On Feb 26, 8:48*pm, "george [dicegeorge]"
wrote:
What king of device could turn on the power
to an electric storage heater
only when its sunny and my solar panels
are exporting energy to the grid?

[george]

Now you have found the problem of having the inverter in the loft, you
can't see what it's doing/generating on the display.

I think on a day when the sun is so strong, you won't need your
storage heaters anyway.

May be you could find a PV switch (outdoor lighting sort of thing)
that has sufficient adjustment range to be useful. Or maybe site it
indoors where light levels are reduced?
You would need a suitable relay to carry the load and reverse it's
action.

Then you have the problem of warming the heaters when there's no PV.

The problem with trying to reduce your electricity bills with PV is
that you have to be there to at PV max time (ie midday).
We are there & save around 25% off our bill.