Solar PV immersion heater switch??

[Hightower]

Originally Posted by Pikey Dave

You don't need to touch the wiring, the pickup (current transformer) just clips around the cable, completely non-invasive

It's running multi-core wire everywhere, so unless I strip the insulation off the wire to get at the live wire so that I can fit the current transformer there's not a lot I can do. Or am I missing something

[EnglishLes]

Originally Posted by Hightower

It's running multi-core wire everywhere, so unless I strip the insulation off the wire to get at the live wire so that I can fit the current transformer there's not a lot I can do. Or am I missing something

My PV meter is next to my electric meter in the outside cupboard. The red mains is joined to the brown PV and the black mains is joined to the blue PV before the consumer unit (indoors). I have attached the "widget" to the blue PV wire after the PV Generator meter.

Picture attached.

Bottom left is mains from grid, top left is mains meter, RHS is PV meter.

Two black boxes in the middle are where the joins are made.

The big black and red thing is the pickup unit for the "widget" (transmitter to indoors not shown).

Hope this helps clarify things.

[Hightower]

Thanks English Les, the photo helped a lot. I managed to find the leads from the PV meter to the mains meter. Although both leads were grey and unidentifiable from each other the sensor worked on both leads.

What would be really handy is a stand alone meter, similar to the one supplied for monitoring the energy consumption by the utility companies but with settable alarms that could be used to trigger a relay.

Is there anything on the market?

[thushar]

Originally Posted by Hightower

Found a couple of controllers, the first is a voltage/load sensitive one and the second cheaper one controlled by light levels. Let me know what you think?

There are some reasonable costing 1/1.5 KW immersion elements for sale on there too.

Solar Panel Immersion Heater Switch - Use Surplus Power To Heat Water | eBay

IMMERSION WATER HEATER CONTROLLER TO USE SURPLUS SOLAR PV POWER | eBay

I have been using the the solar switch

eBay - The UK's Online Marketplace

( Business Building Kits items in Fair Trade Hub Shop store on eBay! )

and it's working perfectly for the last 2 months without any issues. It will turn on the 1 kw immersion heater bough from Solar Immersion Heater Switch - Use Surplus Solar PV Power to Heat Water & Save Money and provides me with a full tank of hot water during sunny days and effectively preheats the water on dull days, reducing the load on the gas boiler. helps me to save on gas and get better ROI on the solar panel investment. Really good investment

[Hightower]

Originally Posted by thushar

I have been using the the solar switch

eBay - The UK's Online Marketplace

( Business Building Kits items in Fair Trade Hub Shop store on eBay! )

and it's working perfectly for the last 2 months without any issues. It will turn on the 1 kw immersion heater bough from Solar Immersion Heater Switch - Use Surplus Solar PV Power to Heat Water & Save Money and provides me with a full tank of hot water during sunny days and effectively preheats the water on dull days, reducing the load on the gas boiler. helps me to save on gas and get better ROI on the solar panel investment. Really good investment

Thanks for that, do you not think it's a bit on the expensive side though?

[rubbadubdub]

Have a look at www.totalpowershop.com and their TP-S610A power / energy management unit. It is much more sophisticated and would also meet your needs.

It will monitor how much energy your house is consuming and how much power you are getting from your solar panels or any other renewable energy source. It will automatically switch on your immersion heater (and up to 2 other appliances) when enough surplus energy is being generated.

And its only £300!! It should pay for itself as well, although it may take a year or two to get the money back. And it will make sure that your home is not consuming anymore power than you want to. The control unit will also record your energy production and consumption and download it to a pc.

[fredfred2]

I'm new to this forum, but have been looking to find out who makes this box. The owners of the house weren't in when we were doing some wiring, but this thing controls a standard 3kW immersion heater directly. The panels are only 2kW capacity, so my guess is that some electronics must turn down the mains to the heater element. There is nothing between the box and the immersion heater, which is rated at 3kW.

How can you run a 3kW heater with a 2kW solar panel, and still not draw grid power? Beats me.

But does anyone know who makes this little unit?

cheers,

fred

Sorry about the pic quality- taken with my phone...

[Hightower]

from reading posts from other forums I have found that some are using low voltage elements that give out 3kw of power but use less power from the mains. Perhaps that is what they did?

[fredfred2]

Originally Posted by Hightower

from reading posts from other forums I have found that some are using low voltage elements that give out 3kw of power but use less power from the mains. Perhaps that is what they did?

I've found some more info out on a way to run a 3kW heater element at 1.5kW... There is something called half wave rectification, where you put the power from the solar panels through a rectafier. It somehow blocks half the power to the element, so you can use a regular 3kW immersion, but run it at only half the power. Perhaps that's how they do it.

Its all black box magic...

Anyone know anything about this technology?

-fred

[Pikey Dave]

Originally Posted by fredfred2

I've found some more info out on a way to run a 3kW heater element at 1.5kW... There is something called half wave rectification, where you put the power from the solar panels through a rectafier. It somehow blocks half the power to the element, so you can use a regular 3kW immersion, but run it at only half the power. Perhaps that's how they do it.

Its all black box magic...

Anyone know anything about this technology?

-fred

Failing that, you can use a 240-110v tool transformer, supply the transformer from your mains 240 & run the immersion heater from the 110v side. On a 3kw heater, this system will knock it down to about 700W. I had a 1kw heater fitted in the base of the cylinder which is the best place for it in this application, not in the top as usual.

[rubbadubdub]

Although you have probably found a solution it might be useful for others....I bought a unit sold at Selling control units that monitor control solar wind water generated electricity. I bought their TP-S610A starter kit (they call it a Renewable Energy Monitoring Unit or their REMU I).
It monitors how much energy my house is consuming and how much power I am getting from my solar panels or any other renewable energy source. I've set it up so it automatically switches on my 1kw immersion heater (and up to 2 other appliances) when enough surplus energy is being generated.
It is only £199. I think it will pay for itself as well, although it may take a year or two to get my money back. In the mean time it will make sure that my home is not consuming anymore power than I want to. The control unit will also record my home’s energy production and consumption and download it to a pc.