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Map of SW Solar Resources on BLM Lands. Source: BLM.

Just a year and a half after a breakthrough Solar Grand Plan study was published in the January 2008 Scientific American, the U.S. government has begun plans to implement major elements of such a Plan.

Measures announced Monday by the U.S. Department of the Interior identified initial solar project areas for the extremely sunny desert areas of the U.S. Southwest. These Solar Energy Study Areas could site utility-scale solar projects totaling 100,000 MegaWatts (MW) capacity. By comparison, the extremely successful U.S. wind energy industry had total installed capacity by the end of 1st Qtr 2009 equaling 28,206 MW, and “new nuclear power” Generation III+ nuclear plants installed worldwide to date equals zero MW.

Salazar Announces BLM Plans to “Fast-Track” Solar. On Monday, U.S. Interior Secretary Ken Salazar, appearing in Las Vegas with Senate Majority leader Harry Reid (D-NV), announced Bureau of Land Management (BLM) plans to move quickly on solar projects in the desert Southwest. Plans to “Fast-Track” solar include:

  • Identification of 24 “Solar Study Areas” in 6 Western States, on land administered by the BLM. (Click here for detailed state-by-state maps of the Solar Study Areas.)
  • In-depth evaluation of these 24 areas will begin immediately for their suitability for “large-scale solar energy production”.
  • The 24 areas will be segregated from new mining claims and other actions initiated by third parties under public land laws. Existing claims will be honored. This segregation will allow solar resource plans to be evaluated and authorized first before conflicting new resource claims would be considered. The BLM noted that “most of the solar energy study areas are located in alluvial valleys are unlikely to contain significant mineral values”.
  • 4 new BLM Renewable Energy Coordination Offices — in Nevada, California, Arizona, and Wyoming (which has major wind resources) will be opened to expedite processing of renewable project applications The NV office opened Monday.
  • The BLM has already received applications for 158 SW solar projects. The new processes are expected to complete study area evaluations by the end of 2010, with construction of approved projects to begin thereafter.

Optimum Areas Selected. The announcement by Interior follows exactly two weeks after release on June 15th of the Western Governor’s Association “Western Renewable Energy Zones – Phase 1 Report”, a collaborative effort of the Western Governors, the U.S. Dept. of Energy, the Interior Department, and the Federal Energy Regulatory Commission. BLM’s “Solar Energy Study Areas” were clearly developed in concert with the Western Governor’s Association project.

The “Western Renewable Energy Zones” (WREZ’s) study was aimed at finding areas which had very concentrated, high-quality renewable energy resources. These “hub” areas would then be the logical places to construct renewable energy generation projects, and the transmission lines to serve them. In the WREZ study, public comments were taken from utilities, businesses, environmental and wildlife groups, local governments and citizens.

The Solar Energy Study Areas of BLM further selected only those areas with limited impacts on wildlife, other natural resources or other land users. (In other words, land where no one would care if you put a large solar farm.) This might seem to favor very remote areas. However, it is also very important to be close to existing or proposed transmission corridors, and be accessible by roads. The slope of the terrain was also considered in finding the most optimum areas.

Though a major effort, a map of the optimal Western Renewable Energy Zones was developed in just a year’s time, aided by consulting firm Black & Veatch. Below is the portion of the WREZ map covering the SW states, including solar WREZ areas (orange) identified:

Western Renewable Energy Zones in SW States Source: WREZPh1

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Relative Size of Circles Reflects MWh/yr Potential Generation

(Orange = solar; Blue = wind; triangles = geothermal sites)

Public Lands Crucial to Solar Utility Scale Projects. Wind farm developers have had few problems siting massive wind farms on existing farmland, because of the very small “footprint” per acre of the wind turbines. Farmers can receive lucrative cash royalty payments for allowing the wind farm on their land, yet still continue to farm undisturbed right around the base of the wind turbines.

This simply will not be the case with large “solar farms” consisting of acres of solar collection mirrors, trough collectors, or photovoltaic panels. Of necessity, collecting the solar rays that fall upon the land requires using most of the land area, either for the collectors themselves or for access pathways.

Installation of large utility-scale solar farms thus would require purchase of any land used, at a high cost for the projects, if not for the availability of largely unused Federally-owned lands. Hence, the BLM lands hold the key to siting of large solar projects in the Southwest. Though the BLM will charge leasing fees to solar developers, these will be market value based for a solar project, and thus reasonable enough to allow the projects to succeed.

Transmission Corridors to Follow. While many of the 24 Solar Energy Study Areas are close to already-existing transmission lines, many have no access to transmission lines, or the existing transmission lines would need to be upgraded. The WREZ Phase I study was in fact by definition an effort to define the best renewable energy areas to develop which would need transmission corridors to deliver the power to market. (For instance, rooftop solar PV within cities was not considered in the WREZ study, a limitation that may prove important if PV prices soon tumble.)

