Naked Science Forum

Non Life Sciences => Technology => Topic started by: Jolly- Joliver on 31/03/2011 15:47:42

Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 31/03/2011 15:47:42
If every roof of every building was covered in Solar panels, potentially how much electricity could that generate?

For a given country?

For the whole planet?

For a town?
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 31/03/2011 16:09:21
I think average energy yeald per day per sq metre over a full year is of the order 250 to 500 Watt-hours.  They say roof panels can generate 1/3 to 1/2 of a home's demand.   

The problem is the huge cost of the panels, batteries and electronics.  Without hefty subsidies (which the UK is likely to pull the plug on soon...excuse the pun) they never pay for themselves.

Even on an industrial scale Solar Power produces a very small proportion of our elec' needs.

A real system to study is that of St James's Church, Piccadilly London.


http://www.simondawson.com/sjpenv/sjppv1.htm

 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 31/03/2011 16:18:41
I think average energy yeald per day per sq metre over a full year is of the order 250 to 500 Watt-hours.  They say roof panels can generate 1/3 to 1/2 of a home's demand. 

Relative to how many a home uses.
  


The problem is the huge cost of the panels, batteries and electronics.  Without hefty subsidies (which the UK is likely to pull the plug on soon...excuse the pun) they never pay for themselves.

No they will always pay for themselves eventually.



Even on an industrial scale Solar Power produces a very small proportion of our elec' needs.

A real system to study is that of St James's Church, Piccadilly London.


http://www.simondawson.com/sjpenv/sjppv1.htm

 

Thanks for the link.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 31/03/2011 16:36:27
No they will always pay for themselves eventually.
Panels do degrade over their lifetime - causing lower and lower Kw's available at a rate depending on the technology used.  For that reason their ability to 'pay for themselves' is not necessarily a given (ie. it depends on other economic factors also).
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 31/03/2011 16:53:01
You could say that if every domestic UK roof was covered that the equiv of about 8+ million homes could be supplied out of 25....Not that it would be possible to supply the 8 million 100% of the time.

Even if the panels remained as good as on the first day and no batteries etc had to be replaced the payback time is of the order of 40++ years...  In practice it means never as they will not remain as on day one and batteries certainly will have to be replaced several times in 40++ years. 

You can spend as much as  £20,000 and save as little as £200 a year = 100 years.  No sense at all economically.  Again no replacement costs considered.   

You would need a 5+ fold increase in elec prices or a 5+ fold decrease in the cost of panels.   Panels may drop in price but the reduction of subsidies in the UK and other countries will kill demand and economies of scale can't kick in.  Batteries are actually going up steeply in price.  I used to buy small lead acid at £5 a go.  Now they are £13!
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 31/03/2011 19:56:13
No they will always pay for themselves eventually.
Panels do degrade over their lifetime - causing lower and lower Kw's available at a rate depending on the technology used.  For that reason their ability to 'pay for themselves' is not necessarily a given (ie. it depends on other economic factors also).

That could be a design flaw. Sounds like we need to make longer lasting panels, that will come over time, I'm sure.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 31/03/2011 20:07:11
You could say that if every domestic UK roof was covered that the equiv of about 8+ million homes could be supplied out of 25....Not that it would be possible to supply the 8 million 100% of the time.

On what do you base that statement? If they can supply now upto a half of a houses energy, and normally they simply use a few panels on a house, they never cover the whole roof, or use systems to assist the panels in recieving more light, or have panels that follow the sunlight.
Even today they potencially could give electricity to 12.5 million homes, not 8.

Industry isn't interested, and industry will rubbish renewable tech where ever it can but still, there is a lot more potencial avaliable.

 

Even if the panels remained as good as on the first day and no batteries etc had to be replaced the payback time is of the order of 40++ years...  In practice it means never as they will not remain as on day one and batteries certainly will have to be replaced several times in 40++ years. 

You can spend as much as  £20,000 and save as little as £200 a year = 100 years.  No sense at all economically.  Again no replacement costs considered.

That should change over time as technology improves esp if there is a good market out there, the newest stuff will be expensive and the older very cheep, just like with computer technology.



   
You would need a 5+ fold increase in elec prices or a 5+ fold decrease in the cost of panels.   

Energy is about to start increasing in cost isnt it. Better technology is comming everyday, I would say that's a fore-gone-conclusion that over the next few years solar will be taking over.



Panels may drop in price but the reduction of subsidies in the UK and other countries will kill demand and economies of scale can't kick in.  Batteries are actually going up steeply in price.  I used to buy small lead acid at £5 a go.  Now they are £13!

It's a supply issue it sounds like lots of people want them, increased producers will come in to fill that gap, but also some of that might also be inflation.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 31/03/2011 21:26:37
Sounds like we need to make longer lasting panels, that will come over time, I'm sure.

