I have FIT with new battery and inverter, do I have the right meters?

Hi ​@Astraroy ,

Looks like you’ve exported 212.1kWh of eco-juice so far. The value you want is EXP which is shown whenever the arrow indicator is on the top left corner. That Meter appears to be an Export Meter - there should be another one somewhere else for Generation.

Thanks for the response. Does it ever get to a positive in the summer? The installers have assured me it does but very nervous rot potentially get to summer and it’s incorrect and lose out on FIT

We only have 1 meter as this is bidirectional and only way I can track generation right now is through the EcoFlow app which Ovo won’t accept 

Yes it does .. but I agree that the NET metering system looks odd, especially if you had a more standard generation meter previously.

As I mentioned, when you charge the batteries overnight from the grid, that counts as IMP (imported). Anything coming out of the inverter (including any solar generation) counts as EXP (exported - but not actually a grid export).

Because the inverter isn’t 100% efficient, your import/charge from the grid will be higher than any output and so during winter, if your overnight charging is ‘high’ compared to any solar generation, that inevitably shows on the NET meter as negative. (NET = EXP - IMP)

Super thanks for the explanation.

We have always had the standard generation meter so looked very odd to us.

in your experience was the reading similar to previous years after you moved to a new bidirectional meter? Trying to understand if we would receive the same generation fit as last year now we’ve moved to this new meter or would we lose some generation?

I agree - the update looks odd (we went through the same).

From what I’ve seen (1 year on the new Net meter), the generation is down overall but the phasing is what throws things out so much as I guess you won’t take as much from the grid as the days get better. I do think installers are often not the best at explaining everything. 

Yes I agree, I would have hoped the fit provider would be able to take the reading from the inverter app as that is clear as to what the solar panels are generating.. was the generation down by much year on year? As I’m on the old FIT payments part of what we receive was to recoup some of the outlay we’ve paid for batteries and inverters.

I have done the same, adding batteries to increase our solar gathering. We had our panels fitted early in 2012 so are also on the old FIT scheme. 
As I mentioned, the reading was reduced after using the Net meter but of course, each year is different anyway so it’s difficult to get a precise answer.

The inverter is always a rough guide but as it’s not calibrated and often fed from a CT (they are notorious for inaccuracy), the inverter readings are never accepted unfortunately.

Just a bit of reassurance ​@Astraroy here’s my Net meter from December 

Amazing thanks for putting my mind at ease 

Hi

I joined to reply to this thread! I am in the same situation with an old FIT scheme from 2011. I got my old grid tied inverter replaced by a Hybrid one and I have about 15kwh of battery storage.

The new bi directional meter was fitted end of January and from then until now it’s just showing a net of 9kwh when the battery is at 10% SOC (night)

I have generated approximately 100kwh since the meter was installed. Why isn’t this reflected?

Any ideas?

https://sonnenbatterie.co.uk/knowledge/efficiency-and-conversion-losses/

Could this partially explain some of the losses?

A little. 
Using any batteries means power input never gives the same as output - generally a 10% loss is expected.

Charging batteries from the grid (often during winter months ) can show more input power than output and as a net meter records the difference between import and export (output in this case) , then can result is reduced generation records. 
You need to be careful how/why you use grid to battery charging unless you have a decent off peak tariff to make use of

7p Off peak vs 24p peak. From the net meter numbers going from 10 to 100% SOC overnight which on paper is 13.5kw of battery storage capacity cost 15.5kw of grid AC. So looks like 2kwh gets lost everyday.. That'll soon tot up..

Yes - FIT was designed just as a generation tariff and not to include what’s know as ‘grey’ energy (battery storage from grid power).

While using grid power during winter to cover the lack of solar is useful, you have to carefully consider the losses and missing generation segment from pure generation

Agreed

Overanalysing my data for the last 48hrs, I can see losses of 2 to 3kwh in the AC to DC conversation at night and then DC to AC conversion back down the wire.

