A concentrating solar power plant is an electricity-generating system that makes use of sunlight to produce electrical power. Sunlight is concentrated onto a receiver by the means of an array of mirrors or lenses. These mirrors/lenses refract sunlight rays from a large area to converge onto a receiver. The receiver is designed and connected to a steam turbine so that the sunlight heats water to generate steam, which turns turbines connected to an electrical power generator.
CSP plants have existed for decades as of now. However, these plants are not high capacity since the receivers in production today do not go beyond 600°C. Several receivers can be connected in series to increase the amount of steam produced and the overall capacity of the plant. To increase power output, more capital investment is needed. The total cost may be broken down into three:
A publication by the international renewable energy agency (IRENA) reveals that a parabolic trough plant would have a low capital cost to the tune of $4,600/Kw without a thermal storage system. A solar power plant, on the other hand, can as low as $6,300/Kw, also without a thermal storage system. Both systems would cost $7,100 and $10,500 if an energy storage system is built alongside.
Another type of cost is the operations and maintenance cost, which is considerably higher as compared to other plants like HEP plants. The price ranges between $0.02 and 0.035 per kilowatt-hour.
Levelised cost of electricity is determined by the amount of normal irradiance and the capital cost. If the capital cost is estimated at 10% of the total, a parabolic trough system would cost between $0.2 and $0.36 per kilowatt-hour. A solar tower, on the other hand, can operate on as low as $0.14/kWh and a high of $0.18/kWh.
Towards the end of November 2019, CNN reported that a small green-energy company located in California had made a solar technology breakthrough by employing artificial intelligence (AI) to develop a system of mirrors that could concentrate sun’s light to rack up a temperature of over 1,000°C.
According to the CEO, this company, Heliogen, has a vision of integrating industrial furnace heating to the receivers instead of producing steam (electricity). That could see a new era where a CSP plant could power a steel or cement factory. Notably, the cement industry alone accounts for not less than 8% of the total carbon emission. That might have been the motivation that led Heliogen to their groundbreaking invention.
Heliogen’s mirrors are to be mounted on computer-controlled towers, which are then connected to a compact receiver, from where the heating would take place.
The highest attainable temperature on Heliogen’s system is not sufficient to complete cement manufacturing. Still, it is just enough for the initial stage, which accounts for the highest carbon emission for the whole process.
CSP technology didn’t have a significant global presence until after the first 21st century’s decade. For instance, in 2005, there was a total of 354MW produced globally by CSP plants. In 2018, the global production had skyrocketed to 5,500MW. That is a significant increase in green energy. Currently, Spain is the world leader in concentrated solar power production with 2,300MW, which is above 50% global production. The United States is the second, producing over 1,700MW, followed by China, North African countries as well as those in the middle east.
The largest-by-capacity CSP plant in the world is the Ivanpah Solar Power Facility in the US. As expected, this modern power plant uses the solar tower machinery instead of the parabolic-trough design, which attains lower receiver temperatures. The plant has a peak capacity of 392MW. It is closely followed by Ouarzazate Solar Power Station in morocco West Africa, which is a diversified plant consisting of three sections, which produce a total of 510 MW.
Looking at the trends in green energy and the pro-green energy campaigns, it is evident that CSP plants will soon be present in more countries. The technology around CSP production is also set to improve significantly with the increasing number of stakeholders. That, in turn, will reduce the overall cost of production, making it compete favorably against other power production plants such as fossil and nuclear-powered systems.