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153 Advisory Circular: A type of publication offered by the FAA to provide guidance and recom- mendations for compliance with aviation regulations, policies, and programs. Aeronautical uses: Any activity that involves, makes possible, or is required for the operation of aircraft or that contributes to or is required for the safety of such operations. Air conditioning: Cooling and dehumidifying the air in an enclosed space by use of a refrigera- tion unit powered by electricity or natural gas. Note: Fans, blowers, and evaporative cooling systems (swamp coolers) not connected to a refrigeration unit are excluded. Airport: An area of land or water that is used, or intended to be used, for the aircraft takeoff and landing. It includes any appurtenant areas used, or intended to be used, for airport buildings or other airport facilities or rights-of-way, together with all airport buildings and facilities located thereon. It also includes any heliport. Airport Improvement Program (AIP): The AIP is authorized by the Airport and Airway Improve- ment Act of 1982 (AAIA) (P.L. No. 97-248, as amended). The broad objective of the AAIA is to assist in the development of a nationwide system of public use airports adequate to meet the cur- rent and projected growth of civil aviation. The AAIA provides funding for airport planning and development projects at airports included in the National Plan of Integrated Airport Systems. Airport Layout Plan (ALP): A scale drawing of existing and proposed airport facilities, their location on an airport, and the pertinent clearance and dimensional information required to demonstrate conformance with applicable standards. Airport Master Plan: A long-range plan for development of an airport, including descriptions of the data and alternative analyses on which the plan is based. Airport sponsor: A public agency or tax-supported organization, such as an airport authority, city, county, state or federal government, that is authorized to own and operate an airport, to obtain property interests, to obtain funds, and to be legally, financially, and otherwise able to meet all applicable requirements of the current laws and regulations. Alternating current (AC): An electric current that reverses its direction at regularly recurring intervals. AC occurs when charge carriers in a conductor or semiconductor periodically reverse their direction of movement. The voltage of an AC power source can be easily changed by means of a power transformer. This allows the voltage to be stepped up (increased) for transmission and distribution. High-voltage transmission is more efficient than low-voltage transmission over long distances, because the loss caused by conductor resistance decreases as the voltage increases. Array (solar): Any number of solar photovoltaic modules or solar thermal collectors or reflectors connected together to provide electrical or thermal energy. Glossary of Aviation, Energy, and Related Financial Terms
154 Renewable Energy as an Airport Revenue Source Azimuth: The angle between true south and the point on the horizon directly below the sun. Backup power: Electric energy supplied by a utility or on-site generating unit to replace power and energy lost during an unscheduled equipment outage. Balance of system (or plant): In a renewable energy system, refers to all components other than the mechanism used to harvest the resource (such as PV panels or a wind turbine). Balance-of- system costs can include design, land, site preparation, system installation, support structures, power conditioning, operation and maintenance, and storage. Base load: The minimum amount of electric power delivered or required over a given period of time at a steady rate. Base load capacity: The generating equipment normally operated to serve loads on an around- the-clock basis. Base load plant: A plant, usually housing high-efficiency steam-electric units, which is normally operated to take all or part of the minimum load of a system, and which consequently produces electricity at an essentially constant rate and runs continuously. These units are operated to maximize system mechanical and thermal efficiency and minimize system operating costs. Benefit cost analysis (BCA): Used by the FAA to identify proposed projects that will provide a net benefit to the aviation community. FAA requires BCAs for all capacity projects that require more than $10 million in AIP discretionary funds but can request them for less costly projects, as well. Biomass: Organic non-fossil material of biological origin constituting a renewable energy source. Boiler: A device for generating steam for power, processing, or heating purposes; or hot water for heating purposes or hot water supply. Heat from an external combustion source is transmit- ted to a fluid contained within the tubes found in the boiler shell. This fluid is delivered to an end-use at a desired pressure, temperature, and quality. Boiler fuel: An energy source to produce heat that is transferred to the boiler vessel in order to generate steam or hot water. Fossil fuel is the primary energy source used to produce heat for boilers. British thermal unit: The quantity of heat required to raise the temperature of 1 pound of liquid water by 1 degree Fahrenheit at the temperature at which water has its greatest density (approxi- mately 39 degrees Fahrenheit). Built-environment Wind Turbine (BWT): BWTs are defined as wind turbines located in an urban or suburban environment (built environment). Most BWTs are also classified as small wind turbines, which are 100 kilowatts (kW) or less. Capacity factor: The ratio of the electrical energy produced by a generating unit for the period of time considered to the electrical energy that could have been produced at continuous full power operation during the same period. Capital cost: The cost of field development and plant construction and the equipment required for industry operations. Central chiller: Any centrally located air conditioning system that produces chilled water in order to cool air. The chilled water or cold air is then distributed throughout the building, using pipes or air ducts or both. These systems are also commonly known as âchillers,â âcentrifugal chillers,â âreciprocating chillers,â or âabsorption chillers.â Chillers are generally located in or just outside the building they serve. Buildings receiving district chilled water are served by chillers located at central physical plants.
