The Naked Scientists

The Naked Scientists Forum

Author Topic: How efficient are solar panels?  (Read 12743 times)

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
How efficient are solar panels?
« on: 28/04/2006 22:50:34 »
Hi Everybody.

Happy Friday Evening to you.

How efficient are the latest solar panels ?

I do realise there are many different types but do you think the possibility is there in the near future that they will be a credible and economic source of energy ? I also realise that to fit each and every building with it's own solar array may be not be cost and time effective and so I wonder if the future lies in large solar panel stations.

How much fuel is there left ? gas ? oil ? coal ?....do you think Nuclear will inevitably be the final source of energy ?

<font color="blue"> Men are the same as women, just inside out !</font id="blue">
« Last Edit: 20/03/2010 10:05:17 by chris »


 

another_someone

  • Guest
Re: How efficient are solar panels?
« Reply #1 on: 28/04/2006 23:13:02 »
I think I have seen figures like 13% to 20% for efficiency.

But the question that matters is not efficiency (although that might indicate how much better you might get in the future), but rather, how much power per unit area one can get out of solar panels.

In terms of covering roofs of domestic buildings with solar cells, it may be expensive, but still seems to me to be preferable that covering vast areas of space that has no other use (e.g. land that was previously agricultural or forest land, but cannot grow anything in the shade of the solar panels).

Or, are you talking about space based solar panels beaming massive amounts of energy (e.g. through laser or microwave beams) down to Earth I do hope you never get to fly though one of these high energy beams.

Oil and gas may last longer than people would think, but the question is not how long it will last, but how long before the falling cost of another energy source passes the rising cost of oil and gas.

It is unlikely that there will ever be a 'final source of energy', excepting the energy source we happen to be using at the time the human race finally gasps its last breath.  Nuclear may possibly be the 'next' energy source, but that wont make it the 'final' energy source.

One great advantage that oil has, that nuclear still present us with a problem with, is not only that it provides  both the source of energy and the means to distribute it (you can get oil directly into your car, albeit is a slightly refined form, whereas that would not be practical with nuclear, which would have to be converted to another form of energy).



George
« Last Edit: 28/04/2006 23:27:41 by another_someone »
 

Offline tony6789

  • Neilep Level Member
  • ******
  • Posts: 1127
    • View Profile
Re: How efficient are solar panels?
« Reply #2 on: 04/05/2006 14:22:42 »
i really cant answer that 1 neil...

- Big T
 

Offline VAlibrarian

  • Sr. Member
  • ****
  • Posts: 173
    • View Profile
Re: How efficient are solar panels?
« Reply #3 on: 06/05/2006 02:34:58 »
Hi Neilep-
In my view photovoltaic power is one of the pieces to the puzzle of generating enough energy to meet the needs of an expanding and very demanding human race. It has many advantages over fossil fuel insofar as it is renewable and does not lead to global warming; currently it is not the cheapest energy, but fossil fuel prices are rising.

In our desperate need for a fuel or energy source that will not trap heat in our atmosphere, I will accept nuclear as a necesary element also. Every nuclear plant that will be built in India or China will eliminate the need for a couple of coal-fired plants, and that is a very good thing.

I believe it is critical for us to avoid complacency with fuels and energy sources. But it is even more critical for us to look at price as only one factor, and a less important factor than sustainability.
Sustainability is the bottom line value. Cheap is unacceptable if it will result in our grandchildren falling off a cliff in terms of sustainability.

chris wiegard
 

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
Re: How efficient are solar panels?
« Reply #4 on: 06/05/2006 03:46:45 »
Hi Chris,:)

Perhaps in the future,  photovoltaic technology of sorts will be built into the very building components of a structure such as roof tiles, bricks, even windows...which all interconnect ...so that the very building itself absorbs the radiation to form a power source.

 How would it be if the need for power from an external provider was eliminated altogether ?  

 How much gas is there left ?...I would miss cooking with it !...The thought of a completely self powering home is fascinating.

Men are the same as women, just inside out !
« Last Edit: 06/05/2006 20:59:24 by neilep »
 

Offline daveshorts

  • Neilep Level Member
  • ******
  • Posts: 2583
  • Physics, Experiments
    • View Profile
    • http://www.chaosscience.org.uk
Re: How efficient are solar panels?
« Reply #5 on: 06/05/2006 18:18:28 »
The most critcal number isn't the efficiency or even the power per square meter, but how much each KW of capacity costs to build. The other huge problem to be solved before we can have a largely renewable based electricity system is how we store huge amounts of energy, as some days it is cloudy and not windy...
 

