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The development of solar energy benefits society in many ways. When used in place of fossil fuels, solar energy reduces pollution and decreases the United States’ dependence on foreign and domestic fossil fuel producers. Solar systems can also be sized for small, on-site installation, which makes solar energy a popular renewable energy resource for individual homeowners. Solar energy is not without costs, however. Current solar energy technology is still very expensive. An industrial-size solar system costs 20.56 cents per kWh in a sunny climate and 45.23 cents per kWh in a cloudy climate. By contrast, the average price of electricity for the industrial sector in the United States was only 6.84 cents per kWh in March of 2009. For all sectors in the United States, the average price was 9.75 cents per kWh in March of 2009. Solar energy development is also cost-prohibitive or unfeasible in areas of the United States that do not receive enough direct and continued access to sunlight. On the other hand, southwestern states—especially California, Colorado, Arizona, New Mexico, Utah, and Nevada—have plenty of sunshine and a great deal of potential for large-scale solar energy development. This discussion provides an overview of the legal and policy issues that arise in producing solar electricty. For a discussion of renewable energy laws and policies, see the separate Renewable Energy section.
Solar Energy
Key Concepts Types of Solar Energy: Solar Thermal Systems Types of Solar Energy: Concentrating Solar Power Systems Types of Solar Energy: Solar Photovoltaic Systems Solar Energy and the Grid Is There a Right to Sunlight? Process Essentials: Federal Process Essentials: States Homeowners’ Association Covenants Local Ordinances Solar Energy Development in the Western States Arizona California Colorado Nevada New Mexico Controversies: Solar Energy Development on Public Lands Collaboration in Action Other Resources/ Links Key ConceptsTypes of Solar Energy: Solar Thermal SystemsSolar thermal systems use the sun’s energy to heat water and are most commonly used as domestic water heater and space heater systems. Solar panels are usually affixed to a roof where they collect sunlight and warm water, or other heat-transfer fluids, which are circulated through the panels via electric pumps. There are two types of active solar water-heating systems: direct circulation systems and indirect circulation systems. Direct circulation systems use pumps to circulate water directly through the solar collectors. These systems work best in areas that do not freeze often and that do not have hard or acidic water. Indirect-circulation systems use pumps to circulate heat-transfer fluids through the solar collectors. Heat exchangers then transfer the heat from the fluids to the water. The two most common indirect systems are antifreeze and drainback systems. Antifreeze systems usually use a non-toxic, glycol-water mixture as the heat transfer fluid. Drainback systems use pumps to circulate water through the collectors and are carefully designed so that all the pipes slope downward. When the pumps stop, the water drains back into the reservoir tank, which helps to prevent pipe freezes in colder climates. Solar thermal energy can also be used for space heating. Solar space-heating systems use sunlight collectors combined with electric fans or pumps to distribute the solar heat. Either water or air is used to transfer the heat from the collector to the space. Solar space-heating systems usually have an energy storage system as well, to provide heat when the sun is not shining. Types of Solar Energy: Concentrating Solar Power SystemsConcentrating solar power (CSP) systems use the sun’s energy to heat water into steam, which powers a turbine and generates electricity. Some CSP systems are capable of thermal storage, which means that they can provide power during peak electricity demand periods even if the sun is not shining. There are three main types of CSP systems: linear concentrator, dish/ engine, and power tower systems. Linear concentrator systems collect the sun’s energy in long U-shaped mirrors, tilted toward the sun. The sunlight heats fluid that flows through tubes in the mirrors. The hot fluid is used to boil water in a steam turbine which generates electricity. A dish/ engine system resembles a large, mirrored satellite dish. The dish shape concentrates the sunlight onto a thermal receiver which absorbs the heat and transfers it to an engine generator. The Stirling engine is the most common type of heat engine generator. It uses heated fluid from the receiver to move pistons and provide mechanical power for an electricity generator or alternator. A power tower system collects the sunlight with a large field of flat, sun-tracking mirrors, which concentrate the sunlight onto a receiver on the top of a tower. The receiver then heats a fluid which provides steam for an electricity-generating turbine. Some power towers use water as the receiver fluid, while others are experimenting with molten nitrate salt because of its superior heat-transfer and thermal-storage capabilities. With thermal storage, the power tower can continue to generate electricity at night and in cloudy weather. Types of Solar Energy: Solar Photovoltaic Systems Solar photovoltaic (PV) systems use the sun’s energy to generate electricity