Engineers are brimming with ideas of how to extract every last tonne of fossil fuel: one company is now showing that all it takes is common fertiliser.

A rush to extract methane from the depths of Africa's Lake Kivu could trigger a huge upwelling of suffocating gas, potentially affecting over 2 million people.

The launch of a UK project to extract geothermal energy from hot dry rocks comes soon after two high-profile setbacks elsewhere in the world.

Sending an email across the Atlantic Ocean does not burn any jet fuel, but the internet is not without its own, huge carbon footprint.

The first Formula 1 cars to be fitted with a controversial energy recovery system are due to race in this season's opening Grand Prix in Melbourne, Australia, on Sunday. But questions over the safety of the system remain unresolved in the run-up to the race.

Power lines stretching across continents would allow us to ditch fossil fuels for good

What do a small Italian village, a community of millionaires in Oregon and a town in Austria have in common? Nearly all of their electricity needs are supplied by renewable energy. They are by no means the only ones. A growing number of communities are working towards using only electricity generated by renewables.

The unwavering predictability and scale of the tides in some parts of the world make them an attractive renewable energy source. Some estimates put the energy in the world's tides at as much as 1 million GWh per year, or about 5 per cent of the electricity generated worldwide, though only a fraction of this is likely to be exploited due to practical constraints.

One of the key problems with renewables is their intermittent availability. You can only generate energy from the wind when it is blowing, or from the sun when it's shining. Critics argue this is why we will never be able to rely on renewables for the majority of our electricity generation. But that criticism may soon be silenced.

THE price of a cup of coffee. That's one estimate of what it will cost each American every day for the next 20 years to break the fossil fuel habit of generations and turn to renewables instead. A daily outlay of a shade under a couple of dollars does add up to trillions over the decades, but is it really that much to ask? (Editorial)