Biogas digester update

Biogas digester unit 2.0 – performance update

We’ve been using our biogas digester from HomeBiogas for two years now, and think it’s time for a performance update.

You might know that we started out with the first generation biogas digester HomeBiogas brought on the market. Click here to read the blog post. We were very excited about the idea of producing our own cooking gas from food scraps because it completes our off-grid setup. So how does it?

“Bacteria break down organic waste in a naturally occurring process, and HomeBiogas stores and harnesses the energy created so that you can use it.”

I found this explanation on HomeBiogas’ website. It’s a very short and high-level explanation but essentially this is what happens. Microorganisms break down organic matter (food scraps) in the absence of oxygen (anaerobic digestion). The result is biogas and a liquid fertilizer concentrate which can be used on the garden. For a more detailed description click here to read our first post about activating the biogas digester.

When it comes to feeding the digester, you can add up to 6L of food scraps per day for 2 hours of cooking gas in return. We usually add less and still have enough gas.

Going full circle

For us, it’s the best way of getting rid of food scraps and toilet waste. Yes, that’s right, we’re going full circle. The digester breaks down our toilet waste, produces gas from it and we use it to cook our meals. This cycle repeats itself on a daily basis. We think this is really cool and one of the most sustainable ways of dealing with toilet waste.

Performance review

Anyway, I’m getting off-topic and will just say it straight up: we LOVE our biogas digester. When it comes to rating our biogas digester on a scale from 1 to 10, we would give it a 10 out of 10. This is just the most amazing product and every household should have one. We are very pleased with its performance as we always have enough gas to cook a meal or two per day plus coffees and boil water for tea.

So far, we rarely ran out of gas. The only times when we are low on gas or ran out are when temperatures drop below 20 degrees Celcius for a number of consecutive days or when we intentionally use it up.

Warm climate

The digester performs best in temperatures above 25 degrees Celcius. So in our subtropical summer, we can’t use up the gas fast enough. Gas production definitely slows down in winter when temperatures drop down to 10 degrees. However, since the sun is out on most days the digester sill generates gas but at a slower pace. HomeBiogas recommends adding a water heater if temperatures drop below 20 degrees or stop feeding the digester at all.

To sum it up, in a warm subtropical climate like ours, the biogas digester produces all-year-round.

Feeding the digester

What kind of “food” does the digester like? HomeBiogas recommends to only feed it kitchen waste and manure and to avoid things like paper, sand, plastic, leaves, branches, straw, dirt, large quantities of citrus peels or cooking oil.

On a daily basis, we feed the digester 1 or 2 litres of food scraps in addition to our and the cats’ toilet waste. Sometimes we only feed it our toilet waste and the digester still produces incredible amounts of gas. It’s so cool.

I’m having a hard time coming up with cons since everything is so easy and simply works. The digester is easy to set up and requires very little maintenance (except for emptying it every two years). I’m not sure how well or if the digester performs in colder climates. Potentially, it might be more suitable for warmer climates. It would be interesting to find out though, so please leave a comment if you have experience with this.

Conclusion

We are very happy with our biogas digester and wouldn’t want to live without it. The unit is very handy and useful. It’s a great way of putting kitchen waste to good use. We can only recommend it.

By the way, HomeBiogas does not pay or sponsor us … although they probably should. Lol.

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17 thoughts on “Biogas digester unit 2.0 – performance update

  1. Interestingly the latest units are being sent with heaters as part of the package so I guess they’re pre empting problems there.

    1. Graham, I think it would but also think we still need to look at rules and regulations of having methane gas indoors. This is something we are gonna need to push

    2. Hi Graham, this is one of the methods Homebiogas suggests for cooler climates besides the water heater. Visit their website for more information.

  2. Hi Paul & Annette, thanks for the update on the Home Biogas 2 – it’s amazing! Question on how you use the methane gas in your kitchen, did you need to buy a specific methane gas suitable range? I saw in your video that you have 2 gas burners and 2 induction burners. Looks like you’ve installed your own double gas burner instead of the single burner that Home Biogas provides.