Hmmm. Well, we may have fusion reactors and flying cars over time. The problem is what we have now!
The many crises arising from humanities currently unsustainable approach to energy usage can't wait for what might be.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 31/03/2011 21:40:35
Sounds like we need to make longer lasting panels, that will come over time, I'm sure.

Hmmm. Well, we may have fusion reactors and flying cars over time. The problem is what we have now!
The many crises arising from humanities currently unsustainable approach to energy usage can't wait for what might be.


No think you'll find there is lots of research going on in that field and it's improving rapidly.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 31/03/2011 21:50:10
You would need a 5+ fold increase in elec prices or a 5+ fold decrease in the cost of
panels.
Energy is about to start increasing in cost isnt it. Better technology is comming everyday, I would say that's a fore-gone-conclusion that over the next few years solar will be taking over.
It seems obvious that you are making a great number of assumptions/predictions about subjects that you clearly only have a outline understanding of.
Yes - traditional energy sources are increasing in cost.
Yes - New and better technologies are emerging.
But, what leads you to predict a five times (500%) increase in the economic effectiveness of solar panels will occur in a 'few' years?  -  This is no more than wishful thinking. - IOW extremely unlikely!
Further, there is such a thing as base-load power (http://en.wikipedia.org/wiki/Base_load_power_plant) to take into account.

No think you'll find there is lots of research going on in that field and it's improving rapidly.

And?
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 01/04/2011 10:34:44
I am not predicting a 5 fold decrease in solar prices.  I am saying that is what you would need (at least).  Given poor economic conditions in many countries subsidies are likley to be reduced or removed.  This will kill demand and I think solar has no future really.  Similarly susidies for electric vehicles are likely to go and given the high cost of these vehicles they have no future either.

There is no rapid improvement in the technology on the horizon unless there a quantum leap breakthrough all of a sudden....unlikely.













Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 01/04/2011 12:07:10
I am not predicting a 5 fold decrease in solar prices.  I am saying that is what you would need (at least).  Given poor economic conditions in many countries subsidies are likley to be reduced or removed.  This will kill demand and I think solar has no future really. 

I disgree those involved in solar will look to improve costs. But also subisides are not defiantely getting removed.


 Similarly susidies for electric vehicles are likely to go and given the high cost of these vehicles they have no future either.

There is no rapid improvement in the technology on the horizon unless there a quantum leap breakthrough all of a sudden....unlikely.


There are planty of technologies out there. Big industry is more of an issue, than that the tech.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 01/04/2011 12:13:35
You would need a 5+ fold increase in elec prices or a 5+ fold decrease in the cost of
panels.
Energy is about to start increasing in cost isnt it. Better technology is comming everyday, I would say that's a fore-gone-conclusion that over the next few years solar will be taking over.
It seems obvious that you are making a great number of assumptions/predictions about subjects that you clearly only have a outline understanding of.
Yes - traditional energy sources are increasing in cost.
Yes - New and better technologies are emerging.
But, what leads you to predict a five times (500%) increase in the economic effectiveness of solar panels will occur in a 'few' years?  -  This is no more than wishful thinking. - IOW extremely unlikely!

Doesnt have to come in the next few years, but it will come eventually.

 


Further, there is such a thing as base-load power (http://en.wikipedia.org/wiki/Base_load_power_plant) to take into account.

The base load will just change as more renewables are taken up by consumers, but again the industry doesnt want them, the coal plant owner wants you all using his energy, as does the nuclear plant owner.




No think you'll find there is lots of research going on in that field and it's improving rapidly.

And?

Have a little hope.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 01/04/2011 19:01:21
I would say that's a fore-gone-conclusion that over the next few years solar will be taking over.
It seems obvious that you are making a great number of assumptions/predictions...
then...
Doesn't have to come in the next few years, but it will come eventually.
Errrrr?.... [Please fill in the answer yourselves.]


The base load will just change as more renewable are taken up by consumers, but again the industry doesn't want them.
Even though I've given you a link to it, you still appear not have fathomed out what 'base-load' power is.  Please read through the link before responding.


No think you'll find there is lots of research going on in that field and it's improving rapidly.
And?
Have a little hope.
I do, but mine is realistic.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 01/04/2011 20:36:50
I would say that's a fore-gone-conclusion that over the next few years solar will be taking over.
It seems obvious that you are making a great number of assumptions/predictions...
then...
Doesn't have to come in the next few years, but it will come eventually.
Errrrr?.... [Please fill in the answer yourselves.]


The base load will just change as more renewable are taken up by consumers, but again the industry doesn't want them.
Even though I've given you a link to it, you still appear not have fathomed out what 'base-load' power is.  Please read through the link before responding.

It's the minimum needed amount of energy, that is increasing, yet at the same time we are conserving also.


No think you'll find there is lots of research going on in that field and it's improving rapidly.
And?
Have a little hope.
I do, but mine is realistic.

