Page 42 - Respond 2016 Magazine
P. 42



        solar power:

        a 24-hour



       Given commitments made by the leaders of 195 nations at Cop21
       in 2015 to decarbonise electricity generation by the year 2050,
       a significant component of the energy mix of the future must
       utilize the heat and the light radiated by the sun.

       While it is the renewable energy generated by sunlight, the photons from the solar rays that   By Paddy Padmanathan
       has captivated the imagination and caused so much excitement in recent times by producing   President & CEO, ACWA Power
       electricity through the photovoltaic (PV) process at ever reducing cost, it is also this electricity
       generated by the PV process that has caused much debate about the real viability of solar
       energy being a reliable solution given the intermittency of this resource.

       In simple terms, given that PV generated electricity cannot be produced while there is no
       sunlight and without having access to affordable utility scale battery storage solutions PV
       generated electricity will not be available at night or even during daylight hours when the light
       is diminished due to cloud cover.

       Then there is heat, the other source of energy from sun light. Using a technology to concentrate
       that heat to generate temperatures as high as 1,000 degrees Celsius, we can then store the heat
       in a molten salt medium and draw upon it as and when required over a 24-hour period.

       The heat is then used to generate electricity by driving a steam turbine and generator, allowing
       us to break away from the intermittency constraint of the PV technology. So all of a sudden, solar
       energy via this Concentrated Solar Power (CSP) technology does provide considerable promise
       to make available electricity as and when we need it, to use as and how we want to utilize it.

       Cost competitive?
       Given we do not use the same amount of electricity at all hours of the day and thus the
       demand itself is intermittent, a supply system needs to be not only flexible but can be
       designed to incorporate the full range of energy generating sources available.
       While today most needs are fulfilled by fossil fuel-based energy generating sources, we now have
       a range of renewable energy technologies that can progressively takeover and in time fully replace

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