Posted by Doctor Drivel on December 10, 2008, 2:06 pm
> On Mon, 8 Dec 2008 10:54:05 -0800 (PST), harry
>>> Not so great with wind-generated energy is the fact that you need a
>>> battery bank, and batteries are expensive.
>>>
>>> So why not store the energy as gravitational potential energy?
>>>
>>> E.g. make the generated energy lift a large weight, controlled in such
>>> a way that it falls when you need it to, yielding just the amount of
>>> electrical power you need?
>>>
>>> ??
>>>
>>> Parts would need replacing far less often than batteries.
>>>
>>> John
>>
>>This is already done. We pump water up a hill & recover the enegy by
>>letting it run back down. (Pump is also a turbine) Called a pumped
>>storage scheme.
>>All been thought of forty years ago!
>>http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
>>
>>Water being cheaper and more amendable than concrete blocks.
> OK.
> We (UK) need about 50 of them.
> Why do we have only one ?
> It is not as if we are short of water.
It take more energy to pump the water up than what you get when it falls. It
is a standby top cope with peaks.
Posted by Andy Dingley on December 10, 2008, 12:34 pm
> So why not store the energy as gravitational potential energy?
http://en.wikipedia.org/wiki/Hydraulic_accumulator
Posted by Doctor Drivel on December 10, 2008, 1:25 pm
> Not so great with wind-generated energy is the fact that you need a
> battery bank, and batteries are expensive.
> So why not store the energy as gravitational potential energy?
> E.g. make the generated energy lift a large weight, controlled in such
> a way that it falls when you need it to, yielding just the amount of
> electrical power you need?
> ??
> Parts would need replacing far less often than batteries.
Just have it heat a large insulated thermal store of water, used for heating
and DHW.
Posted by Andy Dingley on December 10, 2008, 3:55 pm
> Just have it heat a large insulated thermal store of water, used for heating
> and DHW.
You seem to understand "energy" in thermodynamics. Now go and look up
"enthalpy" and "entropy".
Posted by Doctor Drivel on December 10, 2008, 6:01 pm
>> Just have it heat a large insulated thermal store of water, used for
>> heating
>> and DHW.
> You seem to understand "energy" in thermodynamics. Now go and look up
> "enthalpy" and "entropy".
I know exactly what they are. He can store even low grade heat in a thermal
store and use it for pre-heating DHW.
Exactly what DPs are doing here using solid fuel and solar. They store low
grade heat (could be high grade at times) and use it to pre-heat a combi.
They even use a flue gas heat recovery unit to heat the thermal store too.
http://www.heatweb.com/Dublin/index.htm
>>> Not so great with wind-generated energy is the fact that you need a
>>> battery bank, and batteries are expensive.
>>>
>>> So why not store the energy as gravitational potential energy?
>>>
>>> E.g. make the generated energy lift a large weight, controlled in such
>>> a way that it falls when you need it to, yielding just the amount of
>>> electrical power you need?
>>>
>>> ??
>>>
>>> Parts would need replacing far less often than batteries.
>>>
>>> John
>>
>>This is already done. We pump water up a hill & recover the enegy by
>>letting it run back down. (Pump is also a turbine) Called a pumped
>>storage scheme.
>>All been thought of forty years ago!
>>http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
>>
>>Water being cheaper and more amendable than concrete blocks.
> OK.
> We (UK) need about 50 of them.
> Why do we have only one ?
> It is not as if we are short of water.