Proceedings of the 2nd Annual International Conference on Energy Sustainability ES2008 August 10-14, 2008, Jacksonville, Florida, USA

ES2008-54148

An Assessment and Comparison of Installed Solar and Wind Capacity in Texas

Erin Keys Michael E. Webber, Ph.D. Department of Mechanical Engineering Assistant Professor, Mechanical Engineering University of Texas at Austin Associate Director, Center for International Energy and 512/656-7404 Environmental Policy [email protected] University of Texas at Austin 1 University Station C2200 Austin, TX 78712 (512) 475-6867 [email protected] http://www.webberenergygroup.com

Abstract of development, whereas few significant solar projects have been announced. This paper presents the first-ever comprehensive This solar assessment exposes a stark difference in assessment of the installed solar capacity in Texas. While the pace, cost and total size of installation for these two power power generated from grid-tied solar photovoltaic installations sources, which is the likely experience for many other states. can be tracked, an inventory including the capacity of these While these differences do not negate solar as a future power and other types of solar installations has never been option, they raise further questions about the technical, social, performed. In contrast, installed wind capacity in Texas is and economic barriers each renewable technology faces, as closely tracked and widely publicized. Because of this well as the feasibility and design of incentives to further discrepancy, decision-makers have lacked critical information market penetration. Understanding this mixed history for to gauge the appropriateness of solar versus wind power for these two power sources offers instructive guidance and useful future installations, complicating their ability to prioritize insights to policymakers nationwide. which renewable power sources to incentivize. The work presented in this paper fills this knowledge Introduction gap by providing the methodology and results from a bottoms- up survey of major solar installers, large solar customers, and This paper presents an analysis of the total installed relevant government agencies (for example government solar capacity in Texas. Recently, Texas has made agencies that are responsible for issuing rebates, or those that considerable progress installing renewable power capacity are major solar customers themselves). Over thirty entities thanks to the passage of Senate Bill 7 in 1999, which set a were systematically contacted to obtain proprietary data that renewable portfolio standard (RPS) of 2000 MW of renewable were then aggregated to determine the total installed by 2009 [1]. In 2005, the Texas legislature updated the capacity in Texas. RPS in Senate Bill 20 to 5880 MW by 2015, 500 MW of Both power generation and heating applications are which should originate from non-wind and non-hydro considered, including the following: photovoltaic (on- and off- resources [1]. Currently, Texas is leading the nation in grid), concentrating solar power (CSP), solar pond, and solar installed wind capacity, but the legislature is pushing for other water heating (SWH). Other heating forms such as room and renewable installations [2]. As a result, solar power has the pool heating are not considered. opportunity to expand its share of Texas’ electricity mix. An aggregate figure is presented and then Solar power is an important form of renewable benchmarked against installed wind capacity. Findings reveal energy for Texas because of the state’s excellent solar that after 30 years and roughly $56 million in installation costs resource. Solar resource relates to the quantity of solar (at approximately $8300/kW), Texas possesses about 6.7 radiation, or insolation, that a site receives. Insolation is the megawatts (MW) of installed solar electric capacity. “amount of solar energy reaching a surface per unit of time” Comparatively, in over 6 years and an estimated $6.9 billion and is usually expressed in kilowatt-hours per square meter in installation costs (at approximately $1600/kW), installed per day (kWh/m2/day) [3]. When insolation is aggregated wind capacity in Texas approaches 5000 MW, which is more over available land in Texas, the result corresponds to the than any other state in the United States. Notably, at least state’s “gross energy potential,” and can also be reported in another 8000 MW of new wind projects are in various stages terms of power, or solar electric, potential [3]. With the number one solar resource in the US and In the context of the state RPS, the booming wind high levels of direct normal insolation, which is essential for industry, an excellent solar resource, and recent media concentrating solar power (CSP) plants, Texas has a good attention, we have analyzed the total installed solar capacity in chance to meet its updated RPS [4, 5]. In fact, according to a Texas. 