directly. Individual PV cells, known as solar cells, are made of semiconductor materials, which produce electricity when they come into contact with sunlight. Photons from the sun strike the semiconductor material, dislodging electrons and creating an electrical current. Common semiconductor materials include silicon in various forms, polycrystalline thin films of various chemical compounds, and single-crystalline thin films of various chemical compounds. Solar cells can be smaller than a postage stamp or they can be several inches across. Solar cells are usually joined together to form PV modules, and PV modules can then be joined together to form PV arrays. The size of a PV array depends on how much sunlight is available in an area as well as the needs of the particular solar energy user. The array is the major part of a PV system but it cannot function alone. PV systems also include “balance of system” components such as electrical connections, mounting hardware, power-conditioning equipment, and batteries to store energy for times when the sun is not shining.Solar Energy and the GridIn the early days of solar energy development, most homes with solar systems were not connected to the utility grid. In fact, these homes had solar systems precisely because they could not connect to the grid unless the power company agreed to spend tens of thousands of dollars to extend power lines. Now that renewable energy has become something of a hot topic and a means to help the environment, many homeowners are choosing solar energy because of its environmental benefits and not because they have no other options. On the contrary, these homeowners are taking full advantage of their options by installing solar systems while remaining connected to the local utility grid. The solar systems’ steep, upfront installation costs are offset by the greater independence from rising utility costs that they provide. Staying connected to the grid is now just a backup method for cloudy days or at night.Grid-connected solar systems are usually billed by the utility company through a process called net metering or net billing. If the solar system is connected to the grid through a single meter, the meter runs backwards when excess solar energy is sent to the utility grid. Any excess electricity produced by a homeowner’s solar system is therefore credited to them at the same retail rate as electricity taken from the utility grid. Some utilities require homeowners with solar systems to use two meters, one for grid energy consumption and one for solar energy contribution. By separating consumption and contribution, the utility may credit excess solar energy at the same retail rate as grid consumption, or it may apply a lower wholesale rate to any extra solar energy. In addition to determining the billing method, Homeowners interested in solar power should ask their local utility companies whether there is any fixed cost for staying connected to the grid. Some utility companies send a small monthly bill whether or not a homeowner has used any energy from the grid. This cost is usually attributed to a monthly meter-reading fee. So what about the solar system owners who do not use any grid energy and are still able to produce excess solar energy? Some states allow small-scale solar energy producers to sell their solar energy to utility companies in the form of Renewable Energy Credits (RECs). States with Renewable Portfolio Standards (RPSs) require their utility companies to purchase a certain number of RECs from renewable energy providers. In some cases, these renewable energy providers include local home and business owners with solar systems. Is There a Right to Sunlight?American law says no. In 1959, a case came before the Florida Third District Court of Appeals that asked this very question. The Eden Roc Hotel brought a suit against the Fontainebleau Hotel to prevent it from adding additional stories to its existing building. The Eden Roc argued that the addition to the Fontainebleau would cast a shadow over the cabana, swimming pool, and sunbathing areas of the neighboring Eden Roc, rendering the area wholly unfit for the use and enjoyment of the Eden Roc’s guests. The Eden Roc was granted a temporary injunction and the Fontainebleau appealed. The appellate court reversed the lower court’s decision, holding that there is no legal right to the free flow of light and air from adjoining land, absent any contractual or statutory obligation. The court mentioned that, by 1959, American courts had unanimously rejected the English doctrine of “ancient lights.” Under the ancient lights doctrine, a landowner gained a legal right to the free flow of light and air from the adjoining land only when the landowner had had uninterrupted use and enjoyment of the light and air flow for a twenty year period. (Fontainebleau Hotel Corp. v. Forty-Five Twenty-Five, Inc., 114 So. 2d 357, 359 (Fla. Dist. Ct. App. 3d Dist. 1959)).Although there is no American common law right to sunlight, a solar panel owner’s legal rights can be established by state statute. In 2005, two California residents were convicted of violating the state’s Solar Shade Control Act of 1978. Under the Act, tree owners are prohibited from planting or allowing a tree to grow to cast a shadow over more than ten percent of a neighbor’s solar collector between the hours of 10 a.m. and 2 p.m. A Santa Clara