Super-Sized Solar Power Plant Plans, San Luis Valley
Written by Imogen Reed
At an elevation of 7,500 feet, the San Luis valley bordering Southern Colorado and New Mexico is notable as the driest location at this elevation in the US and now as the site for one of the largest and most technically advanced solar power projects in the world. With its temperate climate and high exposure the valley has long been the proving ground for solar and wind power projects, many of them on a large scale, but the proposed new site is likely to be much greater than would be covered by any landlord insurance, and will set some records when it is complete.
Approval from the board of commissioners
The Sagauche County Board of Commissioners just this week approved the permit for the project, which, when it does go ahead, will better than triple the output of any other plants currently in the valley with a predicted output of 200 megawatts (mw).
Santa Monica Company driving the project
The company responsible for the project is the Californian based SolarReserve, founded initially in 2008 from the US Renewables Group, in conjunction with United Technologies Corporation (UTC). SolarReserve, through its affiliation with UTC holds the exclusive global license to develop solar power using Rocketdyne technology; the technology used in the US Departments Solar One and Two projects.
Sprawling location proposed
The technology on the proposed plant has already been the focal point of much debate and discussion amongst renewable engineering strategists. The proposed process is to use heliostats, which are mirrors that track the direction of the sun, and then direct this energy onto molten salt (or water), which through this process is turned into steam. There have been some questions raised as to the efficacy of the process, due to the large volume of space required in which to generate the energy. In this respect the San Luis Valley offers the perfect working ground. The valley is 8,000 square miles of desolate beauty. In order to achieve the 200mw output the plant will be sprawled over an impressive 4,000 acres of ground. The operation will also house two towers at almost 700 feet apiece and the heliostats alone will cover 1,700 acres.
Buyers for the power have not yet been fully confirmed
There are a number of firms who have registered interest in handling the energy output from the plant, but as yet only one has been confirmed. Xcel Energy, who has the advantage of closely located Xcel power lines, have been contracted to handle 100mw of the transmission capacity from the plant. For the remaining 50 percent of the power a buyer has yet to be found.
Technology in the plant under close scrutiny
There is no doubt that the technology for the proposed San Luis site will be watched closely by competitors in the market; particularly by those in the production of conventional solar power which is produced through a photovoltaic system known as concentrated solar power (CSP). There has not yet been a successful alternative to this and the approval for the San Luis site comes hot on the heels of the asset auction of Stirling Energy System’s Maricopa Solar which bankrupted in September 2011.
Firms viewing dry cooling systems
Among the difficulties faced by CSP are the energy requirements for the process, in particular the volume of water required for the cooling of mirrors and lenses. In this respect a location like the San Luis Valley stands at a distinct disadvantage. The lack of natural precipitation in the area means that there is a considerable energy drain in obtaining and maintaining the water requirements for the system. Many solar energy providers are turning their interests to dry cooling systems despite the fact that they are initially more expensive to operate.
Companies championing Concentrating Solar Power
There is some global impetus behind the rise of concentrating solar power and among those championing its progress are the German technology giant Siemens AG; the Spanish energy firm Acciona SA and the Swiss outfit ABB Ltd. These have joined with other firms to create a lobbying group Concentrating Solar Power Alliance in an effort to influence US lawmakers and regulators on the advantages of CPS technology. The performance of the San Luis Plant will provide some leverage for the group in support of their arguments.
Drax advances biomass strategy with Pinnacle acquisition
The Group’s enlarged supply chain will have access to 4.9 million tonnes of operational capacity from 2022. Of this total, 2.9 million tonnes are available for Drax’s self-supply requirements in 2022, which will rise to 3.4 million tonnes in 2027.
The £424 million acquisition of the Canadian biomass pellet producer supports Drax' ambition to be carbon negative by 2030, using bioenergy with carbon capture and storage (BECCS) and will make a "significant contribution" in the UK cutting emissions by 78% by 2035 (click here).
This summer Drax will undertake maintenance on its CfD(2) biomass unit, including a high-pressure turbine upgrade to reduce maintenance costs and improve thermal efficiency, contributing to lower generation costs for Drax Power Station.
In March, Drax secured Capacity Market agreements for its hydro and pumped storage assets worth around £10 million for delivery October 2024-September 2025.
The limitations on BECCS are not technology but supply, with every gigatonne of CO2 stored per year requiring approximately 30-40 million hectares of BECCS feedstock, according to the Global CCS Institute. Nonetheless, BECCS should be seen as an essential complement to the required, wide-scale deployment of CCS to meet climate change targets, it concludes.