> On Aug 19, 3:10 pm, Eeyore hotmail.com>
> wrote:

>> z wrote:

>>> Eeyore wrote:

>>>> "Daniel T." wrote:

>>>>> John Larkin wrote:

>>

>>>>>> Sure, but where does the electricity come from?

>>

>>>>> Power plants that run at much higher efficiency

>>

>>>> Not that great actually.

>>

>>>>> (and much cleaner per kilowatt of energy produced) than any
>>>>> automobile engine

>>

>>>> How do you reckon they're cleaner ?

>>

>>>>> could ever hope to do.

>>

>>>> Overall thermal efficiency from typical power plant to power
>>>> socket is in the 30-40%% region.

>>

>>>> A very large marine diesel can and does EXCEED 50%% thermal
>>>> efficiency. Only now are combined cycle gas turbine generators
>>>> coming on line that can beat that but you still have transmission
>>>> losses.

>>

>>>> Graham

>>

>>> Little known fact; efficiency of electrical generation is currently
>>> half of what it was in Edison's day. Well, it's a trick question,
>>> though; Edison was businessman enough to sell off the heat as a
>>> byproduct (isn't that what they call cogeneration?) but today
>>> utilities, as monopolies, are too lazy too chase that
>>> efficiency/cash. too bad for all of us.

>>
>> Good point.
>>
>> Certain Scandinavian countries in particular make use of this 'waste
>> heat' for district heating.
>>
>> I can see a potential move to local district co-gen (as opposed to
>> GW central plants) being very attractive.
>>
>> Graham

>
> There's always a tendency to think about heating and forget about
> cooling. The US population has shifted towards the South, and there is
> that pesky warming trend we hear about...
>
> The point is, without AC it would be difficult to live in lots of
> places, so waste heat would have to be converted to cooling to get the
> same effect. Can be done, but requires big changes. For places like
> Texas, solar panels that generate the most when the sun is beating
> down on your roof seem like a better bet---plus they would shade the
> roof.