Green living weekly: clean, renewable human power!

Not willing to be outdone by Bex and Jamie with their new weekly columns, I've decided to start my own. Every Monday (hopefully I haven't already set myself a standard I can't keep up) I will bring some interesting, some useful, some purely insane ideas and tips for a greener lifestyle.

While we usually focus on governments and industry for global change, what we do know about tackling climate change is that we all need to play a part - nobody is off the hook. And if we want governments to make some bold moves, we better show them how it's done. And there is one clean, green energy we can all harness - our own (yes, crusty hippies still count as clean energy).

An average person stores as much energy in fat as a 1000kg battery and there are some interesting developments that are trying to harness some of this energy. We're not just talking riding a bike. What if your walk or bike not only got you to your destination, but also charged a battery or a portable device?

Scientists in the US and Canada have started developing what they are calling biomechanical energy harvesters. The journal Science reports that it is an adapted knee brace which you wear while you walk and it harvests energy from your movements with little extra effort - enough to power a mobile phone or MP3 player. Besides the potential to power portable devices, it could also be used to power prosthetic limbs and other medical devices.

At the far end of research to harness human energy scientists have started developing nano-generators. The researchers at the Georgia Institute of Technology are showing how self-powered nanotechnology combined with textile fibres could turn a t-shirt into a charging device. The fibres embedding in clothing would be powered by movement.

The journal Nature says this micro-fibre nanosystem could "scavenge" energy from the vibrations of "footsteps, heartbeats, ambient noise and airflow".

The creators estimate that a square metre of fabric could theoretically generate as much as 80 milliwatts of power, but real world use of this technology is likely to start in the medical or military sectors.

While these technologies are fascinating, they are still a way off if you're wanting to do something today to harness that stored up fat energy.

There are an endless number of products out there that capture human energy for charging. You could get a crank mobile phone charger. There are hand crank radios. Watches and flashlights powered by wrist movement have been in the shops for years.

But if you're looking for a weekend project and a bit of a challenge, how about turning your bicycle into a charging device?

Mark Hoekstra at Geektechnique has adapted a standard bicycle dynamo electricity generator that is used to power a bike light to charge his iPod and has posted a great "how to" on his site. The same could be done for mobile phones and other handheld devices. Who will be the first to charge their laptop by bicycle on the way to the office?

But the simplest solutions to harnessing human energy is to ask yourself every time you flick the switch: do I need this? Could you walk or ide a bike instead of driving? Do you use the mixer for scrambled egg when a little wrist action could suffice? Are you filling your life with unnecessarily appliances when you could be harnessing the power of your muscles?

Give it a try and let me know how you get on.