2002 National Renewable Energy Laboratory (NREL) study, Texas could, as an upper limit (and not including other social, Solar History economic or policy limitations), produce 127 gigawatts (GW)1 of photovoltaic (PV) power, which is far above the non-wind Solar power is not an infant industry in Texas, much threshold specified in Senate Bill 20 [6]. less in the US. Efficient production of solar electricity has Unfortunately, Texas has not yet capitalized on its existed since the 1950s when the first PV cell to output great solar resource. In 2006, the Texas grid only included .7 sufficient power to run everyday equipment was developed at MW, DC of solar power [7]. On the other hand, California, Bell Labs [11]. However, varying levels of federal support which has a solar resource of 98 GW2, AC, included 63.5 have resulted in large fluctuations in solar’s popularity, and MW, DC of solar power in its grid in 2006 [6, 7]. In other define four periods in the industry’s existence. words, California is utilizing 100 times the percentage of its solar resource than is Texas. California is less capable than 1. 1971 to 1974 – US Congress and the Texas of generating solar electricity yet produces more of it administration view solar and renewable energy because of higher rates of solar installation [6]. as futuristic energy options closely related to the On the international level, Germany outperforms US space program Texas and California, as well as the entire United States (US). 2. 1975 to 1980 – Solar technologies are seriously Despite having a solar resource similar to that of Alaska (the discussed in federal arenas in response to the state with the worst solar resource in the US), Germany has 1973 and 1979 oil embargoes “install[ed] eight times as much PV as the US” [7]. From 3. 1981 to 1988 – An inactive or even regressive these statistics, it looks like Texas still has the opportunity to period develops when the President and the US significantly increase its solar power output. public have little interest in energy matters. The Solar water heating (SWH) potential is calculated Reagan administration is ideologically opposed slightly differently than solar electric resource. Solar fraction, to solar and renewable energy and institutes or the “fraction of a building’s water heating energy demand policies to close down federal programs in these met by the SWH system,” in conjunction with rooftop technologies availability and total water heating energy consumption, are 4. 1989 onward - Rebirth period [12]. the factors that determine a region’s SWH potential [8]. In Texas, this potential is 4.7 billion thermal kilowatt-hours per The National Science Foundation (NSF) focused on year (kWht/yr) out of a total consumption of 11 billion research rather than technology development prior to the 1973 kWht/yr [8]. However, as the paper will show, energy savings oil embargo. After the embargo and into the Carter from SWH installations do not come close to matching the administration, federal support blossomed with the passage of state’s potential. numerous bills spurred by the Congressional Solar Coalition Because of growing concerns about the need to [12]. For example, the Federal Photovoltaic Utilization Act mitigate greenhouse-gas emissions and Texas’ role as the top established a federal technology procurement program “which energy consumer in the US (the US consumes 100 quadrillion was the first real solar commercialization effort” in the nation British thermal units (quads) of energy per year, of which [12]. Coupled with the creation of the Department of Energy more than 12 quads/yr is consumed in Texas alone), there (DOE) in 1977, this act caused support for solar to skyrocket exists a growing need in Texas to incorporate cleaner ways of [12]. It was during this time that the solar water and pool generating electricity [9]. As an emissions-free source, solar heating markets boomed in Texas; installation companies power is expected to be a growing part of Texas’s future began to spring up all over the state and solar thermal panels power mix. It might also alleviate electricity costs, as solar became more common [13]. power is well-matched with peak load. After Reagan assumed the presidency, however, Solar headlines are frequent in Texas (especially in federal incentives related to solar energy plummeted. Austin), with a variety of news agencies releasing stories Reagan’s removal of the solar panels from the roof of the related to municipal solar initiatives or the recent activity of White House symbolically signaled the end of the solar boom Texas-based solar startups like HelioVolt, which specializes in [12]. In an effort to “introduce an energy policy which thin film technology. On a national scale (particularly in place[d] greater reliance on market forces and private sector states like California and Florida), solar is gaining the investments,” Reagan slashed solar funding to decrease the spotlight. In a recent article in Scientific American, it is deficit [14]. Consequently, the solar thermal wave that had hit estimated that solar power plants could produce up to 69% of Texas during the late 1970s and early 1980s slowly started to US electricity by 2050 [10]. fade and numerous installers went out of business. If the solar market experienced a period of rebirth

