Renewables milestone in Spain
We reported on the start up of Spanish company Torresol's 19.9 megawatt solar tower last year.
Now there's a chance to take a video tour the plant. It's beautiful as well as functional - the film includes aerial views of it's 2800 heliostats - who's layout was modelled on the layout of a sunflowers petals to use space and angles in the most efficient way possible
The Gemsolar solar concentrating solar power plant produces enough power to supply 24,000 homes 24 hours a day. It's heat storage tanks can keep the plants turbines running for up to 15 hours without sun.
Unlike conventional solar thermal power plants, that can only operates when the sun is shining, Torresol's plant stores energy. The plant's 2,800 mirrors are focussed on a solar tower boiler and heat liquid salt to 500oC plus. The hot liquid is stored in a reservoir and, using a heat exchanger, delivers high pressure, high temperature steam to a conventional steam turbine.
The system – developed by SENAR is a major breakthrough in renewable energy. Until last years dramatic fall in the price of photovoltaics, solar thermal power had the capacity to produce electricity more cheaply than solar panels. It's lost that advantage now but Torresol's hot salt technology solves another major drawback of renewables - intermittency. Most renewables only produce power when the sun shines and the wind blows. This plant produces power 24 hours a day on most summer days, and an average of 20 hours a day over the year, providing an annual capacity factor higher than most baseload plant.
Torresol's storage technology is changing the rules for concentrated solar power (CSP). A second CSP plant using two 50 MW conventional parabolic trough concentrators is currently being being commissioned near Cadiz, in southern Spain.