‘Go solar’ may sound to be the best option for power-starved utilities given the sun’s pre-eminence as the largest energy resource.
But as is true in the case of all prescriptions offered for riding out crises of such scale and magnitude, solar energy is one that is good in parts only, says an expert.
LAND-INTENSIVE
First and foremost, solar PV (photo voltaic that uses solar PV panels) is highly land-intensive, says N.T. Nair, technocrat and chief editor of ‘Executive Knowledge Lines’ magazine.
Five to10 acres are needed to farm out these panels to produce one megawatt of electricity, he said while making a presentation to an invited audience here. Exercising this option could render agriculture as an unintended casualty.
Solar power cannot be harnessed during a storm, a cloudy day or at night. Hence massive electricity storage systems are needed. Batteries used to store solar power throw up the challenge of their safe disposal.
WATER CONSUMPTION
Concentrated solar plants where sunlight is directed by mirrors or lenses onto solar receivers in the focal line of the parabolas, require plenty of water. Concentrated solar rays might also affect the fauna in the area.
Solar panel making industries could throw up pollution issues mainly from chemicals used, Nair said.
In Kerala, the government has a target of setting up solar panels over one million roof-tops over the next 10 years.
The proposal aims to generate at 180 units of solar electricity every month from each of these homes. They would need a 1.5-kW solar PV system to get going, Nair said.
ENORMOUS POWER-HOUSE
Just outside the earth’s atmosphere, the sun’s energy is continuously available at the rate of 1,367 watts on every sq m facing the sun. But due to the earth’s rotation, asymmetric orbit, and atmospheric contents, a large fraction of this energy does not reach the ground.
One hour of solar radiation is equivalent to more than the world’s energy consumption for an entire year. One year’s solar energy reaching the earth would be twice the amount of all non-renewable resources available.
Solar energy that hits the earth every second is sufficient to light up four trillion 100 W bulbs. The energy hitting one sq mile a year is equivalent to that produced by four million barrels of oil, Nair said.