The growth of solar energy globally is being determined not only by large power plants but also by individual and local use and plummeting manufacturing costs.
For those emerging economies that don’t have energy infrastructures and power grids it can present a way for isolated inhabitants to benefit from simple stand-alone power solutions. Collecting the sun’s heat using ‘black bodies’ is the most direct way solar energy can be used. By converting sunlight into heat, solar thermal collectors can power equipment such as home solar water heaters.
Solar energy is an immense energy resource which can be used for so many of our everyday needs including electrical power, heating and cooling, water heating, industrial process heat, cooking, transportation, fuel production and even environmental clean-up. We receive this sunlight as radiation which is pure energy which is the highest form of energy and this can be converted into many other forms for our everyday use.
Research has shown that only a tiny amount of the solar energy that falls on the earth would be enough to care for all the needs of our planet. However, it is only available during day time and then not during cloudy or rainy times. It is obvious therefore that if we are to depend on solar power in the future we must be able to store it efficiently and cost effectively. It is interesting to note that wind, biomass, ocean energy, hydro etc. are the indirect forms of solar energy, that is, nature converts solar energy to these forms for our benefit.
Much research is currently being concentrated on the following three goals:
- Increasing the efficiency of conversion to other forms while also reducing the cost.
- Storing energy more efficiently and reducing the costs.
- Finding newer ways to convert solar energy to useful forms.
As electricity has become the favoured form of energy for most of our needs more emphasis has been placed on research in how to increase the efficiency of conversion to electricity and reduce the costs. The two main methods of converting solar energy to electricity are photovoltaics (PV) and solar thermal power (commonly known as CSP, acronym for concentrating solar power).
The current research trend for PV is to look for earth abundant materials as some of the materials used today such as Cadmium, Tellurium, Gallium, indium, selenium etc. are not abundant. However, silicon the major material used currently in solar cells is abundantly available on earth. Research is being done into using earth abundant dye sensitised solar cells (DSSC), polymer solar cells and Perovskite solar cells (PSC) to improve their efficiency and stability over time.
Costs of PV have come down a great deal in the last decade making it difficult for CSP to compete commercially in the world.
However, many scientists are confident that this will change as CSP has the following two advantages over PV:
- It uses the same thermal power conversion as the conventional thermal power (fossil fuel or nuclear based) and can therefore be integrated with the existing power infra-structure easily.
- It uses thermal energy storage which is about one tenth the cost of battery storage.
A fifth of the world’s electricity is produced by renewable energy today. 2016 saw the inclusion of 160GW of clean energy installations globally which was 10% more than in 2015 but cost almost a quarter less. New solar power gave the biggest boost, providing half of all new capacity followed by wind power, which provided a third, and hydropower, which gave 15%. Added Solar capacity outstripped any other electricity-producing technology for the first time in history.
In the words of Sir Norman Foster:
“Solar Power is not about fashion, it’s about survival.”
Find out more about solar here.