Anyone had any experience with Biogas for the home cooking fuel?

Hi,

Have been reading a lot about using Biogas as a potential source of fuel for a cooking stove. I ran into an article about home biogas that sounds great, but curious to know anyone else's experience with this type of thing?  Is the 'output' fertilizer practical, is it safe?

I like the idea, and it seems practical as the general year round temperatures here would likely work for such a system...

Any thoughts or opinions on this type of thing?

Thanks in Advance