County Superior Court Judge held that three of Carolynn Bissett and Richard Treanor’s redwood trees were in violation of the law because they had grown to shade more then ten percent of neighbor Mark Vargas’s solar panel system. Bisset and Treanor were ordered to cut down the trees on penalty of a $1,000 per day nuisance fine. This controversial case pitted tree lovers against solar panel advocates, an odd war of the environmentally conscious. The controversy was relatively short-lived, however. In 2008, California signed the Solar Energy Systems Bill into law, which exempts existing trees from the requirements of the Solar Shade Control Act. It also authorizes a property owner to notify affected neighbors prior to installing a solar collector and provides a template. If notice is effectively provided pursuant to the law, the property owner will have an easier time winning any later disputes arising under the Solar Shade Control Act. The new law also simplifies the process for municipalities to opt out of the Solar Shade Control Act and adopt a local ordinance instead. Some statutes, like the California Solar Energy Systems Bill, grant one party the presumptive right to sunlight under certain circumstances, while other statutes provide for and recognize explicit solar easement arrangements between landowners. (See, for example, COLO. REV. STAT. § 38-32.5 (2008)). Before installing a solar system, it is therefore wise for a property owner to carefully review applicable state statutes, and perhaps to obtain an explicit solar easement from any neighboring land owner. See Tawny L. Alvarez, Comment, Don’t Take My Sunshine Away: Right-to-Light and Solar Energy in the Twenty-First Century, 28 Pace L. Rev. 535 (2008) for more information on the right to sunlight. See Conservation Easements page on RLCH website for more general information on easements. Process Essentials: FederalThe Department of Energy – Office of Energy Efficiency and Renewable Energy (DOE – EERE) has established a Solar Energy Technologies Program (SETP) to develop cost-competitive solar energy systems in the United States. More specifically, the SETP promotes the development of solar energy technologies by addressing existing barriers to solar energy commercialization through specific activities and external partnerships.
Market Barriers to Solar Energy Development (Identified by the SETP)
The Bureau of Land Management is responsible for solar energy development projects on public lands. In order to facilitate the project approval process, The BLM, DOE, and EERE are currently developing a Programmatic Environmental Impact Statement (PEIS) for solar energy development in six western states (Arizona, California, Colorado, New Mexico, Nevada, and Utah). • A shortage of information about solar technologies and limited consumer awareness • Insufficient product standards • Inconsistent interconnection, net metering, and utility rate structures and practices for solar systems • Inadequate codes and complex and expensive permitting procedures • Inconsistent and inefficient state and local financial incentives and other market drivers • A lack of flexible, sophisticated, and proven financing mechanisms • Insufficiently educated personnel and services and too few personnel and services Federal SETP Programs Designed to Overcome These Barriers • Solar America Cities -- financial and technical assistance to cities committed to the widespread adoption of solar energy technologies. • Solar America Showcases – technical assistance to large-scale solar installations in high-visibility locations. • Solar America Board for Codes and Standards – the creation of a collaborative board of experts who formally gather and prioritize input from solar photovoltaic stakeholders (e.g., policymakers, manufacturers, installers), resulting in coordinated recommendations to organizations establishing codes and standards for existing and new solar technologies. • State Technical Outreach – information and tools for state governments and energy agencies developing state solar energy programs. • Utility Technical Outreach – information and tools for utilities to assist them in developing utility solar energy programs. • Builder Technical Outreach – information for builders wanting to incorporate solar energy technologies into their building practices. • Workforce Education, Training, and Development – resources for educators, professionals, and prospective students seeking education and training in solar energy technologies. The BLM’s current Solar Energy Development Policy (IM No. 2007-097) is designed to “facilitate environmentally responsible commercial development of solar energy projects on public lands and to use solar systems on BLM facilities where feasible.” To achieve this goal, the policy states that all future BLM land use plans or revisions will take into account the potential impacts of solar energy development and any local environment or community issues. BLM policy further states that commercial solar energy project applications will be processed as right-of-way authorizations under Title V of the Federal Land Policy and Management Act (FLPMA) and Title 43, Part 2804 of the Code of Federal Regulations (CFR). These applications will need to use Form SF-299, Application for Transportation and Utility Systems and Facilities on Federal Land. If an existing, authorized facility (such