PV Gap

Sharon Said:

Supplemental water heater/solar conversion?

We Answered:

If I were you I would look into getting the newer " on demand" hot water heating system. There are no tanks, and therefore water is not constantly heated day and nite whether it is needed or not. Especially since now you need to use a boiler to keep it that way.
They make whole house models and models that you can put in just one application . Like a "on demand" water heater for the bathroom only or just the kitchen sink.
They are either electrically heated or gas heated.
The initial cost is higher BUT the moment you install it ,,,it starts paying for itself because it only operates when you turn on the hot water faucet. Your monthly bill willl drop like a stone.
Also it never runs out of hot water.
Its a win win situation.

Lisa Said:

Heating using Solar & Wind Energy + Insulation?

We Answered:

The simplest idea is to paint a cardboard box flat black and place the water in a heat-proof container (a metal pot) inside the box.

A more complicated idea is to bend a sheet of cardboard into a parabola. Coat the surface with a piece of shiny metal (such as aluminum foil). Aim it at the sun and at the line of focus you'll have a couple of hundred degrees F. A long, skinny trough of water placed along the focus line will be the hottest in your class.

Wallace Said:

What's the feasibility of having solar energy concentrated onto a solar power station from a satellite?

We Answered:

They're already considering using satellites, but not in that way.


They're thinking of using satellites equipped with thin film solar cells to generate electricity that is then beamed down to receivers on Earth using microwaves.

This is probably more sensible than just using mirrors when you consider that mirrors reflect visible light (and I'm not sure what their full wavelength response will be either...), which can be blocked by clouds.

Thin film solar panels aren't much heavier than mirrors anyway (the ones we make in my lab are 2-3mm of glass, the solar cell itself is about a thousand times thinner and stuck to the back), and by converting to microwaves, you can beam the power back down regardless of whether it's cloudy or not!


Wiki has a page:
http://en.wikipedia.org/wiki/Space-based…

Japan are talking about putting one in orbit by about 2030 iirc!

Renee Said:

Which of these is an example of mechanical weathering?

We Answered:

A. Rock is broken by ice expanding cracks