Maybe but you seem pessimistic
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 02/04/2011 12:43:48
Even though I've given you a link to it, you still appear not have fathomed out what 'base-load' power is.  Please read through the link before responding.
It's the minimum needed amount of energy, that is increasing, yet at the same time we are conserving also.
No.

Since you don't seem to want to take the initiative and spend time understanding base-load energy completely, the aspect I am talking about is this: http://en.wikipedia.org/wiki/Dispatchable_generation (referenced off the main article).  Note the separation between the defined of 'Dispatchable generation' and 'intermittent power sources' (like wind) and also with constrained base load generation (like nuclear).

Therefore, having pure wind generation is infeasibly impractical for the reasons outlined (as well as economically non-viable).
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 02/04/2011 21:22:59
Even though I've given you a link to it, you still appear not have fathomed out what 'base-load' power is.  Please read through the link before responding.
It's the minimum needed amount of energy, that is increasing, yet at the same time we are conserving also.
No.

Since you don't seem to want to take the initiative and spend time understanding base-load energy completely, the aspect I am talking about is this: http://en.wikipedia.org/wiki/Dispatchable_generation (referenced off the main article).  Note the separation between the defined of 'Dispatchable generation' and 'intermittent power sources' (like wind) and also with constrained base load generation (like nuclear).

Therefore, having pure wind generation is infeasibly impractical for the reasons outlined (as well as economically non-viable).

Do not see your point base load power and base load plant are different things. But anyway I do not have an issue with coal and others base load forms of generation, I have an issue with nuclear, but Clean coal potencially can not only deal with base load issues it can also, be used to manufacture plastics, oil, diesel, and lots of other things, through feeding algie beds.

While there are issues we can address them, long term better answers are on there way.

I believe in many solutions to any problem. There is a lot of waste at the moment. 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 03/04/2011 09:23:14
Since you don't seem to want to take the initiative and spend time understanding base-load energy completely, the aspect I am talking about is this: http://en.wikipedia.org/wiki/Dispatchable_generation (referenced off the main article).  Note the separation between the defined of 'Dispatchable generation' and 'intermittent power sources' (like wind) and also with constrained base load generation (like nuclear).

Therefore, having pure wind generation is infeasibly impractical for the reasons outlined (as well as economically non-viable).

Do not see your point base load power and base load plant are different things. But anyway I do not have an issue with coal and others base load forms of generation, I have an issue with nuclear.

How quickly you forget your own arguments!
Trying to educate you about base-load power generation (requiring BL power plants - there's no other industry definition whether you like it or not) is done in the hope that you will finally understand why it is practically infeasible to solely use Intermittent energy sources (http://en.wikipedia.org/wiki/Intermittent_energy_source) (like wind and solar PV) for grid-scale power requirement, without the integration with base-load plants (one type of which is nuclear, even though you imply it's not).
Maybe if you stopped starting (ill-educated) arguments on so many fronts, you might keep a grip on the relevance of the responses you are getting. and learn a thing or two!
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 03/04/2011 10:35:40
Since you don't seem to want to take the initiative and spend time understanding base-load energy completely, the aspect I am talking about is this: http://en.wikipedia.org/wiki/Dispatchable_generation (referenced off the main article).  Note the separation between the defined of 'Dispatchable generation' and 'intermittent power sources' (like wind) and also with constrained base load generation (like nuclear).

Therefore, having pure wind generation is infeasibly impractical for the reasons outlined (as well as economically non-viable).

Do not see your point base load power and base load plant are different things. But anyway I do not have an issue with coal and others base load forms of generation, I have an issue with nuclear.

How quickly you forget your own arguments!

What arguement? You asked me to look into Base load power, I did then you moan I havent understood what you meant, I read what you sent me which was about base load plants and point out there is a difference. Then I said I don't have an issue with clean Coal which is a base load plant, no change at all on other threads I was talking about how we can use clean coal to feed algie beds I give you the reference if you want.



Trying to educate you about base-load power generation (requiring BL power plants - there's no other industry definition whether you like it or not) is done in the hope that you will finally understand why it is practically infeasible to solely use Intermittent energy sources (http://en.wikipedia.org/wiki/Intermittent_energy_source) (like wind and solar PV)

But I never suggested that anyway
Quote
I believe in many solutions to any problem. There is a lot of waste at the moment.

Sorry you presume to think I was just saying everything should be renewable, as much as possible should, but I never for a moment said everything should be renewable, eventually it could be possible, anything is possible. 




 for grid-scale power requirement, without the integration with base-load plants (one type of which is nuclear, even though you imply it's not).

No I never said or implied that Nuclear wasnt base load I said "I have an issue with nuclear", issues that include what's been happening in Japan.


Maybe if you stopped starting (ill-educated) arguments on so many fronts, you might keep a grip on the relevance of the responses you are getting. and learn a thing or two!