    Any info you can share on the differences between methane and LPG burners (cost, availability, manufacturers, etc.) would be appreciated. Home Biogas is the future!

    1. Hi Jonah,
      Thanks for your comment. In their first digester model Homebiogas didn’t provide a gas burner so we bought one second hand and simply removed the LGP nozzle. ?

  3. What an amazing product!
    I’m in the process of researching to build my own tiny house and was amazed that I could use this option instead of a composting toilet and create my own energy. Because I will be in a similar situation to yours and using the toilet system with human waste can you let me know what you do with the liquid fertiliser, is it still suitable to be put on plants ?

    1. Hi Philippa, thanks for your comment. We’re using the fertilizer on the garden. For more information visit Homebiogas website.

  4. Hi, i was just wondering – did you buy your unit from the company in Israel or is the Australian seller still in business?

    1. Hi Kerrie,
      We ordered ours from Israel over 3 years ago but there might be more sellers in OZ these days.

  5. Hi guys,

    Thanks for the update! Honestly your feature on LBIATH totally changed our life. We always wanted to go off grid and I thought it meant no gas as I also count buying propane as not fully off grid. Anyway I see that you guys are putting human waste (and kitty waste) in there too. Is that before or after you have allowed it to sit for 6+ months? I would like to know if the fertiliser is still okay to use in the veggie garden? I have emailed biogas but have had no luck. I am thinking of getting the biotoilet as well as the biogas as my wife will not budge on the composting toilet. I think having the biotoilet hooked up would just be perfect the system will be more stream lined.

    1. Hi Ben,
      Thanks for your comment. We add the human and kitty waste straight into the digester. Unfortunately, I can’t answer your question about the fertiliser and if it is ok to use on your veggies that’s a question for Homebiogas. Keep emailing them or perhaps they’re more approachable on social media?
      All the best with your tiny house build!

  6. Hi there! I just found your website. You have a great setup and its fantastic that you share so much of your learnings with us all online like this.

    I’m in Fremantle, WA, and have been considering biogas for a heating and cooking supplement. I really like the homebiogas system compared to building one from scratch as they look like they would be less out of place in a city backyard compared to anything i would make myself.

    I’ve written loads of questions, If you have time i would love to know how the system is working for you!

    when you placed them, how much do you notice smells coming from them? other than the feeding time, do you notice any smells?

    How do you find cooking on biogas compared with cooking on the induction?
    If its a day where you can choose, which do you prefer?

    Do you ever heat your home with the biogas?

    Do you have an oven? is it electric or does it run on biogas?

    I know the Homebiogas system uses weights as pressure, have you found in cooking you ever run out of pressure before it finishes? Are you able to estimate how much gas you have by having a squiz out the window?

    I understand it has some kind of gas filtration to purify the gas to be mainly methane, has that required any maintenance?

    You’ve got two editions of the home biogas system, do you notice any difference in gas production between the two? any other differences you like?

    Do you have the toilet like the one supplied by the homebiogas company, or do you have some other way of processing human waste, like a bucket or something?

    There is an aussie youtuber who has built a biodigester in his shed and uses biogas for all sorts of fun projects, I’ve popped a link in this text box to a vid where he converts a heater to run on biogas. If that doesn’t work his youtube handle is “Lucky Hill Farms” . If anyone finds this page looking for more biogas info I find his stuff really informative also!

    Thanks so much for such a great website!

    https://www.youtube.com/watch?v=yElczI8coL8

    1. Hi Wyatt,
      Thanks for the link, we’ll check it out.
      The biogas digester doesn’t smell and doesn’t require any maintenance. We only use the gas for cooking. According to Homebiogas’ website, 6L of organic waste produces 2 hours of cooking gas per day. So gas production is up to how much you feed the digester. I recommend checking out http://www.homebiogas.com for more information.
      We only use one biogas digester as the first one broke due to material failure, so we replaced it under warranty for the next 2nd model.
      We’re still using our original composting toilet and empty the bucket into the digester every day.

      I hope that helps.

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