device to use unused soler pv export power to run heater or hot water

EricMears

hp4020 wrote: »

I have a set of these switches and a relay, hit a snag, my meter was changed last week and they have put a meter in that does not display a light when exporting....only a light that blinks when you are importing. Can anyone think of a workaround.

I have changed the immersion to a 1kw with thermostat, and have a 4kw system.

eg

Any way to make a switch that detects when importing and turns off relay to immersion ?

Any way to use electro magnetic sensoring ( as in electricity monitors) to gauge export, I have identified two tails and when a monitor is applied, one measures Invertor output and the other measures live domestic use, any way to combine those ?


Anyway to use export to turn on a small led, maybe in conjunction with above, ie useing monitors.

Any thoughts appreciated.

My meter alas blinks whether it's importing or exporting - so I'm still relying on a nett reading from a Wattson and switching things on manually.

If your light blinks when importing but is OFF when exporting, you need a relay that switches OFF when a light is seen then stays OFF for (say) 30 seconds then back ON. Thus an intermittent flash will turn off your immersion heater but a steady lack of light would allow it to stay on.

If your light blinks when importing AND when exporting, I can't see any work around (but would appreciate any tips from anyone who can see a solution).

Dave_Fowler

hp4020 wrote: »

I have a set of these switches and a relay, hit a snag, my meter was changed last week and they have put a meter in that does not display a light when exporting....only a light that blinks when you are importing. Can anyone think of a workaround.

I have changed the immersion to a 1kw with thermostat, and have a 4kw system.

eg

Any way to make a switch that detects when importing and turns off relay to immersion ?

Any way to use electro magnetic sensoring ( as in electricity monitors) to gauge export, I have identified two tails and when a monitor is applied, one measures Invertor output and the other measures live domestic use, any way to combine those ?


Anyway to use export to turn on a small led, maybe in conjunction with above, ie useing monitors.

Any thoughts appreciated.

The circuit I've developed here https://forums.moneysavingexpert.com/discussion/3921935 Turns on an LED when the current flows in one direction only.

Dave F

woodstoke

hi we would love details of this as we have a 9.5 kw system and have plenty of surplus leccy.....thanks

Dave_Fowler

woodstoke wrote: »

hi we would love details of this as we have a 9.5 kw system and have plenty of surplus leccy.....thanks

I intend to put the strip-board layout details of the current sense circuit on the website early next week.

The next circuit under development is one to replace the photo resistor sensor on the roof with a circuit which picks up the flashes from the LED on the generation meter. A preset level between 1kW and 4kW (ok 9.5kW if you want it as a modification) can be set as the trigger level. Probably another week away from the publication of the circuit.

Check my posts on the other forum thread.

Dave F

hp4020

Thanks Dave, can you tell me what you intend to use to "sense" the flashing led ?

Dave_Fowler

hp4020 wrote: »

Thanks Dave, can you tell me what you intend to use to "sense" the flashing led ?

The circuit uses a photo-transistor type BPW85 connected to a retriggerable monostable 74HC123 to sense the LED and provide a setable trigger level. This section of the circuit was designed a few weeks ago and works well. I'll be checking on a suitable output part to drive the semiconductor switch when I get back in the design workshop tomorrow.

Dave F

Mandragorin

Can you pm me details please

legoman62

I have put together one of energysavingexp's (with a lot of help & advice from Phill) kits to use excess power. The idea works fine. I have been testing it for the last 2 weeks. Total cost was around £25.00, so even if it was not totally sucessful I have enjoyed doing it.My electric meter is the new type. I have sourced a supplier of "made to measure" immersion heaters (good price) and am running a 1kw one at the moment. My cylinder allows me to fit another 2 immersions if required.
Anyone wanting a picture is welcome.

hp4020

Thanks Dave.

Dave_b_5

Sounds like exactly what I've been looking for. Any chance of details please. :-)