1 during the 1990s, then it is now in a state of re-growth. Total resource is split into premium, excellent and good Especially with recent developments in thin film technologies categories, with capacity factors of 25%, 22.5%, and 20%, and grid-tied applications, solar power could start to comprise respectively. Assumptions include .04% land coverage and 5 a significant portion of Texas’s power mix [15]. In the near acres per MW, AC for electric generation. future, multiple-junction PV cells and organic semiconductors 2 .50% land coverage and 5 acres per MW, AC for electric generation. might make solar an increasingly economical energy option is the most efficient means of utilizing solar radiation as it can [4]. be nearly 60% efficient in warm climates [20]. SWH for indoor use in a warm climate only boasts 40% efficiency, Analytical Approach which is still much higher than PV systems [20]. Instead of converting all data into kW of capacity, In order to gather accurate and comprehensive data SWH installations are reported in energy saved per year on the installed solar capacity in Texas, we contacted major (kWht/yr). The Solar Rating and Certification Corporation solar installers and customers within the state asking details (SRCC), a nonprofit organization dedicated to certification about their installation or purchase records. A list of private programs and national rating standards for solar energy installers who are currently active in Texas was compiled from equipment, publishes data regarding the average energy saved the Texas Renewable Energy Industry Association (TREIA), per year for SWH systems. We used these data, in findsolar.com (an online directory sponsored in part by the conjunction with the assumption that an average system is 40- American Solar Energy Society and the DOE), and 64 ft2, to convert SWH data reported in total collector area to endorsements by city organizations promoting the use of solar energy saved per year [8]. SWH data provided in energy power in the area. In addition to privately owned businesses, produced per year was left as reported. we contacted publicly-owned utilities that offer rebates for In all cases, proprietary installation data collected installations as a way of accelerating the use of solar power. from private installers is kept confidential and only shared Major government programs and agencies including Texas here in aggregate. Statistics related to participating Solar for Schools and the Texas Department of Transportation government agencies and publicly-owned entities are reported. (TxDoT) comprised our remaining points of contact. These data, as well as the names of participating private Solar power meets various energy needs. In entities, can be seen in Table 1. collecting data, we considered both solar electric (power generation) and solar thermal (heating and cooling) Table 1.1: Participating Private Companies applications of solar installations. Power generation technologies include PV, which convert solar radiation directly into electricity. Alternatively, purely solar thermal Private Companies systems provide energy in the form of heat. This paper Apoenergy, Inc. includes data for PV, CSP, solar pond, and SWH applications. Applied Solar CSP takes advantage of “concentrating optics” to Ark-La-Tex Solar Power focus solar radiation in a small area and thus increase Armadillo Solar efficiency (for high temperature applications) [16]. In solar Cherokee Diversified Services, Inc. thermal applications, CSP utilizes trough systems, dish/engine Custom Solar Electric EcoVantage Energy, Inc. systems, or power towers to indirectly produce electricity with Entech, Inc. heat [16]. CSP is applicable to large-scale power plants and EverGreen Energy Systems comparatively large projects, whereas PV installed by Freedom Solar LLC commercial or residential customers can be connected to the Global Energy Designs grid, or kept off-grid for personal use [16]. Currently, Texas Industrial Solar Technology Corp. accommodates minimal CSP, but the state is included in a Lighthouse Solar DOE initiative to install 1000 MW of new CSP capacity in the Meridian Solar Systems southwestern US by 2010 [17]. West Texas, which boasts the New Point Energy Solutions highest direct normal insolation in the state, is a likely site for North Texas Renewable Energy, Inc. Rancher's Lifestyle CSP plant development [4]. Sol Technologies PV installers reported data on peak AC power output Solar System Installations in kW as defined by the panel manufacturer, while solar Solarplex of Texas thermal installers reported data in either energy produced per Sunflower Solar 2 year (kWht/yr) or total collector area (ft ). Standard reporting Sunrise Solar practice differs between PV and solar thermal due to Techsun Solar, Inc. numerous