Solar panels generating but no saving on bills

1961Nick

Martyn1981 wrote: »

OK, I'm going to ask a really stupid question now, and it's for everyone.

I've just looked at my set-up as I also have a second CU, the classic 'garage board' installed recently. The PV however (both feeds) go into the original CU.

Now, the main power comes in, it goes through the big breaker (mine's a 100A unit), then goes to the import meter, then to two blocks, which I think are called 'Henley Blocks'(?) with a feed then going off to each of the CU's.

Now, whilst my PV isn't on the new board, if it was, is there any way for it to avoid my old CU, and the vast majority of my household consumption and instead 'sneak out' the house?

I'm assuming this is complete and utter gibberish and that in such a situation the leccy would flow from the Henley Blocks to the CU asking for power, but I figured I'd throw myself in front of the bus, and ask the daftest question(s) just to clear up any possibilities. Or if by accident I've raised some related mis-wiring issue that could have happened.

There’s nothing wrong with that setup. All the import & export has to go through the smart meter so it should be recorded correctly.

Time to do some testing.....the primary one being making sure there’s no import while the iBoost is operational. If that’s working fine, move on to basic meter testing.

Martyn1981

mmmmikey wrote: »

Not a stupid question of you don't know the answer - none of us are born as electricians


Simple answer is everything as it should be.

Thanks, but just to be clear I was using my set up just as an example so it could be pictured easily, it all works fine.

So, having exhausted my limited knowledge, and now my imagination too, unless there is fault with some household devices, I'd guess that the smart meter is reporting the sum of movement (in and out) rather than just the ins? If consumption of generation is approx 50% then the maths would work, I think, whereas in my case I'd see a massive increase as 3,000 export got added to 1,500 import and my pre gen import would jump from 3k to 4.5k.

I do like a good puzzle, hope we get the answer when it's solved.

EricMears

Martyn1981 wrote: »

Now, whilst my PV isn't on the new board, if it was, is there any way for it to avoid my old CU, and the vast majority of my household consumption and instead 'sneak out' the house?

That could only happen if there was a direct connection to the 'wrong' side of the meter !

FWIW, I'd tend to agree with joefizz in that if the immersion diverter is faulty and hence immersion is always on, that would be equivalent to bannerman having fitted a 'new' appliance and hence his 'normal' power usage this year being a great deal higher than last year's.

bannerman

Have you measured how much gas saving you have made? Or do you turn it off every summer.

How many KW is the system? The immersion control starts at 70W

Gas usage June and July 2018 were 927kWh and for June and July 2019 when I turned off the boiler were 367kWh which sounds a large saving but is only £18 as gas is quite cheap compared to electricity!


Immersion heater is 3kW

markin

Energy Savings only are estimated at around 200 a year, Have you actually submitted a reading for the fit yet? What is your fit estimate?


The site i used says a 20 year payback without the fit.

bannerman

Did the test which mmmmikey suggested at noon today. Not sunny all the time but at start of test generation was 2.14kWh.

Turned all power off on the circuit breakers, including immersion heater, on both of the Consumer Units except the circuit to the shed the Electric meter reading was 12633 at start and Generation meter 2595.56. After 15 minutes the Electric meter reading was the same at 12633 and generation was 2595.75. Screen on electric meter was also showing words EXPORT. Then turned 1kW electric fire on for 15 minutes, electric meter still showed 12633, generation meter gone up to 2596.33.
So this must mean it was exporting and using the power from the solar panels.

Looks like the immersion heater diverter is the problem as some people have said. Can anyone suggest a good way to test this apart from turning it off for a few days and seeing what difference it makes?

Energy Savings only are estimated at around 200 a year, Have you actually submitted a reading for the fit yet? What is your fit estimate?

Yes have submitted FIT claims, in the 7 months system has been running and have received 2 cheques totalling £95

1961Nick

bannerman wrote: »

Looks like the immersion heater diverter is the problem as some people have said. Can anyone suggest a good way to test this apart from turning it off for a few days and seeing what difference it makes?

Do the test again with all the breakers off except the immersion heater & the solar pv. You may need to run some water off if the tank is already very hot.

The smart meter reading should stay static for the duration of the test.

You could also cycle one of the other breakers during the test to see if that upsets the diverter.

nobby1963

Hi,
I’m not sure and am not clever enough to know if this is already being suspected by others but .....
Our set up with an Immersun diverter for our immersion tank has us with an immersion switch that is permanently on. We know that it is getting its power from the solar panels and is heating the water from them when a red light integrated in the switch flashes or shows constant red when the water is fully hot.
Could it be that instead of your diverter sending excess power to the immersion that in fact you are just constantly heating the water from your mains supply ?
That would explain why the water is so hot and why your electricity usage is not reducing.
Just a thought and sorry if that is the conclusion that you had already arrived at.
Good luck......Nobby.

pinnks

These diverters are just intelligent switches. Whereas a normal electrical switch simply makes the connection, thus allowing the demand to take whatever power it needs (3kW in the case of an immersion element), a diverter makes the connection but only allows the demand to take whatever power is available, usually anything between 50W and 3kW.

So, when doing the above test with only the immersion breaker "on" the tank should reach full temp without importing anything.

Also, if the diverter is faulty it is likely to be feeding the immersion element after sundown. You could turn the immersion off using its original switch during the day and then turn it back on at, say 10pm, and see if you suddenly start heating your water and importing. You should see this on your meter as 3kW will be visible over and above your house's background load of perhaps 200W.

I took a quick look at the manual file:///C:/Users/coomb/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/Optimise%20PV%20manual%20(1).pdf. Page 7 suggests you would see a red light when importing (presumably general import but useful when doing the suggested tests) and blue when diverting. Green suggests the tank is hot. Viewing these during your tests might help.

The "immersion operation check" on page 20 may also help because boost does nothing more than operate the unit like a normal "dumb" switch to supply max power to the immersion until it is hot or boost is turned off...

HTH

joefizz

pinnks wrote: »

Also, if the diverter is faulty it is likely to be feeding the immersion element after sundown.

It could fault in any condition. It may only fault when it senses generation, hence my post and it diverts all output to the tank regardless of temperature, output, input etc.


First ascertain that that actually is the fault, remove it completely from the system, run the system for a week or so and then maybe put it back (or manually use immersion and not bother). It might even be something as simple as a break in the or misplaced sensor wires, if wifi it could default signal or any number of things including internal short or wired up incorrectly (override jumpers on the pcb or anything).



If its not that then you have a clean system to start testing other things.


First thing to do is get the OP exporting their electric and stop importing and costing them money. Get that working then work from there.