Hope its Ok to ask this?

[Wellhouse]

Hi All,

Just joined in the hope I can find some help. (ultimately I'm even happy to pay for it!)

We've new built house that is currently heated by economy 7 via a 30 electric (night storage) AGA that does cooking and space heating (house is fairly open plan). DHW and as required wet underfloor comes from a 1000 litre akvaterm cylinder / thermal store - also heated by economy 7 via a immersion heater.

We were going to be installing (and have already bought!) a boiler stove that would have given us an input to the thermal store. The problem is the house is too warm as it is so lighting the stove would make it unbearable and we'd end up opening all the doors.

The overheating "problem" is down to the AGA as it leaks heat into the house continuously and the insulation / glazing is of such a standard the heat cant get out!

If we turn the AGA off we cant cook and the thermal mass is huge (1/2 tonne of firebrick) that on off operation is impractical.

We're not complaining but it has now moved us to consider solar PV - we got plenty ground and a mis-oreinted house so would probably go for a ground mount array - we've got a bit of spare cash so are tempted to look towards a bigger than 4 kw system (subject to the "G59").

My question is - we have two big electrically charged "heat batteries" and at face value this would appear to provide a perfect solution for absorbing PV derived electricity when available, maximising our usage (and minimising our spend on imported power)

What I cant answer is will it actually work - we would have to change the timer and / or wiring of the AGa as its configured to draw only during a limited period, although there is a boost function that could be examined. Similar question re the immersion heater though probably a simpler fix.

I'm fearful (and ignorant!) that the unless the elements in both the AGa and IH see "big" currents they wont bother to warm up at all and the (typical) trickle from the PV will do little to help, meanwhile we'll be topping up using expensive daytime power.

Hope this makes some sense and happy to explain more fully if required . hoping too that I'll find someone who knows this stuff rather than getting glib assurances or blank expressions from visiting sales people !

Thanks

 

[JTPR]

You can certainly use your Solar PV generated electricity to provide for your Immersion heater, its pretty standard.

 

[shanky887614]

You can certainly use your Solar PV generated electricity to provide for your Immersion heater, its pretty standard.

its not an imersion heater they want to use it on.

they want to use it for storage heaters.

if i remember right you get the fit for what you generate and it isnt affected by your usage so in theory there is no way to get it to run directly off the solar.


i was reading about it before and hybrid battery/export systems are either not common or availible in the uk.


there is always the option off an autochanger switch from a battery bank and mains with a ups before ccu.

this way if you use up all the stored power it will transfer to mains.

 

[Richard Burns]

There are a few devices on the market for diverting power from the solar to (generally immersions) various means of heat storage or resistive variable power use.
The only one I can remember at the moment is immersun, but there are others out there some of which are specifically designed to divert to any load.
They monitor your powr generation and once it is over a certain amount is will operate the power consuming device, once the generation drops below the cutoff the device is switched off again.

It may be worth searching the forum for Immersun or solar immersion and seeing what comes up as I am sure this has been discussed before.

 

[Gavin A]

oops.

either, or both loads could be controlled via a combined timer and export limiting coontroller, but how practical this is depends on the actual ratings involved.

 

[Worcester]

Everything CAN be done, the question is is it worthwhile or practical, and what are the implications. There are products available off the shelf to do what you want to do - #1 in this scenario is the ImmerSun. However designing and confifuring your system will take a while, so you'll need to pay for the propoer design.

The ImmerSun unit has a number of specific functional features that the others don't which means that it can be configured to meet your specific needs.

In practice you are talking about 3-4 hours work to fully identify how to configure the system to meet your needs and to design it.

We make a nominal £150 charge for that service