One of the main reasons for building our tiny house was to be fully off the grid and to only use renewable energies. The solar panels on our roof have been working a treat already since they ran all our power tools during the build. We’re so happy with how they and our battery bank perform. Now the panels will power our kitchen appliances as well as electronic devices.
Be prepared for overcast days
But we don’t want to rely only on solar power. We live in a very sunny place but from time to time we still get overcast and cloudy days. On those days we have to watch our electricity usage and make sure that we don’t discharge our batteries below a certain percentage. That’s why we added a small biogas unit to the mix. The biogas will run our gas cooktop in the evenings or on overcast days.
How does the biogas digester work?
Essentially, the biogas digester mimics a cows’ stomach. We feed the unit daily with organic waste and eventually get biogas in return. Easy! But how does it work?
The main part of the digester is a big tank. This tank is filled with water, so the food scraps are completely submerged. Bacteria in the water eat or digest the organic waste (hence the name) and produce biogas. This is called anaerobic digestion. The biogas is directed into a second tank where it is stored. The “gas tank” is connected to the gas cooktop in the kitchen via a gas pipe.
Before we can produce biogas though we have to “activate” the biogas digester by adding animal manure to it. After a few weeks, the bacteria in the water should produce gas. As we feed the digester tank with more organic waste every day, the tank releases water. This water is very nutritious and can be used as a liquid fertilizer for the garden. Double win!
Another thing to keep an eye on is the temperature of the unit. We placed the biogas digester in a sunny spot because the temperature can’t fall below 25 C degrees. In winter we will probably insulate it to ensure that the digester stays warm.
Clean biogas for us
I’m sure there are a few different biogas systems out there suitable for a normal household. We went for the Home biogas system. So far we’re happy with it but we’re also still in the “activate” phase of our biogas production. It will be very interesting to see how the system performs. We’re very excited about producing our own clean cooking gas and can’t wait to use it.
Hello,
I am interested in using the Biogas system as a Gas producer for cooking from a stove top and fueling the gas burner to heat our water. However we have a large 6 bedroom house with 3 toilets and 5 to 6 people living in the house and therefore a fair amount of human waste would be produced each day, would you system manage that?. Also is it a unit which can be placed in a normal size back yard, in a typical Australia House block,?. thanks
Hi Paul, thanks for your comment. Your questions are probably best directed at Homebiogas support https://homebiogas.com/
The digester works well for us but we’re only two people and we’re only using the gas for cooking.
Hello,
I am interested in using the Biogas system as a Gas producer for cooking from a stove top and fueling the gas burner to heat our water. However we have a large 6 bedroom house with 3 toilets and 5 to 6 people living in the house and therefore a fair amount of human waste would be produced each day, would you system manage that?. Also is it a unit which can be placed in a normal size back yard, in a typical Australia House block,?. thanks
Hi
I just watched a video featuring your beautiful home and was interested in the biogas system. This looks awesome. We have a wood fired stove and have been trying to workout what to use in summer to cook with, this looks like the answer. We have solar but this is/would be a backup. What is the brand/model and cost of gas stove you installed? Same question but for the induction stove?
Hi Roger,
Thanks for your comment. We bought our induction cooktop second-hand from Gumtree, the brand is Miele and we spent around AU$200. Our gas cooktop is from ebay, the brand is called Millar and cost around AU$200 also.
Just watched Living big in a tiny house and really impressed with your home. We are off grid ourselves and using natural gas for cooking but loved your biogas set up. I assuming it’s American and freight is expensive, would I be correct?
Defiantly worth a look though.
Just got to convince my adult kids that our way is the way to go.
Perry & Elizabeth
Emmaville NSW
Hi Perry and Elizabeth,
Thanks for your comment. We bought the biogas digester from a company in Israel and spent around AU$1200 for it including shipping. We felt that the price was quite reasonable. Also, we really wanted to have a biodigester 😉
I ddon’t know if you answer questions, but I am curious about this product after seeing a video with you guys using one.
In the video it seems you guys use non-food waste, while the product website says it only uses food waste. From your experience, which is it?
I am considering buying this product, but I am single, and will continue to be single, and as a result; I produce very little food waste. Which would be a problem right?
We are considering the biogas digester and I have a couple of concerns. How well does the set up cope in cold winter and hot summer? We live near gresford in nsw and have occasional frosts in winter with 40° plus in summer. Many thanks Dawn.
Hi Dawn, thanks for your comment. In order for the digester to perform well, outside temperatures have to be at least at around 25 degrees C. The warmer the better! Gas production definitely slowed down for us in winter since temperatures dropped down to 18 degrees C and even more at night. Our winters here are mild though so production didn’t completely stop. Overall, this is not a big problem for us because we planned ahead and also installed an induction cooktop in our kitchen.
For more information about the biodigester visit the Homebiogas website https://homebiogas.com/ Cheers, Annett
If you are in Australia and wish to buy locally, please visit our website.
http://www.qualitysolar.com.au
Thanks, we’re set for the moment but will keep you guys on mind and recommend you.
I there,
I thought there might have been a requirement for odourants in fuel gases, here in Australia. I also had the impression that hydrogen sulphide can’t be counted as that odourant.
Do you know if this is all the case, or if there are any actual legislative requirements on this kind of domestic device here in Aus?
Hiya,
I was wondering how moving the biogas setup works? If you’re moving your tiny house will you move the digester too? Is it heavy? Sorry for the intrusive questions but I’m a fellow tiny house on wheels person and I love the idea but I’m not sure how it would go moving it regularly? Say every 6 months?