Solar Thermal Electricity (STE) is unique in that it marries conventional power generation technology with clean solar energy as well as the capability to store energy.
IT GOES without saying that the existing electricity supply and demand imbalance in SA is making alternative energy sources, especially solar power, a lot more attractive, viable and necessary than ever before. This is especially true during the peak consumption periods, between 5pm and 10pm, where current supply falls significantly short in satisfying the demand. This imbalance has resulted in rotational load shedding as well as the costly operation of diesel-burning gas turbines that are costing Eskom billions of rands in unplanned expenditure.
Countries all around the world are looking to tap into the power of the sun to increase their energy independence, improve their energy affordability, enhance their economic growth and reduce their carbon emissions. Areas such as the Northern Cape in SA and other parts of Africa average about 2,500 hours of sunshine a year, making solar technology a no-brainer for the country and the continent.
Although the renewable energy sector is still at an early stage of its development and implementation in SA (and in many other countries that have a long tradition of relying on fossil fuel energy sources), it is already contributing to the national grid and saving hundreds of millions of rand.
Over the next few years, there is an excellent case for a big surge in public-private partnerships in the renewable energy sector. This is specifically true in the adoption and application of solar thermal technology, which has the potential to be a major game changer for the country in that it is the only large-scale, dispatchable, renewable energy power generation option that can assist the country with its peak power crisis.
Research in a recent report published by the Integrated Energy Research Centre at the Council for Scientific and Industrial Research (CSIR) has shown that solar and wind power projects in 2014 contributed R800m more in benefits to SA than they cost to operate, indicating that they are already making a substantial difference. They also save diesel and coal costs worth R3,7bn.
Their study also shows that the cost per kilowatt-hour (kWh) of renewable energy has fallen sharply and is falling further, making it increasingly cost effective to implement. By 2020, solar power is expected to be considerably cheaper per kWh than electricity coming from coal-fired power stations.
Dr Tobias Bischof-Niemz, chief engineer at the CSIR research centre says in the report that the cost per kWh of renewable energy for new projects is now well below R1 for solar photovoltaic, underlining the huge potential for solar thermal solutions as well.
While it is estimated that there will be more than 5-million solar panels operational in SA in 2015, with an installed capacity of more than 1,000 megawatt (MW), the belief is that by 2030 installed solar energy capacity (including solar thermal electricity which uses mirrors to concentrate the power of the sun) will be about 8,400MW, equivalent to about 20% of Eskom’s grid capacity at the moment.
Already, Eskom has signed agreements that will see as much as 1,450MW of solar power coming from solar photovoltaic projects.
Solar Thermal Electricity (STE) is unique in that it marries conventional power generation technology with clean solar energy as well as the capability to store energy. As such STE facilitates an increase in the proportion of renewable energy integrated in the energy mix and enhances system reliability as the result of its dispatchability or the ability to adapt production to demand.
Dispatchability is considered an essential factor for electricity systems. Being able to adjust energy generation to the demand curve has the benefit of selling electricity into the grid at peak generation hours, with a resulting increase in value of the provided service, and the ability to compensate for the effects of intermittent sources. This is desperately needed in SA where the peak demand cannot be met.
Although many people think that solar power technology is just a decade or so old, it has actually been around for much longer. In the US, for example, parabolic trough technology has been used commercially for more than 30 years.
As with any technology, solar technology has improved over time and significant technological developments have led to cost reduction and higher efficiency. STE is neither an experimental technology nor one undergoing testing, but rather a commercial solution that can be adapted to a variety of geographic locations.
Apart from the obvious resource, financial and environmental benefits that solar technology can provide, it is also a good generator of jobs, both in the construction and operational phases of solar power plants. As a general rule of thumb, 10 to 15 jobs are created for each MW during construction and project execution, lowering to one or two permanent jobs per MW during the operational phase. In a country such as SA where unemployment is a major problem, this is an important additional benefit. This job creation often takes place in remote areas where work opportunities are scarce.
But this is only the tip of the iceberg, as there is also a big potential for indirect and flow-on employment and entrepreneurial development once the solar power sector really gets moving. This can translate into manufacturing supply chains, value-added product development, public-private partnerships and the creation of research and development facilities and opportunities.
Van Heerden is GM of Abengoa Solar for sub-Saharan Africa.
