Coal is a tricky situation – it's cheap and widely available, but it's oh so dirty. However, until a reliable (in any weather condition) and easily accessed renewable source of energy comes about, we'll be forced to stick with coal for a while longer.

Thankfully, Google, the megahouse search engine firm that has now branched out to spend its loads of money very wisely by investing in and researching in clean energy, is now focused on creating a source of electricity that is cheaper than coal. It's looking primarily to solar thermal power, wind power and enhanced geothermal systems. It hopes to produce one gigawatt of renewable energy (enough to power San Francisco) within years instead of decades.

The BBC mentions that Google is interested in high-altitude wind power, which shows huge promise and has gained a lot of attention recently.