What’s the reason to subsidize alternative energy companies?

bob135 asked:


I’m not asking about raw research that occurs at universities – like discovering totally new technologies.

I’m wondering if there are any good reasons to subsidize existing solar, nuclear, wind, etc power companies. By reducing the price of nuclear power below the market equilibrium, people consume more nuclear power than they otherwise would, so there’s a deadweight loss.

If you just want to discourage gas consumption, wouldn’t a gas/petroleum tax be more efficient? That way private firms can optimally choose between other options.