Naked Science Forum
Non Life Sciences => Technology => Topic started by: liam on 15/04/2009 19:18:05
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hi again another idea for consideration
energy generation by wind in the home is not ideal as we are dependant on a constant supply of wind so you couldnt rely on it as a sole source of energy but what if !
it becomes windy during the night and there are no energy demands at this time its just wasted energy - i do realise most turbines dont power homes directly but instead feed the national grid and this generated power is then deducted off you're energy bill but if for a moment we were to assume that a particular house relied solely on wind turbine and not using it to store in batteries either as i believe that to be another waste of time as energy converted is energy wasted thru heat etc
ok well anyway getting back to my point if the wind generator could somehow store this unused energy and have it for when the demand was there it would be of great benefit
my idea is this that a shaft is dug down into the ground and above this vertical shaft you're turbine is fitted when the wind blows and there are no energy demands a motor in the turbine powers a winch to hoist a large weight up thru the shaft by use of a reduction gearbox once the weight is at the top we have potential energy waiting to be used - there is no wind blowing and you need to use the kettle flick the switch on the kettle and the current drain activates a release on the weight again thru a reduction gearbox to work the generator which in turn gives you energy to power your kettle once boiled if the wind has picked up again the turbine either powers the house as before or it hoists that big weight back up whatever distance it traveled !
it may not work and im sure its riddled with flaws but again its an idea i just wanted to put out there
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This is basically a small version of the hydro-electric pumped energy storage schemes which the electricity companies use. The problem is that you need to lift a very big weight a very long way to store significant amounts of energy. (In North Wales they pump lakefulls of water up and down mountains!)
Potential Energy = Force (Newtons) x distance (metres) (in Joules = 1W.s)
= weight (in kg) x10 x distance in metres
Someone follow through and tell me the weight and distance you need to store 1kWh... [;)]
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Potential Energy = Force (Newtons) x distance (metres) (in Joules = 1W.s)
= weight (in kg) x10 x distance in metres
Someone follow through and tell me the weight and distance you need to store 1kWh... [;)]
1KWh is I think 3.6 Megajoules, so you need approximately 10 tonnes (100,000Newtons) and a 36 metre drop, or the equivalent. This rounds up g to 10. In practice, the mechanical efficiency of the system would reduce the amount of energy stored. However, this is a reasonable suggestion.
I personally wonder why, as there are few sites suitable for hydro pumped storage schemes, there is not more interest in using compressed air energy storage (CAES). These schemes are operating successfully in some parts of the world. The idea of compressing air in underground spaces seems to me infinitely preferable to using those spaces to store waste CO2 as in carcon capture. The CO2 will have to remain secure for thousands of years. Remember also that a (natural) escape of CO2 from a lake bed in Africa led to hundreds of people dying of suffocation.
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1KWh is I think 3.6 Megajoules, so you need approximately 10 tonnes (100,000Newtons) and a 36 metre drop, or the equivalent.
Thankyou teragram.
The latest government figures I have put the average UK household electricity consumption at 4600kWh/year, which works out at 12.6kWh per day.
So the original poster can see that you need a dangerously large weight and a deep hole (or dangerous tall tower) to be able to store anything approaching a day's worth of energy for one house in this way...
The concept is absolutely valid, but unfortunately the large amount of energy we'd need to store doesn't make it very practical for domestic installations for the application suggested.