The outcome of COP15, the conference on climate change in Copenhagen, was the Copenhagen Accord which was recognised by the 193 countries that attended. The Accord set no compulsory limits on carbon emissions, and none of the countries that introduced it – USA, China, India [with Brazil and...

When hydroelectric power systems became widespread, associated developments for energy storage, using pumped water, soon followed. Many other methods of storage have since been considered. Today's interest in other renewables, notably wind energy has led to assertions that, because it is...