Basic principles behind solar energy usage

15 posts / 0 new
Last post
Anonymous's picture
Anonymous
Basic principles behind solar energy usage

The light and heat emitted by the sun in the form of electromagnetic radiation is the main source solar energy.  Solar energy is trapped and turned in to an utilizable form with the help of solar cells. Thus it is used for heating or for the preparation of low cost electricity.

 

Solar energy is one of the cleanest energy resources for your homes and offices. In order to get the maximum benefit of using solar energy, the user has to know certain basic facts. An average person who plans to use solar panel for the extraction of solar energy has to know only these and need not make a technical dissertation on the electromagnetic radiation obtained or the conversion of these radiations to solar energy. These basic facts will help the user to take wise and timely decisions about solar energy extraction and usage.

 

The area that you choose to place solar panel or solar heater should have plentiful amount of sunlight. The amount of sunlight is one of the most important factors behind solar energy extraction. A few other factors that determine the possibility of solar energy extraction include

 

  • Geographic location
  • Time
  • Seasons
  • Landscape & weather of the local area

 

These factors will help in the easy extraction of solar energy. Solar energy is one of the cleanest energy resources, and is one of the perfect substitutes to fossil fuels. Read the latest energy news on solar energy to know more about the principles and benefits of using solar energy resources.

yoshhash's picture
yoshhash
Status: Martenson Brigade Member (Offline)
Joined: Sep 20 2008
Posts: 271
leasing your rooftop?

I don't mean to hijack this thread, but I have a related comment/question:

Here in Ontario, Canada, there have been some amazing developments which (I think) will be the catalyst we need to see the solar industry really take off.  Regular people who could not afford a solar setup can now get one by leasing their rooftop out to companies.  ( You pay absolutely zero to install it/maintain it and get to keep it after the 20 year contract expires.  There are other ways you can set it up, you can lease the equipment from them instead, etc.) 

http://www.yourhome.ca/homes/green/article/777492--solar-panel-startup-t...

Even though we would not be getting the direct benefits of solar generation, there are many good things that come out of it.  I think the biggest factor for why people don't go solar is that they can't afford it- this neutralizes this tendency, allows people to think long term.  I also think it will KEEP OUR ROOF COOL on the hottest days, similar to the "paint your roof white" theory put forth by the US Secretary of Energy and a Nobel prize-winning scientist Steven Chu. 

We have a perfect unobstructed south exposure.  Even with our best case scenario, we would not be able to afford solar panels for another 10 years.  We could really use the extra income.  I also feel that a lot of people are reluctant to "be the first one on the block" to do such a thing- I want to set an example (I also realize that there are some people who might consider it a visual blight, and might want to challenge my enthusiasm.  For the exact same reasons of setting an example, I relish the opportunity to debate).

HERE IS MY QUESTION:  I am ready to sign the contract.  My wife, however, is skeptical.  (I love the idea so much that I admittedly feel that it is "to good to be true".)  Are there factors I have not considered?  Am I wrong about the idea that it could keep my attic cooler?  I would like to hear from anyone out there with panels on their roof (paid for by themselves or otherwise) who have regretted the decision or (conversely) love it and maybe even won over converts in their neighbourhoods.

SagerXX's picture
SagerXX
Status: Diamond Member (Offline)
Joined: Feb 11 2009
Posts: 2236
Re: Basic principles behind solar energy usage

Hey Yosh --

The only thing I can think of is that in 20 years the solar panels will be obsolete.  Assuming that R&D in this department continues.  Otherwise that seems pretty sweet.  And yes, I'd think that you'd be helping the process of getting solar a deeper penetration into the mind and marketplace because everybody on your block will want to ask you questions and so forth.  Assuming your experience is a positive one and you have good things to say, I'd bet other folks would jump on the bandwagon.

In *my* United States, we'd have done something like this 30 years ago...

Viva -- Sager

V's picture
V
Status: Platinum Member (Offline)
Joined: Dec 14 2009
Posts: 849
Re: Basic principles behind solar energy usage

I believe Berkeley Ca. Has made it possible to finance solar panels  through property taxes. The payout is 20 years. It just gets added on to your property taxes. Of course with tax revenue falling this may not be feasible now.