Maybe if you didnt make assumptions this conversation would be easier.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 03/04/2011 13:27:27
Better technology is coming everyday, I would say that's a fore-gone-conclusion that over the next few years solar will be taking over [from unsustainable fossil-fuelled power stations.]
The overwhelming implication of your meaning in what I've already quoted you as writing (along with the context you were writing in) is that solar could (& will!) become the vast majority of all power generated.  Therefore it was necessary for me to go on to explain what base-load generation means and why it rules this view out.

No I never said or implied that Nuclear wasnt base load
but
I do not have an issue with coal and others base load forms of generation, I have an issue with nuclear.
This implies you don't view nuclear as a base-load source, as I said. Nothing more.

I read what you sent me which was about base load plants and point out there is a difference.
Okay - explain the difference.

Maybe if you didn't make assumptions this conversation would be easier.
The whole point is that I am not making assumptions. Your badly structured sentences lead to the confusion in the first place.

It sounds like you have finally grasped (more-or-less) what base-load is - thank goodness!
BTW, contrary to your last post, an all renewable mix of generation can balance providing it includes renewable base-load stations, like hydroelectric.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 03/04/2011 13:53:49
Better technology is coming everyday, I would say that's a fore-gone-conclusion that over the next few years solar will be taking over [from unsustainable fossil-fuelled power stations.]
The overwhelming implication of your meaning in what I've already quoted you as writing (along with the context you were writing in) is that solar could (& will!) become the vast majority of all power generated.

No it isnt a total assumption on your part, My question on this thread was how much could be generated, a desire to get as much as possible, but that in no way implies it replaces all other forms of power generation.



  Therefore it was necessary for me to go on to explain what base-load generation means and why it rules this view out.

Your mis-interpritation.



No I never said or implied that Nuclear wasnt base load
but
I do not have an issue with coal and others base load forms of generation, I have an issue with nuclear.
This implies you don't view nuclear as a base-load source, as I said. Nothing more.


No as I said, The "issue" I have is with it's dangers, nothing to do with it being a base load power generation plant, again you make leaps and assuming things. But I can see your point slightly, just slightly- to the point of hair spliting.



I read what you sent me which was about base load plants and point out there is a difference.
Okay - explain the difference.

That base load power is the minimal power people need, the plants that are 'base load' generate that power.

Hence why I said
Quote
It's the minimum needed amount of energy, that is increasing, yet at the same time we are conserving also


to say "the base load is increasing"(as people use more), but we are also saving on the energy we use at the same time.



Maybe if you didn't make assumptions this conversation would be easier.
The whole point is that I am not making assumptions. Your badly structured sentences lead to the confusion in the first place.

It sounds like you have finally grasped (more-or-less) what base-load is - thank goodness!
BTW, contrary to your last post, an all renewable mix of generation can balance providing it includes renewable base-load stations, like hydroelectric.


That's right it's my sentence structure, clearly. I tell you what. Well say 50% is down to my "bad grammar" and the other 50% is down to you assuming things.

Lets just call it quits there.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: teragram on 04/04/2011 18:51:09
May I stick my oar in?:-

In answer to the original question:-
The average yield is about 500Wh per day in the U.K. (“Sustainable Energy - without the hot air”, by David MacKay. Incidentally, a very interesting book, the contents of which are available online, www.withouthotair.com). This book is “to those who will not have the benefit of two billion years’ accumulated energy reserves”.

The roof of my small house is about 16 square metres, so should collect about 8KWh per day, or nearly 3000KWh per year, maybe one quarter to one third of total (all electric).
Not an insignificant amount.
I don’t know how many houses there are, but there are also shops, offices, factories, shopping centres….., all of which have roofs.


“New Scientist”  2nd April 2011:-
The relevant article is “The Fantasy of Renewable Energy”. This suggests that the energy requirements of the human race, if fulfilled by wind and wave, may change the dynamics of the atmosphere, with uncertain consequences. The article states that with hydro-electric generation, only solar energy (including photosynthesis) can supply the necessary energy renewably without side-effects.
But then, perhaps we are happy to continue increasing our reliance on fossil and nuclear.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 04/04/2011 20:16:22

Solar was discussed on Radio 4 today with the usual pro / anti representative.   The feed in tarrif (FIT) is a ridiculous 40 p per kWh which is around 3 to 4 times more than the going domestic rate and maybe 8 - 10 times the wholesale price (from a gas powered station)... = A massive subsidy.   

8 kWh is only about £1 worth of elec and on the Radio 4 prog they interviewed a bloke who had paid £11,000 for such a system.   

You could end up with the farcical situation of exporting all your solar elec for 40p a kwH and use elec for your own use via a cable from your neighbour at 12p a kWh. Even then payback would be about 11 years.


Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 04/04/2011 20:27:38
May I stick my oar in?:-

You certainly may


In answer to the original question:-
The average yield is about 500Wh per day in the U.K. (“Sustainable Energy - without the hot air”, by David MacKay. Incidentally, a very interesting book, the contents of which are available online, www.withouthotair.com). This book is “to those who will not have the benefit of two billion years’ accumulated energy reserves”.

The roof of my small house is about 16 square metres, so should collect about 8KWh per day, or nearly 3000KWh per year, maybe one quarter to one third of total (all electric).
Not an insignificant amount.

No it isnt, that's pretty good.



I don’t know how many houses there are, but there are also shops, offices, factories, shopping centres….., all of which have roofs.


“New Scientist”  2nd April 2011:-
The relevant article is “The Fantasy of Renewable Energy”. This suggests that the energy requirements of the human race, if fulfilled by wind and wave, may change the dynamics of the atmosphere, with uncertain consequences. The article states that with hydro-electric generation, only solar energy (including photosynthesis) can supply the necessary energy renewably without side-effects.

That's windmills changing the wether. Tidal shouldn't have an impact either, that could come under hydro electric tho.


But then, perhaps we are happy to continue increasing our reliance on fossil and nuclear.


There are better fossil power generators comming, Nuclear I can't see continuing really not in the long-long term. We'll see, but some fossil power generation is hadly a big issue, it's too much of it, that's the real problem and as renewables get better, the fossils and others systems can deminish.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 04/04/2011 20:35:35

Solar was discussed on Radio 4 today with the usual pro / anti representative.   The feed in tarrif (FIT) is a ridiculous 40 p per kWh which is around 3 to 4 times more than the going domestic rate and maybe 8 - 10 times the wholesale price (from a gas powered station)... = A massive subsidy.  

8 kWh is only about £1 worth of elec and on the Radio 4 prog they interviewed a bloke who had paid £11,000 for such a system.  

11,000 for what system?


You could end up with the farcical situation of exporting all your solar elec for 40p a kwH and use elec for your own use via a cable from your neighbour at 12p a kWh. Even then payback would be about 11 years.

The point is you get 40p for each Kwh you give the grid, but then your system will still take energy from the grid at 12p a kwh, that in theory would seriuosly reduce you electricity bill, provided you actually didnt use all the solar you generated and did give some over to the grid.

 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 04/04/2011 21:26:07

You could end up with the farcical situation of exporting all your solar elec for 40p a kwH and use elec for your own use via a cable from your neighbour at 12p a kWh. Even then payback would be about 11 years.

The point is you get 40p for each Kwh you give the grid, but then your system will still take energy from the grid at 12p a kwh, that in theory would seriuosly reduce you electricity bill, provided you actually didnt use all the solar you generated and did give some over to the grid.

 

No. You seem to be missing the point.

Pum is pointing out that the idiotically huge subsidy might encourage people to game the system by only supplying power through their meter to the grid, but even if they did, their investment in solar power has a very poor return.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 04/04/2011 21:34:43
The £11,000 was for a domestic system..maybe of the order of 16 sq metres.  The man who had bought the system kept saying his elec was free???   Yeah right..having forked out 11 Grand and having battery replacement and other costs to come?

The point is that most of the 40p comes from tax payers.
That was the central point of the BBC item.

I suspect most of these systems cannot supply heavy loads like cookers, showers, kettles, heaters, washing machines (cold fill)  particularly when you use 2 or 3 of these on at once and you have to rely on the mains for those.






Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 01:02:45

You could end up with the farcical situation of exporting all your solar elec for 40p a kwH and use elec for your own use via a cable from your neighbour at 12p a kWh. Even then payback would be about 11 years.

The point is you get 40p for each Kwh you give the grid, but then your system will still take energy from the grid at 12p a kwh, that in theory would seriuosly reduce you electricity bill, provided you actually didnt use all the solar you generated and did give some over to the grid.

 

No. You seem to be missing the point.

Pum is pointing out that the idiotically huge subsidy might encourage people to game the system by only supplying power through their meter to the grid, but even if they did, their investment in solar power has a very poor return.

A very small finacial return, but it's not about that, isnt the point to be using energy that is better for the enviroment, and getting cheaper bills. For each Kwh they give to the grid, they can use 3kwh from the grid and pay nothing for them, effectively and potecially they could end up not paying for electricity but actaully be paid by others for the energy they produce. That would be savings and money back on the investment.

It is a lot to buy but once paid for you have very low energy costs. I agree with the asisstence it will encourage others to take up solar.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 01:09:45
The £11,000 was for a domestic system..maybe of the order of 16 sq metres.  The man who had bought the system kept saying his elec was free???   Yeah right..having forked out 11 Grand and having battery replacement and other costs to come?

The point is that most of the 40p comes from tax payers.
That was the central point of the BBC item.