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
Re: How efficient are solar panels?
« Reply #6 on: 06/05/2006 18:35:41 »
THANK YOU DAVID,

I would hope that either the panels will be so efficient that even ambient light will provide power, perhaps backed up by some kind of efficient battery system. Maybe a communal power source where each house/building is also interlinked with others...I know that may cause some to abuse the amount of power available but where there's a will there's a way !

I know cost is the crux here, but could it be achieved as apart from maintenance it would be a one off build......maybe not now, or tomorrow...but in the foreseeable future !

Men are the same as women, just inside out !
« Last Edit: 06/05/2006 18:37:04 by neilep »
 

another_someone

  • Guest
Re: How efficient are solar panels?
« Reply #7 on: 06/05/2006 21:58:48 »


The above is for the USA, and will be slightly different for other regions of the world, nonetheless should give a reasonable indication of the amount of power available.

Assuming 100% efficiency (rather that the current less than 20% device efficiency, and then adding installation inefficiencies on top of that), it suggests that average power for each square meter covered is between 4 and 7 Kwh/day, i.e. an average continuous power of between 160 and 290 watts per square meter.

The average house in the UK would probably cover an area of about 50 square meters, and thus probably receives an average of 8KW of continuous light on a flat roof.

Thus, you might have enough there to run a couple of 3 KW electric heaters all day, and power the lighting for the house as well.  It would not be enough to run the shower or electric cookers or ovens in the kitchen.  True that you would not continuously run either, nonetheless it does show that it is just about a marginal possibility to run a house if you can extract 100% of the power available over the totality of a flat roof over your house.

If you live in a bigger house, or wish to cover your garden with solar cells, then more power might be extracted.  If you live in sunnier climes, then you may get up to twice as much power, but you may wish to consume some in running your air conditioning.

If you live in a block of flats ('apartment block' for those on the other side of the pond), then the amount of light available would have to be shared amongst more people, and if there are lots of other high rise buildings around, it could also reduce the amount of sunlight you get.

If you have walls covered with 100% efficient solar collectors, it would possibly double the amount of power you might receive, but in urban areas, it would also drastically reduce the amount of sunlight reaching street level, and hence increase the need for artificial lighting (a 100% efficient solar collector will inevitably reflect no light, for any light reflected will reduce the efficiency of the conversion of solar power).



George
« Last Edit: 08/05/2006 10:06:16 by daveshorts »
 

Offline VAlibrarian

  • Sr. Member
  • ****
  • Posts: 173
    • View Profile
Re: How efficient are solar panels?
« Reply #8 on: 08/05/2006 01:36:56 »
Wow, it looks like the Promised Land for solar energy is southern Arizona, USA. UK by contrast is a place with entirely too many rainy, overcast days.
Following this thought, there are probably some nations that will find photovoltaic power more practical and some which will find it less practical, just like Denmark is in a good Wind Power situation and many other nations lack dependable high winds.
Logically, one answer is to use what you got.

chris wiegard
 

another_someone

  • Guest
Re: How efficient are solar panels?
« Reply #9 on: 08/05/2006 01:59:35 »
quote:
Originally posted by VAlibrarian
Wow, it looks like the Promised Land for solar energy is southern Arizona, USA. UK by contrast is a place with entirely too many rainy, overcast days.
Following this thought, there are probably some nations that will find photovoltaic power more practical and some which will find it less practical, just like Denmark is in a good Wind Power situation and many other nations lack dependable high winds.
Logically, one answer is to use what you got.



And what does Alaska have certainly not sunshine, probably not wind, but oil! [}:)]



George
 

Offline Laith

  • Sr. Member
  • ****
  • Posts: 164
    • View Profile
Re: How efficient are solar panels?
« Reply #10 on: 08/05/2006 19:08:06 »
what about about Nikola Tesla's experiments of harvesting free energy from the atmosphere or ionosphere or soemthing, is that real by the way?

