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Concentrating Solar Power: Read an Excerpt from Innovation by Sarah Wild for More on the Helio100 Project

InnovationSarah Wild’s new book Innovation: Shaping South Africa through Science celebrates the science and innovation happening in South Africa right now, featuring projects which address the needs of everyday South Africans. It focusses on current initiatives, shedding light on the many ways people from this country are contributing to the future of various industries.

The Helio100 project, located on Stellenbosch University’s Mariendahl experimental farm, is one of the incredible projects elaborated on in Wild’s book. Funded by the Technology Innovation Agency (TIA), it is a test-bed for concentrating solar power (CSP) technology. Wild describes in laymen’s terms how the plant will eventually work and why it is such an important project in terms of renewable energy and solar power generation.

Read an excerpt from Innovation: Shaping South Africa through Science for all you need to know about this project and the challenges and triumphs that go with it:

CSP is the solar equivalent of the Drakensberg Pumped Storage Scheme, in which water from a dam is pumped to a dam with a higher elevation: when electricity is needed, the water from the higher dam is released, to flow down to the lower dam, generating electricity as it goes. With CSP, the sun’s energy is stored – currently within a molten salt mixture – and then released when it is needed.

According to the International Energy Agency, “by 2050, with appropriate support, CSP could provide 11.3% of global electricity … In the sunniest countries, CSP can be expected to become a competitive source of bulk power in peak and intermediate loads by 2020, and of base-load power by 2025-2030.”

This is good news for a country like South Africa. The nation has one of the highest rates of direct normal irradiation, a measure of sunniness. But the difficulty is: How do you harness and store this solar energy?

Molten salt mixture
In a CSP plant, mirrors position themselves independently to best reflect the sun’s rays to a receiver on top of a tower, converting the solar energy (concentrated solar flux) into thermal energy (heat). This heat can either be stored, usually in a molten salt mixture, to be released later or used immediately to heat water to superheated steam to power turbines – similar to what already happens in a coal-fired power station, except that it uses the sun’s heat instead of burning coal for energy. This technology is different from photovoltaic (PV) technology – such as solar panels on a roof – which directly converts sunlight into electricity.

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