Well there is a social benefit to using solar, minimally cleaner air etc, But at the same time the electrical companies I believe also have to pay something towards it, at least I saw somewhere that they did but that might not have been in England. I cannot agree with the idea that an energy company will take electricity you produce and sell it to someone else but get the state to pay you from the tax payer the 40p for each kWh. If that is what is happening then the energy companies are just ripping of the people.



I suspect most of these systems cannot supply heavy loads like cookers, showers, kettles, heaters, washing machines (cold fill)  particularly when you use 2 or 3 of these on at once and you have to rely on the mains for those.

Exactly which is why it's unlikely to become a scam for householders that have it, they will always need some grid power.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 05/04/2011 01:54:09
Unfortunately, at the moment, the economic benefits of solar energy, particularly in the UK, are negligible, if they even exist.

So, it comes down to the socio/political benefits. If that's the case, it requires taxpayer (voter) approval. Solar energy should be nationalized so that it can be operated at a loss. Pretending it is economically viable is only deception.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 05/04/2011 10:22:42


However you look at it the financial return is very poor even negative.  Solar must be the most expensive source of elec we have.   

If you want to argue about saving the planet that is another matter but even there the picture is not clear cut. 

But why should the tax payer who maybe like me thinks solar is a waste of time subsidise it?
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 05/04/2011 10:24:52


However you look at it the financial return is very poor even negative.  Solar must be the most expensive source of elec we have.  

If you want to argue about saving the planet that is another matter but even there the picture is not clear cut. 

But why should the tax payer who maybe like me thinks solar is a waste of time subsidise it?

Even the much more financially viable nuclear is essentially a nationalised business. 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 15:42:12
Unfortunately, at the moment, the economic benefits of solar energy, particularly in the UK, are negligible, if they even exist.

So, it comes down to the socio/political benefits. If that's the case, it requires taxpayer (voter) approval. Solar energy should be nationalized so that it can be operated at a loss. Pretending it is economically viable is only deception.

Nationalising pushes all the costs on to the tax payer. Yet these system are for indiviudal private houses, the house holder does get a benefit for them, in the case of the mains grid going down they will still have access to eletricity for example, but there is also a benefit to the society in general also, the subsidy should reflect that social benefit and work to encourage it's promotion.
How could you nationalise them anyway? Hardly going to replace the base loads generating plants, or be put onto every house? so you would then have to decide whic houses got them and which didn't, at least this way people that are prepared to spend money on a solar system get some assistence.
As I said before the power companies that buy the solar kWh off of the people that have these systems, should be paying for that purcase, the extra money should come from tax, but as always business' see government as a way to make money extra profits- hopefully that isnt happening.

But it is also possible that people could install a wind system on there land, or if they had a river running through, some form of hydo-electric also, sub pumps for heating, where possible I think that should be encouraged and assisted, for the benefits it does provide the society at large. 
 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 15:50:16


However you look at it the financial return is very poor even negative.  Solar must be the most expensive source of elec we have.  

If you want to argue about saving the planet that is another matter

In some ways it's the whole matter, we would not be having this conversation if the other base load forms of power generation, were not poluting and using resourses unsustainably.



but even there the picture is not clear cut. 

But why should the tax payer who maybe like me thinks solar is a waste of time subsidise it?

Because of the social benefits it does provide for us all, but if you want to start down that path there are lots of things government subsised people have issue with. Big business being one of them.


Even the much more financially viable nuclear is essentially a nationalised business. 

Apparently Japan is looking to or talking about taking TEPCO national also, considering that private corporate business always seeks profit over it's safety reponsibilities, it kinda understandable, business can't be trusted to run some things safely and we are all potencially effected when it goes wrong.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 05/04/2011 17:45:27
Solar must be the most expensive source of elec we have. 
We would not be having this conversation if the other base load forms of power generation, were not polluting and using resources unsustainably.
For the fifth time, solar can not be used as a form of base-load generation. This is critical to the discussion.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 17:53:43
Solar must be the most expensive source of elec we have. 
We would not be having this conversation if the other base load forms of power generation, were not polluting and using resources unsustainably.
For the fifth time, solar can not be used as a form of base-load generation. This is critical to the discussion.

Look your miss reading, other base loads was not suggesting that solar was a base load. Stop it!

I was saying the "other" forms of power generation, that are base load cause polution ect.

You wanna split hairs go for it, I was not suggesting that solar was a base load form of generation.

However:- if your house only needed the amount of electricity that the solar system you bought provided it, it would be base load for your house, As it would meet the base needs of your home. 
Title: If every roof of every building was made of solar panels how much electricity?
Post by: teragram on 05/04/2011 18:08:31
Pumblechook:-
I also heard the Radio 4 (BBC) program. It seemed to say that other countries, notably Germany, are embracing solar energy technology with much greater enthusiasm than the U.K. It also said that solar p.v. is about the only technology whose price is falling rapidly.

