[Digestion] Solar powered methane

[Peter Allison]

Dear Han,
I have found solar heated water an excellent temperature raiser for the
supernatant. I have directed it to both internal heat exchangers and
external heating coils. Solar heat works very well to achieve and maintain
40 deg. C in a moderate climate. The heated water does need to be pumped and
a temperature differential switching arrangement would be advantageous.
Best Regards,
Peter.