Solar Freaks

In the UK we get just a little less sun than Australia.. and am trying to maximise the power that is generated instead of it being put back into the grid (grid tie invertor).
Is there a way of identifying when the solar panels are generating power and switching loads on automatically?

For example, when the panels are generating at least 2kw, it switches on a water heater to provide domestic hot water, and off again if the output falls below 2kw.

Hey rossoreed,

Welcome to the forum!

What about just heating the water directly?

Most grid tie inverters will automatically power your home from solar panels when available, and draw power from the power co. otherwise.

You say "instead of ... grid tie inverter." Does that mean you want a different setup? A grid tie inverter is really your best choice, money wise.

Yes

dch wrote:Hey rossoreed,
Welcome to the forum!
1) What about just heating the water directly?
2) Most grid tie inverters will automatically power your home from solar panels when available, and draw power from the power co. otherwise.
3) You say "instead of ... grid tie inverter." Does that mean you want a different setup? A grid tie inverter is really your best choice, money wise.

1) Because I don't have a solar water heating system - only solar PV panels to generate electricity.
2) Yes, but I don't want to draw power from the power co, I only want the appliance to draw power ONLY IF the solar panels are generating enough power.
3) No, I'm trying to use the power for my own benefit instead of it going into the grid (for which I don't get any money as it's a government backed sponsored system)

There is a commercially available controller http://www.coolpower.ie/energycontrol/index.html which does what I want, but it is very expensive.

Ok, as far as switching loads on automatically --

If there is no power coming out of the panels, the load can't help but switch off.

Do you want to store power when you're not using it? If so, that's a normal "off grid" system setup. The prices for a brand new battery setup, charge controller, and inverter aren't cheap.

If you only want to use power when available, then look at getting DC appliances. (The kind used in vehicles & boats.)