differences between the technologies and how they Texas Solar Power Company are used. Because solar thermal is utilized in heating rather US Elemental Energy than electrical applications, energy saved rather than power delivered is a more relevant metric. In addition, the efficiency of panels used for solar thermal applications covers a wide range of values. Efficiency for PV panels, on the other hand, is typically about 12-18% [18]. PV efficiency (as quoted by the manufacturer) is calculated based on the quantity of power outputted under “one sun,” or 1000 W/m2, at 25 degrees Celsius (°C) [19]. Solar thermal efficiency is contingent on the difference between the panel’s collection temperature and the ambient temperature [19]. In other words, efficiency varies for SWH versus solar pool heating applications, which deliver water at very different temperatures. When in use, solar pool heating Table 1.2: Participating Government Agencies and Numerous districts have installed solar capacity in the form of Utilities and Their Solar Electric Capacities school zone signals and flashing beacons. Of the 12 districts that replied, Brownwood and Odessa comprised the largest Government Agencies percentage of the roughly 57 kW of installed solar capacity Capacity (kW, Entity related to transportation throughout Texas. AC) State Energy Conservation Office (SECO) - Texas Solar for Schools 77 Texas Department of Transportation (TxDoT) 57 Austin Energy Solar PV Rebate Program University of Texas at El Paso (UTEP) - Solar Pond 100 Department of Energy (DOE) - Solar The Austin Energy Solar PV Rebate Program was Decathlon 14 launched on June 1, 2004 [27]. Today, with nearly $3 million in funding from the Austin City Council, the program has Utilities installed solar arrays for some 35 Austin businesses. These Capacity (kW, Entity installations, 67% of whose cost Austin Energy paid, will AC) Austin Energy PV 2000 reduce greenhouse gas emissions by 620 tons per year. In City Public Service (CPS) 448 addition, 511 Austin Energy residential customers have Green Mountain Energy 136 American Electric Power (AEP) 64 utilized the program to offset the cost of installing solar arrays. In total, 2 MW of installed solar capacity in Texas is associated with the Austin Energy Solar PV Rebate Program, making it by far the greatest contributor to installed solar Largest Solar Installation in Texas electric capacity in Texas. [28]

The largest solar installation in Texas is located at University of Texas at El Paso Solar Pond Fort Sam Houston in San Antonio [21]. Solar water heating 2 needs at the base are provided by 4515 ft of solar collectors, A salinity gradient solar pond located in northeast El yielding approximately 217 megawatt-hours (MWh) of Paso is included in our tally. Online since 1986, the thermal energy savings per year. As a Roof Mounted University of Texas at El Paso (UTEP) operates the pond, Parabolic Trough (RMT) system, the installation is considered which is not only used for research purposes but is also CSP. [22] connected to a 100 kW, grid-connected generator. Cold water In the future, the largest solar installation in the state with minimal salt content resides above a gradient layer, and will be in Reeves County (just south of Pecos), where Austin hot brine resides below that gradient layer. Due to the Energy is leasing 438 acres of Permanent School Fund land. difference in salt concentration, and thus density, of these This land will be used for the first utility-scale solar array in layers, they remain separated. The hot brine is then pumped Texas. Not only will the array power Austin homes, but also out of the pond and the heat is extracted to produce electricity. proceeds from the lease are helping to fund Texas public [29] education. [23] Challenges to Data Collection Educational Solar Systems Many challenges complicated the data collection One prominent solar effort is the Texas Solar for process. For example, the several thousands of SWH systems Schools Program. This program, which the State Energy installed during the solar thermal boom of 1977 to 1985 are Conservation Office (SECO) initiated in 2001, provides nearly impossible to track [19]. Since 1985, when federal “small-scale energy systems and complementary educational incentives for renewable energy development expired, many tools to school districts across the state.” Participating schools solar thermal companies have dissolved, leaving no evidence receive a 1 kilowatt (kW) or 3 kW grid-connected solar or permanent record of their installations [8, 30]. In addition, system that teaches students about energy conservation and it is not known whether these systems still operate or even clean power. The solar arrays also help the schools conserve exist, since “conservative estimates report a 20 year lifespan” energy and save money on their electric bills. In aggregate, 70 for solar panels [4]. kW have been installed through the program to date. [24] Risk of double counting in our tallies