The Crestone Eagle, January 2007:

San Luis Valley expected to lead the way in renewable energy—
solar, wind & ethanol projects get support
by Nicholas Chambers

On December 2 many residents and affiliates of the San Luis Valley participated in a cornerstone symposium on renewable energy at Adams State College. Through the collaboration of Adams State Community Partnerships, the San Luis Valley Resource Conservation & Development Council, the Colorado Field Institute, and the Colorado Energy Research Institute at the Colorado School of Mines, a highly significant and powerful renewable energy memorandum was signed by SLV stakeholders and state and federal policymakers.

Renewable energy: can the San Luis Valley lead the way?
Newly re-elected U.S. Congressman John Salazar is emphatically passionate about renewable energy. In his opening remarks, he laid down a pledge and a vision of how the renewable energy economy will take place. According to him, as a native farmer of the Valley, this quest will largely begin in agriculture. With the new Farm Bill of 2007, he along with Representative Colin Peterson (D-Minn.), plan to redesign farm policy “to put the profit back into agriculture.” This means shifting the emphasis from protecting the consumer to protecting the farm by ensuring younger generations will stay in farming. The average age of a farmer right now is 55.

Salazar said we can accomplish this farm sustainability by providing farmers incentives to grow for the ethanol and biodiesel industries, or provide the land and support for solar and wind farms. And contrary to popular belief, a farmer can grow corn for an ethanol plant and still have a valuable animal feed from the by-product mash. Now with cellulostic ethanol technologies, the corn stover (stalk) is also a viable feedstock for ethanol. Citing some numbers from a cellulostic plant in Idaho, he said they are making 524 gallons of ethanol from one ton of straw. Any cellulostic material can be used, including various grasses and even the SLV nemesis of tumbleweed.

Salazar emphasized renewable energy being a matter of national security. “The only way to have peace in the Middle East is to de-value the only resource that is there,” he proclaimed. Drilling in the Alaska National Wildlife Refuge (ANWR) for a short term return will not lead to energy independence and is no solution for the energy crisis. The economic development for a renewable energy economy will be driven from within. Fortunately, the greatest policy comes when there is a balance of power, as there is now, he added.

Colorado Energy Research Institute
The stout Scandinavian Dag Nummendal gave a brief and poignant symposium kick-off talk about Zero Emissions Energy Systems. He brought a three point approach to the argument for “no more coal.” Yes, we need to curb coal consumption, but maybe even more importantly we need to look at the fundamentals. One, we need to simply reduce carbon emissions. Two, we have to reduce the need for energy, and three, we need to reduce Middle East fossil fuel supply.

Inherent in all three of these points is just simply making energy more efficient. Presently we accept the loss of 50 percent or more of the energy that we create. Nummendal also called for a strengthening of the partnership between the people of the SLV and the researchers in the Front Range.

Sun Edison Alamosa Solar Farm
Brian Hammond is the program manager for Sun Edison, the solar finance and construction company that is installing the photovoltaic (PV) farm near Mosca. He described this project as the largest solar installation in the United States and the largest solar concentrator installation in the world, for now at least. The tracking solar concentrators they are using employ a mirror-dish configuration to focus the sun’s energy onto small PV cells at the rate of two suns’ magnification. The San Luis Valley is well suited for this type of PV because of our cool sunshine. In some areas where the sunshine is hotter they have to use active cooling to keep the temperature on the cell within an appropriate range. They would have used all concentrators to make up the 8 megawatt array, but they couldn’t get enough from the manufacturing company so they will be filling in the balance with standard, fixed flat-plate collectors. Construction will begin in March 2007 and the energy to power about 4,000 average homes will enter Excel’s grid next December.

Solar energy from crop circle corners
Jim Mietz from the SLV Resource Conservation and Development Council gave a briefing on the potential of setting up PV arrays on the presently unused corners of the Valley’s 2,200 crop circles. This means there are 8800, five-to-seven acre sites that can be potentially used for PV installations. The present project they are looking at is a 10 kW array on just .05 acre using grid-tied net metering as a way to “store” the energy during non-irrigating hours. An average center pivot consumes about 25kW of electricity. With rebates and tax credits, an $80,000 system can cost the farmer only $10,000.

Potential of next generation photovoltaic solar power
A professor of Physics from the Colorado School of Mines, Craig Taylor, gave a sweeping overview of what is termed “the next generation” of photovoltaic (PV) panels. These typically have flexible substrates at the expense of a loss in efficiency, such as the panels built to resemble roofing shingles.