Glossary of Aviation, Energy, and Related Financial Terms 155 Central physical plant: A plant owned by, and on the grounds of, a multi-building facility that provides district heating, district cooling, or electricity to other buildings on the same facility. To qualify as a central plant it must provide district heat, district chilled water, or electricity to at least one other building. The central physical plant may be by itself in a separate building or may be located in a building where other activities occur. Cogeneration: The production of electrical energy and another form of useful energy (such as heat or steam) through the sequential use of energy. Combined cycle: An electric generating technology in which electricity is produced from otherwise lost waste heat exiting from one or more gas (combustion) turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for utilization by a steam turbine in the production of electricity. This process increases the efficiency of the electric generating unit. Combined heat and power (CHP) plant: A plant designed to produce both heat and electric- ity from a single heat source. Note: This term is being used in place of the term âcogeneratorâ that was used by EIA in the past. CHP better describes the facilities because some of the plants included do not produce heat and power in a sequential fashion and, as a result, do not meet the legal definition of cogeneration specified in the Public Utility Regulatory Policies Act (PURPA). Combustion: Chemical oxidation accompanied by the generation of light and heat. Concentrating solar power or solar thermal power system: A solar energy conversion system characterized by the optical concentration of solar rays through an arrangement of mirrors to generate a high temperature working fluid. Concentrating solar power (but not solar thermal power) may also refer to a system that focuses solar rays on a photovoltaic cell to increase con- version efficiency. Concurrent Land Use: Land that can be used for more than one purpose at the same time. For example, portions of land needed for clear zone purposes could also be used for agriculture purposes at the same time. Cost of capital: The rate of return a utility must offer to obtain additional funds. The cost of capital varies with the leverage ratio, the effective income tax rate, conditions in the bond and stock markets, growth rate of the utility, its dividend strategy, stability of net income, the amount of new capital required, and other factors dealing with business and financial risks. It is a composite of the cost for debt interest, preferred stock dividends, and common stockholdersâ earnings that provide the facilities used in supplying utility service. Cost of debt: The interest rate paid on new increments of debt capital multiplied by 1 minus the tax rate. Degradation rate: Quantification of power decline over time from a generating facility most often used in performance of solar photovoltaic modules. Demand charge: That portion of the consumerâs bill for electric service based on the consumerâs maximum electric capacity usage and calculated based on the billing demand charges under the applicable rate schedule. Derate factor: A decrease in the available capacity of an electric generating unit, commonly due to a system or equipment modification or environmental, operational, or reliability consider- ations. Causes of generator capacity deratings include high cooling water temperatures, equip- ment degradation, and historical performance during peak demand periods. In this context, a derate is typically temporary and due to transient conditions. Direct current (DC): DC is the unidirectional flow or movement of electric charge carriers (which are usually electrons). The intensity of the current can vary with time, but the general
156 Renewable Energy as an Airport Revenue Source direction of movement stays the same at all times. Direct current is produced by electrochemi- cal and photovoltaic cells and batteries. In contrast, the electricity available from utility mains in most countries is AC (alternating current). Utility AC can be converted to DC by means of a power supply consisting of a transformer, a rectifier (which prevents the flow of current from reversing), and a filter (which eliminates current pulsations in the output of the rectifier). Distributed generator: A generator that is located close to the particular load that it is intended to serve. General, but non-exclusive, characteristics of these generators include: an operating strategy that supports the served load and interconnection to a distribution or sub-transmission system (138 kV or less). Electric generator: A facility that produces only electricity, commonly expressed in kilowatt- hours (kWh) or megawatthours (MWh). Electric generators include electric utilities and inde- pendent power producers. Electric power grid: A system of synchronized power providers and consumers connected by transmission and distribution lines and operated by one or more control centers. In the conti- nental United States, the electric power grid