Donnachadh McCarthy, 44, from Camberwell, south London, was a ballet dancer before a chance trip to the Amazon rainforest changed his life. Now the committed Liberal Democrat lives a green lifestyle in his solar powered cottage.
Mr McCarthy says being green can be cheaper
When I was a dancer I always turned to alternative therapies to heal injuries.
A group of therapists were going to the middle of the Amazon in 1992 and they asked me to go.
I ended up staying with a Yanomami tribe and saw how their lifestyle supports them as it used to 20,000 years ago.
They are self-sufficient and no danger to their environment - unlike us in London.
I resolved to change the way people lived when I returned to Britain.
To live a green lifestyle you should question if you've got to do something. Is it necessary?
For example when my fence fell down I thought about getting recycled fencing but realised I didn't need it as I had a hedge there already.
Mr McCarthy wants to install a wind turbine on his cottage
By doing nothing I found a green solution.
When leaves fall down instead of putting them in a plastic bag I use them as mulch for the garden.
A filter tank on top of my entrance roof catches rainwater to fill my loo and provides around 85% of my household water.
When Thames Water talks about building huge reservoirs outside London to supply us with water, it's not necessary.
About 20,000 gallons of water fall on our roofs each year but it is pumped to the water company who put chemicals in it, then they pump it back and we flush it down the loo.
If all our houses were built with their roofs south facing then when the market for solar power grows the houses will be ready.
In the living room I have a meter which shows me how much energy I am producing and using.
I used to have a lodger who would boil a full kettle. It's not for me to impose my ideas on other people but the metre showed him how much electricity was being used when the kettle was on and he started boiling just a cup at a time!
This year I have put more electricity back into the National Grid than I have used. I'll get paid around £50.
The average household spends about £250 on electricity each year.
Every house should also be built with space for storing bicycles, especially shared housing.
Getting people cycling in London would be cheaper than massive public transport investment and it keeps you fit.
'Drop in the ocean'
All my bulbs are energy saving. I have 10 bulbs in total, which comes to under 200 watts. In a normal house that's just two bulbs' wattage.
I don't have a wheely bin because I don't need it.
I empty my small bin on the first of every month. One month's rubbish in one bag.
I do like to travel so I plant a tree every time I go on holiday. If you plant a tree every time you go on a plane you are making an investment for the future for the CO2 that is used.
I've got planning permission for the first grid connected windmill in London. I'm waiting for the technology to be right as I'm installing the first one and I want to set a precedent.
What I do at home is significant for me but just a drop in the ocean for London.
I'm just helping to build momentum. And if all of London does it, then all of Britain can.
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