8,000 anaerobic digesters in the EU, says systems maker, but less than 200 in the US: why?

In Canada, Solutions4CO2 reports that EU countries have an installed base of over 8,000 Anaerobic Digesters (AD) that were developed over the last ten years with the support of government regulation and subsidies. The EU has therefore demonstrated that renewable energy generated from this source of biogas is an attractive alternative to the use of fossil fuels. Without similar forms of support, the development of this source of renewable energy in North America has been limited to 200 AD installations to date – but  Solutions4CO2 noted that there are over 65,000 dairy farms in the U.S., with herds ranging in size from 50 cows in the northeast, to over 15,000 cows in California. The potential for AD biogas based on dairy manure from the 1.7 million cows in California is 1.5 billion m3 of biogas per year, with the potential to produce nearly 450MW of power while sequestering over one million tons of CO2 annually.