In South Africa, Stellenbosch University’s Helio100 project is set to be the answer to the challenge of generating cheap CSP electricity using a small-scale array of mirrors to concentrate the sun’s energy, the Guardian reported.
Paul Gauché, a former Intel strategy planner, is the founding director of the Solar Thermal Research Group at Stellenbosch University that is testing a new approach.
The group plans to roll out the technology once they have completed their CSP prototype system in October.
CSP technology includes a field of mirrors called heliostats. These shaped mirrors are usually large with a huge central base set in concrete. Situated on the ground the heliostats track the sun and concentrate its rays on to a central point, which heats up. The heat is converted into electricity.
There are a handful of large-scale examples of CSP plants around the world generating electricity, and there are predictions that the technology could generate a quarter of the world’s energy by 2050, states the Guardian.
However, CSP plants are expensive and it has proved difficult to make them work on a smaller scale.
Helio100, solution for small-scale CSP?
With current technology, they are expensive to produce, have to be connected through wiring and need to be installed by highly skilled construction crews. This is the main factor that makes CSP more expensive than traditional PV panels, which have fallen in price by 75% since 2009.
Gauché explains the groups objective: “We are developing plonkable heliostats. Plonkable means that from factory to installation you can just drop them down on to the ground and they work.
“This means that no costly cement, no highly-trained workforce, no wires, just two workers to lay out the steel frames on the ground and a streetlight-style central tower.”
The group’s work has already attracted the interest of well-known foreign companies, including a German consortium and a Massachusetts Institute of Technology solar company.
Gauché said:“Every part in it is manufacturable (sic) and installable by two sets of hands, or one rugby player as we found out.”
Helio100 pilot project
Helio100 is a pilot project with over 100 heliostats of 2.2 sq meters each, generating 150 kW in total – enough to power about 10 households.
According to Gauché, the array is already cheaper than using diesel, the go-to fuel for most companies and businesses during regular power outages in the country.
In 2007, Google launched the Renewable Energy Cheaper than Coal (RE<C) initiative through Google.org in an effort to drive down the cost of renewable energy. However, the RE<C initiative abandoned their research after reporting that they could not do it cheaply enough.
What Gauché’s team has done differently is to reduce the cost of creating heliostats.
Prof Tobias Bischoff-Neimz, manager for energy at South Africa’s Centre for Scientific and Industrial Research, explained that globally, CSP is in decline after an initial growth spurt. This is due to the current cost being about three times more than using a hybrid system of PV panels together with wind power to generate electricity.
Bischoff-Neimz stated that: “The future for CSP rests with creating power at changing rates, not like a base load power station that runs at full power all the time, but a system that makes the grid more flexible.” He says Gauché’s work to reduce the cost of the technology is vital if CSP is to reach its potential.
The team aims to have the Helio100 system fully functional by the end of October 2015 but Gauché predicts that once they refine the technology, then economies of scale will follow.