Talk:Solar power

Template:Energy development

This page needs some work. There are some very unclear paragraphs that probably ought to be deleted, re-worked and/or checked for bias.

---

Yes, in particular:

"The basic cost advantage is that the home-owner does not pay income tax on electric power that is not purchased. " (2nd sent. of 2nd pp in Applying Solar Power)

I removed it for now. --Erauch 02:51, 11 Sep 2004 (UTC)

Contents

1 Help on solar power 2 Fix this passage 3 Power 4 Potential Energy Generated 5 Economics of Solar Power 6 Inexaustible

Help on solar power

Does anyone know a good place to find pictures of concentrated solar energies? i tried Google and Yahoo search and it came up blank. Help is appreciated

Fix this passage

I removed this passage (under "Deployment of Solar Power") as confusing:

"For example, while certain European or U.S. states could benefit from a public hot water utility, such systems would be both impractical and counter-productive in countries like Australia or states like New Mexico. " Erauch 04:15, 23 Oct 2004 (UTC)

Power

can somebody confirm the 1.4 W number please? See Wikipedia:Reference_desk#http:.2F.2Fen.wikipedia.org.2Fwiki.2F1_E48_J. dab (ᛏ) 14:44, 6 Feb 2005 (UTC)

The article states that the earth recieves "1,410 W / m2 of energy, as measured upon a surface kept normal (at a right angle) to the sun." Thats 1.4 Kw not 1.4 watts. This intuitively sounds about the right order of magnitude but I cannot confirm it. Lumos3 11:00, 7 Feb 2005 (UTC)

A 0.25sq M solar panel can generate 20W hence 1 sq.m is around 80W. Solar is say 10% efficient, that is 800W. So it is ball park right --Rjstott 11:36, 7 Feb 2005 (UTC)

Potential Energy Generated

I'd like some info included on the theoretical maximum energy that solar energy could provide. I.e. if the entire earth were covered with solar panels, how much power would be generated? Would it meet the total energy requirements of the world? What's the practical maximum coverage we could ever hope to achieve? How much energy would that provide? Provide results with 90-100% solar cell efficiency, and with current efficiency. --CraigBuchek 24 Mar 2005

Why limit yourself to the surface of the Earth? Vast solar panels could be built in space and the energy they recieve beamed back to earth as microwaves. You would also have to build a system to tramsit the waste heat from this back into space or the earths temerature would increase. Lumos3 22:19, 26 Mar 2005 (UTC)

And on the other hand, for those of us who prefer something more within arm's length, what about a calculation based on 1/10 of 1% of the Earth's land area (disregarding the water)? And using the currently most advanved proven solar p.v. tech. This would give some idea of something tangible, even though we realize no one is going to cover that much land area with solar arrays. It would offer food for thought for the reader.

I won't attempt to define "proven" (as in "proven solar technology") -- that's out of my field of expertise. But I think you'll understand what I'm getting at.

Just a point for consideration with respect to the article. - J.R.

Eps, my first chat contribution... I'm not sure if this helps or not... The "standar" ratiation at sea level is 1 Kw/h but the photovoltaic panels have an efficiency of just 15-16% aprox... That means that for a standar on-grid installation (5 kW) we need some 50 square meters... Any hair dryer takes more than 1 Kw...

On the other hand, recently there has been an agreement acording the "equivalency" between PV solar panels - thermal solar panels, with some 700 wats/square meter... so you can produce 5 Kw with just 7 square meters (5 Kw used for heating water, for heating the house or swimming pool or even air conditioning, under development...). Maybe it's a better idea try to save energy instead of produce more...

JordiG june 2.005

Economics of Solar Power

I think somebody ought to have another look at the section of this article dealing with cost-effectiveness. In particular, there's the part that asserts that at $9/watt, a solar panel yields a 9% ROI assuming the power can be sold at 9cents/kwh. That ROI figure seems wrong. Let's say I build a 1 watt solar power plant for 9 bucks. Every hour that it is sunny, I make a watt-hour worth of electricity that I can sell for .009 cents. If it's sunny 12 hours a day, every day all year round, thats (12 x 365 x .009) = 39 cents worth of power, for a one year ROI of 4.3%. This neglects costs of maintenance on the plant, which even at 1-2% per year will take the ROI down to what you could get from T-Bills (and with a lot less risk). Nobody in their right mind would invest in such a project unless the government were showering them with subsidies, in which case the plant can hardly be said to be cost-effective.

Inexaustible

Is solar power inexaustible, renewable, or nonrenewable?

Yes.

• Inexhaustible on practical terms, as long as the Sun shines and sunlight can reach the surface.
  • Exhaustible because there is a limit to how much can be gathered on the surface over any time period.
• Renewable because there is always more the next day.
• Nonrenewable because the Sun will eventually stop shining the way it now does.

The above becomes slightly different in space, for example by being able to build much larger collection structures and the ability to be closer to the Sun. (SEWilco 18:56, 12 May 2005 (UTC))