consists of three systems: the Eastern Interconnect, the Western Interconnect, and the Texas Interconnect. In Alaska and Hawaii, several systems encompass areas smaller than the state (e.g., the interconnect serving Anchorage, Fairbanks, and the Kenai Peninsula; individual islands). Electric power plant: A station containing prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or fission energy into electric energy. Electric system reliability: The degree to which the performance of the elements of the elec- trical system results in power being delivered to consumers within accepted standards and in the amount desired. Reliability encompasses two concepts, adequacy and security. Adequacy implies that there are sufficient generation and transmission resources installed and available to meet projected electrical demand plus reserves for contingencies. Security implies that the system will remain intact operationally (i.e., will have sufficient available operating capacity) even after outages or other equipment failure. The degree of reliability may be measured by the frequency, duration, and magnitude of adverse effects on consumer service. Electric utility: A corporation, person, agency, authority, or other legal entity or instrumentality aligned with distribution facilities for delivery of electric energy for use primarily by the public. Included are investor-owned electric utilities, municipal and state utilities, federal electric utili- ties, and rural electric cooperatives. A few entities that are tariff based and corporately aligned with companies that own distribution facilities are also included. Electricity generation: The process of producing electric energy or the amount of electric energy produced by transforming other forms of energy, commonly expressed in kilowatt hours (kWh) or megawatt hours (MWh). Energy service provider: An energy entity that provides service to a retail or end-use customer. Fair market value (FMV): The sale price at which a property would change hands between a willing buyer and willing seller, neither being under any compulsion to buy or sell, and both having reasonable knowledge of the relevant facts. Federal Aviation Regulations (FAR) Part 77: Objects Affecting Navigable Airspace - Part 77 (a) establishes standards for determining obstructions in navigable airspace, (b) defines the require- ments for notice to the FAA Administrator of certain proposed construction or alteration, (c) pro- vides for aeronautical studies of obstructions to air navigation, to determine their effect on the safe and efficient use of the airspace, (d) provides for public hearings on the hazardous effect of proposed construction or alteration on air navigation, and (e) provides for establishing antenna farm areas.
Glossary of Aviation, Energy, and Related Financial Terms 157 Feed in Tariff: A Feed in Tariff (FIT) provides a fixed price for the purchase of electricity gener- ated (per kWh) from a qualifying renewable resource for a given period of time. All of the elec- tricity generated is sold to the utility at the fixed price, which is usually set above the retail price of electricity. A FIT guarantees a fixed premium rate for a given period of time, which provides a reliable revenue stream for developers to finance investments in renewable energy. Feedstock: A raw material that can be converted to one or more products. Fixed-base operator (FBO): Provides aviation services to the general public, including, but not limited to, the sale of fuel and oil; aircraft sales, rental, maintenance, and repair; parking and tie-down or storage of aircraft; flight training; air taxi/charter operations; and specialty services such as instrument and avionics maintenance, painting, overhaul, aerial application, aerial pho- tography, aerial hoists, and pipeline patrol. Fuel cell: A device capable of generating an electrical current by converting the chemical energy of a fuel (e.g., hydrogen) directly into electrical energy. Fuel cells differ from conventional elec- trical cells in that the active materials such as fuel and oxygen are not contained within the cell but are supplied from outside. It does not contain an intermediate heat cycle, as do most other electrical generation techniques. General aviation (GA): That portion of civil aviation that encompasses all facets of aviation, except air carriers. Generator nameplate capacity (installed): The maximum rated output of a generator, prime mover, or other electric power production equipment under specific conditions designated by the manufacturer. Installed generator nameplate capacity is commonly expressed in megawatts (MW) and is usually indicated on a nameplate physically attached to the generator. Geothermal energy: Hot water or steam extracted from geothermal reservoirs in the earthâs crust. Water or steam extracted from geothermal reservoirs can be used for geothermal heat pumps, water heating, or electricity generation. Grant assurances: Any agreement made between the FAA (on behalf of the United States) and an airport sponsor in that the airport sponsor agrees to certain