Energy Biz - March/April 2008 - (Page 38) rooftop solar panels — by 2050 is a huge assumption. I have no idea what the penetration rate may be, but if the price of solar drops to the levels envisioned by the authors, then grid parity will occur quickly and the increase in the PV installation rate among residential and commercial customers will be dramatic. In addition, available roof space doesn’t have any of the land use issues of centralized greenfield PV plants. laNd CONCERNS The article may understate the magnitude of land issues. For instance, 46,000 square miles of arrays by 2050 is an astonishing number, and it’s unclear if the cost to purchase such land is included in the authors’ costs. Even if only half of the land needs to be purchased, at a reasonable price of $5,000 an acre, the cost of purchasing this land is more than $73 billion. Keep in mind that although the authors may not put much intrinsic value in this land, other people do. Desert land has extraordinary meaning and value to the people who make it their home, not to mention its environmental value for species diversity and its stunning scenic vistas. In addition, even though the authors believe that environmental concerns would be minimized since solar power is benign, the energy industry’s experience with other seemingly benign types of generation raises substantive questions. While solar is more benign than fossil fuels, nothing is truly benign. Concerns about the effect of wind farms on bird populations and visual vistas is a case in point. The environmental impact of covering approximately one out of five of the suitable 250,000 square miles of Southwest land with photovoltaic arrays is, in point of fact, unknown. TRaNSMISSION CONCERNS Concentrating large, centralized, energy-generation facilities in a single area of the country risks reduced grid reliability and likely heightens the concerns around energy and grid security. Furthermore, generation and transmission of close to 70 percent of U.S. electricity from the Southwest to major load centers over an entirely new HVDC transmission system defies certain basic operating rules about grid efficiency, stability, reliability, and options for contingencies when a major element of the grid ceases to function. AC-DC-AC terminals cost about $45 million to $60 million each, and it’s unclear whether these costs are included in the authors’ estimates. It is also not clear whether the necessary redundant generation and transmission resources necessary for contingency planning on the HVDC backbone are included in the authors’ plan. Finally, let’s not underestimate the political issues inherent in the idea of one area of the country supplying power to another. Just as Arizona did not want to act as an extension cord for California so that it could have clean affordable energy, the Southwest might negatively perceive the idea of paving over its land with solar panels for the benefit of other areas of the country. 38 a PORTFOlIO OF OPTIONS Clearly there are some fundamental engineering and financial challenges as well as practical realities that are of concern. But let’s assume this grand solar plan can actually be done. Should it be done? I don’t think so. It would be imprudent, as well as costly and inefficient, to put most or all of our energy eggs in one basket. The optimal grand plan that speaks to both emissions and dependence on foreign oil involves a portfolio of options, starting and ending with energy efficiency and involving renewable energy, distributed resources, nuclear and advanced coal generation, carbon capture and sequestration, and plug-in hybrid electric vehicles. Location and timing are crucial to effective, on-demand power delivery, and a mix of technologies and generation locations has a greater chance of providing the lowest-cost and most-secure electric system. The Electric Power Research Institute has been intensely studying this very issue. Its recent work on the electricity sector’s potential for reducing CO2 emissions and the economic value of deploying the associated technology is enlightening. Its PRISM and MERGE analyses show the clear benefits of deploying a diverse set of new and existing technologies, both from an economic and an emissions standpoint. This deployment would not require large distortions of the generation-and-transmission systems, and its technological and economic assumptions are relatively conservative and straightforward. Importantly, a portfolio approach hedges against the real potential for delays in technology development. Solar power will play a necessary and important role in the future of electric generation, as research and technology advances solve the intermittency concerns and the issues around integrating renewable energy into the grid. PV has a significant benefit in that it does not require water and is inherently modular, which allows for rapid deployment. PV systems have excellent potential to offset summer air conditioning loads and provide significant distributed generation inside our cities. I also believe that solar thermal technology along with integrated thermal storage will very likely play at least as large a role in the solar solution as photovoltaics. With the development of adequate and cost-effective storage, solar can move from providing peaking and intermediate capacity to serving our baseload energy needs. The authors are spot-on when they write that without subsidies, solar power will not reach its full potential. However, I believe the future of an electricity system that is secure, reliable and as free of emissions as possible lies in a comprehensive portfolio of robust generation options, and the collective will of citizens, scientists, engineers, policy makers and industry leaders to make it so. Jeffry E. Sterba is chairman, president and CEO of PNM Resources and chairman of the Edison Electric Institute and the Electric Power Research Institute. E n E rgyB i z March/April 2008
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