Fuel of the future: The new power generation

There is more to renewable energy than acres of wind turbines. Gillian Orr discovers that potatoes, clothing and human waste are all being mooted as the future of fuel

The Royal Bank of Scotland might at first seem an unusual focus for climate change activists' ire. But since last Thursday, members of Climate Camp have been campaigning outside their headquarters in Edinburgh. The reason? They are protesting over the huge loans the bank has provided to oil companies, oil being one of the biggest culprits in contributing to climate change. Climate Camp wants us to stop burning fossil fuels and look for green alternatives for our energy. But what are the alternatives and will we be able to establish a sustainable network of environmentally friendly energy providers to replace our reliance on fossil fuels? There is more to green energy than wind and solar power; in fact, there is a plethora of innovative and intriguing ideas around and forward-thinking scientists are finding solutions from unconventional sources.

Potato-powered batteries

It might remind you of a school science project but researchers at the University of Jerusalem have developed a new way to construct an efficient battery using zinc and copper electrodes and a slice of potato: by boiling the potato prior to hooking it up to electrodes, it increases the electric power output by up to 10 times compared to an untreated one. They believe that the boiling part reduces the internal salt bridge resistance. It is green, cheap and simple, and could potentially be a huge benefit to the developing world. At present, 1.6 billion people have no access to electrical infrastructure and potato-powered batteries could provide energy for important demands such as lighting, telecommunication, and information transfer in those areas.

Cars running on sewage

Finding a green alternative to gas-guzzling motor vehicles is one of the most pressing environmental issues around. We already have the electric car but what about a car that runs on methane gas produced by human waste? The Bio-Bug is a normal 2 litre VW Beetle convertible been modified to run on both conventional fuel and compressed methane gas. The car is started with unleaded petrol but switches to methane when the engine has warmed up. While it still produces CO2, it is carbon neutral because all of that CO2 would have been released into the atmosphere from sewage treatment works. Excrement flushed down the lavatories of just 70 homes is enough to power the car for 10,000 miles. Its makers claim that drivers cannot tell the difference from a regular car – after all, they say, it can reach an impressive 114 mph.

Energy harvesting

Wouldn't it be fantastic if we could bottle the energy that we produce with every little movement we make and use it to power gadgets? Scientists at the University of Southampton's School of Electronics and Computer Science may have come up with a way of doing just that. They are currently developing an energy-harvesting film that can be screened on to the clothes you wear. The film will use printing processes and active printed inks to create clothing that will be capable of catching 67 watts with every step you take. Barely detectable and low cost, it certainly takes the idea of green fashion to a whole new level.

Solar power from space

Solar power is a fantastic green alternative energy source but it is one with an abundance of problems, the main one being that on cloudy days and during the night they provide no power. But what if you combat those issues by taking solar power into space? Japanese engineers are proposing to put solar collectors into geostationary orbit, which is an orbit directly above the earth's equator and matching the Earth's rotational period, at 35,700km in space. At this position the solar collectors will have access to direct sunlight, 24 hours a day. The satellites would convert the solar energy into electrical energy and beam it back to earth using microwaves. Understandably, scientists are incredibly excited about this but they will have to be patient: the first prototype is not due to start orbiting until 2030.