assurances. In general, the airport sponsor assures it will operate the airport for the use and benefit of the public as an airport for aeronautical purposes. The grant agreement and assurances will apply whether the airport spon- sor receives the grant of federal funding or a conveyance of land. Green pricing: In the case of renewable electricity, green pricing represents a market solution to the various problems associated with regulatory valuation of the nonmarket benefits of renew- ables. Green pricing programs allow electricity customers to express their willingness to pay for renewable energy development through direct payments on their monthly utility bills. Ground loop: In geothermal heat pump systems, a series of fluid-filled plastic pipes buried in the shallow ground, or placed in a body of water, near a building. The fluid within the pipes is used to transfer heat between the building and the shallow ground (or water) in order to heat and cool the building. Ground Support Equipment: Typically associated with the servicing of aircraft during the air- port turnaround process consisting of the ground operations that are undertaken from the time the rubber blocks (chocks) are placed in front of the aircraft wheels until the time the blocks are removed and the aircraft is ready to leave the gate. During this period, there are a number of tasks that are performed including loading and unloading passengers and baggage, aircraft cleaning and maintenance, refueling and replenishment of provisions, and other similar ser- vices. Other common GSE functions pertain to the servicing and maintenance of the airside infrastructure and airfield of the airport.
158 Renewable Energy as an Airport Revenue Source Heat pump (geothermal): A heat pump in which the refrigerant exchanges heat (in a heat exchanger) with a fluid circulating through an earth connection medium (ground or ground water). The fluid is contained in a variety of loop (pipe) configurations depending on the tem- perature of the ground and the ground area available. Loops may be installed horizontally or vertically in the ground or submersed in a body of water. HVAC: An abbreviation for the heating, ventilation, and air-conditioning system; the system or systems that condition air in a building. Hydroelectric power: The use of flowing water to produce electrical energy. Installed Cost: The up-front cost paid by the system owner to construct a generating system. Internal Rate of Return (IRR): A widely used rate of return for performing economic analysis. This method solves for the interest rate that equates the equivalent worth of an alternativeâs cash receipts or savings to the equivalent worth of cash expenditures, including investments. The resultant interest rate is termed the IRR. Inverter: A device that converts direct current electricity (from for example a solar photovoltaic module or array) to alternating current for use directly to operate appliances or to supply power to an electricity grid. Irradiance: A measure of the intensity of the solar power recorded in W/m2. Kilowatt (kW): One thousand watts. Kilowatt-electric (kWe): One thousand watts of electric capacity. Kilowatt hour (kWh): A measure of electricity defined as a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu. Landfill gas: Gas that is generated by decomposition of organic material at landfill disposal sites. The average composition of landfill gas is approximately 50% methane and 50% carbon dioxide and water vapor by volume. The methane percentage, however, can vary from 40 to 60%, depending on several factors including waste composition (e.g., carbohydrate and cellulose content). The methane in landfill gas may be vented, flared, combusted to generate electricity or useful thermal energy on-site, or injected into a pipeline for combustion off-site. Land lease: A long-term land lease, generally for the purpose of erecting a building or buildings, or for constructing improvements to the land to be used by lessee. At the end of lease, the land and all structures and enhancements revert to the owner. Land leases should follow the basic for- mat of the hangar lease and include all of the same references to the airportâs rules, regulations, and minimum standards. The land lease price per square foot could vary by location, and pos- sibly by the length of the term, and may also be connected to a business permit or an FBO lease. Lease: An agreement whereby the owner of real property (landlord or lessor) gives the right of possession to another (tenant or lessee) for a specified period of time (term) and for a specified consideration (rent). Levelized cost: The present value of the total cost of building and operating a generating plant over its economic life, converted to equal annual payments. Costs are levelized in real dollars (i.e., adjusted to remove the impact of inflation). Megawatt (MW): One million watts of electricity. Megawatt electric (MWe): One million watts of electric capacity. Megawatt hour (MWh): One thousand kilowatt hours or 1 million watt-hours. MMBtu: One million (106) British thermal units.