also existed American Electric Power (AEP), a prominent electric because of overlaps in staff or projects among companies with utility in the US, sponsors another educational solar effort no apparent correlation. For example, one company owned an called Watts on Schools (WOS). Solar arrays of 4 kW at 16 entirely different company, which in turn subcontracted to schools total 64 kW [25]. Just like Texas Solar for Schools, another, with all companies potentially claiming the same WOS acts more as an educational initiative than a power installed capacity as their own. In addition, due to fluidity in provider. Children as well as the community learn about the the solar industry labor markets, many employees have benefits of solar power due to these installations. worked at various companies over the years, making it difficult for them to isolate data from a single company. Some installers were surprisingly candid about their TxDoT poor bookkeeping, reflecting the relatively small size and immaturity of the solar industry. On more than one occasion a TxDoT consists of 25 districts, each of which is source provided an estimate of installed capacity from responsible for local projects under its jurisdiction [26]. memory. Instead of referencing written records, owners confessed that hard data did not exist for every installation they had ever performed. Although these estimates are assumed to be conservative and relatively accurate, they may include a high level of human error. Above all, the lack of a statewide incentive to coordinate solar installers under a single governmental agency decreased the certainty in determining a fairly accurate estimate of total capacity [29]. Organizations like the Texas Solar Energy Society and TREIA only provide a service to solar businesses. The ability for these organizations to establish a comprehensive list of solar installers is not possible since affiliation with them is purely voluntary. Alternatively, installation records kept by government agencies, municipal utilities and large purchasers Figure 2: Government vs. Private Solar Electric were in excellent order. These entities, including Austin Installations Energy, CPS, TxDoT and SECO, were highly responsive to our initial inquiry and provided precise estimates of their Solar thermal installations are dominated by private installed capacities. companies specializing in SWH applications (see Figure 3). Even government entities like Austin Energy, which is a huge Aggregate Capacity contributor to the PV market, have yet to sponsor the installation of many solar thermal systems. As a highly Solar installations by private companies comprise the efficient application of solar energy, SWH might gain largest percentage of the total installed solar electric capacity popularity if energy prices continue to rise. in Texas (see Figure 1). These private companies are scattered across the state, but a large number are concentrated in Austin. The next most prominent contributor is the Austin Energy Solar PV Rebate Program. With claims to over one quarter of the solar electric aggregate, this program has greatly impacted the solar industry in Texas. CPS, another municipal utility like Austin Energy that subsidizes solar installations, claims a noteworthy portion of the total solar electric tally as well.

Figure 3: Breakdown of Total Installed Solar Thermal Capacity (5700 MWht/yr)

The total installed solar electric and thermal capacity does not include solar pool heating or solar panels powering electric gates and receivers used by the oil industry. The PV contribution from the latter two sources is expected to be no Figure 1: Breakdown of Total Installed Solar Electric larger than that from TxDoT. However, solar pool heating is Capacity (6.7 MW) likely to account for a large percentage of the total installed solar thermal capacity in Texas. In fact, NREL states that The solar electric capacity of government supported “much of the existing market for SWH is swimming pool installations is less than that of private installations (see Figure heating” [8]. 2). TxDoT installations for flashing beacons and school zone Aggregate capacity is generally not a static number signals account for the smallest portion of the government and the same applies here, especially considering the total. Every TxDoT district did not report data, but the stimulation that the solar industry will receive from recent majority of them did; even with 100% participation, TxDoT initiatives like Solar America [4]. Proposed in Bush’s 2006 installations would most likely not surpass those by Texas State of the Union Address, this $148 million federal program Solar for Schools and WOS. Other government solar electric “involves strengthened efforts in the development of installations include the UTEP solar pond and installations semiconductor materials for direct sunlight to electricity related to the DOE Solar Decathlon, which “joins 20 college conversion with the goal of serving rural areas and and