Forum Archive (Read Only!)
Read-only archive · 7119 discussions

Solar diverter NOT RECOMMENDED...!

23 comments started 2023-03-17 last 2023-03-19
GivEnergy Products
B
#1 BigAl

Afternoon all,

I, like most people on here, want to make the absolute best of my system and the lovely sunlight we are slowly starting to enjoy as the days draw out.

I am producing way more electricity than I currently consume and figure, offsetting the very expensive gas bill, with free solar electricity, is a fabulous way of saving both money and the environment.

My installer however doesn't agree and has stated that "they would not advise a hot water solar controller".

They go onto state that it would be "a conflict of interest as your battery's is prioritised always until full" and that if I was to install a solar diverter their "validating regulator won't validate battery systems anymore with divertors".

However they'd be happy to do the work as long as I signed a disclaimer and understood it would invalidate my battery warranty.

They also state that there are many isnatnce of the solar diverter not doing what I would want it to do and they wont be responsible in that event...

Can this be right... am I the only person to have a dual 9.5 battery set up and want to divert solar electricity to their boiler...? Is it more to do with how they set my system up?

I'd love to hear some opinions and from those with a dual battery/eddi set up to see how/if it works and if I simply need to find an installer who knows what they're doing...

P
#2 pacemaker

BigAl

Rubbish, though some work better than others. Search on here about the iBoost+ I have that one, and it's not as simple as battery charges until full then iBoost+ takes any excess... due to how fast the GivEnergy inverter reacts to changes. Sometimes the iBoost+ "steals" solar electricity away from charging the battery. Sometimes I've seen the battery discharge to the iBoost+ (the worse scenario).

Anyway it works when it works and I've heated my tank completely a few times in March

#3 TheDragon (GivEnergy)

With the latest firmware (Still in testing) I can confidently leave my old iBoost with Sender250, alone knowing the GivEnergy Inverter will always win the battle for excess

The newer ones can have threshold set ( Use 250 for safe) and a delay, 30s would be really safe

#5 dbt85

Diverters work fine. The question now is really is it worth it financially. Depending on your tariff and circumstances it might take a looong time to pay for itself given export rates can now be had above off peak import costs.

If you're on FIT and deemed export then its a no brained.

P
#6 pacemaker

dbt85

yeah I'm on flux, I'm disabling my iBoost+ during peak export to get the most bang

B
#7 BigAl

I currently have no export tariff set up... yep, I know, criminal...!!!

However, this week I'm on target to use about £30 in gas... if assume this is an average week as its been a little milder and the heating has done a little bit...

If I saved that much every week, based on a fitted cost of £800 it would pay for its self in under 3 years...? I know that's pigeon maths BTW.

#8 Stevef1964

I have the Myengeri Eddi heater heating my hot water tank.

I have it set to only start taking excess ( going to the grid) over 400w's and a delay of 5 seconds.

Although it's sometimes "steals" wattage that should be going to the batteries it quickly rectifies itself, I've found it to work absolutly fine.

It is able to heat my large Megaflow tank using the two elements very efficiently (usually needs appr 6.5 Kw's for a full tank but we don't need anywhere near that).

I installed it myself - very straight forward.

Cost - £500.

Last summer I hardly used any gas and was only paying the standing charge.

I'd change your installer!!

#9 Stevef1964

Just to add:

The myenrgi Eddi is not connected to the solar system in any way.

Mine is connected to the power outlet where the immersion heater was connected, next to the tank in the airing cupboard. The immersion elements are then wired to the Eddi.
There is a CT clamp that can be directly wired to the unit, which sits around one of the power cables and monitors the KW's being exported to the grid (as long as you have attached it to the correct cable and in the correct place!!)
In the event your eddi and tank are too far away from the meter, then you will need a Harvi to connect the clamp to and which will then speak remotely to the Eddi.

Z
#10 Zakalwe

iBoosts only have a threshold setting. I think that you need an Eddi to get a delay and a threshold.

I am using my iBoost very happily with my GE system, so I've no idea where that particular installer got his schtick from. I can't see anyway that a solar diverter would invalidate a battery warranty....it's just another device drawing power after all.

Does it stack up economically? Dunno. I 12 months of use mine has used up approx 750kWh. Which is 750kWh of gas that I didn't need to burn to heat our water and 750kWhs worth of CO2 that we didn't send into the atmosphere, so for me that makes it well worthwhile.

