Talk:Photovoltaics

Merge with Photovoltaic module

This article ought to be merged with the Photovoltaic module article as they both essentially talk about the same thing. Ufim (talk) 05:54, 16 December 2009 (UTC)

Merge with solar cell

This article ought to be merged with the solar cell article as they both essentially talk about the same thing. —Preceding unsigned comment added by Happytohelp21 (talk • contribs) 09:13, 11 December 2009 (UTC) solar

Materials used in PVs

It seems that the first reference link is a dead link, this should get fixed. 150.250.213.174 (talk) 13:04, 24 November 2009 (UTC)

Cost calculation

Hi. I'm struggling to replicate the cost calculation. Here's a google spreadsheet in which I've done the calculation for a single example. The calculation is pretty simple. Unless someone can point out a mistake in mine, or justify a different method I think the numbers in the table should be updated? Grj23 (talk) 08:40, 23 February 2010 (UTC)

In my opinion the table is original research and ought to be deleted unless a reference for it can be provided. Besides, based on the small amount of information provided about it, it is difficult to understand exactly how the calculations were performed, which would explain why you're having trouble reproducing it. Furthermore, I'm rather certain they neglect mortgage tax credits (for residential systems), investment tax credits (for commercial systems), inflation, discounting of cash flows, and degradation of panels over time, among other things. Yes, all of those things make the analysis rather complicated, but when you're talking about a system paid for over 20-30 years these all have a significant impact on the final calculation and neglecting them necessarily leads to distorted conclusions.--Squirmymcphee (talk) 15:18, 28 February 2010 (UTC)

Caltech does not claim 85% efficiency!

I just reversed an edit indicating that Caltech researchers are claiming 85%-efficient solar cells in the lab. 85% is about the theoretical thermodynamic limit on the conversion of solar energy to electricity, but achieving it requires a perfectly lossless solar cell with an infinite number of bandgaps (i.e., made of an infinite number of materials). Caltech is not claiming to have achieved this, rather they have simply issued a poorly worded press release about an innovative single-junction silicon solar cell (which, therefore, has a theoretical maximum efficiency of about 32%).

In greater detail, they claim only that their cell "absorbs 85 percent of total collectible sunlight," which is much different from claiming 85% efficiency. First of all, only about 65% of the photons in the solar spectrum are collectible by single-junction silicon solar cells, so only about 56% of the total solar spectrum can be collected by these cells. The high quantum efficiency of these cells means that nearly every photon collected will be converted to an electron-hole pair, but nearly every photon collected will also carry an amount of energy higher than the bandgap energy of silicon -- and anything in excess of that will be converted to heat, not electricity.

I believe I read someplace that the actual efficiency of their device is expected to be in the 12-15% range (but don't hold me to that). Considering how little silicon they used, that is a much bigger achievement than it might sound, particularly if they can do it cheaply.--Squirmymcphee (talk) 15:31, 7 March 2010 (UTC)

Intro is gushy, not neutral POV.

The introduction is overly gushy about how good it is and how fast it's growing. Gag me! It sounds like what they said about soccer in the 1970's. "Fastest growing sport!" Yada Yada Yada. Is the rest of the article the same drivel? ...... I will see. But please, neutralize the intro. Make if dry and straightforward, not promotional. Gah!

108.7.12.26 (talk) 03:50, 27 June 2010 (UTC)

So, is there a neutral way that states the same facts that would meet with your approval? How would you relate the statistics? *Sombody* is dead keen on solar PV and that's making the growth notable; even cloudy places like Ontario and Germany are building solar PV capacity, independent of what the Wikipedia is saying. --Wtshymanski (talk) 18:55, 27 June 2010 (UTC)

Although the fuel to make electricity from solar (the sun's rays) may be free and pollution free, the process of manufacture of the panels and installation is not free or pollution free. Also there may be a disposal fee when the panels expire. There is also a maintenance consideration, the panels are probably not maintenance free (they are subject to hail damage and may need to be cleaned and the inverter and metering equipment needs to be maintained). The sun only shines for 1/3 of the day, the capital costs are incurred 24 hours a day. At least 1/2 the cost of electricty is capital costs as opposed to fuel costs. It is a subsidy in itself to require the power company to purchase the kwh at the retail cost. A more market fair purchase price would be the wholesale cost of electricty which is more like $.06 per kwh as opposed to the $0.12 typical wholesale cost (although California has higher PEAK rates, not all localities charge PEAK rates, especially for homeowners.

Electricity from solar panels will be most successful in areas with high electricity rates. Right now the island of Lanai in Hawaii has the highest cost per kwh (somewhere around $.50 per kwh). If the panels start making economic sense it will be in locations such as these first.