Home Biogas - an Israeli company.
The only thing we don't like about it is the large footprint the external bladder has, but we're in especially for the fact that our wee has all the nutrients our garden needs to thrive.
Which means a lot less trips to Bunnings.
Small blocks, big houses, may be deterred to invest in one of these.
There are others, submerged tanks that are available through Engineers Without Borders, but not in Australia. Even though we have pestered them at least 3 times they haven't shared their designs. Which we did offer to pay for each time we built one, but alas, no replies to our emails.....
These are submersed and the more suburb friendly option as you are giving up a fair amount of space for the HomeBiogas system but it is where we are going for our first biogas solution.
The best thing to compliment it is a bide as flushing toilet paper is not an option.
So let's break down their system and how by using your Poo and Wee you can generate gas for your kitchen stove and get off Ergon in FNQ.