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Solar panels - more energy than they are worth?
Posted: Fri Aug 04, 2006 8:18 am
by Andy Hamilton
I have been having a debate with some folk that PV solar panels are not the green miracle that they are spouted to be. I have heard that they use more energy to make and use some unrenewable resources to be made also the mining techniques that are used to get the parts for them are not the best.
AS you can tell the facts I have are a little hazy, pub talk hazy. So what are the facts? Rather than just cost effective are they envionmental cost effective?
Posted: Fri Aug 04, 2006 9:38 am
by Chickpea
I don't know either, Andy. Not heard that before. But I have heard that one gram of PV material can produce more energy in its lifetime than one gram of uranium in a nuclear reactor.
I also noticed that the parking ticket machine in the car park on my local high street has a little PV panel, which I thought was cute. I reckon you could have them on phone boxes, streetlights, all kinds of things.
Posted: Fri Aug 04, 2006 10:43 am
by hedgewizard
chickpea, they're all over the place on the roads down here. There are little masts with PV plates on the top of them powering fun stuff like speeding cameras!
Posted: Fri Aug 04, 2006 11:44 am
by Muddypause
Andy, I think you ought to stop drinking in pubs. Or at least be more selective. You'll probably find the same people say the same thing about wind turbines and bio-diesel.
It's my understanding that the energy payback time was a problem with early versions of the PV cell, but remember that that would have been 50 or more years ago, when conversion efficiency was something like 2%. The 'break-even' point in their development seems to have been long passed.
This pdf file from the New Zealand Photovoltaic Association says "PV systems recoup their energy cost to manufacture them in roughly 2-4 years and then go on to produce clean energy for 30 or more years."
This pdf file from Home Power (American magazine) says "We found that the skeptics’ assertions are false. PVs recoup their production energy in two to four years, and go on to produce clean, renewable energy for twenty to thirty years or more!" (Of course I realise that the internet is only as reliable as the pub for factual information - do your own cross checking).
I also read an article online a while ago suggesting that there are new techniques being introduced that will result in a step change in the efficiency of their manufacture.
Chickpea wrote:I have heard that one gram of PV material can produce more energy in its lifetime than one gram of uranium in a nuclear reactor.
What a lovely little factiod! If only the whole of life could be summed up so easily. In fact, wait a minute - how about "One gram of a self-sufficientish person will consume less energy than one gram of a merchant banker"
Posted: Fri Aug 04, 2006 12:00 pm
by ina
Muddypause wrote:"One gram of a self-sufficientish person will consume less energy than one gram of a merchant banker"
Now, if that is energy as in food calories... In that case, I think most self-sufficientish person will consume MORE, as they'd be walking and cycling a lot more, and gardening can take it out of you, too... Whereas the most exercise an average merchant banker will get is the walk from the car to the office desk!

Posted: Fri Aug 04, 2006 12:19 pm
by Muddypause
Oh, Ina, you disappoint me. Think of 'lifestyle'.
The MB will drive his BMW instead of cycling. He thinks walking is what he bought the walking machine for. He will watch endless DVDs on his widescreen, thousand channel TV, whilst considering which country to fly to for his third holiday of the year. He will only eat exotic foods from far off places. His air conditioned luxury apartment is kept at a constant 70 degrees. He has a huge 'American style' fridge. He has no concept of what 'public transport' is really for, and thinks that being green means having his garden 're-landscaped'.
Posted: Fri Aug 04, 2006 12:29 pm
by ina

I was thinking solely of food calories! However, if that was correct, we should all be as slim as anything - you'd only have to look at me to know that doesn't always work out that way...
Oh, don't forget - the MB will fly to some far-away place for his golf holidays! He (or indeed, she) needs his/her sport, too.
Posted: Fri Aug 04, 2006 2:45 pm
by Andy Hamilton
ah ha, I thought I was right - thanks for the links muddy most useful.
This is up there with the other stuff you end up in arguments about. The latest was with my girlfriends sister, it uses as much energy to travel on a train to scotland as it does flying.

now if a long haul flight uses as much energy as a running a car for a year then surely that is lot more than even the most inefficient train.
How did I end the argument with her, well I nodded my head and said ok that's what you think then. To fair I just could not be bothered with another argument after insisting that she puts on her purfume outside as I am allergic.
I also read an argument about hydorgen powered car which I thought were the way forward but according
to this they will produce more greenhouse gasses than petrol driven cars.
Posted: Mon Sep 04, 2006 9:58 am
by Haddock
Hope this helps
SOLAR
Question #1: Do solar panels ever pay back the energy needed to make them?
Answer: Yes. As of the late 1990's, systems based on crystalline silicon PV panels returned their energy of manufacture in less than 4 years (about 3 years for the module and frame), and systems based on thin-film panels in a bit over two years (2 years for the module and frame); advances were expected to reduce the system figures to about 2 years and 1 year, respectively.
Source: NREL
Taken/borrowed from
http://ergosphere.blogspot.com/2005/09/faq.html
This site is very good and the author (an engineer) does a lot of very good green articles with facts & figures
Posted: Mon Sep 04, 2006 10:01 am
by Haddock
Think for the main page at Engineer poet (Ergosphere) is
http://ergosphere.blogspot.com/
Posted: Mon Sep 04, 2006 10:19 am
by steve64
Is there an alternative route to energy independence?
04.09.2006ld surf our way to energy independence?
Complete freedom from fossil fuels is a pipe dream - for the next few decades, anyway. But maybe we can get to a place of significantly less dependence on them. As demand relentlessly outstrips supply in the coming years, we’ll have to cut back no matter what. It will merely be a question of how rough the ride turns out to be.
Going back to the surfing analogy, the basic ingredients of a good wave aren’t hard to guess: wind, water and sun. There are interesting developments taking place in all three areas.
Alternative energy: wind power
We’ll start with wind. On June 28, at the 2006 Wind Power Asia exhibition in Beijing, China unveiled a major technological breakthrough: the first ever “Maglev generator,â€Â
Posted: Mon Sep 04, 2006 10:36 am
by Martin
in everyday terms, pv panels are a wonderful technology, BUT even if you can get a grant, they are still a very expensive way of generating electricity - payback of the cost is around 35 years! My tip is to wait awhile, there are developments afoot which may well lead to the price plumetting in the next year or two
There are some exciting developments afoot, using slow-revving diesels for chp running on recycled veg oil, Tom Good style anaerobic digesters to supply gas/run gensets, prices are falling on most of the technologies too, as economy of scale kicks in - I predict exciting times ahead!

Posted: Wed Sep 13, 2006 7:48 am
by Imp
We just got a quote for solar panels - £4,600 INCLUDING the £2000+ grant!!!
I'd just use that amount of leccy in 30 or so years (if I last that long

) - sooo, my motivation for buying this is... what?
Posted: Wed Sep 13, 2006 8:06 am
by Martin
and when you consider that the £2,000 grant is OUR money, that probably took £3,000 to administer.................
Let's be honest, grants are a useless way of getting anything to work - all they do is provide work for the otherwise unemployable in administering the things - if "Clear Skies" is anything to go by, they are monstrously inefficient
The present government is only "making noises" about renewables - they've sold us out to Atom Corp. Inc............

Posted: Wed Sep 13, 2006 9:46 am
by Chickpea
I had a chappie round here yesterday to do me a quote for PV panels. I haven't had it yet but when he emails me the quote I thought I'd stick it up here so you chaps can tell me if he's trying to rip us off or not.
The rate electricity prices are going up, becoming self-sufficient in leccy sounds like a good idea to me.