26 August 2015
It has been predicted that concentrated solar power (CSP) will be the key to making solar energy a viable energy source over the next 30 years. The quest to harness an effective and operational system has preoccupied some the best science and technology minds in the world, including the Google RE
The challenge with CSP systems is that they require large mirrors, called heliostats, across a large area to generate enough energy to make the technology feasible and cost-effective. Mirrors track the sun’s movement throughout the day and reflect its energy to the top of a generator tower, where the heat is transferred to moving water that can create electricity.
At Ivanpah, 143 000 heliostats across 1 420 hectares centralise the energy gathered on to three central solar power generators. The plant’s capacity factor – its ratio of actual output over time – is 31%, meaning for every hour it operates, the plant can generate 18.6 minutes of energy. Naturally, the technology is inhibited by its size and cost, so any way to cut these down is greatly anticipated.
South African solar energy researchers at Stellenbosch University have designed and developed the Helio100 system, which deals with the size issue. It is portable and easy to install without losing the technology’s effectiveness: Helio100 has only 100 heliostat panels, but can generate 150kW of energy collectively, enough to power a small suburb. At the moment, the system is aimed at relieving the effects of load shedding, but once fully developed, Helio100 will be a viable alternative power source.
Paul Gauche, a former strategic planner at Intel, is the founding director of the university’s Solar Thermal Research Group that developed Helio100. He explains that the system is remarkable in its portability, referring to what he calls “plonkable heliostats. (meaning) that, from factory to installation, you can just drop them down on to the ground and they work”. There is no major construction involved and minimum effort to install. “Every part in it is manufacturable (sic) and installable by two sets of hands,” Gauche told Britain’s The Guardian newspaper earlier this month.
Athi Ntisana, a technologist on the team tasked with conceptualising, prototyping and building the finished systems, is convinced the technology is right for South Africa. Helio100 “requires (local) labour, components manufactured here in the country and we have land here where sunlight is abundant – and that’s also where there is not much employment. It solves all these problems.”
The Helio100 system is expected to be fully functional by the end of October, and Gauche predicts that once the technology is perfected, economies of scale will follow to possibly create the first affordable, small-scale, consumer-friendly CSP system.
Source: The Guardian