In the future the government will install light meters on buildings and you will have to pay a tax on how much sunlight falls on your roof. God they think of everything.

I have an issue with the statement that solar energy is one of the perfect substitutes for fossil fuels. Waine you got some splainin to do with that comment. Do you have an alternative energy business?

V

markf57's picture
markf57
Status: Bronze Member (Offline)
Joined: Aug 25 2008
Posts: 62
Re: Basic principles behind solar energy usage
V wrote:

I believe Berkeley Ca. Has made it possible to finance solar panels  through property taxes. The payout is 20 years. It just gets added on to your property taxes. Of course with tax revenue falling this may not be feasible now.

 

Boulder County (Colorado) where I live also has this program. The problem is the interest rates are 8+% and the program fees make it a bad deal for most. And it adds a mortgage (tax) obligation to your property that frankly, I don't want to have.

rhare's picture
rhare
Status: Diamond Member (Offline)
Joined: Mar 30 2009
Posts: 1325
Re: Basic principles behind solar energy usage
V wrote:

I have an issue with the statement that solar energy is one of the perfect substitutes for fossil fuels. Waine you got some splainin to do with that comment. Do you have an alternative energy business?

I was about to flag this forum topic as SPAM.  Pretty sure it is since it's a new member, 1st post, and reads like an advertisement, but people seem to want a conversation.

I can tell you here in NM, it's quite easy to cost justify PV if you have the money to buy the system.  For about 50K, you can get a 7kW system (depending on your racking which can make a big difference in your cost).  With the tax credits (10% state and 30% federal), you get down to about 30K.  Then you get the current utility incentives (vary by utility), but here you get REC credits and net metering, which means you get paid for what you produce and you get to use it as well (that is about to change with my utility).  With the REC credits and the savings in power costs the ROI is about 10% and the savings portion is essentially inflation adjusted.  So very very easy to justify.  Note - this is not a DIY, but having a contractor do the work.

As far as having the panels in 20 years, most panels degrade at about 1%/year. In fact most manufacturers seem to warantee their panels for 80% performance at the end of 20 years.  Panels will continue to be useful, just produce less power.  As far as becoming obsolete, unless things change drastically, probably not.  If you look at the past 35 years, you will see that while panels efficiencies have improved, it's not dramatic.  What has changed is the price.  So the panels should still be useful at the end of 20 years, but will be producing less and replacing them would be cheaper.  Of course if TSHTF, then you may not be able to buy new panels due to energy and resource availablity. 

So my opinion, if you have the $, have incentives that make it cost justified, do it.  After all where else are you getting 10% return on an investment that is realitively guaranteed?

 

earthwise's picture
earthwise
Status: Platinum Member (Offline)
Joined: Aug 10 2009
Posts: 848
Re: Basic principles behind solar energy usage
rhare wrote:

I was about to flag this forum topic as SPAM.  Pretty sure it is since it's a new member, 1st post, and reads like an advertisement, but people seem to want a conversation.

 

+1        I too smelled SPAM here, but hesitated on pulling the trigger because CMers were participating. I'll flag it and let the moderaters decide how to proceed.

 

EndGamePlayer's picture
EndGamePlayer
Status: Platinum Member (Offline)
Joined: Sep 2 2008
Posts: 546
Re: Basic principles behind solar energy usage

Yosh-

Several countries, including Germany and Canada have incentives programs for solar. I was just talking to another Canadian who was thinking about the same thing and thought it sounded too good to be true. Do keep us posted.

Davos's picture
Davos
Status: Diamond Member (Offline)
Joined: Sep 17 2008
Posts: 3620
Re: leasing your rooftop?
yoshhash wrote:

I don't mean to hijack this thread, but I have a related comment/question:

Here in Ontario, Canada, there have been some amazing developments which (I think) will be the catalyst we need to see the solar industry really take off.  Regular people who could not afford a solar setup can now get one by leasing their rooftop out to companies.  ( You pay absolutely zero to install it/maintain it and get to keep it after the 20 year contract expires.  There are other ways you can set it up, you can lease the equipment from them instead, etc.) 

http://www.yourhome.ca/homes/green/article/777492--solar-panel-startup-t...