Taylor said that globally humans are consuming about 13 terawatts (13,000,000,000,000 watts) a year, and by the year 2050 we will be consuming about 30 terawatts. For reference of scale, a land area of 1000 square miles would provide enough energy to meet all of America’s present consumption. The third generation of PVs will consist of thin-film crystalline-silicon quantum dots and wires with a lower cost and lower efficiency.

Sarah Kurtz, Principal Scientist at the National Renewable Energy Laboratory (NREL), followed Taylor with a discussion of the PV industry from concentrator costs and efficiencies, to our solar potential in the SLV.

The PV industry has experienced exponential growth since its inception in 1959, with a current value of five million dollars a year. The current factors in the cost of PVs relate to the amount of semiconductor material and the cost of glass in a PV module. Thus, solar concentrators effectively mitigate these two factors by having a large amount of reflective surface area (mirrors) or focusing lens (such as a fernell lens) concentrating the sun’s energy on a small PV cell area. These concentrator systems can achieve efficiencies of up to 40 percent.

Kurtz also reminds us that the possible drilling in ANWAR will only provide four percent of the nation’s oil for 25-50 years. Conversely, a ten percent coverage of PVs in the San Luis Valley could power the entire nation “until the sun burns out!”

Energy storage studies
Professor of Engineering at the University of Colorado, Frank Barnes, along with a team of graduate students, Jonah Levine, Gregory Martin, Richard Moutoux, and Jessica Neumiller (from Colorado School of Mines), gave several thought provoking presentations about different ways we can store renewable energy. The problem arises from the fact that much renewable energy is intermittent in production while consumption is variably constant.

Typically, when we think of energy storage we think of electro-chemical devices such as batteries or hydrogen/fuel cells, but what the next generation of these researchers are looking at is Compressed Air Energy Storage (CAES), surface-to-aquifer hydroelectric, and pumped reservoir hydroelectric.

The principle of CAES systems is that you store the electrical energy created by a wind turbine, for instance, by compressing air and storing it in the ground under 620-1000 psi in a natural geologic formation such as a salt dome or sandstone reservoir. Then when you need to draw off that energy you release that compressed air, mix it with a small amount of natural gas, and fuel a gas turbine generator. Efficiencies are reportedly 77-89 percent (similar to lead-acid batteries) and the energy can be stored for up to a year with capacities ranging from 50-300 megawatts. The two existing facilities of this technology exist at a 290 megawatt plant in Germany, and a plant in Alabama. The team is looking into a 15 megawatt wind farm on a mountain ridge above Georgetown, CO and storing the excess energy in an abandoned adjacent mine.

Surface-to-aquifer hydroelectric involves pumping water from the aquifer with a renewable energy source and storing it in a surface reservoir during off-peak hours. Then when needed the water can be run back down the well to drive a hydro-electric generator that is in the well casing at an efficiency of 65 percent. Potential issues with the Division of Water, the shallowness (lack of head) of many Valley wells, and the fact that it takes more energy to pump the water up than a farmer would need to irrigate were questionable factors raised by symposium participants.

Lastly, pumped reservoir hydroelectric involves having two reservoirs, one up and one down. When you have excess energy to store, the water is pumped to the upper reservoir and when the energy is needed the water is run down through a hydroelectric generator. This technology has been around since 1890 and boasts an 89 percent efficiency. Excel has a 324 megawatt system in place on Cabin Creek near Georgetown, CO. The SLV is cited as being especially suitable for this sort of energy storage given our elevation contrast of the Valley floor to the surrounding mountains.

Local geothermal potential
The San Luis Valley has the largest potential for low-temperature geothermal resource development over anywhere else in the state, said Jim McCalpin of GEO-Haz Consultants of Crestone. Based on the analysis of the existing geothermal wells and springs in the Valley, it is just a matter of drilling in the right place to a depth of 3,000 feet to reach 128°F geothermal water. This water is of course not going to make electricity but can heat residential and commercial buildings, green houses and aquaculture tanks, and community swimming pools. Once the heat value has been extracted from the water, however, it would have to be returned to the aquifer through an additional well.

Bioenergy and Colorado fuel cell center
In next month’s edition of The Crestone Eagle we will look in depth at bioenergy research being conducted at the Colorado School of Mines and the National Renewable Energy Laboratory, as well as work being done at the Colorado Fuel Cell Center.

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