#11 dbt85

BigAl If you have no export tariff then of course it makes sense to do it. Just like if you're on FIT deemed export.

However I hope that you're getting onto some export soon and as soon as that happens you might well find yourself being able to buy off peak at 12p and export at 15p, or buy off peak at 20p and export at 22p or even 36p. In which case you'd be better off sending 3kwh to the grid for 15p and using the immersion at night for 12p, or similar. Even its its a net zero difference, it still means the diverter has no monetary benefits, only green ones. Not that they aren't important, but an Eddi is £435 now. That's not nothing if the financial payback is ... nothing.

As much as we want to use it all ourselves and be super green, Octopus are finally rewarding those who can export with a half decent rate well above the standard crappy SEG that people have been on since FIT ended.

We have 2 Eddis here and due to the distances involved I ran cat5 from the meter boxes to the Eddi's as there was no way any kind of signal was getting there wirelessly. I basically installed it, made sure it all worked and then took the connections out so that an electrician could come and actually terminate it with bits of paper that say its safe.

#12 positor1

I have an ac3 with 2x 8.2 batteries, eddi and Harvi. System works faultlessly, no hang on it says it has lost the Internet approx once a month but recovers.
Already in March I have had some free hot water from electricity (41.4 kwh) that would have gone to the grid.
Keep in mind that the inverters can only charge the batteries at a fixed upper limit so when you are producing (in my case) over 3kw the surplus is wasted , well exported .
Eddi and harvi is expensive but it will pay for itself. The app is nice too and with the Harvington also shows battery charging or discharging but not percentage.

W
#13 wilfleek

My iBoost will initially "steal" solar power from going to the batteries under intermittent sunshine conditions, (even with a high threshold set) but once the sun stays out, the AC3 (still on D0.534-A0.534) slowly steals it all back! I have proved this now so many times that I simply leave the iBoost on all the time to do its thing. Never once has it actually taken power directly from the batteries.

My conclusion is that the two systems (AC3 and iBoost) actually play nicely together. If you went by the instantaneous readings, you might worry - just give it a little time and it all comes good.

A
#14 anglefire

One issue I had with my Innersun diverter was force exporting resulted in the diverter assuming excess and heated the water - other than that I can leave it at 100w and it doesn't nick the battery charge too much - I have tried 50w and that is fine unless the sun is in and out like a fiddlers elbow - I have no doubt if my inverter is suitable for the fast operation, then that will be sorted too. I then just need to add a switch to it to stop if diverting when I want to export - not that I do it very often, so is a bit moot until I can get around to it!

S
#15 SilverArt

BigAl I would suggest that they are covering their backsides, unfortunately in the wrong way. I suspect that they want to avoid being drawn into any solar diverter / battery conflict issues perceived by the Customer and that is their way of discouraging it.
For the non technical end user the 'fight' between battery control and diverters is possibly difficult to grasp, especially when sometimes it works and sometimes it doesn't dependant on the weather!. Perhaps their stance is based on previous experience and time/cost of trying to resolve an issue in the past.
This problem is obviously understood by the diverter companies and GivEnergy (and I guess others) as they are taking steps to improve performance in this area..
What to do in your case? How far do you want to push it with them, how much trust do you loose in them with their stance. Perhaps just ask for a copy of their "validating regulator's" document, on the other hand, just get them to install without the diverter and add one later.

T
#16 Tim

BigAl With the PV you have you will be exporting from spring right through to autumn at points during most days (assuming you have two hybrid inverters), We have a similarly sized plant and divert excess solar to charge the EV (no off-peak charge from last March to October). Even with the EV being charged and an export limit of 3.68kW, we exported nearly 4MWh last year. I think fitting a water heater diverter would help to self-consume your PV and swapping to an EV more so.

A
#17 anglefire

Tim Bloody hell - we generated less than you export!

#18 Simon_C

Given you have the 9.5 kWh battery, I cannot see how having a solar diverter could invalidate the battery warranty.

I have had both a My Energi Eddi (solar diverter) and Zappi (EV chargepoint) for some time now, and recently swapped out my solar inverter to the GivEnergy Hy5-Gen2 also with the 9.5 kWh battery.

After some experimentation the My Energi equipment is now set with the following:

Export margin = 100 W
Zappi start delay = 60 seconds
Zappi stop delay = 120 seconds
Eddi output limit = 6 Amps (The maximum heating element power is reduced from 3 kW to around 1.4 kW in order to reduce temperature stratification in the hot water tank).

