Australians love cooking with gas, but what if you could make your own supply, using leftover food waste? It may be time for more households to embrace home biogas – and stop paying gas bills.
In practical terms, I put in about 2kg of food waste each day and so far I have had enough gas to cook with, sometimes twice a day. If I ever needed more gas, I could put in more organic matter. I will continue to monitor the system as part of my research and will publish updates in due course. If interested, watch this space.
I've looked at these before, really cool idea. I think one issue is the amount of waste needed. How does the author get 2kg a day? I reckon my house (of 4 people) chuck about 4kg a week into the compost.
A good way to supplement it would be with yer chook droppings, but still not enough to cook for a household.
Yeah, seems like they take up quite a lot of space, too. Only really an option if you live in the countryside or have a huge garden.
EDIT: Plus, the amount of food waste required seems quite high. Sounds like it would be most practical if you had some chickens or goats, or a really big family, to generate that amount of compost.
It takes some careful waste management for sure and probably only makes sense if you grow food in your garden (where you can also use the slurry as fertilizer).
I also think it might be useful to have some high starch or sugary material in reserve to spike the gas production temporarily if you know you will be doing some more extensive cooking in the near future.
A potential solution could be having a larger central community plant taking the scraps from several households. But again it won't be enough to provide cooking power for all, maybe it could give back some other type of community benefit.
Spitballing here but that slurry could go to community gardens.
Should be fairly simple to build yourself too (look up floating drum bio digestor), but the low pressure requires modified nozzles in the gas burners of the stove.
I have a functioning biogas plant at home. It functions as a spetic tank and also takes biowaste from the kitchen. Turn around time is 30-60 days and it gives about 45-60 minutes of cooking per day on our two person household.
I've also read that because the bioreactor is hot from the bacteria, people in colder countries can run water through insulated tubing to get 20C water.
I think any such numbers are really subjective and depend on your cooking style. If you want to cook lentils for hours each day then the gas is probably insufficient.