http://www.linkoping.se/international/English/index.htm
I visited this Linkoping plant http://www.managenergy.net/products/R403.htm in Sweden in 2000 when I attended the International Biogas Event held at Eskilstuna
http://en.wikipedia.org/wiki/Eskilstuna.I was one of 4 people from the UK.  One had no interest in promoting biogas in the Uk but preferred to work elsewhere on the planet. One came from a government related organisation whose interest in the event was to help locate potentially good sites for biogas plants using satellite technology.  The third has been very active in the UK and Ireland as an indeendent consultant (with lots of letters after her name).  The UK government interest was in helping others but evidently had no interest in the technology for the UK itself.  I wonder why..  My only role there was to learn about the technology to bring back awareness of it to the UK at my expense.
Linkoping now runs a train service with biogas as well as the city's entire bus fleet and many other vehicles.
http://news.bbc.co.uk/1/hi/sci/tech/4373440.stm