How does the cost of solar energy compare to the cost of fossil fuels?
GK: Harvesting solar energy from radiation takes more effort than just pumping oil from the ground, so solar energy is slightly more costly. However, right now, the technology is so advanced that the energy contained in one barrel of oil could be gotten from solar power for about 50 dollars. We know that the world market price of a barrel of oil is already above that, and the cost of oil does not include the follow-up costs of climate change, of pollution and all of these devastating effects, so solar energy is really becoming competitive with fossil fuels. CNN: To what degree do you think solar energy will have to become important in the future? GK: Well, the potential of solar energy is several hundred times the amount of energy we will ever need. However, we have other renewable energies available — wind, hydropower, geothermal, biomass and so on. My guess is that solar energy will be 40 to 70 percent of the total energy consumption, 30 to 60 years from now. It will be combined wit