Glossary of Aviation, Energy, and Related Financial Terms 159 Modules: PV cells or an assembly of cells into panels (modules) intended for and shipped for final consumption or to another organization for resale. When exported, incomplete modules and unencapsulated cells are also included. Modules used for space applications are not included. National Airspace System: It is made up of a network of air navigation facilities, ATC facili- ties, airports, technology, and appropriate rules and regulations that are needed to operate the system. Navigational Aids: Any sort of marker that aids the traveler in navigation. In aviation, NAVAIDs include both visible markers and those identified with radar. Net Metering: The practice of using a single meter to measure consumption and generation of elec- tricity by a small generation facility (such as a house with a wind or solar photovoltaic system). The net energy produced or consumed is purchased from or sold to the power provider, respectively. Net Present Value: The value of a personal portfolio, product, or investment after depreciation and interest on debt capital are subtracted from operating income. It can also be thought of as the equivalent worth of all cash flows relative to a base point called the present. Non-aeronautical Uses: Any activity that is not directly involved with, made possible, or required for the operation of aircraft or that contributes to or is required for the safety of such operations. Obstruction: Any object or natural growth, terrain, or permanent or temporary construction or alteration, including equipment or materials used therein, the height of which exceed the standards established in Subpart C of FAR Part 77, Objects Affecting Navigable Airspace. Ocean energy systems: Energy conversion technologies that harness the energy in tides, waves, and thermal gradients in the oceans. Off peak: Period of relatively low system demand. These periods often occur in daily, weekly, and seasonal patterns; these off-peak periods differ for each individual electric utility. Operations and Maintenance: A set of activities, most of them technical in nature, which enable power generation facilities to perform their task of producing energy in compliance with appli- cable rules and regulations. Passenger Facility Charge (PFC): The PFC program, first authorized by the Aviation Safety and Capacity Expansion Act of 1990 and now codified under Section 40117 of Title 49 U.S.C., provides a source of additional capital to improve, expand, and repair the nationâs airport infrastructure. The legislation allows public agencies controlling commercial service airports to charge enplaning passengers using the airport a facility charge. The FAA must approve any facility charges imposed on enplaning passengers. Payback Period: The amount of time required before the savings resulting from the system equal the system cost. Peak Demand: The maximum load during a specified period of time. Peak Shaving: The process of implementing measures to reduce peak power demands on a system. Photovoltaic and solar thermal energy (as used at electric utilities): Energy radiated by the sun as electromagnetic waves (electromagnetic radiation) that is converted at electric utilities into electricity by means of solar (PV) cells or concentrating (focusing) collectors. Power purchase agreements (PPAs): PPA is a contract between a buyer and seller of energy that obligates the party to deliver and pay for energy for a pre-determined price and term. PPAs guarantee a future revenue stream and therefore can be an important component to securing project financing.