Laith
 

Offline VAlibrarian

  • Sr. Member
  • ****
  • Posts: 173
    • View Profile
Re: How efficient are solar panels?
« Reply #11 on: 10/05/2006 02:01:28 »
Well, wind energy is "free", right?



chris wiegard
 

Offline Matthewsb

  • First timers
  • *
  • Posts: 4
    • View Profile
    • http://www.dme.gov.za
Re: How efficient are solar panels?
« Reply #12 on: 29/06/2006 20:27:44 »
By Matthews Mooketsane Bantsijang

Nuclear will inevitably be the final source of energy ?

The answer is no, the pimary energy sources are diverse, even if we diffent countries opt for nuclear, it is just to diversify energy sources that we use in this good planet of ours, having dffrent sources.

Thanks,
Matthews Mooketsane Bantsijang
 

Offline Matthewsb

  • First timers
  • *
  • Posts: 4
    • View Profile
    • http://www.dme.gov.za
Re: How efficient are solar panels?
« Reply #13 on: 29/06/2006 20:27:44 »
By Matthews Mooketsane Bantsijang

Nuclear will inevitably be the final source of energy ?

The answer is no, the pimary energy sources are diverse, even if we diffent countries opt for nuclear, it is just to diversify energy sources that we use in this good planet of ours, having dffrent sources.

Thanks,
Matthews Mooketsane Bantsijang
 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
Re: How efficient are solar panels?
« Reply #14 on: 14/01/2008 19:25:46 »
American companies seem to quote higher efficiency figures than European or Japanese companies for smimilar technologies.   They must be measuring it in a different way... like Octane numbers USA v Europe are different.

The max power efficiency is a starting parameter but more inportant is the energy output over 24 hours or more realistically over a full year.  The average power output is much lower than the max ouput because on average it is dark half the time and even when the Sun is up it may be at a steep angle to the panel.   Average output is 10 - 15% of max output so a so-called 100 Watts panel may only produce an average of 10 - 15 Watts.

 



 

Offline that mad man

  • Hero Member
  • *****
  • Posts: 724
    • View Profile
    • My music
Re: How efficient are solar panels?
« Reply #15 on: 14/01/2008 20:21:40 »
This may be of interest to some, its about Germany building the worlds largest solar power station. They have some novel ideas about financing it too.

It was a bbc radio broadcast last week but you can "listen again" to it on the pc with realplayer.

http://www.bbc.co.uk/radio4/news/inbusiness/inbusiness.shtml

 

Offline danieltosmith

  • First timers
  • *
  • Posts: 1
    • View Profile
    • The Diyenergy Guy
Re: How efficient are solar panels?
« Reply #16 on: 20/03/2010 09:57:25 »
Efficiency is how well light energy is converted into electrical energy.Check out solar Radiance and Irradiance.There are some cells with higher efficiency. Like the ones on the Mars rovers.


« Last Edit: 20/03/2010 12:31:26 by danieltosmith »
 

Offline willamtarker

  • First timers
  • *
  • Posts: 1
    • View Profile
How efficient are solar panels?
« Reply #17 on: 25/03/2010 12:48:48 »
Hey Friend! answering to your question  I wish to state that solar planes working on the principal of photovoltaic effect is one of the very remarkable research by the scientist.Since they use the most basic and never ending source of energy that is SUN LIGHT they have got a very large importance in all the technological research.So form this it is easily understood that they tend to provide truly amazing efficiency in whatever purpose they are used.     
 

Offline fonlenmalesen

  • First timers
  • *
  • Posts: 1
    • View Profile
    • Pro Cleanse Gold
How efficient are solar panels?
« Reply #18 on: 17/04/2010 07:27:54 »
The internet is full of sites that suggest you can power your whole house with just $200 or less of homemade panels.

 

Offline doppler1

  • Sr. Member
  • ****
  • Posts: 156
  • Bazinga
    • View Profile
How efficient are solar panels?
« Reply #19 on: 19/04/2010 14:01:05 »
Hey Neilep, Welcome back from your break :). I started a new thread before noticing this one...I agree that this technology should be incorporated into the structure of a building as well as all the roofing and all external sides of the building. I think that the key to making the change required could be found in nanotechnology and using it to improve efficiency, weight and storage options.
 

The Naked Scientists Forum

How efficient are solar panels?
« Reply #19 on: 19/04/2010 14:01:05 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums