Intensive Hamster Farming

[sleepybubble]

Dear All,

When I was a kid, bike lights were lit up by dynamo's running off the back wheel. If a barn full of a few thausand hamsters also had a few thausand hamster wheels with dynamo's then surely you could get a fair bit of electricity to sell back to the grid. I know the hamsters normally work their wheels off peak, but you could mess up their body clocks using artificial light to get them to produce Leccy at peak time.

Better still and more realistic maybe somebody could market a hamster wheel that doubles as a gadget charger. Perhaps Apple could give away vouchers for free hamsters with their ipods.

just another thought....


Mark

p.s. I dont own hamsters or have anything to do with the British Hamster Marketing board

[Eleanor]

Not a bad idea as it goes sleepybubble, there are some more ideas to think about here :

http://www.physics.bc.edu/sps/hamster.html

This is a "proper" link from a highly respected source.

http://www.otherpower.com/hamster.html

Well worth considering

[sleepybubble]

Eleanor,

I'm stunned! and also gratified that I am not the only daft Heinz in the world. Not only does the first link mention hamster wheels, but they also mention cross breeding hamsters with Electric eels. My personal favourite was;
Give them little magnetic collars, and run them through a maze of coiled wires.
But I think this might be more useful for retired lab rats....

Fascinating stuff.

[Eleanor]

sleepybubble, this is what is needed, more thinking outside the cage. We're all too busy on our little hamster wheels to really see where we should be going. Keep thinking, you just never know, the solutions to the problems of the world are most likely to be simple.

[Ivan]

actually, it does raise the question, in a future age when energy costs are excessive, perhaps it would be economically feasible to produce energy using animals (horses, oxes etc spring to mind) fed on low grade energy (eg hay). Hey, it may actually be economically-feasible today. Anyone know the energy efficiency (ie food in - to - mechanical energy out) of working animals?

[stephend]

I'm just guessing here, but isn't using an animal as an intermediary step inefficient?  First solar energy is converted into plants, then animals eat the plants, then we harvest mechanical energy from the animals - why not just burn the plants directly?

[welshboy]

Ivan - A rule of thumb from the olden days one third of a farm was set aside to produce fodder for the horses to work the land. Given the price/shortage of oil that rule of thumb might now convert to one third producing biofuel to farm the remainder !

[Ivan]

well we're pretty low on efficiency turning burnable material into electricity. I bet it's 40%

[Ted]

Feeding grass/hay to a horse in return for mechanical energy is pretty efficient. Every day a horse needs about 20lb and could travel 40 miles. At a guess, based on energy content in wood, wet grass is probably around 2,000 BTUs per lb. So a horse gives us a nice round figure of 1,000 BTUs/mile.

A car will need about 5 litres of petrol (30,000 BTUs/litre) for the same 40 mile journey - or 3,750 BTUs/mile.

One horse needs about 2 acres of grass to feed it over a whole year.

2 acres of oilseed rape (yield approx 1.5 tonne/acre) would give 3 tonnes and make (300 litres/tonne) 900 litres of biodiesel. 10,000 miles at 50 mpg.

Miscanthus yields about 20 tonnes per acre per year at 15 Million BTUs/tonne (depending on moisture content). So 2 acres will produce :

2 x 20 x 15 Million BTUs = 600 Million BTUs = 175,850 kWh. This could be converted to electricity at maybe 30% efficiency = 52,755 kWh.

So with 2 acres of land you could produce enough grass each year to feed a horse to travel about 15,000 miles or make biodiesel to travel 10,000 miles in a car or provide heat or electricity for, say, 10-12 homes.

Growing just grass would require minimal other inputs (mowing, fertiliser, harvesting, etc) whereas the other crops have some additonal input requirements - oilseed rape, especially, needs lots of nitrogen fertiliser (with high embedded energy presently) to get good yields. Also oilseed rape is used as a 'break' crop in rotation with cereals. Different regions in the UK will have differing soil types suited to different cropping regimes too.

[NickW]

I believe Richard Gere is behind a similar business venture

[djh]

Feeding grass/hay to a horse in return for mechanical energy is pretty efficient.

Absolutely 

Biology is very efficient at what it does. So efficient that we don't have a clue how to do many of the same things ourselves. Walking/cycling/whatever is way more efficient than mechanical transport, even if it is 'public' transport and blessed by pope Brown himself. (Note that we did contribute to cycling, though

Extracting energy from sunlight or the wind or whatever however appears to be something we can do better at than vegetation or animals can generally manage. So that gives us hope to continue. But also a niggling worry that if it was that easy, nature would have already done it. And we'll find out why the hard way ...

Cheers, Dave

[Ivan]

I had a feeling it would be fairly efficient. Just think about how much food you eat during a day, which constantly keeps your relatively poorly insulated body at ~20C hotter than its environment (think of uninsulated hot water cylinder and related cost of heating), plus all the walking/running/climbing we could do in a day (if we wanted to).

We're used to thinking about turning vegetable energy into meat energy which is a very inefficient process (because most of it has gone into heating the animal and into mechanical work). The actual conversion to mechanical work is really quite efficient, and if you take a working animal which is able to sustain heavy work for long periods, it becomes a potentially efficient conversion machine. Of course,  hard labour isn't much fun for man nor beast.

Incidentally, plants convert sunlight to biomass at about 1% efficiency, the most limiting factor is lack of CO2 in the air (we're changing that!) although C4 ('co2 pumping') plants can go as good as 4%. But they are pretty cheap compared with PV!!

[stephend]

So with 2 acres of land you could produce enough grass each year to feed a horse to travel about 15,000 miles or make biodiesel to travel 10,000 miles in a car or provide heat or electricity for, say, 10-12 homes.

Interesting numbers Ted!  But are you comparing like for like here?  A diesel car doing 50mpg is far more powerful than a single horse (by about 100 times).  A diesel motorcycle (which is still more powerful than a single horse) could get around 200 mpg = 40,000 miles. 

[Ted]

I wonder what percentage of cars are used for journeys of less than a 40 mile round trip every day to transport just a single person? Of course the car is more powerful and faster - that's the trade off for using something that consumes 4 times the energy and delivers 100 times the 'horsepower'.  The comparison I was really making was in terms of the most efficient use of biomass from an area of land.

But the implicit projection here was into a future where there are no more cars or at least no factories to build them!

Personally I'm interested in investigating the agricultural growing of hemp which might make even better returns than Miscanthus but the yield figures I've seen for this are way higher than I would have expected so I excluded it from my comparison. 

[KenB]

Ted,

Personally I'm interested in investigating the agricultural growing of hemp which might make even better returns than Miscanthus but the yield figures I've seen for this are way higher than I would have expected so I excluded it from my comparison.

I hear that the profit return on "hemp" farming can be quite high 

http://news.bbc.co.uk/1/hi/magazine/7412654.stm



Ken