Have you sat by a campfire or fireplace, watching the flickering flames? You are watching biomass energy in action!
Biomass is any substance that is made of living or recently dead natural material. Most of the time when we think of using biomass for energy we think of using specially grown crops. But biomass fuels can come in many different shapes and sizes.
These fuels are called biofuels and can be specially grown crops or can be stuff that we normally think of as rubbish: dead trees, tree branches, lawn clippings, wood, bark and sawdust from timber mills and animal poo.
The great thing about using this sort of waste is that instead of it being buried in rubbish dumps; this waste can be put to good use and turned into energy for electricity. Why do we bury stuff when it is still useful?
This works by putting this ‘waste’ in a furnace and burning it. The heat from this fire is then used to boil water that creates steam, and the steam is then used to spin turbines and power generators to create electricity.
If that sounds a bit tricky, then how about this? As biomass decomposes it releases methane – a potent Green House Gas (GHG).
In some countries they put pipes into rubbish dumps and collect the methane gas from the rotting waste underground and use it to make electricity. Ok, it’s not quite as simple as that, it’s a bit more involved, but you get the gist.
A similar thing can be done with animals. As our hunger for all things meaty is on the rise we have an excellent opportunity to capture the methane gas from the decomposing animal poo from farms and use that methane gas to make electricity.
Another alternative is to attach entertaining giant balloons to the backs of cows to collect their recently emitted methane. The cow in this picture has been fitted with a “Rectal Methane-Collecting Backpack” which collects methane that can then be used to produce electricity.
While we’re on the subject of poo the same can be done at sewage treatment plants (there must be good gag in there somewhere about clean energy, poo and time spent on the loo).
So with all this good news, how come biomass isn’t getting a better run? Why aren’t we using more of it? It is, after all renewable, it stops the powerful methane gas reaching the atmosphere, and is GHG neutral.
What are the problems of biomass and biofuels?
One significant problem associated with biofuels is that, growing crops for fuel requires a lot of land and water, and these crops are vulnerable to changes in the weather. Unlike other renewable energy sources biomass is unpredictable as biomass crops encounter good and bad seasons like any other crop and may not be able to produce energy for electricity.
Another major problem is that many farmers, lured by higher prices, are seeing a way out of hard times by swapping their food crops for fuel crops. This means that instead of growing crops to feed people they are growing crops to produce energy – this means there is not as much food for people. This is one of the contributing reasons to our frequent food crisis.
What is Australia doing about biomass and biofuels?
Biomass is primarily used in Australia for low cost space heating, especially in households without access to natural gas for heating.
The wood that we use for burning in our fireplaces and in our pot-bellies (fireplaces, not our big tum-tum’s) is the main source of biomass energy in Australia.
However, we do use gas captured from landfill and sewage treatment sites in several places too. Australia currently has more than 65 sites using landfill gas to generate electricity, and a further 50 that operate away from landfill dumps.