VANCOUVER — As the green energy movement charges ahead, backed by tax dollars, there are as many boosters as there are critics. What do the critics have to say? The Fraser Institute think tank summarizes the downside.

"To a great extent, there is currently no sensible substitute for fossil fuels," writes think-tank researcher Diane Katz. "But that is not stopping governments from instituting quotas for renewable energy use to create artificial demand."

No fan of green energy, the Vancouver-based think tank says this about ethanol and other biofuels: "A recent study published in Science reports that the cultivation of corn for ethanol and other biofuel feed stocks substantially increases emissions of greenhouse gases. The study calculated that corn-based ethanol nearly doubles greenhouse gas emissions over 30 years."

On solar power, the Fraser Institute argues that it is "inherently inefficient and unreliable. Even the most advanced experimental solar cells convert no more than 45 per cent of the captured sunlight into energy; the typical efficiency is 25 per cent. Much of the energy is lost through heat. The other limitation, of course, is that sunlight is variable.

"Wind power is likewise intermittent and the turbines require a wind speed of about 15 mph to generate electricity and 25 mph to reach maximum output."