🚀 go-pugleaf

On 9/03/2013 10:09 AM, jimp@specsol.spam.sux.com wrote:
> In sci.physics jg <jg@nospam.com> wrote:
>> On 9/03/2013 8:59 AM, jimp@specsol.spam.sux.com wrote:
>>> In sci.physics jg <jg@nospam.com> wrote:
>>>> On 9/03/2013 7:17 AM, jimp@specsol.spam.sux.com wrote:
>>>>> In sci.physics jg <jg@nospam.com> wrote:
>>>
>>> <snip>
>>>
>>>>>> Yes it's a problem, as all methods of generation have problems.
>>>>>>
>>>>>> But not a big enough problem that solar isn't still a very useful tool
>>>>>> in producing electricity.
>>>>>>
>>>>>> Typically a house produces 1kWh for 6 hours, when no one is home it goes
>>>>>> to the main user - industry, which operates mainly at those same hours.
>>>>>
>>>>> Peak electrical demand occurs in the late afternoon and doesn't go
>>>>> away until well after sunset.
>>>>>
>>>>> The main users are households and lighting in general.
>>>>>
>>>>> Here is an example for California:
>>>>>
>>>>> http://www.caiso.com/SystemStatus.html
>>>>>
>>>>> This is typical no matter what the area.
>>>>>
>>>>>
>>>>>
>>>> The highest peak demand happens at night, for about 4 hours.
>>>>
>>>> The system has to provide 3/4 of that demand for about another 12 hours
>>>> in daylight, then much less for the remaining 8 hours.
>>>
>>> That ratio is highly seasonly dependant.
>>>
>>
>> Oh, a minute ago it was typical no matter what area.
>
> It is.
>
> There is a difference between a season and an area.
>
> An area is a place on the planet while a season is a time of year.
>
> The night time peak happens no matter what the area or the season but
> the ratio between what happens during the day and night depends on the
> season.
>
> During the summer the total demand rises because of air conditioning.
>
> Also, the day time load tends to have a secondary smaller peak a little
> after solar noon as A/C loads peak.
>
>>> In the summer the evening/night demand goes way up with everyone turning
>>> on the house A/C and stays up until close to midnight.
>>>
>>
>> And in cold places it goes way up in winter for central heating.
>
> Not really.
>
> Heating is a very small user of electricity in most of the US; gas and
> fuel oil provide most of the heat.
>
> This may vary in other countries.
>

Yes, it does. The one constant is that the bulk of energy demand is 
during the day, when industry operates.

Peak is irrelevant to whether solar cells contribute to energy use, it 
would only be relevant if it was suggested as an all-round replacement 
for energy production.


>> So I should throw away my solar panels because they don't address peak
>> demand?
>
> Nope, that would be both stupid and childish.
>
> But if you haven't already thrown money away on solar panels, unless you
> are in a very limited niche where it might pay back, you shouldn't do it.
>
> Or if you live somewhere that the government is going to basically give
> you the system with other people's tax dollars.
>

Dunno what's niche about where I live, but our cells save about $1.50 a 
day at current raw unsubsidised rates, making $550 a year. They cost 
$2000, so that's payback in 3-4 years. Then it's clear profit, even 
without subsidies or local prices rising.



>>>> Would if solar panels could cover all demand and better if it was at
>>>> peak, but they do contribute for 6 hours if not at the highest demanding
>>>> 4 hours of day.
>>>
>>> The problem is solar contributes nothing useful during the peak demand.
>>>
>>
>> That would be a problem at peak demand, for about 4 hours a day.
>> Perhaps you can think of a way to address that, without burning more coal.
>
> It is longer than that in the summer and there are several conventional
> ways to generate electricty much cheaper than solar that are not coal.
>

As long as there is use for the energy solar cells provide, they contribute.


>>> Now if solar were really extremely cheap compared to gas, then it might
>>> be worth something to run it during the day and turn off the gas
>>> generators, but solar is not cheaper than gas by a long shot.
>
>> Cheap was never the prime motivation for renewable energy,
>
> And there you have the essence of why it is such a loser in the market
> place and why energy prices at the consumer level are going through the
> roof.
>

Does the market know this?

http://en.wikipedia.org/wiki/List_of_photovoltaics_companies


>> but with the
>> price of fossil energy increasing the economics look better all the
>> time. Especially if you are an exporter or importer of fuel.
>
> Nope, natural gas prices are dropping, and gas is just about the only
> "fossil fuel" used to generate electricity unless you concider coal
> to be a "fossil fuel", and coal use is declining.
>

Coal is not a fossil fuel?? Why is it declining?
Gas prices might be dropping where you live, but not here.
What's more it's a valuable export.


>>>> Solar water heaters for instance do a better job of that.
>>>
>>> Water heating is a trivial electricity consumer.
>>>
>>
>> About 1/4 of household energy use, and mostly at times when solar cells
>> don't operate.
>
> Not hardly unless you have some obsession about taking 6 showers a day.
>

http://www.sa.gov.au/subject/Water,+energy+and+environment/Energy/Energy+efficiency/Home+energy+efficiency/How+energy+is+used+in+the+home


>>>> They are only part of the answer, but fossil fuels are the question.
>>>
>>> That makes no sense what so ever.
>>>
>>>
>>>
>> Not to anyone who thinks fossil fuel use is just fine as it is.
>
> Not to anyone speaking English.
>
>
>
Don't assume others don't get it because you can't.