"She's a thirsty bitch, but she'll keep you warm, mind." The plumber's verdict on our new, oil-fired boiler summed up our attitude to fuel when we moved to this draughty Welsh mill house four years ago.
We'd relocated because we could: as former barristers turned writers, we had the freedom to go where we wanted. But we were also motivated by the prospect of a cleaner, greener way of life. So when we got here, we traded the Jeep for a Prius, dug a vegetable patch and believed we were doing our bit.
A few years in, however, we could no longer overlook our profligacy. Running a home and two offices was taking its toll. Lights burning, heat on you can't type if your fingers are numb we had a shameful annual electricity bill of 800 and were making serious inroads on Opec's reserves.
As we watched the stream gushing past the house, our thoughts turned to hydro-electricity. The brook had been used to power the village since medieval times first for wireworks, then paper mills and more recently, thanks to a forward-thinking resident in the 1920s, electricity for our house. It was only in the Fifties that the stream was rejected in favour of fossil fuels.
Spurred on by the promise of grants, we considered a switch back to hydro power would be a simple solution. We fondly imagined, too, that this would let us continue our wasteful ways without guilt. How wrong we proved to be.
The first hurdle was to find someone to install the system. We had a choice: employ a registered installer and get a government grant, or use an independent engineer and bypass the system and the grants altogether. Either way, we had to look hard: hydro engineers are few and far between. A bit of research turned up Richard Drover a local environmentalist with an encyclopaedic knowledge of micro-generation. On the first visit, his disapproval of our fuel-guzzling ways was palpable. "Most of my clients have cut their consumption in half by the time they get connected," he said, frowning at our halogen lights.
The good news was that we had sufficient water flow and enough of a drop for a hydro system to be feasible. It wasn't going to be cheap, but Drover reckoned we could generate 60 kilowatt-hours per day double our usage. If we really could reduce our electricity use, then after six years we would have clawed back the money. We took a deep breath and decided to forge ahead.
The first obstacle came in the form of the official agencies the very bodies we'd imagined would be so supportive. Planning permission took five months. During that time, a steady stream of officials with clipboards turned up: the local unitary authority, the tree officer, the biodiversity officer.
Then there was the Environment Agency, responsible for all water extractions. They required three separate licenses more form-filling, charts, plans, phone calls and nagging. And clipboards. Hydrologists took their own measurements, specifying a minimum flow for the affected portion of stream to preserve the habitat. A biologist was consulted to ensure safe passage for fish. Finally, the Environment Agency managed to time themselves out, having failed to reach a decision by their own target date. A further delay ensued as they reconsidered the application.
With the red tape all tied up, it was a relief to crack on with the installation. Because much of the original infrastructure was still in place, this was fairly straightforward. We had to dig a 300m-long trench along the line of an old mill leat, lay a PVC pipe and install an intake where the stream joined our land. A little electrical wizardry connecting a turbine to the grid and we'd be off. Of course we anticipated some hitches, but at least the first stage would be easy: draining the millpond and excavating the silt.
Needless to say, by teatime on the first day, the digger had sunk into the mud. Workmen loitered about, scratching their heads and grinning. The operation to retrieve the 12-ton monster took until well after dark; at times it looked as though we might be left with our very own piece of installation art. It took another day to restore the bank to its original condition.
Dignity restored, the project continued. Every few weeks, Drover and his helpers would turn up, pitch their tents and get to work. They were an eclectic bunch; most had lived in a commune together and practised what they preached.
The only problem was the endless delays. The wettest summer on record meant that the pond filled up, even with the sluices open; nothing could be done until the water subsided. In addition, our gang was running several similar projects elsewhere and going on the occasional meditation retreat so work proceeded in fits and starts. Despite the wait, we didn't feel inclined to complain. The guys were charging barely enough to keep them in bio-diesel: most micro-hydro schemes rely on the installers being content to scrape a living. Besides, their Buddhist mindset meant they were endlessly cheerful, even when our unruly dogs stole their food.
As the weeks progressed, their influence rubbed off on us. Instead of rushing to turn off the tumble drier whenever they appeared, I started hanging out the laundry as a matter of course. Soon I was switching off lights, turning down the thermostat even, as the leaves started to fall, tolerating some cold air in my study. I was in danger of developing a Gore-like eco-piety.
Any smugness was soon snuffed out by neighbours and special interest groups who were monitoring the project. Strangers would stop us in the street. "How long will the pond be empty?" "Did you ever get that digger out?" "What about the bird life?" And: "Just thought I'd let you know that I've called the police. There's a dodgy-looking bloke in a van [one of the team] parked on your neighbour's drive."
The first frosts came and went and the end was in sight. It was time to think about which company we'd sell our surplus electricity to. Wading through all the suppliers' small print made my head hurt; their tariffs were all differently calculated and depended on endless imponderables. Speaking to the companies directly didn't help, either: some of them knew even less about their microgeneration rates than I did. Eventually, a back-of-the-envelope calculation and a chat with our electricians persuaded us to sign up with Good Energy: all of their electricity comes from renewable sources and they would pay us for every unit we generated, even if we used it ourselves.
Finally, 18 months after we first floated the idea, we were ready to go live. A wheel turned, the water gushed, a cork popped and the turbine started to rotate. We watched, mesmerised, as our stream started to make energy for the first time in more than 50 years.
So, what now? It's too early to say how much we're going to generate, but I can report one immediate benefit. There's something about seeing the electricity produced that makes you appreciate it more. We're still far from perfect on the carbon front, but we're mending our ways. The heater in my study is still turned off and I've discovered that I can type just as well wearing several layers and fingerless gloves. And the thirsty bitch by the back door? Well, she's not on the wagon yet, but her binge-drinking days are definitely over.
How does it work?
Water is siphoned from a source, run downhill and passed through a turbine connected to a generator
What do you need?
A reasonable flow of water plus a head (drop), with the source relatively close to the grid connection
What does it cost?
It depends on the installer, the head and the site. For a low head, a scheme with a registered installer might cost 15,000-20,000; for a medium head, 20,000-25,000. Grants of up to 2,500 are available for each property.
What can you make?
Most micro-hydro schemes more than provide for a household's needs. You also get a Renewables Obligation Certificate, which you sell to your electricity supplier or trade on the market.
* www.energysavingtrust.org.uk (0800 512 012): advice on energy saving techniques and microgeneration
* www.berr.gov.uk/energy/sources/renewables (020-7215 5000): government information about renewable energy
* www.lowcarbonbuildings.org.uk: advice on energy efficiency and microgeneration, plus a list of accredited installers
* www.cat.org.uk (01654 705 950): advice, information and courses on renewable energy at the Centre for Alternative Technology in Wales
* www.good-energy.co.uk (0845 456 1640)