university teams in a competition to design, build, and commercializing building incorporated PV cells for potential operate the most attractive and energy-efficient solar-powered ‘zero-energy’ homes” [4]. house” [31]. Solar Cost Setting aside the installation costs associated with The price of PV modules just over 15 years ago was Texas wind and solar projects, the federal government has nearly seven times higher than it is today [31]. Since modules pumped money into both renewable energy technologies. account for nearly 50% of installed project cost, this price From 1943 to 1999, cumulative federal subsidies3 allocated trend can be extended to overall solar systems [32]. toward nuclear, wind, PV and solar thermal electricity Improving manufacturing techniques and increased module generating technologies totaled $151 billion. PV and solar scale have led to this steady decline in system cost. Better thermal technologies claimed $4.4 billion of that total while efficiency has also played a role in the price decline since wind only claimed $1.3 billion. When considering cumulative more power can be obtained from essentially the same subsidies together with electricity generation over the module. It was not until recently that module costs rose due to specified years, wind power, at 4 cents per kWh (¢/kWh), has a shortage in silicon, the material from which most modules received far less funding per unit of energy delivered than are made. [33] solar power, at 51 ¢/kWh. More federal money has been The capital cost associated with installing Texas’ allocated to solar technologies yet less solar electricity has total solar capacity is expressed in today’s dollars. In other been produced. [42] words, in calculating the price paid for the solar capacity, we One reason for the discrepancy in federal spending did not account for the price fluctuation of modules over the between wind and solar power is the time that each renewable years; instead, we used the current cost of solar electric and technology has been implemented. PV and solar thermal solar thermal systems. In the case of PV, we assumed an technologies, for example, have claimed federal funds in the average price of $8333/kW [6, 34, 35]. For SWH systems, we form of research and development, as well as incentives for considered $5184 as the average system cost, 52 ft2 as the installations, for nearly 30 years. On the other hand, average system size, and 2400 kWht as the average system significant federal attention to wind power has only been paid energy savings per year [8, 19, 20, 36, 37]. The only in the past decade. For example, a production tax credit (PTC) exception to this approach was the SWH system at Fort Sam of 2 ¢/kWh exists for wind, but not solar, power generation Houston, whose cost we took as twice that of its [43]. Still, the federal government only spent (in the form of approximately $40/ft2 parabolic troughs [31, 36]. Under these PTC subsidies) an additional $0.1 billion4 on wind power from assumptions, Texas accommodates roughly $56 million worth 2000 to 2006, bringing the estimated total to $1.4 billion from of installed solar electric systems and $12 million worth of 1943 to 2006 [43, 44, 45]. The incremental cost associated installed SWH systems. Taken together, approximately 68 with the PTC, which has been crucial to the installation and million of today’s dollars would be needed to install the total thus use of wind as a renewable power source, is a tiny solar capacity that currently exists in Texas. percentage of the federal funding dedicated to solar power over its lifetime [35]. Solar Benchmarked Against Wind The stark contrast in pace, cost and size of solar versus wind installations in Texas is significant (see Table 2). Texas leads the nation in total installed wind Higher commodity prices and manufacturing costs for solar capacity. In 2007 alone, Texas installed 1618 MW of new modules versus wind turbines are the driving factors for the wind capacity [2]. Worth $3 billion in investment, these new price difference (PV’s installed cost is approximately five additions caused Texas’ installed wind capacity to reach 4356 times more than that of wind) between the two power sources. MW [2]. In total, this capacity has cost nearly $7 billion However, this price gap might slowly tighten if the upturn of assuming a capital cost of $1580/kW, which is an average wind turbine prices and downturn of solar module prices installation cost over the years of 2003 to 2007 when most of continue to follow recent trends. the installations took place [2, 38]. Just as the cost of solar is heavily dependent on module price, the cost of wind depends greatly on turbine Table 2: Difference in Pace, Cost and Size of Solar price. Although it steadily decreased from 1997 to the early versus Wind Installations in Texas at the End of 2007 2000s, turbine price since around 2002 has been increasing due to factors such as “the declining value of the U.S. dollar Wind PV SWH relative to the Euro, increased