1/ With just the Eddi active, there is one scenario when there is a drain on the battery, which is when the battery has been charged to 100% (grid or solar) and the battery SoC has not dropped back below 95%. Under these conditions the battery is refusing any more charge and the inverter does not control well in targetting 0 W import/export, so can spend a number of minutes discharging the battery. Normally a change in generation or load will bring the inverter back in line, and there is a new GE firmware release due that supposedly overcomes this issue.
This does not happen when the battery SoC is below 95%, and even with fluctuating generation or load any battery discharge is short term and the inverter controls to 0 W import/export within around 30 seconds.

2/ The only other issue I have seen is when the Zappi is charging the car and the generation excess repeatedly fluctuates above and below the 1.4 kW minimum charge rate for all BEVs. When the generation excess rises quickly above the 1.4 kW threshold, the Eddi is faster to respond than the Zappi + BEV so starts to take the excess. The Eddi backs off to 0 W once the generation excess remains consistently above the 1.4 kW threshold. This is an issue with the MyEnergi kit rather than GivEnergy. When the generation excess is rapidly fluctuating I either set the Eddi to stopped whilst the car is charging, or put the Zappi in ECO mode rather than ECO+ which does discharge the GE battery but only by the shortfall of excess when it is below the 1.4 kW threshold.

In general if you have a decent amount of predicted export then get a solar diverter, but choose a model with a programmable export margin and ideally startup time delay. Only you can decide if it is worthwhile from a monetary standpoint or green ethics if you want to reduce your gas consumption.

P
#19 pacemaker

SilverArt

exactly - when I had an issue my installer told me to contact iBoost

G
#20 Graham_Harrison

I have a Solar iBoost+(early model without adjustable kick in level bought 2nd via eBay in 2018)
For many years it worked alongside a 4kW (East & West) solar array and a 40+ year old gas boiler (with gravity feed hot water) to my 95 litre hot water storage cylinder with 1 x 500w immersion element. The iBoost did its thing with spare power through the summer months and my gas consumption dropped drastically. All good stuff
NOW I have..
A total of 8.3kW (East / West / South & East / West) of solar
2 x 9.5kW Batteries
1 x AC3 Inverter
125 litre hot water storage cylinder (same 40+ year old boiler)
Solar iBoost+ (same 1)
2 x 3000w immersion elements
The Solar iBoost+ is still doing its thing, playing nicely alongside the batteries, all be it that hasn't been a vast amount this year yet
Would I recommend a Solar iBoost+ or something similar "Hell Yes!"
I'm a bit of a data / spreadsheet freak and have had energy monitoring equipment setup on my gas / electric & solar for many years before adding my GivEnergy equipment and have all the facts and figures that could possibly be required to prove its a worthwhile thing to do

S
#21 SilverArt

Simon_C Given you have the 9.5 kWh battery, I cannot see how having a solar diverter could invalidate the battery warranty.
But which' Warranty? this is the real problem I suspect. As the supplier of everything he will be responsible for supplying all the warranty and although he might be highly qualified in installation he may not have the tools, skills or experience to do multi-supplier problem determination. Add to that if he determines the problem to be a GivEnergy problem that he can't fix he has to pay the £150 for them to come out (quite rightly so IMHO) and only gets that back if it's proven to be a GivEnergy problem. The only other option is to carry spare inverters
His mistake, again IMHO, is his disclaimer, perhaps a more suitably worded warranty or disclaimer statement briefly explaining the issue and limiting his liability would be better.

#22 Simon_C

SilverArt , from the OP the installer is specifically referring to the battery warranty.

Quite who the 'validating regulator' is in this instance, who knows. It sounds made up to me.

My installer however doesn't agree and has stated that "they would not advise a hot water solar controller".

They go onto state that it would be "a conflict of interest as your battery's is prioritised always until full" and that if I was to install a solar diverter their "validating regulator won't validate battery systems anymore with divertors".

However they'd be happy to do the work as long as I signed a disclaimer and understood it would invalidate my battery warranty.

The GivEnergy portal keeps track of the historical battery charge and discharge energy values, so can prove how many cycles have taken place, not that it matters with the unlimited throughput allowed with the 9.5 kWh battery.

If there is an issue with the battery capacity it should be straightforward to prove with a calibration cycle carried out by GivEnergy that they can initiate remotely.
If there is an issue with poor quality connections made between the inverter and battery by the installer then they should be paying the GivEnergy callout fee to prove one way or the other.