Play the generation game
The term wind farm could take on a new meaning if one Cornish farmers system becomes accepted. John Burns reports on wind-generated electricity
THE thought of not having any electricity bills to pay is appealing yet, for most of us, perhaps something of a pipe-dream.
But Cornwall-based Alan Howes determination to avoid such bills not only meant he didnt have to pay for his electricity, it led to the creation of Windpower – a company supplying small-scale systems for wind-powered electricity generation.
In 1987 he bought 15ha (38 acres) of bare land at Crackington, Bude, Cornwall, with planning consent for a dwelling. Although the site was near a mains electricity supply, Mr Howe was not prepared to pay the £6000 SWEB wanted to connect it.
His first venture into windpower was the purchase of a 12V, 50W Rutland WG910 wind charger to keep an electric fence battery charged up.
Then came a Rutland 24V, 360W charger and a 1kW 24/240V Tornado inverter for a Portacabin office from which he was running another business. A farm building constructed later was also lit from this system.
While Mr Howes new bungalow was being built his family lived in a mobile home lit by eight 12V leisure lights powered from two 90 Amp/hour batteries which were charged by the same generator as the fence unit.
The bungalow was wired for both 240V and 24V supplies. A 300W windmill charges a 240 Amp/hour battery bank. The 24V supply runs 26 leisure lights (16W) and a small TV. A 2kW inverter converts the 24V supply to 240V to run a TV, video, food mixer, vacuum cleaner, hairdrier, or spin-drier – though not all at once.
For appliances taking more than 2kW, and when the windmills are not turning for prolonged periods, a diesel-powered generator is brought into use.
A gas-fired Aga (not mains) is used for cooking, hot water, and room heating, with further heating from a solid fuel fire.
"To get the best out of small scale wind generated electricity supplies, careful planning and thoughtful use are required," insists Mr Howe.
Demand and supply
"Ideally, adjust demand to supply. To add up the power requirements of all the apparatus requiring electricity, and then instal a windmill to cope with that load, would probably not be cost effective," he says. "Remember, there are lower power alternatives for most items of equipment, if they are looked for."
One Windpower customer had a small farm with only a Lister Start-o-matic 240V system which started up whenever even just one light was switched on. Windpower supplied a windmill and inverter system which in practice met about a third of the domestic electricity requirements on a quantity basis.
But it cut generator running time by two-thirds, giving a substantial saving on fuel and wear-and-tear on the engine, as well as less noise.
Another customer had a prefab stable block already wired for 240V with mains bulb holders. By using 10W halogen bulbs in the mains fittings, a 12V windmill-powered supply was adequate.
Mr Howe has located equipment made by companies big enough to guarantee that spares and back-up will be available. Once assembled, he can supply complete systems ready to install.
Recently he developed a rubber bracket to allow windmills to be fastened to buildings rather than having to mount them on free-standing poles. The shock absorbing rubber brackets prevent resonance problems occurring when windmills are attached solidly to steel framed buildings.
Sample package: Rubber-mounted pole complete; Rutland 12V wind charger; panel with ammeter, voltage regulator, volt meter, supply fuse; six 12V, 16W fluorescent leisure lights; two 90 amp/hour batteries; 15m twin 17.5 amp supply cable; 15m twin 8.5 amp lighting cable; cord-pull switch; full instructions; delivered. All-in price £750 + VAT.
Where theres wind theres power. One of Alan Howes generators converts wind into low-cost electricity for farm and domestic power.
Cornwall-based Alan Howe:"Getting the best from small-scale, wind-generated electricity requires careful planning."