materials and energy input Capacity 4365 MW 6.7 MW 5700 MWh t/yr prices (e.g., steel and oil), a general move by manufacturers to Cost (MM$) $6,870 $56 $12 improve their profitability, shortages in certain turbine Time Span (Yrs) 6 30 30 components, and an up-scaling of turbine size” [38]. Wind projects are thus becoming more expensive, though the full effect of higher turbine prices has not yet been felt [38]. For example, General Electric (GE) recently installed a wind farm Today, both the Texas and federal governments in Texas at a capital cost of roughly $2100/kW, which well continue to invest a significant amount of money into exceeds the $1580/kW average of the recent past [39]. maturing the solar industry. For example, corporations in Additionally, Boone Pickens, a renowned oilman in Texas, Texas dedicated to manufacturing, selling, or installing solar plans to build 4000 MW of wind capacity in the Panhandle (or wind) energy are exempt from the franchise tax. Still, no worth $10 billion, which translates to $2500/kW [40]. Even with these higher costs and projections of future upturns, wind 3 installations are not lagging. In fact, Texas has nearly 5600 “Includes direct and off-budget expenditures, revenue losses, MW of installed wind capacity when including projects and implied subsidies by the federal government that directly scheduled to come online by 2009 [41]. target commercial development and adoption” [42]. 4 Value assumes the current PTC of 2 ¢/kWh. match currently exists for the PTC, which has given wind an 1. “Texas Renewable Portfolio Standard,” enormous boost. Even the federal government’s renewable http://www.seco.cpa.state.tx.us/re_rps-portfolio.htm, energy production incentive (for which solar qualifies) fails to accessed February 13, 2008. compete with the PTC since it is only applicable to not-for- 2. “Installed Wind Capacity Surged 45% in 2007,” profit electrical cooperatives, public utilities, and other similar http://www.awea.org/newsroom/releases/AWEA_Market organizations. On the other hand, the PTC encourages all _Release_Q4_011708.html, accessed February 10, 2008. types of electricity providers to produce wind energy. 3. Virtus Energy Research Associates, 1995, “Texas Unfortunately, the PTC and many other incentives are Renewable Energy Resource Assessment: Survey, scheduled to expire at the end of 2008, which would affect the Overview and Recommendations,” Texas General Land outlook for either renewable energy technology. (Please Office, Austin, TX. reference [46, 47] and references therein) 4. Shivers, M., 2006, “Electricity for Texas: Exploring the Even though 30 years and billions of dollars of Potential of Solar and ,” The federal investment have produced minimal results in the form University of Texas at Austin, Austin, TX. of installed solar capacity for Texas, the benefits of solar 5. “Texas Renewable Energy Resources,” power for the state are still present. Not only cost, but also http://www.infinitepower.org/ressolar.htm and capacity factor5, location within the state (with regard to http://www.infinitepower.org/resglossary.htm, accessed transmission), and level of matching with peak demand are December 20, 2007. qualities of a renewable energy source that must be 6. Leitner, A., 2002, “Fuel from the Sky: Solar Power’s considered. Although the statistics do not show solar energy Potential for Western ,” SR-550-32160, as a favorite in the past, further increases in efficiency and National Renewable Energy Laboratory, Golden, CO. manufacturability might help its case for the future. 7. Prometheus Institute & SEIA, 2006, “US Solar Industry Charging Ahead,” US Solar Industry: Year in Review, pp. Recommendations 1-8. 8. Denholm, P., 2007, “The Technical Potential of Solar Given the complexity and difficulty of accessing Water Heating to Reduce Fossil Fuel Use and Greenhouse solar data for Texas, we recommend the creation of a central Gas Emissions in the United States,” TP-640-41157, repository of solar information that can be maintained similar National Renewable Energy Laboratory, Golden, CO. to the Public Utility Commission of Texas’ (PUCT) 9. “Energy Consumption by Sector, Ranked by State, 2004,” maintenance of wind power figures. Restrictions on the mode http://www.eia.doe.gov/emeu/states/sep_sum/html/pdf/ra and frequency of submissions would ensure consistent and up- nk_use.pdf, accessed February 26, 2008. to-date information on solar power in Texas and throughout 10. “A Solar Grand Plan: Scientific American,” the United States. This repository would allow easy access to http://www.sciam.com/article.cfm?id=a-solar-grand-plan, crucial information for not only policymakers, but players in accessed January 15, 2008. the solar industry. 11. “Solar Energy Technologies Program: Solar History Timeline: 1900s,” Acknowledgments http://www1.eere.energy.gov/solar/solar_time_1900.html, accessed February 18, 2008 This work was done at the request of the General 12. 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