160 Renewable Energy as an Airport Revenue Source Rebate program: A utility company-sponsored conservation program whereby the utility com- pany returns a portion of the purchase price cost when a more energy-efficient refrigerator, water heater, air conditioner, or other appliance is purchased. Reliability (electric system): A measure of the ability of the system to continue operation while some lines or generators are out of service. Reliability deals with the performance of the system under stress. Renewable Energy Certificates (RECs): RECs represent the environmental attributes of elec- tricity generated through a qualifying renewable energy resource. One REC is issued for every 1 megawatt-hour (MWh) of electricity produced by the qualifying source. Since renewable elec- tricity fed into the electric grid is distributed according to physical laws rather than contrac- tual agreements, RECs help account for who can claim the use of renewable electricity. A State Renewable Portfolio Standard (RPS) typically requires the utilities to procure a certain amount of RECs to demonstrate compliance with their renewable energy requirement. RECs can be bought and sold as commodities in the market, and are issued and tracked by various Genera- tion Information Systems (GIS) that operate within the U.S. electric grid. RECs are also known as green tags, green certificates, or tradable renewable certificates. Renewable energy resources: Energy resources that are naturally replenishing but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Renewable energy resources include biomass, hydro, geothermal, solar, wind, ocean thermal, wave action, and tidal action. Renewable Portfolio Standards (RPSs): RPSs require utilities to use or procure renewable energy or RECs to account for a certain percentage of their retail electricity salesâor a certain amount of generating capacityâaccording to a specified schedule. (Renewable portfolio goals are similar to RPS policies, but goals are not legally binding.) Most U.S. states have established an RPS. The term âset-asideâ or âcarve-outâ refers to a provision within an RPS that requires utilities to use a specific renewable resource (usually solar energy) to account for a certain per- centage of their retail electricity sales (or a certain amount of generating capacity) according to a set schedule. Return on investment (ROI): A performance measure used to evaluate the efficiency of an investment or to compare the efficiency of a number of different investments. To calculate ROI, the benefit (return) of an investment is divided by the cost of the investment; the result is expressed as a percentage or a ratio. Run-of-river hydroelectric plant: A low-head plant using the flow of a stream as it occurs and having little or no reservoir capacity for storage. Runway Protection Zone (RPZ): A trapezoid-shaped area off the runway end that enhances the protection of people and property on the ground. Runway Safety Area (RSA): A defined surface surrounding the runway, prepared or suitable for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway. Service area: The territory in which a utility system or distributor is authorized to provide ser- vice to consumers. Solar energy: The radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity. Solar thermal panels: A system that actively concentrates thermal energy from the sun by means of solar collector panels. The panels typically consist of flat, sun-oriented boxes with transparent
Glossary of Aviation, Energy, and Related Financial Terms 161 covers, containing water tubes of air baffles under a blackened heat absorbent panel. The energy is usually used for space heating, for water heating, and for heating swimming pools. Tariff: A published volume of rate schedules and general terms and conditions under which a product or service will be supplied. Tax Incentives: Tax incentives include tax credits, deductions, and exemptions. They can be applied to corporate, personal, property, and sales tax liability. These incentives are available in some states to individuals and organizations that purchase and install eligible renewable energy or energy efficiency equipment, or to construct green buildings. In a few cases, the incentive is based on the amount of energy produced by an eligible facility. Some states allow the tax credit only if a corporation has invested a minimum amount in an eligible project. Typically, there is a maximum limit on the dollar amount of the credit or deduction. In recent years, the federal government has offered corporate tax incentives for renewables and energy efficiency. Third party: Third-party transactions are arms-length transactions between non-affiliated firms. Time of day rate: The rate charged by an electric utility for service to various classes of customers. The rate reflects the different costs of providing the service at different times of the day. Transmission line (electric): A system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power system. Lines are oper- ated at relatively high voltages varying from 69 kV up to 765 kV and are capable of transmitting large quantities of electricity over long distances. Useful Life: An estimate of how long one can expect to use an income-producing item in a trade or business setting. Useful life usually refers to the duration for which the item will be useful (to the business), and not how long the property will actually last. Waste materials: Otherwise discarded combustible materials that, when burned, produce energy for such purposes as space heating and electric power generation. The size of the waste may be reduced by shredders, grinders, or hammermills. Noncombustible materials, if any, may be removed. The waste may be dried and then burned, either alone or in combination with fossil fuels. Wholesale power market: The purchase and sale of electricity from generators to resellers (who sell to retail customers), along with the ancillary services needed to maintain reliability and power quality at the transmission level. Wind energy: Kinetic energy present in wind motion that can be converted to mechanical energy for driving pumps, mills, and electric power generators. Wind turbine: Wind energy conversion device that produces electricity; typically three blades rotating about a horizontal axis and positioned up-wind of the supporting tower. Wood pellets: Saw dust compressed into uniform diameter pellets to be burned in a heating stove. Source of definitions: Energy Information Administration: http://www.eia.gov/tools/glossary/, U.S. Department of Energy: http://energy.gov/eere/energybasics/articles/glossary-energy-related- terms#R, the Database of State Incentives for Renewable Energy: http://www.dsireusa.org/support/ glossary/, as well as several other Department of Energy and Federal Aviation documents and sources.