Even though we would not be getting the direct benefits of solar generation, there are many good things that come out of it.  I think the biggest factor for why people don't go solar is that they can't afford it- this neutralizes this tendency, allows people to think long term.  I also think it will KEEP OUR ROOF COOL on the hottest days, similar to the "paint your roof white" theory put forth by the US Secretary of Energy and a Nobel prize-winning scientist Steven Chu. 

We have a perfect unobstructed south exposure.  Even with our best case scenario, we would not be able to afford solar panels for another 10 years.  We could really use the extra income.  I also feel that a lot of people are reluctant to "be the first one on the block" to do such a thing- I want to set an example (I also realize that there are some people who might consider it a visual blight, and might want to challenge my enthusiasm.  For the exact same reasons of setting an example, I relish the opportunity to debate).

HERE IS MY QUESTION:  I am ready to sign the contract.  My wife, however, is skeptical.  (I love the idea so much that I admittedly feel that it is "to good to be true".)  Are there factors I have not considered?  Am I wrong about the idea that it could keep my attic cooler?  I would like to hear from anyone out there with panels on their roof (paid for by themselves or otherwise) who have regretted the decision or (conversely) love it and maybe even won over converts in their neighbourhoods.

Hello Yoshhash:

I'd be hesitant for a few reasons:

  1. About 3 years or so ago when we built I looked into solar. I did a ROI on the back of an envelope and found it to be about 20 years --- providing rates for electric don't tank or soar. 
  2. Then I looked at the specs on the panels, they degradate about 1% per year (tapping memory, you'd want to Google that), so in 20 in 20 years when the warranty goes, then is it time to get new panels?
  3. Re-roofing, shingles are 20 and 30 year, if all goes well. I'd assume roofs last longer with panels, but in places they may fade, the panels will add to the cost of roofing I suspect as you can't nail under them, or take the existing roof off and I would want to as to avoid even more weight.
  4. What sort of right-of-way are they getting?
  5. Resale value, someone may want some of that new R&D SagerXX was talking about, not all buyers are green and are there any restrictions in the mortgage (if you have one).
  6. When things go to heck in a handbasket (energy wise) governments may give massive solar incentives (don't know if they will do it that far north) but things do change.

Best wishes with whatever you decide! Take care

devassocx's picture
devassocx
Status: Member (Offline)
Joined: Apr 21 2010
Posts: 1
Re: leasing your rooftop?

I don't see any comments about the batteries. I don't think they will last 20 years and I also don't think they are cheap to replace.

Even the DC/AC converter might also need repair/replacement at some point...nothing lasts forever.

EndGamePlayer's picture
EndGamePlayer
Status: Platinum Member (Offline)
Joined: Sep 2 2008
Posts: 546
Re: leasing your rooftop

Whether you go "OFF-grid" or stay connected should in part, depend on where you are. North? South? City? Rural?

If you go off-grid it will be more likely because you are miles from a town which (IMHO) will shut off power going out of the town in emergencies, or at the least, be the last place to get reconnected if a seriouos disruption in power occured. In-town homes would be more apt to stay on-line since the battery bank can be toxic as well as take up a lot of space.

The further rural you are - the more likely you are to think about batteries to supply evening and cloudy day needs. Also, the more rural you are, the more you might have options for other fuels (like home-made fuels) and the land for feed stock production, which then becomes your stored energy.  To add to the "locality" nature of "What source to choose", living up north has a big influence over the choices from living in the south. So though they are very important, battery systems can be the major obsticle in any solar or wind system and are often more costly than the actual solar or wind system. In any event, get to know how to manage battery systems before you get one and seriously consider your own situation, needs and location before making any commitment.

We tested units (solar, wind & a small battery bank for 10 yrs and they all still run) and we looked into methane gas production, bio-fuel and ethanol before we decided that since we are rural, we would do our own ethanol production (See permaculture.com for more info and our journey to production on MyBackAchers.com) as our main source of energy (but need to keep the solar & wind units as well). We're now (after 10 yrs of researching) ready to make our choice to jump into a system =) that we're sure will work for us, but everyone needs to do what will work for them and fill their energy need now and in the future.

