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 solar power 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].