how and where energy is used and also what factors contribute to energy use (EPA and DOW 2009). WEBLINK--Benchmarking Resources FIGURE 7 Solar photovoltaic array in Fresno, California. Energy Star Portfolio Manager: On-line tools The 2.4 mW field shown in the lower right provides more than 50% of the electrical power required for the airport terminal. to track and assess energy consumption: (Courtesy: FresnoYosemite International Airport.)

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24 General Metering Impacts Advanced Meters $ (with utility support) As noted in the last chapter, by communicating intentions An advanced metering system gathers energy use data on a to provide more precise metering and goals for energy effi- defined schedule as well as on-demand, enabling real-time ciency to personnel behaviors may be adjusted because new monitoring of electrical use, time-based electrical rates, and monitoring is in place. The Hawthorne Effect alone may continuous commissioning. The system can, at a minimum, provide savings of up to 2% (Sullivan et al. 2007, p. 8.3). provide data daily to support operations and other energy man- Typically, the use of meter data "will result in energy cost agement functions (Sullivan et al., 2007, p. 2.1). Only one sur- savings that can be used to justify the cost to purchase, vey respondent reported the use of advanced metering systems. install, and operate the metering system" (Sullivan et al. Their "real-time meters" were provided by the utility. 2007, p. 2.5). Cost/Payback/Savings: "Metering system costs vary widely Interviewees noted that data provided by metering has for a number of reasons: equipment specifications and capa- allowed airport managers to more effectively negotiate lease bilities, existing infrastructure, site-specific design conditions, rates and tenant fees. Data also provide concrete information local cost factors, etc." (Turner et al. 2007, p. 8.1). EPAact Sec- to communicate to staff to gain support for sustainability pro- tion 1252 regarding smart metering technology may require grams at the airport. utilities to provide smart meters to their customers in the event that the utility can offer time-base rates (Sullivan et al. The potential cost savings from additional metering depends 2007, p. 2.3). See the next section on Energy Rates for rate on a number of factors, primarily the unit cost of energy and adjustment information. the ability to implement projects derived from the meter data. By using meter data for optimization or "building tune-up" Electronic Sub-Metering $$ or in support of a continuous commissioning process, observed savings of 5% to 15% of yearly energy costs may be possible As a complement to standard meters, electronic sub-metering (Sullivan et al. 2007, p. 8.3). Savings of greater than 15% may is endorsed as a way to cost-effectively determine energy only be realized if significant opportunities for energy effi- use by multiple users, systems or tenants, add a finer grain ciency exist as a result of insufficient operations or worse, to energy data, and prepare for emerging energy guidelines neglect (Sullivan et al. 2007, p. 8.3). (Millstein 2008). Sub-meters provide a fair and time saving method of processing bills that can reduce conflict between management and tenants. They also send price signals, alerting Service Meter Data Baseline $ wasteful tenants and encouraging conservation (Turner et al. 2007, p. 6). Finally, and perhaps most important to the focus of Determining an energy use baseline for a system or building this report, sub-meters allow accurate tracking of energy use is useful to begin the energy efficiency and cost reduction and monitoring of energy efficiency improvements. process. With a baseline, the energy savings of an improve- ment or retrofit project can be accurately estimated and Sub-meters saw limited utilization among survey respon- precisely confirmed. In addition, any optimization or re- dents. St. Louis International Airport indicated that sub-meters commissioning process should begin with an accurate energy are used in terminal areas to monitor tenant energy use, whereas use baseline for that system or piece of equipment (Turner another airport indicated a limited capability to sub-meter et al. 2007, p. 11). owing to unknown reasons. Most airport respondents noted that electrical power usage Cost/Payback/Savings: Research noted that by using meters was currently measured with one meter. Although not ideal for to provide "bill allocation only--savings of 21/2% to 5% can tracking energy use and identifying energy projects, because be attained, largely owing to improved occupant awareness" individual users cannot be identified, basic assessments, audits, (Sullivan et al. 2007, p. 8.3). and baseline information can be performed and established using meter data and energy bills. In comparison to advanced or smart meters, most meters at airports would be classi- Energy Rates fied as "standard meters," which can be defined as "electro- mechanical or solid state meters that cumulatively measure, By understanding utility rate structures, incentive programs record, and store aggregated usage data that are periodically for reducing loads and penalties, or peak demand charges, air- retrieved for use in customer billing or energy management" port terminals are better prepared to manage energy use and (Sullivan et al. 2007, p. 2.1). reduce costs. Cost/Payback/Savings: As with many other O&M prac- Energy rates continue to rise for airports in most parts of tices, a payback period of less than 2 years is typical when the country--in some cases with dramatic monthly increases establishing an energy baseline. (CAP 2004). When billing history is reviewed, yearly rate