as an oil and gas plant) wishes to install a PV solar system on their buildings, no separate authorization is needed. Right-of-way applications for solar energy development projects will be considered high priority and will be processed in a timely manner. If a right-of-way application is approved, a right-of-way grant (Form 2800-14) will be used to authorize all facilities necessary to a solar energy project including solar collectors, a tower, a turbine generator, thermal storage, access roads, and transmission facilities. The BLM will grant right-of-way for the smallest amount of land that will still meet the needs of the development project. The grant will include stipulations related to all aspects of the project including road construction and maintenance, vegetation removal, natural and biological resources mitigation and monitoring, and site reclamation. The project will also need a Plan of Development (POD) prior to beginning construction. The term of the authorization grant should not exceed the expected life of the solar project, typically 30 years. It can be renewed according to BLM regulations (43 CFR 2807.22(a)). All final authorization decisions for solar projects can be appealed under 43 CFR part 4 and 43 CFR 2801.10, but the right-of-way grants will remain effective during an appeal period. The holder of a right-of-way authorization will be required to pay an annual rent to the BLM according to the appraised value of the solar development rights and the land. The rent will be phased in over three years to allow for additional data collection and construction of the facility. The first year’s rent will be 25 percent of the full BLM rent, the second year’s rent will be 50 percent, and the third year’s rent will be the full 100 percent. Solar energy project applications with the BLM are also required to conduct an environmental analysis under the National Environmental Policy Act (NEPA). (Link to NEPA page). The environmental analysis may also need to address the compliance requirements of the Endangered Species Act, the Migratory Bird Treaty Act, the National Historic Preservation Act, and other relevant laws to the site in question. Furthermore, the environmental analysis should address all aspects of the solar project, including direct, indirect, and cumulative effects of the proposed development. BLM policy states that it may be possible in some cases to combine the required NEPA environmental analysis with other state or local environmental requirements, consistent with the BLM’s policy on intergovernmental cooperation. The above-mentioned BLM policy on solar energy development will expire on September 30, 2009. At that time, interested persons and organizations should be on the lookout for amendments and modifications to the policy in the updated BLM Instruction Memorandum that is sure to come. • The U.S. General Services Administrator is authorized to use up to $30 million to install a solar photovoltaic (PV) system on the Department of Energy headquarters building in Washington D.C. (Title V, Subtitle C, Section 521) • 30 percent of the hot water demand in new federal buildings (or in major renovations to existing federal buildings) must be met with solar hot water heaters, provided the equipment is life-cycle cost-effective. (Title V, Subtitle C, Section 523) • A research and development program will be established to lower the cost and improve the effectiveness of thermal energy storage technologies, which will in turn improve the operation of concentrating solar power (CSP) electric generating plans. (Title VI, Subtitle A, Section 602) • Regional electricity transmission grids will improve integration of CSP and utility-scale PV solar power systems. (Title VI, Subtitle A, Section 603) Process Essentials: StatesSolar energy development is affected at the local and state level by homeowners’ association covenants, local ordinances, and solar rights statutes.Homeowners’ Association CovenantsHomeowners’ association covenants only apply to property owners within the association boundaries, but over the past few decades the number of homeowners’ associations (H0As) , and therefore the number of properties affected, has been growing. In 1970, HOAs made up only one percent of all American housing units, but by 2007, their prevalence had grown to twenty percent. Between 1980 and 2000, half of all new housing developments involved HOAs. HOAs are attractive to many prospective homebuyers because they establish community rules or bylaws by which all neighbors agree to be bound. HOA bylaws can include restrictions on tree planting, vehicle parking, and house paint colors, among other things. Bylaws may also restrict the size and location of solar energy collectors. It is therefore wise for property owners subject to a homeowners’ association to check the association bylaws before installing a solar energy system. Homeowners who do not follow the HOA bylaws may be able to save their solar system by going to court if the restrictive covenants are highly unreasonable or contrary to public policy. American courts could probably find covenants prohibiting solar systems altogether to be contrary to public policy, but covenants restricting size and location of solar systems might be deemed reasonable in a particular case. Thus, a homeowner should carefully consider the terms of a solar covenant before deciding to challenge