I've always wondered........

stimpy17

Can a panel, over the course of it's life time produce more energy or as much energy it took to produce it?

Let's use simple math;

100 watt panel.
The heat it takes to form the cells.
Life span of say 25 years.
Hey! I live in New Mexico! Not really, make that PA. And lets start with the mining of the basic materials to the transportation, to the mark up of the vendors then the installers. and let's not forget building permits!

Thank-you.

CRMW

Re: I've always wondered........

Interesting question. I think the only way to compare apples to apples would be to translate everything to dollars. Assuming the manufactures are not going to sell the panels under cost, and the cost is reflects the energy required to produce the panels it should be a simple formula.

(Total Power Produced by panel)x(Cost of power received over the lines)-(Cost of Installed Panel)

If the result is greater than 0 the panels produce more energy than they consume during construction.


Chris

mike95490

Re: I've always wondered........

Panel construction payback is about 4-6 years from #'s I've seen in ads.
(to produce the amount of energy that was consumed to make them.)

icarus

Re: I've always wondered........

CRMW wrote: »

Interesting question. I think the only way to compare apples to apples would be to translate everything to dollars. Assuming the manufactures are not going to sell the panels under cost, and the cost is reflects the energy required to produce the panels it should be a simple formula.

(Total Power Produced by panel)x(Cost of power received over the lines)-(Cost of Installed Panel)

If the result is greater than 0 the panels produce more energy than they consume during construction.


Chris

I don't think the question is dollars/dollars, but energy used/carbon created etc. It is my intuition that PV panels clearly win over any other generating source with the possible exception of hydro.

Icarus

BB.

Re: I've always wondered........

icarus wrote: »

I don't think the question is dollars/dollars, but energy used/carbon created etc. It is my intuition that PV panels clearly win over any other generating source with the possible exception of hydro.

Interestingly, hydro is not always a low CO2 emitter:

Contrary to popular belief, hydroelectric power can seriously damage the climate. Proposed changes to the way countries' climate budgets are calculated aim to take greenhouse gas emissions from hydropower reservoirs into account, but some experts worry that they will not go far enough.

...

Hydroelectric dams produce significant amounts of carbon dioxide and methane, and in some cases produce more of these greenhouse gases than power plants running on fossil fuels. Carbon emissions vary from dam to dam, says Philip Fearnside from Brazil's National Institute for Research in the Amazon in Manaus. "But we do know that there are enough emissions to worry about."

In a study to be published in Mitigation and Adaptation Strategies for Global Change, Fearnside estimates that in 1990 the greenhouse effect of emissions from the Curuá-Una dam in Pará, Brazil, was more than three-and-a-half times what would have been produced by generating the same amount of electricity from oil.

This is because large amounts of carbon tied up in trees and other plants are released when the reservoir is initially flooded and the plants rot. Then after this first pulse of decay, plant matter settling on the reservoir's bottom decomposes without oxygen, resulting in a build-up of dissolved methane. This is released into the atmosphere when water passes through the dam's turbines...

-Bill

Brock

Re: I've always wondered........

I remember reading in ideal situations it was about 2 years to offset the energy to produce, so I 4 to 6 sounds about right to me, even throwing in some transportation energy.

Now someone needs to build a solar manufacturing plant that uses solar energy to make the panels

Wasn't it Kyocera that had a 100k or so on their roof?

System2

Re: I've always wondered........

They have. When you think about it, all these grid-tied panels are feeding power back into the grid to be used by the panel makers. I know it's far-fetched, but something to think about.

Correct me if I'm wrong here. If it takes 5 years of solar operation to equal the embodied energy of a PV panel, then wouldn't it take five years worth of factory PV panel manufacturing to power the plant? Look at it another way, if the manufacturer could only sell the panel after using it long enough to get a return on energy, and that number is five years, then the factory will always have the last five years worth of production on its roof. That's a big roof or a small factory.

stimpy17

Re: I've always wondered........

Thank-you all. It is food for thought.

JDR*energy

Re: I've always wondered........

Evergreen panels only require 15 months for energy payback

http://www.planitsolar.com/pdf/evergreen.pdf


Quote from article above:
Process: The process by which solar panels are made differs widely, with some companies using proprietary technology that
enhances the process in various ways. Evergreen’s manufacturing process was invented by a professor at MIT over 20 years
ago, with the special qualities of its technology being: no need for toxic acids, up to 1/3 less silicon required, production is
easily scalable at low cost, and the fastest energy payback for any solar panel (only 15 months to produce the same amount of
energy it takes to manufacture the panel). Evergreen has the most environmentally friendly manufacturing process in the
industry, with less silicon waste and less toxic by-products for a clean and efficient production process. Your carbon footprint
will definitely be smaller with an Evergreen system, especially since their panels are made in America and don’t have to travel
by ship freight halfway around the planet.