Biogas at Home

Reader Contribution by Warren Weisman

As we head out the door on our road trip to the 2014 Mother Earth News Fair in Topeka, Kansas, I wanted to give an idea of how much energy can be generated at home using biogas while using the example of our home biogas digesters we will be exhibiting at the event. Home biogas and solar – both photovoltaic electric and solar thermal – would complement one another quite well. Biogas provides excellent, clean burning fuel for year-round cooking energy and a small amount of stand-by electric, while PV can do the heavy lifting for electric and solar thermal for heating and hot water.

Just as solar panels depend on the amount of available sunlight, the amount of biogas that can be produced depends on the amount of organic waste available. A typical American household with a lawn or garden will generate enough energy to cook three meals a day. Our two cubic meter (525 gallon) home digesters are intended to be fed between 10 and 30 pounds of mixed waste per day, such as table scraps and garden waste, animal manure, grass clippings and tree leaves. This works out to be between a third and a full 5-gallon bucket per day, depending what temperature they are operated at. The units are fully insulated and have a heat exchanger filled with pet-friendly glycol beneath the digestion chamber intended to connect to an evacuated tube solar heater. Naturally, a wintertime hoop house would help improve performance.    


Temperature (degrees F)

Daily Waste

Energy Equivalent per Month

(25 pound LPG cylinders)


10 pounds


20 pounds


30 pounds

Under the lid is the key to Hestia’s simple operation, indicator lines show when the water level is too high (yellow arrow) and too low (blue arrow). Normal operating water level will be between these two lines. If you cannot see any lines, you know it is time to remove liquid biofertilizer; if you can see two lines, you know to add some water.

This baffle separating the inlet from the digestion chamber serves a further function as a built-in pressure relief system. If gas is allowed to build up for a few days, say, during a family vacation, the gas will push down the water level in the digestion chamber until it “burps” out through the inlet. Eliminating the need for any pressure relief valves that could become clogged and ensuring a failsafe pressure relief.

Recommended Uses

Our company, Hestia Home Biogas, is named after the Greek goddess of the hearth. Hestia was also quite naturally the goddess of the family. Just as it was in ancient times, the kitchen remains the center of American life. Everyone we have ever talked to who loves to cook prefers gas over electric ranges, and cooking without fossil fuels or wood adds a level of enjoyment that really makes mealtime a celebration again. Any LPG stovetop or barbecue can be converted to run on biogas by either removing the jets or drilling out the orifices to allow more air flow. Our units ship with a free double burner stovetop from Puxin of China. The Puxin is specifically jetted for biogas and has the “whirlwind” type burners to provide even heating.

We are often asked about operating electric generators with biogas. This is where the two cubic meter system has its advantages over a one cubic meter system. The 70 cubic feet of biogas per day, it provides enough cooking fuel for three meals per day, while also allowing enough energy to run a generator to watch a couple of movies, while recharging phones and electronics. For home units we recommend 1 kW (1,000 watt) generators or smaller. It is not going to be enough energy to run a clothes dryer or a chest freezer, so the smaller generators will operate much longer. Any generator will require a fuel-gas conversion kit from US Carburetion or similar supplier for around $200. 




Run 55-inch TV on

2 m3 of Biogas

Honda EU1000i


8 hours

Powerhouse 500Wi 


10 hours*

 *estimated. We have not tested this generator at this time.

I hope this brief introduction to our home biogas system encourages everyone to visit our booth at the Mother Earth News Fair this weekend to see one of our home biogas units up close. We look forward to talking to everybody and meeting the Mother Earth News staff and other exhibitors. As always, any technical questions about our products or biogas in general can be posted on the forum on our website. With your help we can build this forum into a central clearinghouse for home biogas users in North American and Europe.

Photo: Hestia Home Biogas 

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