it in court.Homeowners’ association covenants on solar system installation may be overridden or preempted by local ordinances or by state-wide solar rights statutes. For example, if a homeowners’ association prohibits the installation of solar systems and a newly passed local ordinance or statute gives citizens the right to install solar systems in their homes, the HOA covenant will be rendered unenforceable. In Colorado, state law specifically addresses this HOA restrictive covenant issue by prohibiting covenants or deeds from containing any “unreasonable restrictions” on the installation or use of solar or wind energy devices. (For more information on the law, see COLO. REV. STAT. § 38-30-168 (2008). Local OrdinancesAfter considering the applicability of any homeowner’s association covenants, solar energy developers and system users should look next to local ordinances pertaining to solar energy systems. Solar energy development might be regulated by zoning, construction, and energy use ordinances in addition to more specific solar ordinances. Indeed, many modern zoning ordinances include provisions about the effect that construction or property alteration may or may not have on the solar access of neighboring lots. See, for example, the municipal code of the city of Bainbridge Island, WA.Some cities have enacted more specific and creative solar access ordinances. For example, the city of Boulder, Colorado, has an ordinance protecting a certain amount of sunlight for all properties depending on their solar access zone. The city is divided into three solar zones: Solar Access Area I, Solar Access Area II, and Solar Access Area III. In Solar Access Area I, lots are protected by a 12-foot “solar fence.” New structures on neighboring lots are not allowed to shade more of an Area I lot than what would be shaded by the hypothetical 12-foot solar fence. The hypothetical shade calculations from the hypothetical solar fence are designed to protect at least as much solar access on the property as would be available for a four hour period on December 21, the winter solstice. Area I properties are mostly residential and include rural residential properties and estates. Solar Access Area II properties include multi-family residential use and mixed use lots. Area II properties are protected by a 25-foot solar fence. All other properties fall into Solar Access Area III and are protected through the solar permitting process. Developers and homeowners in Boulder are directly affected by the city’s solar ordinance. When applying for a building permit, property owners must submit a shadow analysis as part of the proposed site plan in order to demonstrate that the solar fence rules will not be violated. This involves estimating the shadow that will be cast by all sections of the proposed building between 10 a.m. and 2 p.m. on December 21 and drawing a diagram to show the four hour shadow pattern. Boulder’s solar access ordinance is quite complex. The city of Santa Fe, New Mexico, is more concerned with the aesthetic effect of solar energy development. According to Santa Fe’s land development code , solar equipment that is visible from any public street or place must be screened by: Solar Rights StatutesLocal ordinances like those in Boulder and Santa Fe are well-suited to address specific, local concerns surrounding solar energy development. Nevertheless, states may choose to codify broader, state-wide solar energy development goals via solar rights statutes. These statutes are the highest sources of solar law at the state level and may trump any conflicting local ordinances.The validity of solar rights statutes is typically decided on a case-by-case basis. Consequently, it may be difficult for citizens and organizations to decide whether to go to court and challenge a solar rights statute based on similar case law. Legislators may also find it difficult to determine whether a particular solar rights statute will hold up in court and remain enforceable, unless the statute-in-question is identical to a statute that was upheld in a prior case. This uncertainty is costly because litigation is not cheap.
A Model Solar Rights Statute Must Address:
• Homeowner, condominium, and cooperative associations • Local ordinances (height restrictions,zoning,land use) • Common property • Enforcement without litigation • Retroactive enforcement • All types of solar technologies • Installation guidelines Solar Energy Development in the Western StatesIn June of 2009, Secretary of the Interior Ken Salazar signed a directive designating 676,048 acres of DOI land as solar study zones. These acres will be divided into 24 “solar study areas” in six western states: Arizona, California, Colorado, Nevada, New Mexico, and Utah. The land will be set aside for future solar development for two years, during which time the DOI will conduct studies and analyses to decide whether to set it aside for twenty years.As of June 2009, there were 34 applications for solar projects within the DOI zones and 155 applications for solar projects on BLM lands. On June 29, 2009, Secretary Salazar announced that by the end of 2010 there will be at least 13 commercial-scale solar energy projects under development on public lands in the West. He reiterated this plan in January 2010. See "Interior touts fast-tracking of 13 solar projects," E&E, 1/29/10. ArizonaArizona will soon be home to