posted 1 year ago
Yes you can put things like manure and algae into a anaerobic bio digester (essentially anaerobic composting), and this will produce a biogas that is about 50-50 methane and carbon dioxide. Not sure how economical it is on a small scale. Ordinary (aerobic) composting is simpler and also produces heat, albeit at a lower temperature.
Woody (lignocellulose) biomass can be gasified and can similarly be used like a low-grade natural gas for cooking or even to run an engine if it goes through multiple filters first, but again it’s rather dirty and labor-intensive for what you get so maybe not too practical on a small scale (unless you’re really into it as a hobby).
Honestly, solar cells, while not as organically natural, are much more energy efficient and low labor and can last say 20-50 years.
I have to admit I’m intrigued by the idea of using solar electricity to split water (H2O) into hydrogen (H2) and oxygen. Supposedly if hydrogen is pumped into an anaerobic biodigester, the microbes will convert the H2 and CO2 into methane (CH4). In theory this would essentially make a pipeline quality gas. (>90% methane). Biogas doesn’t contain tar-gas like woodgas does, so it’s probably much easier to fuel a generator on it. There are conversion kits for running a genset on natural gas.
Not sure if there’s a wind resource in Missoula, but like solar this is a somewhat mainstream (accessible) technology.
I even think a thermoelectric peltier device could find application. They are used offgrid in Europe. While only 5% efficient at converting heat to electricity, it’s not really a loss (in a combined heat and power system) since that heat is being used for some other purpose anyway, like cooking, space heating, or domestic hot water. The main advantage I think is it’s potential for being low labor, low maintenance, affordable and long-lasting, all due to it being a solid-state semiconductor very much like a solar cell.