A cow named Hyacinth is leading a campaign to 'green' a city by disposing of all its food waste by anaerobic digestion at Europe's first combined low-carbon energy centre and manufacturing farm. Problems with a reducing milk yield from a herd of Jersey and Guernsey cows, which includes Hyacinth, has led to spectacular green energy solution at Langage Farm, at Lee Mill, on the outskirts of Plymouth, Devon and moved on to a powerful waste disposal campaign.