Happy Earth Day!

yoshhash's picture
yoshhash
Status: Martenson Brigade Member (Offline)
Joined: Sep 20 2008
Posts: 271
Breaking news: large spill at wind farm. No threats reported.

Obviously, my opinion here is biased, because I am now part of the industry (more on this later), but to say that "solar is not cost effective"  does not take into account the subsidies that other energy industries have been receiving, and the fact that it is such a young technology, and does not take into account the externalities (like pollution, oil spills, coal mine collapses).  Yes it is expensive right now, but give it time, please.   Sorry, I don't know how to reduce the font without breaking the link.  And yes, I know the caption is about wind, not solar, but I don't think I need to explain the joke....

BREAKING: Large Air Spill At Wind Farm. No Threats Reported. Some Claim To Enjoy The Breeze. (PICTURE)

ron45's picture
ron45
Status: Bronze Member (Offline)
Joined: Mar 12 2010
Posts: 40
Re: Basic principles behind solar energy usage

Obsolite? That's true but they will probably be still be putting near spec energy for free. I have some that were 20 years old when I got them in 1983. Still making the power that runs or off grid home. We do add new ones from time to time. Better charge controlers are a big boost. Nearly 30% more power from the same array.

Ron

Damnthematrix's picture
Damnthematrix
Status: Diamond Member (Offline)
Joined: Aug 10 2008
Posts: 3998
Thin film PV breakthrough?

Monday, August 1, 2011

New record 17.3 percent of CdTe solar cell achieved by First Solar

 

The new achievement of efficiency record of thin film which use cadmium telluride (CdTe) solar cell has been noted by the U.S. NREL with the latest efficiency of 17.3 percent by a company based in Arizona, First Solar. The company of second-largest manufacturer of Photovoltaic modules has surpassed the previous record of 16.7 percent efficiency of CdTe solar cell.

As a cheaper of production cost as much as 30 percent than CIGS solar cell,CdTe thin film technology is a solar panel semiconductor which used in film vapor deposition process and its specific chemical-combination considered as most cost effective. But besides a low price, CdTe has a disadvantages in efficiency when compared with the modules from crystalline silicon.

In fact, the lab efficiencies will not be the same after the process to make a solar module. Efforts to improve the efficiency of thin-film solar cells can be done by increasing the surface area of solar cell although the result is less efficient for installation in narrow spaces.

The first green wise step is also performed by First Solar to provide recycling programs as well as prefunded solar module collection. Solar modules which discarded by the consumer will be recycled up to 90 percent for their new products. Customers do not need to pay a bit for collection at any time.

High Performance. High Volume.

First Solar PV modules are the first thin film PV modules to reach 2GW of modules in installations. To support the growing demand, First Solar continues to push the limits on volume manufacturing. Integrating each production step, First Solar manufactures the modules on high throughput, automated lines from semiconductor deposition to final assembly and test – all in one continuous process. The whole flow, from a piece of glass to a completed solar module, takes less than 2.5 hours.

Multiple years of high volume production have given way to First Solar's efficiencies, high energy yields, low production costs and excellent system performance ratios. Using a unique proprietary replication process called Copy Smartâ„¢, First Solar can ensure that each manufacturing facility mirrors the others in product efficiency, reliability, and safety.

 
first solar   first solar   first solar
 

More Electricity Under Real World Conditions

With less than 2% of the equivalent semiconductor content found in crystalline silicon PV modules, First Solar modules are engineered to deliver high energy yields. Using cadmium telluride (CdTe) as the semiconductor material, First Solar makes it affordable to convert solar energy into the type of electricity we use everyday.

In general, solar cells become less efficient at converting solar energy into electricity as their cell temperatures increase. At First Solar, however, the efficiency of CdTe, the semiconductor used, is less susceptible to cell temperature variations than traditional semiconductors. — CdTe also converts low and diffuse light to electricity more efficiently than conventional cells. Together, this means First Solar modules produce more electricity on hot days, under cloudy weather and across a larger percent of normal daylight.

