"Solar power..." Topic

…ok, so it's not quite computer, but it's sort of technology.

I have 10 PV solar panels fitted. The other (somewhat warm and sunny) day we (as in half the vilalge) had a power cut.

Should I not still be able to boil the kettle???

Boiling water takes a lot of energy. You'd need a lot of solar panels. Solar power is neat for small items, silly for big things. I'd recommend you keep a camp stove around for such emergencies. Much cheaper.

If it's set up to feed your house, then overflow to the grid, then maybe. If it just feeds into the grid, and you take from the grid, than no. And you won't have been feeding the grid, either.

Ah, we have that anyway, as (despite modern, sophisticated, western electrical supplies) we still seem to suffer from random periodic blackouts.

Cheers guys, I'll have to look into that. Must admit, short of knowing there is an inverter and we get a cheque every quarter (and my electric bill seems to be smaller) I don't have much clue how it works :-)

Yeah, it all depends upon how it's wired. Making it work like an auxiliary generator is more complex, and you also would need to attend carefully to what is and isn't on/plugged in when using it that way.
-Kle.

Oh, it's simple quantum mechanics. The panels are chiefly silicon in a crystal arrangement that wants to keep its electrons in a particular orbit. Photons from the sun knock these electrons loose, and when they fall back into an allowed position they've moved one atom to the right. Eventually all the electrons start to pile up against one side and you have a negative charge. The other end of the panel has a positive charge, of course, since it has a bunch of "hole", which is to say places that should have an electron, but don't.

All the electrons very badly want to get to the holes, but they can't swim upstream against the electrical pressure. Taking the path of least resistance, they follow the wires attached to the panel, flow through the inverter, and back along the other wire to the holes at the other end of the panel. Photons keep hitting the panel, the electrons keep getting nudged across the crystal, and round and round they go.

In the inverter this flow of electrons is turned into a more portable form of electricity. Coming off the panel you have direct current (DC, it's always flowing the same direction) with a relatively low pressure (a volt or two, not enough to run your cell phone) and whomping high current (many amps, enough to melt a typical electrical cord). Low voltage electricity tends to lose more energy in transmission, so a transformer in the inverter will change the power to a higher voltage with lower current. DC electricity won't go through a transformer, so it's converted to AC first. This is good, because your house and the grid work on AC.

Next the real magic kicks in. Thanks to legislation, which is harder to understand that quantum mechanics any day, the power company pays you more for the solar power than they pay to generate electricity at their plants. If they paid you what the electricity is worth the panels wouldn't be worthwhile. This saves them some fuel, but not as much as they paid you. The power company is still making money, of course, so this cost is past on to other customers. This is the crazy part, but you can double check it. I'd be very curious about the numbers. Look at your bill and look at the statement that shows up with the quarterly check. You can probably figure out what they are paying you per kWh (kilowatt-hour, the most common commercial measure of power). Then google around and learn the average cost of production for your power company. In most cases you'll find they're paying you more than they'd pay to make it themselves.

Most amazing, the photons that make it all work are created by nuclear fusion in the center of the sun, but because gravity has compressed all the atoms close together there the photon only travels a millimeter or so before being absorbed by another atom, which then re-emits the energy as another photon. Eventually the photon finds it's way to the outer layer, the photosphere, where it flies off into space. It takes just eight minutes or so for the photon to get to Earth, but it bounced around inside the sun for somewhere between 10,000 and 170,000 years. So the photons that make your electricity were created in a fusion reaction before the pyramids were built, and possibly before humans developed speech.

Not to go too Fezzy, also amazing is that when a nation decides to commit heavily to 'alternate energy' and therefore does not increase or even maintain its 'modern, sophisticated, western electrical supplies' that it has power failures.

'It is not easy being green.'

If you have enough panels, you should be able to boil water. 10 panels is not enough. If you have a battery system where you store power from the solar panels and then send a portion of it back to the grid, you will be able to boil water. Going green isn't as cheap or easy as it sounds.

Maybe a wattage issue? One burner on a stove uses about 1500 watts. Solar Modules used today range from about 130 to 240 watts per module (panel). On the low end that could leave you a bit short, plus the draw of anything else that was on in the house at the time.

Bill

I don't think we could turn anything on, even a light bulb. Power was… off.

Goragrad, power cuts are usually a transmission issue, nothing to do with generation.

If you want to boil water with solar power, your best bet is a parabolic mirror focused on a tea kettle. More efficient and more effective than any panels.
Solar panels are truly only useful on spacecraft; they're too inefficient for anything on earth but "feel-good" "green" politicking.

On the other hand, my father's company had a contract to safely dismantle a solar boiler system in the desert of the American southwest. It consisted of a field of mirrors focused on a boiling tower that used liquid metals as the generating fluid, and was originally set up as a test system. It generated extreme heat at the focal point, as one might imagine, but also significant levels pretty much anywhere over the field. Unfortunately, the local bird species (including some endangered raptors) had no clue what those mirrors could do. They'd fly over the field and be completely cooked halfway through. Flap, flap, sizzle, plop— instant drumsticks.
So much for that idea…