Solar Energy & Co-Generation

Key points

  • High irradiance, low moisture means arid areas suited to solar
  • Arid areas lack clean water and food. Low population, low demand
  • Solar Co-Generation produces electricity and water from the sun
  • Co-Generation increases efficiency, making solar cheaper
Solar Electricity & Co-Generation

Water from the sun

Solar energy is a vast and largely untapped resource. Of the 170 petawatts falling on the earth less than 0.01% would meet total global electricity demand. The Centre for Global Development estimates that India and China could respectively produce 3-4 and 16-23 times their current coal plant capacities by concentrating solar thermal power alone. Only recently have governments begun to recognise this potential with initiatives such as the Indian Solar Mission aiming to rapidly expand solar capacity from 10MW (2010) to 4000MW by 2017 and 20,000MW by 2022.

Equatorial, arid and semi arid regions are particularly suited to solar thermal technologies, having both high solar irradiance and low atmospheric moisture, minimising absorption and scattering. Unfortunately, the best locations for solar also tend to be inhospitable and sparsely populated. Supply of solar energy also depends upon the time of day, season and weather conditions, irrespective of demand. The challenge for business is to devise competitive solutions to these mismatches.

Co-generation is widely employed in the nuclear industry to divert energy from electricity production when demand is below base-load, and to increase the efficiency of fossil installations. Recent work on solar co-generation of electricity and water has highlighted the potential to increase efficiency, mitigate supply mismatches, and address water scarcity issues typical in locations best suited to solar.