BBC: Common sense would surely tell you that if you slash the cost of one source of energy, then alternatives look less appealing.
You might think, therefore, that the crash in the price of oil must be dealing a potentially fatal blow to renewable power.
An illustration from recent history seems to back that up.
When the oil price spiked in the 1970s, the then US president Jimmy Carter had solar panels fixed to the White House roof, only to see his successor Ronald Reagan rip them off when the...