Solar PV, Battery, smart immersion advice.

[Nigel52]

First time posting but would like some advice for those that have gone before me.
Background - new build house with 4 x panels JA Solar 370 watt and Growatt system installed I suspect to meet environmental building regulations.
So on good summer sunny days it puts circa 900 watts back into our system or the grid.
I have estimated we use circa 4040 Kw a year from EDF on a fixed tariff until March 2024. (Luckily)

Heating is Underfloor on all floors with Gas boiler which also heats a 300 litre plus cylinder. As yet we have never used the immersion heater.

Now looking to upgrade the system with more panels to take the panel total to circa 6Kw and possibly add an 8-10Kw battery. Also an EDDI smart solar immersion controller to divert spare energy to the immersion heater to reduce reliance on gas. I would like to also have some built in EPS from the battery so cover short time grid power cuts. Would only need to cover the circuits with fridges etc and the gas boiler and heating pumps.

EDF will not allow us to export to the grid (or at least not pay for us to do it. If we changed tariff say to economy 7 then we would likely lose our fixed tariff rate.

The system I am favouring at the moment is:
5.46Kw Solar PV , 14 x 390W panel Trina Vertex S system + Solaredge optimisation + EDDI immersion boost + 10.4kW Givenergy Battery + EPS. (On this system the EPS will only power up to 3kW from the battery, hence choosing which circuits to put on it.)

I have discounted the Tesla Powerwall as too expensive although I like the way it can back up the grid.

Other considerations:
No electric vehicle (EV) currently but perhaps in three years time. This might say don't but the battery now as if one wants to power the house during the day and summer, put excess energy into the immersion, charge a battery for non-daylight hours and charge an EV then I am asking too much.

If I have the EDDI smart immersion controller I am not sure how this will work if we currently heat the tank from our gas boiler.

Any views or advice on this lot please?

[Countrypaul]

You should read this if you have not already: https://energysavingtrust.org.uk/advice ... guarantee/
I believe that EDF need to offer to buy your electricity exported to the grid, but that you could use a different company - they may not all pay the same rate.
You will easiy heat a 300L tank on a sunny summers day using an Eddi and probably have power to spare so a battery could well be a good idea. If you do go for an EV have a look at the Zappi, an EV charger from the same people as the Eddi which allows both to work together.

Does your 300L tank have one or two immersions, as the Eddi can work with 2, one hear the top (say 100L down) and one near the bottom, that way the water at the top will be heated first and only if there is more excess power will tbe bottom be heated (you dont want a tank of lukewarm water normally).

[Nigel52]

Thanks. Quotes finally coming in.

[jerry2604]

Go bigger with the batteries is my view. Just got 2x8.2 GivEnergy units and will review in a year to see if i might get another. Have got EPS nearly installed - just need the auto changeover wiring in but the electrician is away on holiday . This is whole house but will not do heavy loads as you know - so no hob or oven cooking if there is an interruption but lights, tv, heating etc will be fine - easier to install than just the odd circuit. I have just had another 4kW installed with the batteries having already got 4kW from 2011 and on the 1st FIT tariff. Also have a 30 tube solar array which i have had to take down to fit the additional solar but will re install on a lower, garage roof - not ideal as the roof is shallower and will get early shading from the house but still worthwhile as they are about 60 to 70% efficient.
If the SEG is like the FIT then you don't have to sell to your electricity supplier. I sell (get paid) by Scottish Power but my supplier is OVO.
I have an hybrid inverter fitted with the new system and apparently GivEnergy are in the process of designing an 3kw AC converter that will work side by side with the hybrid so you can fill and empty the batteries at nearly 6kw. This would be ideal as cooking is all electric and filling the batteries on cheap rate electricity would be quicker. We will see what develops

[jerry2604]

Go bigger with the batteries is my view. Just got 2x8.2 GivEnergy units and will review in a year to see if i might get another. Have got EPS nearly installed - just need the auto changeover wiring in but the electrician is away on holiday . This is whole house but will not do heavy loads as you know - so no hob or oven cooking if there is an interruption but lights, tv, heating etc will be fine - easier to install than just the odd circuit. I have just had another 4kW installed with the batteries having already got 4kW from 2011 and on the 1st FIT tariff. Also have a 30 tube solar array which i have had to take down to fit the additional solar but will re install on a lower, garage roof - not ideal as the roof is shallower and will get early shading from the house but still worthwhile as they are about 60 to 70% efficient.
If the SEG is like the FIT then you don't have to sell to your electricity supplier. I sell (get paid) by Scottish Power but my supplier is OVO.
I have an hybrid inverter fitted with the new system and apparently GivEnergy are in the process of designing an 3kw AC converter that will work side by side with the hybrid so you can fill and empty the batteries at nearly 6kw. This would be ideal as cooking is all electric and filling the batteries on cheap rate electricity would be quicker. We will see what develops

[nowty]

Excellent stuff jerry2604, you had the insight to get the max FIT rate in the early days, thermal solar and now more PV and batteries.
We love the photos too.

This is what we need, your my 65th member of my secret list Camelot Members Annual Green Electric Generation.
https://camelot-forum.co.uk/phpBB3/view ... f=13&t=922

I'll do an update later as I tend to do one every 5 members.

[Woodyeyes]

I installed the EDDI last year. Recently got a Zappi EV charger as well. The app that comes with them both is pretty good, and I use this to monitor my solar generation and useage etc. I have two gas heated hot water cyclinders (Big house, two separate central heating systems), so the Eddi diverts to the immersion heating element of each tank. Via the app you can set wgich one gets heated up first which is a nice feature.
I have a 3kw PV system currently (looking to expand it but that's a different thread) and I have not used any gas to produce hot water since April so far this year. Get one!
PS. My export PV has been minimal since the Eddi was installed. Last month the Eddi diverted 91 kwh to the hot water rather than being exported. Result. :-)

[Nigel52]

Well done

[Countrypaul]

If the SEG is like the FIT then you don't have to sell to your electricity supplier. I sell (get paid) by Scottish Power but my supplier is OVO.

Be careful if you have a system on FITS and then try and add another system on SEG, you may lose the FITS income. The SEG works only on a smart meter and measures the export, but it cannot differentiate between what is on which system and therefore what is being exported, so it all has to be doe under SEG. I have been looking at this for a new system on our property, and one quote I had explained the SEG rules, but when I questioned how the IT and SEG work togethe a more senior person got involved and said we could not have both.

[Andy]

If the SEG is like the FIT then you don't have to sell to your electricity supplier. I sell (get paid) by Scottish Power but my supplier is OVO.

Be careful if you have a system on FITS and then try and add another system on SEG, you may lose the FITS income. The SEG works only on a smart meter and measures the export, but it cannot differentiate between what is on which system and therefore what is being exported, so it all has to be doe under SEG. I have been looking at this for a new system on our property, and one quote I had explained the SEG rules, but when I questioned how the IT and SEG work togethe a more senior person got involved and said we could not have both.

And if you do an install without the MCS paperwork then you cannot get SEG either. Which is nuts as it is the same electricity. If it is done to a standard that the DNO is happy with the connection then you should get paid for it. But that is a rant for another time.

EDIT;
I was wrong there is a way.. I don't fancy my chances of getting this through any of the front desks mind.

https://www.ofgem.gov.uk/publications/s ... generators
1.13. If you do not have an MCS certificate, your installation and installer should be accredited in accordance with EN 45011 or EN ISO/IEC 17065:2012. You should speak to your chosen SEG licensee to understand exactly what information they need from you.