🚀 go-pugleaf

On 10/03/2013 1:49 AM, jimp@specsol.spam.sux.com wrote:
> In sci.physics jg <jg@nospam.com> wrote:
>> On 9/03/2013 12:58 PM, jimp@specsol.spam.sux.com wrote:
>
> <snip>
>
>>> The subject was the energy used for heating.
>>>
>>
>> The subject is energy used. Whether it's used for cooling or heating, or
>> augmented with gas or oil (who uses oil anymore to heat a house?)
>
> Oil is still fairly common in the north eastern US.
>

For an aged pensioner here, it costs all their pension to run an oil heater.


>> anywhere, the overall pattern of electricity use is similar.
>> After stating 'this is typical no matter what the area', I don't know
>> why you want to argue that.
>
> Apples and oranges.
>
> What I said was typical is the curve that shows electrical demand versus
> time of day for a region.
>
> It is typical because the curves will be roughly the same whether you
> are plotting the data for California or Western Canada.
>

That's right, but the only difference it makes is that solar panels only 
address daylight demand unless it's stored in places like hot water. 
That doesn't disqualify PV as an energy producer.

> <snip>
>
>>> http://www.caiso.com/SystemStatus.html
>>>
>>> Peak demand is after sundown.
>>>
>>> About 2/3 of the area under the curve is between noon and 1AM.
>>>
>>
>> Whatever the significance of noon here, there is more area under the
>> curve during the time solar cells operate than during your peak hours.
>> Outside those hours there is much less demand.
>
> If you come to that conclusion, I have to assume either you don't know
> what time the Sun rises and sets or you missed the class on how to
> get the area under a curve.
>

The sun doesn't rise or set at noon.
PV cells work between about 9am and 4pm.


>> Nobody said we don't need fossil fuels anymore, just trying to use less
>> for a start.
>
> Why?
>

Saving money, energy independence, technology development, pollution, 
mining land acquisition, mining safety, labour saving, AGW...


>> As far as any renewable energy source is concerned, it reduces total
>> fuel burned if it operates at any time when it can be used.
>
> True as far as that goes, but at a much higher total cost.
>
> I take it you are fabously wealthy and don't care how much money you waste.
>
> I work for a living and care very much that electricity bill are much
> higher than they need to be just to support "renewable energy".
>

That comment is much more relevant to the prices you pay than prices 
here. Even so, without my dad lending the $2000 I could not have 
afforded panels despite the returns which are quite apparent - even 
during payback I'm no worse off than paying the supplier for that power 
saved.


>>>> 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.
>>>
>>> That you say that says you have no clue how the grid and electrical
>>> generation works.
>>>
>>> A source of electricity that produces the most output when demand is low
>>> and none when demand is high is of little use unless that source is
>>> extremely cheap, and solar isn't cheap.
>>>
>>
>> So the coal station runs flat out even when demand is low?
>
> Now that is a really stupid thing to say.
>

Would be if any of the above was really true.


> However, coal station do have to run at a fairly high level even when
> demand is low because it takes a long time to get a coal plant operating.
>
> The is why coal is used mainly for base load.
>
> To cover peaks most places use gas turbines, which can come up to speed
> in minutes instead of hours.
>

Needs to be a better way to address that too.
PV cells lower the base load requirement some of the time.
If they ever approached meeting the base load many arguments would 
become more valid, but the requirement for options to meet peak load are 
likely to prevent that for the intermediate future.


>>> <snip>
>>>
>>>> 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.
>>>
>>> Is the the total installed cost, including building permits or do you
>>> live somewhere without building codes, a requirment that a licensed
>>> electrician wire it up, no UL listed inverter with autocutoff from
>>> the grid, and you just knocked it together yourself?
>>>
>>> <snip>
>>>
>>
>> Clutching at straws? Just google solar panel installers - no hidden
>> costs, no shortcuts. That's a straight out honest assessment. That you
>> don't believe it says a lot.
>
> I have many times and the total installed cost here, including the tax
> payer payed subsidy, comes out to a break even time of roughly 15 years.
>
> That's if nothing breaks in 15 years and needs to be repaired and the
> panels don't degrade over time.
>

Try googling Australian suppliers, you will see a big difference.
I'd like to see a truthful objective answer why that difference.

> <snip>
>
>>> Obviously as no one builds solar anything unless there is a subsidy
>>> attached to it.
>>>
>>
>> No one used to,
>
> No one does today if they care at all about where their money is going.
>
>> they weren't even widely available 20 years ago.
>
> Irrelevant.
>
>> It's still a big outlay for something which will only repay over time,
>> when household budgets are often tight.
>
> And that time is longer than most people will live in their house.
>
> <snip>
>
>> Still manages to provide 45% of all electricity worldwide.
>
> Got a source for that wild assed number?
>

https://en.wikipedia.org/wiki/Electricity_generation


> The biggest users of electricity are North America, Europe, and China
> where solar is a tiny fraction.
>
>>> Gas prices have been dropping everywhere there is gas in the ground
>>> since 2008.
>>>
>>> http://www.infomine.com/investment/metal-prices/natural-gas/all/
>>>
>>>> What's more it's a valuable export.
>>>
>>> So what?
>>>
>>
>> So when you have a lolly shop you don't eat the lollies yourself,
>
> Nor do lolly shops ship all the lolies overseas.
>

They do here, local supply is a major issue. And the cost of 
distribution as with electricity outweighs the cost of the fuel or 
generation.


>> that's
>> why local gas prices and even guaranteed supply are under constant
>> pressure where I live, which is a large exporter of LNG.
>>
>> That, and the high cost of distribution as with any energy source.
>
> <snip>
>
>>>> http://www.sa.gov.au/subject/Water,+energy+and+environment/Energy/Energy+efficiency/Home+energy+efficiency/How+energy+is+used+in+the+home
>>>
>>> Maybe for Australia, but in the US most water heating is done by gas and
>>> therefor irrelevant to electrical use.
>>>
>>> <snip arm waving about fossil fuels>
>>>
>>>
>> Then 1/4 of your household energy use is provided by gas, probably
>> mainly outside sunshine hours.
>
> Nope, most of my hot water usage is during the day.
>

It's still 1/4 of household energy use.


>> Solar water heaters could address that where solar cells don't, though
>> electric storage heaters can.
>
> Again, hot water usage is a trivial fraction of energy usage.
>
> And yes, I have looked into solar water heaters and discovered that for
> only around $2500 I could save all of about $100 a year on hot water.
>
> I will not be living in this house in 25 years.
>
>
Maybe you gas is very cheap, our gas bill is about $400 pa with most of 
it for hot water.