The statement “even the much more financially viable nuclear industry….” made me smile. I heard on T.V not long ago that this industry in the U.K. is still subsidized to the level of around £1 billion per annum. It is still a nationalised business in that the U.K. taxpayer still has to underwrite the risks of accidents, the decommissioning of retired plants, and the storage and disposal of waste. But I remember a few years ago, when energy prices were quite low and the shareholders returns had fallen, the government had to fork out, to make up the difference.

Peppercorn:-
The question of baseload is extremely important, and a problem. How about broadening the discussion to include proposals for industrial scale energy storage, to better cope with the variability of supplies from renewables?

Title: If every roof of every building was made of solar panels how much electricity?
Post by: Jolly- Joliver on 05/04/2011 18:20:08
Pumblechook:-
I also heard the Radio 4 (BBC) program. It seemed to say that other countries, notably Germany, are embracing solar energy technology with much greater enthusiasm than the U.K. It also said that solar p.v. is about the only technology whose price is falling rapidly.

The statement “even the much more financially viable nuclear industry….” made me smile. I heard on T.V not long ago that this industry in the U.K. is still subsidized to the level of around £1 billion per annum. It is still a nationalised business in that the U.K. taxpayer still has to underwrite the risks of accidents, the decommissioning of retired plants, and the storage and disposal of waste. But I remember a few years ago, when energy prices were quite low and the shareholders returns had fallen, the government had to fork out, to make up the difference.

Yeah the real costs of nuclear are huge.



Peppercorn:-
The question of baseload is extremely important, and a problem. How about broadening the discussion to include proposals for industrial scale energy storage, to better cope with the variability of supplies from renewables?

Industrail batteries, that can be called upon when sun, wind are low. I'm pretty sure Hydro from tidal and dams is fairly consistent although rain fall could play a part.

On another thread we did talk about solar farms in the desert charging batteries then selling the batteries on.   
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 06/04/2011 10:49:54
You wanna split hairs go for it, I was not suggesting that solar was a base load form of generation.
I don't. I want to make it clear for anyone following the thread. What you persistently write (in, what I assume is your second language) gives the impression (and more importantly could lead others to think) that solar or wind or other intermittent-sources can be included in the base-load definition; which could cause problems later on. That is all!

The question of baseload is extremely important, and a problem. How about broadening the discussion to include proposals for industrial scale energy storage, to better cope with the variability of supplies from renewables?
Good idea!
As a start: Some of the pressures on renewables can be lessened where super-grids (continent-wide ultra-high-voltage electricity networks) can be implemented.
So, for instance, Germany's solar output can help even out the fluctuations of the UK's wind (at the not insignificant cost of having a seriously heavy-duty under-sea-cable), whilst being backed-up by Scandinavian hydro.  NB. this is a theoretical energy model only - no guarantees! [:)]
Title: If every roof of every building was made of solar panels how much electricity?
Post by: teragram on 07/04/2011 16:06:59
I believe that plans are already afoot for  the said super-grid in Europe, interestingly it will be a DC grid. One or two smaller scale (but still industrial size) DC grid systems are already in place I think. It has even been suggested that such a grid could carry power from the desert areas of North Africa.

Chemical means of electricity storage-:

en.wikipedia.org/wiki/Vanadium_redox_battery

Another method of storage already in use in the U.K is hydro pumped storage, but there are too few suitable sites to build a lot of these.  A similar method, also in use on small scales in parts of Europe and I think the U.S.A. is energy storage by underground compressed air. Excess power on the grid is used to pump air into old mines etc., to be released via turbines when the grid cannot be supplied by renewables (or nuclear). This is rather inefficient of course, unless the heat caused by compression can be retained and re-used. Experimental plant has been built to achieve this.
This seems to me a better use of underground spaces than carbon capture and storage, which I think is a bad idea.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: peppercorn on 07/04/2011 16:48:55
Teragram,

A DC grid! That sounds like a contradiction in terms!  - I'd love to see the thyristors used for stepping voltage on that!

As for Carbon capture and storage, I'm not sure I'm particularly keen on it as a 'band-aid' solution to climate change, but the very fact that the 'caves' are chosen for adsorbing CO2 might make them unsuited to air-storage.  In any case I think we could be a lot more inventive with our energy storing/balancing technologies.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Pumblechook on 07/04/2011 17:14:15
The UK - France interconnector is DC.   In any case the UK is not phased locked to France.  They use lots of IGBT devices.

Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 07/04/2011 19:53:24
I think there are several DC links already in operation in the US, although I suppose you could say that, in a sense, they are not really part of a grid because they interconnect grids, but I don't want to start another fight about semantics  [:D]

Anyway, DC transmission does solve a lot of problems. I seem to remember being taught that it was not possible to use an AC transmission line that went from one end of Russia to the other simply because of the wavelength.

