Salt storage, two 656 ft. high towers possible

by Matie Belle Lakish
Although Tessera Solar, whose application was expected this month, has not yet submitted their revised application, a second concentrated solar company has submitted a Preliminary 1041 Application to Saguache County Land Use Department. SolarReserve, a Los Angeles-based corporation, gave a presentation to County Commissioners and interested public on August 3. Their proposal is for a solar power tower-type facility, which will include storage, thus making the power available over a longer period of up to 24 hours/day.
The current proposal, which can be viewed on the Saguache County website, is for two power towers, each of which will be surrounded by 17,000  heliostats, or reflectors, which will focus the sun’s energy on the 656 foot high tower’s receiver. This looks—from diagrams on their application—like a series of a multi-folded tubes that will hold molten salt. The salt will absorb the heat and reach an ultimate temperature of 1050 degrees C. It will use the heat to run  turbine generator, then, by either air or water, will be cooled back down to 566 degrees C. where it will then be pumped back up the power tower for reheating.

Each of the two planned arrays will cover about 1700 acres and will be located between Co. Rd. D and G going north to south, and between Rd. 53 and 57 east and west. SolarReserve plans to do this project in two phases of 100 MW each. Each 100 MW unit will have a 1.8 sq. mile footprint, and is projected to take about 2.5 years to complete. A prototype of this technology was built by the Department of Energy back in the ‘90s. Known as Solar Two, at the testing grounds in Barstow, CA, it has since been dismantled.  The only other such facility in existence at this time is at Cinco Casas in Spain, where a 50 MW facility is able to generate power 84% of the time.
One of the conditions which the Commissioners set for Tessera was that a power purchase agreement must be in place before they would receive County approval. At this point, SolarReserve does not have a signed PPA. They are counting on using the sub-station to the south in Alamosa County and current 230 KW power lines, and anticipate selling power to Public Service Co. of Colorado. They have mentioned other options as well, but, according to their pre-application, have not yet signed a contract.
The Pre-Application is available on the Saguache County website. Go to Departments, then Land Use, then Events. A public meeting has been scheduled for Tuesday evening, September 14, 6-8pm, at the Center School Auditorium. This is an informal meeting to gather input from citizens, but is not a formal public hearing. That hearing will be scheduled for later in the process. At this time, Commissioners will be seeking citizens’ ideas on what might be important to consider as they go through the application process. Please read the application and come prepared to make brief suggestions.