Backyard Aquaponics
A place to discuss aquaponics

I've been doing a fair bit of reading lately on biogas, biomass and other forms of alternative energy. One of the quoted figures is the energy efficiency of a particular method. ie how much energy out after the amount of energy in has been accounted for.

This is all very well to compare different AEs but how do they compare to coal or oil? Does anyone know? Any studies that people can link to? I've tried google and wiki and will return there shortly but I'd appreciate the answer if someone can point me in the right direction.

Coal-fired electricity runs around 30-45% efficiency for modern power stations, internal combustion engines are more like 20%, but rockets can be 70%! That's just the combustion, ignoring all the energy required to mine/extract, process, and transport the fuel.

Not looking for the energy efficiency in turns of use. I want the energy efficiency in terms of production.

The energy efficiency in terms of use doesn't allow me to compare different ways of getting that energy to use.

So brown coal has an energy value of around 28500kJ/kg. How much does it cost in energy to get it to the powerplant?

There is no hard number for that, it all depends on how much overburden they had to remove to get to it at the mine, how much explosives they used, whether it gets to the power station on a conveyor, truck or train, how far it has to be transported etc.

I'd call it "lots"

I understand that there are a lot of variables but there must be some industry standards. In the absence of averag data I would be more than happy with specific data.

Best of all would be cost of extraction and delivery of brown coal (in terms of energy) in the Latrobe Valley.

That could be a difficult figure to find... but they'd have to include all the energy for pumping water out of the mines too!

I think Hazelwood power station is the least efficient in Oz, and amongst the least efficient in the world, just as far as combustion is concerned, adding the extraction of the coal isn't going to help.

I'd suggest contacting Giles Parkinson at RenewEconomy, he may be able to point you in the right direction.

I wonder how much energy could be harnessed by burning down the Monsanto factory?

enough to make it worth trying, im sure.

Have you thought about composting orange pulp?

My worms got rid of a batch of pulp, or maybe that was the start of the worm farm going bad?