Title: If every roof of every building was made of solar panels how much electricity?
Post by: teragram on 08/04/2011 00:28:45


Anyway, DC transmission does solve a lot of problems. I seem to remember being taught that it was not possible to use an AC transmission line that went from one end of Russia to the other simply because of the wavelength.

 i remember also being told by  an instructor that a particular section of A.C. grid in the U.S.A. was extremely efficient because it was just the right length for (almost) resonance. I cannot verify that. Generally A.C. systems lose energy because of capacitance and inductance.

PC:-
 I didn't know that the cross channel cable was DC. I've learned something.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 08/04/2011 02:53:10


Anyway, DC transmission does solve a lot of problems. I seem to remember being taught that it was not possible to use an AC transmission line that went from one end of Russia to the other simply because of the wavelength.

 i remember also being told by  an instructor that a particular section of A.C. grid in the U.S.A. was extremely efficient because it was just the right length for (almost) resonance. I cannot verify that. Generally A.C. systems lose energy because of capacitance and inductance.


The capacitance and inductance in the line don't directly result in lost power, but the capacitance and inductance of the loads can lead to lost power. Power losses are mainly due to resistance of the line, but if the voltage and current on the line are not in phase because the load is reactive (inductive or capacitive), the reactive current increases and that increases the power dissipated in the line's resistance (P=i²R). To minimize that loss, the tranmission companies add power factor correction equipment to keep the current and voltage in phase.

Of course, you don't have that problem at all on a DC line, but you do have a lot of fancy kit to convert to and from AC, which is why DC lines are only used in certain situations.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: SeanB on 08/04/2011 20:28:25
Geezer, you are wrong about the capacitance and inductance of the line not resulting in loss of power, as the current capacity of the line is fixed ( It is a rating that is limited by the amount the wires sag down due to heating, and is limited both by the lowest temperature the line will experience, giving the shortest line that can be supported without breaking, and the highest summer temperature causing sagging, which is added to the sag caused by heat from the current carried), generally to around 1000A for most 66kV or higher lines. If the line is long the capacitive charging current becomes a significant part of the total current, limiting the power it can carry, and the inductance increases the impedance of the supply, causing a load dependent voltage drop. The capacitive losses can be high, as the voltage drop can be up to 1000V/km for highly loaded lines.

DC lines can run at full load current irrespective of line length, and the longer the line the more the capacitance helps to stabilise the line voltage. The power carried on a DC link is 40% more than what the same line can carry at AC, and you only need 1 conductor instead of 3 if you use an earth return. While you do need thousands of semiconductor switches at each end for the conversion, they are generally quite reliable, and are assembled in field replaceable modules that are quick to change out in case of problems. Interestingly the links are generally 2 way, as power can flow either way depending on generating and load variations without any switching of mode by each end.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 08/04/2011 21:27:52
Ah! I see what you mean. I stand corrected. Thank you Sean.

Ultimately, don't all those losses just end up as i²R losses in the line?
Title: If every roof of every building was made of solar panels how much electricity?
Post by: NewYork on 18/04/2011 15:29:48
There will enough electricity to power the basic gadgets in the house. But the problem is that solar panel is very costly. Compare the price of a solar panel and the price of a rooftop and you will see huge different.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: techmind on 18/04/2011 23:52:26
I think that to ignore the financial and economic cost of PV panels and claim that you are doing your bit for the environment by using PV is naive in the extreme. I believe that a fair bit of the initial cost of PV is related to the energy required to make them - you have an energy-payback time to consider as well as an economic payback time.
If you've invested the energy in making a PV cell, it is best to then use it somewhere very sunny - and not on some north-facing roof in the Outer Hebrides because "every little helps"! It doesn't.


Although the technology is far more mundane, I believe that solar hot-water panels should have a far faster (energy) payback time than PV. Their efficiency is a whole lot better for starters.


I'm also mystified as to why "green" energy seems to be synomymous with microgeneration in the governments' eyes. For everything else, we have economies of scale and have a modest number of "serious" power stations.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: Geezer on 19/04/2011 00:09:06

- and not on some north-facing roof in the Outer Hebrides because


LOL!

Another highly dodgy location would be Greenock!

I'd never heard about a connection with "green" and microgeneration before. Is it because they are running recovered methane or something? One of those systems going in a few miles from here.

I suppose you might make an argument that they save power because the transmission losses might be lower, but I'm not sure that would offset the economy of scale of a large plant.
Title: If every roof of every building was made of solar panels how much electricity?
Post by: SeanB on 19/04/2011 19:47:44
The big push here is solar water heaters, using a strictly solar approach, no electric standby. Mostly to reduce peak load and base load, due to a delay in planning expansion in the power network. There is a subsidy ( paid for naturally by the long suffering public of course) to offset the cost of the system, and of course the other requisite costs that are occurred.

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