one of the largest solar energy plants in the world. The Solana Generating Station, a CSP system, is slated to begin operation in 2011 or 2012. It will use conventional steam turbines to generate electricity from solar energy, providing 280MW of gross output and powering approximately 70,000 homes. The plant will also provide up to six hours of energy when the sun is not shining via thermal storage. The Arizona Public Service Company will purchase 100 percent of the power generated by the Solana solar plant.As of April 2009, the Solana Generating Station was still involved in the permitting process, including local air permits and aquifer protection permits. Once all permits are complete, construction will begin on three square miles of land just west of Gila Bend and approximately 70 miles southwest of metropolitan Phoenix. In addition to helping Arizona achieve its 15 percent Renewable Energy Standard by 2025, the Solana plant is expected to provide 1,500 to 2,000 construction jobs, 85 to 100 skilled permanent jobs, and $300 million to $400 million in 30-year tax revenues for the state of Arizona. It will also add more than $1 billion to Arizona’s gross state product. A list of all solar project applications currently pending within the Arizona Bureau of Land Management is available. CaliforniaCalifornia has made the list of the top ten solar-friendly states due to its sunny climate and solar energy incentive program. In January of 2007, California launched the California Solar Initiative (CSI) Program to continue to build upon nearly a decade of state solar energy support. The California Public Utilities Commission oversees the CSI and provides incentives to customers for solar system installations. The CSI Program has a budget of $2.167 billion over 10 years. The goal of the program is to achieve 1,940 MW of installed solar capacity by the end of 2016. The main CSI program component, the general market incentive program, is administered by the state’s three investor-owned utility companies (Pacific Gas and Electric, Southern California Edison, and San Diego Gas and Electric). To achieve its solar capacity goal, the CSI Program will also use the following four program components:The CSI Program is part of a larger state-wide solar effort known as the Go Solar California campaign . This campaign has a statewide goal of 3,000 MW of solar energy production by 2016 and a budget of $3.3 billion. California’s investments in solar energy development are beginning to pay off. Early in 2009, Southern California Edison forged a deal with solar power plant maker, BrightSource, for construction of the largest series of solar installations in history. The seven solar facilities will be located in the desert outside Los Angeles and are expected to generate more than 1,300 MW of solar electricity. This amount of solar energy would be enough to power 845,000 homes, more than the number of homes in all of San Francisco. If the project performs according to expectations, the clean solar energy produced will decrease California’s dependence on dirtier forms of energy, reducing carbon dioxide emissions by more than two million tons per year. This reduction in carbon dioxide emissions is equivalent to removing more than 335,000 cars from the road every year. The project will also deliver slightly more electricity than the largest of nuclear plants. The first of the seven solar facilities is expected to become operational in 2013 in Ivanpah, California. Notably, however, environmentalists and federal biologists have raised concerns that the proposed development will destroy critical habitat of the threatened desert tortoise and impact other desert species. They have proposed relocating the development to less sensitive tracts of public land. See "Solar showdown in Calif. tortoise's desert home," Salt Lake Tribune, 1/2/10. For a description of the draft EIS released on this project, and a map showing installation plans, see "Developer proposes 30,000 solar dishes in Calif. desert," Land Letter, 2/18/10. ColoradoColorado is one of the top ten solar-friendly states with 300 to 320 sunny days per year and very strong state and federal incentive programs for solar energy development. Colorado demonstrated its strong commitment to renewable energy development in 2004 when it became the first state to establish a Renewable Energy Standard by popular vote. (Link to General Page w/ info on RES and Colorado?). In addition to establishing an RES, Amendment 37 also specifically boosted solar energy development in Colorado. According to Amendment 37, four percent of the RES must come from solar PV systems. Half of this four percent must be generated from individual residential and business solar systems. To encourage residential and business solar system installation, two major utility companies, Xcel Energy and Aquila, are required to offer rebates to their customers for installing PV systems. Under Amendment 37, at least 2,000 solar-powered homes and businesses must exist in Colorado by 2015 in order to meet the two percent RES requirement for customer systems, which is equivalent to about 40 MW of solar energy generation.To comply with the rebate requirement of Amendment 37, Xcel Energy has developed a Solar*Rewards program for Colorado customers. Homeowners and business owners who install a solar photovoltaic electricity generating system on their home