Negative Revenue

[Jimmyrn85]

Good morning all, I have a newly installed system on the garage with a Fox H1 G2 5.0kw inverter. 7x 445w panels at the moment but there is plenty of scope for adding more down the line.

I have setup in the app my tariff, which is purchasing lecci from the grid at 0.239pence per kw/h.

For context, I have an existing "rent-a-roof" system which was installed before I purchased this house and the lease has 12 years to run, therefore I cannot be paid for any export I produce, that all goes to the "rent-a-roof" company. I just get to use any lecci I want. I will install a battery on the Fox system at some point.

So with that in mind, why do I get the odd days showing negative revenue? What is that? I would like it to show me for every kw/h produced by the new system that I've saved 23.9pence.

Your advice/thoughts would be appreciated!

[Will]

can you post a screen shot of the energy flow page so I can confirm how your system is setup.
The short version is the inverter will be recording it's generation without any additional action.

[Jimmyrn85]

Hi Will, this page?

So do you mean by that, the negative value could be the cost of just running the inverter on days when there is no sun?

[MaterialBarracuda48]

Not that page, that is your "home" screen.

Swipe right to left, then scroll to bottom to see the energy graph.

[Jimmyrn85]

Thanks, here is a screenshot of the month, and of the 27th day which had a negative revenue of 17pence.

[MaterialBarracuda48]

Thanks, here is a screenshot of the month, and of the 27th day which had a negative revenue of 17pence.

You are welcome, I will let Dave or Will respond with better information than I can provide.

[WyndStryke]

So do you mean by that, the negative value could be the cost of just running the inverter on days when there is no sun?

My system has a parasitic loss of about 100W 24/7, so 2.4kWh in a day. That's a KH7 with 15kWh of usable battery in an EC4300 stack. Each system will have a different parasitic loss, based on the number of computers in it, the firmware versions, etc.

and the lease has 12 years to run, therefore I cannot be paid for any export I produce, that all goes to the "rent-a-roof" company.

There might be scope for going from deemed export to measured export, which could let you claim for the generation from your own array. It'd depend on the original contract with the rent-a-roof people. Probably best talking to an expert on that.

[PhilipLBrown]

Good morning all, I have a newly installed system on the garage with a Fox H1 G2 5.0kw inverter. 7x 445w panels at the moment but there is plenty of scope for adding more down the line.

I have setup in the app my tariff, which is purchasing lecci from the grid at 0.239pence per kw/h.

For context, I have an existing "rent-a-roof" system which was installed before I purchased this house and the lease has 12 years to run, therefore I cannot be paid for any export I produce, that all goes to the "rent-a-roof" company. I just get to use any lecci I want. I will install a battery on the Fox system at some point.

So with that in mind, why do I get the odd days showing negative revenue? What is that? I would like it to show me for every kw/h produced by the new system that I've saved 23.9pence.

Your advice/thoughts would be appreciated!

[Jimmyrn85]

Interesting WyndStryke, thanks for the response.

Philip, I don't see a reply?

[Jimmyrn85]

Hi all, yesterday we had a decent day of sunshine down in Devon and generated a chunk of lecci.

It's given me negative 55pence in the app revenue. How does that work and what does that mean?

Is there some confusion with the rent-a-roof system going on?
I see PV production for the Fox system as 5.10kWh
To Grid 7.40 kWh
Load Consumption 7.40kWh
From Grid 9.70kWh

[retsplines]

I think the language they use around this part of the system is a bit weird.

"Revenue" as far as Fox is concerned is basically:

The "would-be" cost of any energy you generated on-site and used (they call this "Solar Savings")
plus The profit from any feed-in
minus The cost of any energy used to charge the battery from the grid.

The last two items combined are called "Feed-in Revenue" by Fox.

Here, your "Solar Savings" are showing as negative, which is a bit weird... The only way I can think of that happening is if the tariffs are configured strangely (negative buying price for a period for example)... Maybe post a screenshot of the Tariff page (from the App home screen, tap Total Revenue, then tap Tariff top right, then tap on the tariff plan you have set up there, and screenshot the chart shown?)

[Jimmyrn85]

Thanks, appreciate any help or insight you can give me because I'm finding it odd too!!

I updated the tariff page, it was set at 0.239pence per kWh a couple days ago but actually we purchase lecci at 0.251pence so I've now updated that see my attached screenshot.

Since this small system has been installed in early Jan, the PV production has been 55.40kWh.

So I would expect it to say £13.90 (55.40x0.251) worth of lecci has been generated since installation - appreciate we won't use every last ounce of it sometimes but it would give a bit of indication anyway