     
 
   
   
 
 
 
 
     
 
   
   
 
 
 
 
     
 
   
   
 
 
 
 
CdTe (CADMIUM TELLURIDE)
 
First Solar modules use the stable compound cadmium telluride (CdTe) as the semiconductor. This safe and advanced semiconductor technology contributes to First Solar's ability to provide clean, affordable, and sustainable energy solutions.
 
first solar   first solar   first solar
 

Clean

All photovoltaic (PV) technologies have significant environmental benefits compared to traditional fossil-fuel electricity generating technologies. First Solar's cadmium telluride (CdTe) offers the following benefits.
 
   
First Solar offers the solar industry's first comprehensive prefunded module collection and recycling program, ensuring that the solutions to climate change and energy independence today don't become a waste management challenge for future generations.
 
CdTe PV technology has the smallest carbon footprint and fastest energy payback time of current PV technologies when measured on a life cycle basis.
 
When in operation, First Solar modules generate electricity with no air emissions, no waste production, and no water use.
 
On a life cycle basis, at least 89% of the air emissions associated with electricity generation could be prevented if electricity from First Solar's CdTe modules displaced electricity from the grid.
 
Using CdTe in PV modules converts cadmium, a waste byproduct of zinc refining, into the stable compound of CdTe where it is safely sequestered for the 25+ year lifetime of the module.
 

Affordable

First Solar's CdTe technology is uniquely capable of producing high-volume, low-cost solar modules, driving solar to be an economically viable solution to climate change and energy independence.
 
   
A low-temperature coefficient that results in better performance compared to traditional silicon modules at higher temperatures.
 
Enhanced suitability for high-volume, low-cost module production.
 

Independent Studies

First Solar's CdTe PV technology enables clean, affordable, sustainable electricity generation. CdTe's physical properties, including its extremely low vapor pressure, high boiling and melting points, and its insolubility in water, limit its mobility in the environment.
 
   
In 2009, an in-depth assessment of the environmental, health and safety aspects of First Solar's CdTe PV systems and manufacturing operations was carried out under the authority of the French Ministry of Ecology, Energy, Sustainable Development and the Sea. It concluded that, "During standard operation of CdTe PV systems, there are no cadmium emissions - to air, to water, or to soil. In the exceptional case of accidental fires or broken panels, scientific studies show that cadmium emissions remain negligible. Accordingly, large-scale deployment of CdTe PV can be considered safe to human health and the environment."
 
A peer review of major studies on the environmental profile of CdTe PV organized by the European Commission, Joint Research Center and moderated by the German Environment Ministry concluded, "...CdTe used in PV is in an environmental stable form that does not leak into the environment during normal use or foreseeable accidents...."
 
Independent analysis indicates that CdTe modules do not pose a risk during fires. CdTe has an extremely low vapor pressure, high boiling and melting points and is almost completely encapsulated by molten glass when exposed to fire. Exposure of pieces of CdTe PV modules to flame temperatures from 760 to 1100°C illustrated that CdTe diffuses into glass, rather than being released into the atmosphere. Higher temperatures produce further CdTe diffusion into the glass.
 
Through outdoor leaching experiments with small fragments of CdTe modules, an independent study estimated that in a worst-case scenario materials leached from the modules into water or soil was no higher than the German drinking water concentration limit.
 
First Solar’s CdTe PV modules have been tested in accordance with applicable waste characterization protocols and at end-of-life can be classified as ‘non hazardous waste for recovery’ in Europe and as a federal non-hazardous waste in the US.
Johnny Oxygen's picture
Johnny Oxygen
Status: Diamond Member (Offline)
Joined: Sep 9 2009
Posts: 1443
Graphene electrodes for

Graphene electrodes for organic solar cells

http://web.mit.edu/newsoffice/2011/graphene-solar-0106.html

 

While the specific characteristics of the graphene electrode differ from those of the ITO it would replace, its overall performance in a solar cell is very similar, Kong says. And the flexibility and light weight of organic solar cells with graphene electrodes could open up a variety of different applications that would not be possible with today’s conventional silicon-based solar panels, she says. For example, because of their transparency they could be applied directly to windows without blocking the view, and they could be applied to irregular wall or rooftop surfaces. In addition, they could be stacked on top of other solar panels, increasing the amount of power generated from a given area. And they could even be folded or rolled up for easy transportation.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Login or Register to post comments