or business can qualify for rebates and renewable energy credits depending on the size of the system. For an eligible medium-sized system, producing 10.1 kW–100.0 kW of DC electricity, the owner will receive $2.00 per watt DC capacity, paid upon installation. The owner will also receive a monthly Renewable Energy Credit of $115 per MWh of energy produced. NevadaEldorado Valley, near Boulder City, is home to the Nevada Solar One, a 64-MW solar-thermal plant. It is currently the third largest concentrating solar power (CSP) plant in the world. The Nevada Solar One became operational in 2007, and Nevada has since become the largest per-capita solar energy generator in the U.S. Nevada is also home to the Nellis Solar Star photovoltaic solar plant, located on the Nellis Air Force Base. At 140 acres and 14 MW generation capacity, the Solar Star was the largest PV plant in North America at the time it was installed in 2007.Lately, Nevada’s large solar project development strategy has been facing more resistance. The National Park Service took issue with several proposed solar projects in Nevada in early 2009, due to the projects’ proximity to national parks. Water supply for concentrating solar power systems is also a controversial issue in Nevada. New MexicoNew Mexico is one of the sunniest states in the west with an average of 320 to 340 sunny days per year. New Mexico’s sunshine and solar energy tax credits bring it within the top ten solar-friendly states in the country. Perhaps it is not surprising then that New Mexico will soon be home to the largest concentrating solar power (CSP) plant in the United States. The “suntower” is expected to produce 92 MW of electricity, enough to power 74,000 homes. This would far exceed the capacity of the largest CSP plant currently in operation, which produces about 70 MW. The Suntower will be built on 450 acres of private land near the New Mexico border and El Paso, Texas. El Paso Electric Co., an electricity supplier for southern New Mexico and west Texas, has entered into a twenty-year contract to buy all of the electricity that the plant generates. The Suntower should be fully operationl by the summer of 2011 and will be used to meet New Mexico’s renewable energy standard (RES) of 20 percent by 2020.Controversies: Solar Energy Development on Public LandsOn February 5, 2009, Jon Jarvis, the Regional Director of the Pacific West Region of the National Park Service (NPS), sent a memo to the Nevada Bureau of Land Management The memo was intended to illustrate the NPS’s concerns with CSP solar plant projects on BLM lands in Nevada. When the memo was sent, there were 63 proposed solar energy projects in southern Nevada alone. The National Park Service wants the Nevada BLM to consider the following issues when it considers where to site proposed solar projects:Jarvis’s NPS memo also quotes the Nevada State Engineer, saying “The State Engineer does not believe it is prudent to use substantial quantities of newly appropriated ground water for water-cooled plants in one of the driest places in the nation, particularly with the uncertainty as to what quantity of water is available from the resource, if any.” This quote along with the overall content of the memo upset Nevada Assemblyman Ed Goedhart from Amargosa Valley who wrote an angry letter to the National Park Service on April 27, 2009 reaffirming Nevada’s commitment to solar energy development even in its arid regions. Goedhart asserted that any water rights issues in arid southern Nevada could be overcome using existing agricultural water that is available for lease and diversion. Goedhart also had the following to say to Jarvis and the NPS about quoting the State Engineer: “Please note that the deputy engineer does not set policy. We in the Nevada State Legislature, in conjunction with the governor, set policy.” Similar concerns have been raised in California, where a large development in the Mohave desert threatens to impact habitat of the desert tortoise and other species. In an effort to reconcile solar energy and landscape protection, Sen. Feinstein (D.-Cal.) introduced the "California Desert Protection Act" (S. 2921) in December 2009, which would require the Defense Department to review several million acres of military landsin California, Arizona and Nevada, and identify suitable sites wherewind farms, solar arrays and other renewable resources could bedeveloped. It would also require the BLM and the Forest Service to conduct an assessment of suitable public lands for solar development. Collaboration in ActionIn May of 2009, online registration began for the largest grassroots solar event in the United States to date. The non-profit American Solar Energy Society (ASES) organized a National Solar Tour that began on October 3, 2009. This was the fourteenth year of the Tour which, in 2008, had over 140,000 participants in 49 states, Washington D.C., and Puerto Rico. ASES provides free organizational support, signage, and logistical help to thousands of homeowners, businesses, schools, cities, and non-profits that wish to showcase their solar energy use. The ASES National Solar Tour allows communities across the United States to share ideas and to demonstrate the energy cost savings, property value increases, and government incentives to be had with increased solar energy development.The Solar Energy Industries Association (SEIA) is another good source of information about the current state of the solar energy market in the United States. The SEIA is the leading national trade association for the solar energy industry and has also has many state chapters. In addition to solar businesses, individuals can join the SEIA’s Pro-Solar Community on the SEIA website’s Grassroots and Advocacy Page. SEIA grassroots efforts include call-in campaigns, letter writing, lobbying visits to Washington D.C. and issuing Action Alerts for urgent legislative matters. The SEIA also coordinates efforts with other renewable energy, environmental, energy efficiency, corporate, and financial services groups to create a broad coalition of support for solar energy. Since 2003, the island of Martha’s Vineyard in Massachusetts has been taking the lessons of solar energy to heart. By the early 2000s, Martha’s Vineyard was almost entirely dependent on imported energy. Consequently, island dwellers were seeing their energy bills increasing steadily from year to year. They were also becoming concerned about the higher load being placed on the underwater transmission cables as well as the political and economic issues surrounding the importation of energy. In 2003, the non-profit Vineyard Energy Project (VEP) was founded to address these problems and to make Martha’s Vineyard a “renewable energy island.” The VEP provides energy education to children in grades 3 through 12, organizes community outreach events, and promotes renewable energy projects. With funding from the U.S. Department of Energy’s Million Solar Roofs Program, the VEP has facilitated the installation of fourteen PV solar energy projects across the island. The VEP also secured funding from the Massachusetts Technology Collaborative’s Renewable Energy Trust, which paid for about half of the $195,000 in total solar project costs. Private solar system owners on Martha's Vineyard have the option to sell the “green energy attributes” associated with their solar energy production to the Massachusetts Energy Consumers Alliance as part of Cape Light Compact Green. This program allows for the purchase of green attributes at a rate of $0.06 per kilowatt-hour for three years (as of 2006) and the resale of those attributes to green energy customers in Massachusetts and Rhode Island. The Cape Light Compact website says that the 2009 purchase rate for green attributes is $0.009 per kilowatt-hour for the 50 percent “green power” option, translating to an additional $4.50 per month for a typical consumer. The 100 percent green power option applies a purchase rate for green attributes of $0.016 per kilowatt-hour, or an additional $8.00 per month for a typical consumer. Other Resources/ Links
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| Last Updated ( Wednesday, 17 March 2010 ) |



There are two types of active solar water-heating systems: direct circulation systems and indirect circulation systems. Direct circulation systems use pumps to circulate water directly through the solar collectors. These systems work best in areas that do not freeze often and that do not have hard or acidic water. Indirect-circulation systems use pumps to circulate heat-transfer fluids through the solar collectors. Heat exchangers then transfer the heat from the fluids to the water. The two most common indirect systems are antifreeze and drainback systems. Antifreeze systems usually use a non-toxic, glycol-water mixture as the heat transfer fluid. Drainback systems use pumps to circulate water through the collectors and are carefully designed so that all the pipes slope downward. When the pumps stop, the water drains back into the reservoir tank, which helps to prevent pipe freezes in colder climates.
There are three main types of CSP systems: linear concentrator, dish/ engine, and power tower systems. Linear concentrator systems collect the sun’s energy in long U-shaped mirrors, tilted toward the sun. The sunlight heats fluid that flows through tubes in the mirrors. The hot fluid is used to boil water in a steam turbine which generates electricity.
Solar photovoltaic (PV) systems use the sun’s energy to generate electricity directly. Individual PV cells, known as solar cells, are made of semiconductor materials, which produce electricity when they come into contact with sunlight. Photons from the sun strike the semiconductor material, dislodging electrons and creating an electrical current. Common semiconductor materials include silicon in various forms, polycrystalline thin films of various chemical compounds, and single-crystalline thin films of various chemical compounds. Solar cells can be smaller than a postage stamp or they can be several inches across. Solar cells are usually joined together to form PV modules, and PV modules can then be joined together to form PV arrays. The size of a PV array depends on how much sunlight is available in an area as well as the needs of the particular solar energy user. The array is the major part of a PV system but it cannot function alone. PV systems also include “balance of system” components such as electrical connections, mounting hardware, power-conditioning equipment, and batteries to store energy for times when the sun is not shining.
Nevada is also home to the Nellis Solar Star photovoltaic solar plant, located on the Nellis Air Force Base. At 140 acres and 14 MW generation capacity, the Solar Star was the 