The whitest spring/summer in memory, on this eastern side of the country, anyway. Festoons of hawthorn flowers earlier on, and the elder, which came long ago is still flowering and flowering. But above any perfume from the blossoms hangs the smell of slurry. Yet on this front there is good news on two counts. First, a story in The Farmers Journal of many weeks ago headed "Taking the stink out of slurry". A product, HTPA, or Hi-Tech Pure Air, comes from New Zealand and is said to eliminate toxic slurry gases and reduce slurry odours. One gallon, it is estimated, is enough to treat 100,000 gallons of slurry.
Then, from another source, an article in The Field of England, it appears that, in Britain, work has been going on for some years on the idea of drawing potential energy from farm wastes. From raw pig and cow slurry "biogas" can be produced i.e. a mixture of methane and carbon dioxide which, in turn, could be burned to generate electricity for the national grid. The raw slurry is put into a closed tank, excluding all oxygen and keeping it at a steady 35 degrees C; the rest is done by bacteria. When the biogas is collected, the odourless effluent "can be recycled into an organic liquid fertiliser and fibrous compost material."
There is one such plant in Dorset, supplying, the national grid with one megawatt of power (enough to serve about a hundred homes), and six more are planned. Well, it's a beginning. An on-farm digester might be feasible, if the farm has over 200 cows. But this is not a first. Writes the author of the article, Helen Lewis: "In Germany, slurry digesters have been supplying farmhouses with electricity, using antiquated systems designed around second-hand underground petrol tanks and old Opel Kadett car engines, for many years."
But, surprise; pig and cow muck has nothing on the power which can be produced from the droppings of the chicken. These have an energy value close to that of wood. In Suffolk, on a disused airfield, a power station is producing 12.7 megawatts of electricity (enough for 120,000 homes), from 130,000 tonnes of chicken manure collected from local farmers. Previously this waste was dumped in landfill sites. The manure, in this case, is burned to provide heat for turning water into steam, which drives an electric generator. James Watt's steam engine invention of 1769 put to ingenious use.
Now someone is going to write in and say they're been doing this in Kerry or similar confident areas, for years. Y