Being on an old FIT scheme, folks needs to minimise battery charging even if it means you use a bit more grid…..Ideally off peak

Hi everyone,

I have read the thread above but am still confused. We have just had a hybrid inverter fitted together with a battery. This coincided with our diary reminder to submit the FIT reading for the quarter. I had a photo of the old generation meter, but no-one explained the new bi-directional meter. I foolishly believed the Exp figure was the one required but my FIT provider came back and said they wanted the Net figure which was a negative amount. They explained it was negative because we were taking more to charge the battery from the grid than we were exporting. We are on a fixed price tariff and not a cheap overnight tariff so there’s no gain in using the grid to charge the battery and as far as I am aware our system is not set up to do that ( and the Fox App seems to confirm that as the graphic display never shows any grid power going to the battery). It seems we are being penalised twice over. Any power I import from the grid I pay for via my normal Smart Electricity Meter. My panels are producing power which I consume in the house and any surplus goes to the battery for later consumption at night. By sending a Net reading it seems to me I am paying to import power from the grid and at the same time this is negating the power/£p I generate from the panels. I thought the FIT procedure was to pay the householder for all the power generated by the panels (as it did on the old meter). Surely the same applies now whether you use all you generate, or whether you divert excess PV power to the battery? It seems by upgrading we have achieved one step forward but taken two steps backwards and are now out of pocket and ever will be.

I am with EDF for FIT (a historic thing) and they were quite good explaining that I needed a new meter (something my installer wasn’t aware of) This is due to the fact the old Meter was counting battery discharge as solar. I was also in negative a few weeks back, in part due to blindly charging the batteries to 100% overnight. I have since stopped doing this (I was scheduled to reduce overnight charge to 40% in March) but as has been explained above, the process of charging / discharging and simply being ON means I was losing minimum 2KW a day, sometimes more. This is only 14p of cheap overnight but it’s nearer £1.40 in lost FIT payments. I have therefore ceased all overnight charging. Battery now falls to 10% and hold and will charge purely on solar come what may

In terms of your case, the bi-directional meter doesn’t play tricks

AC Power Exported - AC Power Imported  = Net (The Number you give for FIT)

We had this device installed

https://theecosupermarket.co.uk/product/emlite-eca2-bi-directional-solar-generation-meter/

I found the whole thing a little confusing and it seems I wasn’t the only one, but since changing the way I charge the battery and fully understanding that AC charging the battery WILL result in some losses, you need to work out whether those losses are worthwhile. For me, they simply aren’t. Come winter I will perhaps charge to 40% but I primarily want to keep my FIT ticking over. My generation meter is now + 100 from -3 or so at the start of the month with overnight charging to 100%

I measured Import, Export, Net daily 10pm for 2 or 3 nights and I could see clearly the losses. For example 9kwh of Solar generation only ticked the generation NET meter up by 6kw. Taking the batteries from 10% to 100% should have been 13.5kw but in actual fact the IMPORT meter showed it took 15kw… hopefully you get the pictures. 

Maybe worth looking at your meter reading at the same time daily and compare that to what the inverter is producing to get a sense of what’s going on. I do not feel I am being penalised and my bi directional meter is doing what it’s supposed to. Remember, the meter is ONLY concerned with what goes up to your INVERTER to charge the batteries ONLY. It should be on it’s own dedicated circuit and it should NOT be looking at WHOLE HOUSE AC Import from the grid

Hey ​@David49 

I’m sorry to hear about this, I did pass your comment over to someone in the team to try and help us get to the bottom of this but they would like some more detail as it’s very hard for them to tell exactly.

I’ve sent you a Private Message to gain some details so they can try to help, you can view your PMs here.

If you are not charging from the grid, then you shouldn’t have much reduction in your generation reading. There is a + and - effect when you use surplus solar to charge the batteries but unless there is a huge amount of surplus, it would work out mostly balanced - I say mostly as you never get as much out of the batteries as you put in due to the losses (around 10%).

If you think that the negative effect on your net meter (and therefore generation reading) is significantly higher than it should be, you might want to get the cabling checked out as the grid only part of your supply to the property should not go through the net meter.

Thanks. Another respondent has similarly commented that the cabling might be wrongly connected as my negative net reading is climbing each day in this sunny weather. Have put in an urgent request to the Installer to revisit and check the wiring. Same reader sent me a schematic of the difference between the old generation meter and the bi-directional meter.  Hopefully that diagnosis is the correct one, but then I have the problem of convincing my FIT provider that the negative net reading is actually a positive one!