The identification of the BLM study areas, and even final project approvals for the solar farms to be built, will thus not be the final step to development of these resources. Once projects are identified for development, tandem efforts to develop transmission corridors to serve those projects will be needed. This is a major reason for inclusion of the Federal Energy Regulatory Commission (FERC) in the WREZ study from the beginning.

Central Power Plants Located Far From Loads. The “solar farm” generating plants to be located on BLM lands will essentially be “central power plants” in the traditional sense — large multi-MW generators connected to the utility grid by transmission lines.

This is in direct contrast to “distributed” power generation projects, such as rooftop photovoltaic solar collectors that serve a single or a few buildings, or a substation area.

The advantages of the “central power plant” model of the Solar Energy Study Areas is that the most concentrated, highest value (i.e. sunniest) areas were selected. Therefore, locating solar generating plants in these areas will produce more power for each dollar spent on building the plant. It is just a fact of life, however, that very few people chose to live near these very sunniest areas of the Southwest (probably because they were just too sunny, hot, and dry.)

The other advantage of locating in the desert is that types of facilities that cannot be roof-mounted can be built there. While it might be possible to find rooftops in L.A. to install solar photovoltaic panels, you won’t find any land you can afford in L.A. If the most economical and reliable solar designs use technologies other than rooftop PV, therefore, they will need to be located on public lands.

What Kind of Solar Generating Projects Will Be Built? There are many designs proposed, but one of the most economical may be combination solar thermal/natural gas power plants, such as proposed by solar thermal company Ausra.

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Photo: Ausra.

In these power plants, water runs in tubes through mirrored troughs which focus the sunlight on the tubes and heat the water, which then drives a steam turbine. That’s the “solar thermal” part of the combination.

The “combined cycle gas turbine” part of this “hybrid solar/natural gas power plant” is a gas turbine that first generates power from burning the natural gas in jet-engine-like “turbines” that spin blades to generate power. Then, the very hot exhaust gases are used to heat water which drives a steam turbine.

In the “hybrid solar/natural gas” power plant, both the solar thermal and the natural gas turbines would share the same steam turbine. Not only does this save on construction costs, but it results in a power plant that can run very efficiently from a thermal standpoint. As the solar resource cools off at night, the gas turbines can gradually be ramped up to provide just enough heat to keep the operating fluid at optimum temperature. Then, as the solar becomes available during the day, the gas turbines can be gradually ramped down and shut off.

Not “Sunny Day” Power Plants. The solar thermal/natural gas plant is thus NOT a “variable” power resource the utilities cannot predict. It would be fully dispatchable power available 24 hours a day/7 days a week. A seamless operation of one coordinated power plant, not a “sunny days” power plant.

Ausra CEO Bob Fishman predicted at the Boston Going Green conference in March, that this combination design could lower total generation costs to around 7 to 8 cents per kWh. In contrast, Fishman said the solar thermal plant if built without the natural gas turbine, would produce electricity at total generation costs of around 12 to 13 cents/kWh.

With natural gas supplies in the U.S. now at very abundant levels and low prices, these hybrid solar/natural gas plants could prove the most economical and reliable solar generators for several decades. A real powerhouse of economical and reliable low-carbon electricity for the Western United States.

In future decades, as energy storage solutions advance, and our natural gas resources eventually diminish, other means to “back up” the solar power resources will prove valuable.

A Good Beginning on a Grander Plan? The Solar Grand Plan developed by Ken Zweibel, James Mason, and Vasilis Fthenakis called for a total of 84,000 MW of solar power plants to be built in the Southwest by 2020. The BLM’s 24 Solar Study Areas, as noted above, could exceed this goal, with 100,000 MW to be generated from these areas alone. While the planning processes now underway are likely to take another 2-4 years (especially once transmission planning and development is added to the picture), these plants go up very quickly, so completion of the projects by the year 2020 seems quite achievable, provided there is a need for the power.

The Solar Grand Plan concept, however, does not stop there. Zweibel, Mason, and Fthenakis predict that ramping up manufacturing to produce the (84-100,000 MW) of solar central power plants by 2020 should bring down $/kW production costs. While the plants when built are very large facilities producing many hundreds of MW of power per facility, they are made up of small components (mirror troughs, piping, valves) MADE IN FACTORIES. Mass production curves have proven that when you ramp up production of items made in factories, costs/unit trend downward. (The same applies to solar photovoltaic panels, which may ultimately win the factory-made price competition.)

The Solar Grand Plan authors note this means that by 2020, solar PV and solar thermal power are likely to be some of the cheapest electricity available. Since the Southwest has such an enormous solar resource (see map at the very top of this article), there would be no reason to stop building more solar power plants, and connecting them to other load centers in the U.S. They predict that by 2050, solar power could supply 69% of all U.S. electricity, and 35% of all U.S. energy consumption.

Grand Thinking Needed. In January 2008, I wondered if all of this could really come true. Now, the first phase (the 2020 Goal) seems already poised to become a reality.

Americans have always been an inspired and inspiring people. A Grand Plan? We have grand challenges ahead. Grand thinking sounds right to me.