Solaredge and Batteries

[Heliox]

I see you have Perlight panels, how have you found them to work for you?

Performs well, especially in summer, but we could do with more early morning generation to top the batteries back up after a night of discharging.

I'm also hoping that we can get more winter generation. At the moment production falls off a cliff in October, with next to bugger all through until March. A little bit more could reduce the time we have to run from the grid in winter, perhaps knocking a couple of weeks off either end of the winter "dead period".

Those were my concerns and why I went for SolarEdge optimisers and 14.4kw of panels, If I can pull 2kw at any given moment through winter then I would be happy as we could run most used appliances from that.

I see Viridian are a complete PV panel system (unless there are two Viridians) and not Trays like the GSE, so no good for me as I already have the PV panels.

[Oldgreybeard]

Those were my concerns and why I went for SolarEdge optimisers and 14.4kw of panels, If I can pull 2kw at any given moment through winter then I would be happy as we could run most used appliances from that.

I see Viridian are a complete PV panel system (unless there are two Viridians) and not Trays like the GSE, so no good for me as I already have the PV panels.

I think you're being a bit optimistic to expect 2kW at any time in winter, even with the larger system, TBH. Our system is smaller, at 6.25kWp, but there are plenty of days when we struggle to generate more than around 300W to 400W, in fact we had a day like this only last week where the most we saw was about 420W. Generation falls off a cliff in the UK around October, and doesn't really pick up again until around March. The ratio of June generation to December generation for our system is roughly 4 to 1, so we might generate around 6.4kWh/day on average in December (good day might be 10kWh, bad day might be only 2kWh), but we usually manage to average around 24kWh/day through June to August.

Have you run your system through PVGIS to get an estimate of generation? Worth doing if you haven't, as PVGIS tends to be pretty accurate.

[nowty]

The PVGIS website, Oldgreybeard mentioned.
https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

If you give your approximate location I can stick an image of your expected generation on here.

[Heliox]

Those were my concerns and why I went for SolarEdge optimisers and 14.4kw of panels, If I can pull 2kw at any given moment through winter then I would be happy as we could run most used appliances from that.

I see Viridian are a complete PV panel system (unless there are two Viridians) and not Trays like the GSE, so no good for me as I already have the PV panels.

I think you're being a bit optimistic to expect 2kW at any time in winter, even with the larger system, TBH. Our system is smaller, at 6.25kWp, but there are plenty of days when we struggle to generate more than around 300W to 400W, in fact we had a day like this only last week where the most we saw was about 420W. Generation falls off a cliff in the UK around October, and doesn't really pick up again until around March. The ratio of June generation to December generation for our system is roughly 4 to 1, so we might generate around 6.4kWh/day on average in December (good day might be 10kWh, bad day might be only 2kWh), but we usually manage to average around 24kWh/day through June to August.

Have you run your system through PVGIS to get an estimate of generation? Worth doing if you haven't, as PVGIS tends to be pretty accurate.

Yes funnily enough I done a forecast on PVGIS a few nights ago. But I am not that familiar and was following the method used but somebody online so one can never be sure if you have done it correctly.

I think I got the input parameters right, or there about?

An image is below of the forecast.
Worse month is December at 400Kwh for the month.

I got my hopeful 2KW a day from January which says 472Kwh.

So I roughly divided by 30 days and divided by 8 hrs and got 1.96 kwh per hour or 16Kwh per day.
(reality is it's probably going to be more like 6 hrs per day)



I know I am being very optimistic but as I am self installing and throwing up as many panels as I can, then short of mounting more in the garden I am getting as much of my moneys worth as is humanly possible.

How it performs is anyone's guess and you are the second person to tell me how bad PV is in UK winters, In fact I spoke to someone two miles away and he said the same with a 4kw system. So I am preparing for a disappointment but know at least several months of the year I am going to be self sufficient.

[Heliox]

The PVGIS website, Oldgreybeard mentioned.
https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

If you give your approximate location I can stick an image of your expected generation on here.

Thanks Nowty, I have posted up last posting.

[nowty]

The PVGIS website, Oldgreybeard mentioned.
https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

If you give your approximate location I can stick an image of your expected generation on here.

Thanks Nowty, I have posted up last posting.

PVGIS can be over optimistic for winter and especially if your going to have shading because of a hill. Plus the % variance in winter from one year to the next is larger than the summer.

[Oldgreybeard]

The PVGIS plot looks about right. 402kWh for December compares reasonably well with our figure of 195kWh for December from a smaller system. I know for sure that we have loads of days in winter when we struggle to get above about 500W all day, so using the ratio of December generation for the two systems I would say that you will have lots of winter days when you struggle to get above about 1kW. I think 2kW is very much a pipe dream for any sort of guaranteed output in winter, TBH. May be some days in winter when you see way more than 1kW, but equally there will be days when you probably see less. The ratio between good and bad days can easily be three or four to one in terms of output. For example our best summer day can deliver around 40kWh, but we can easily get days like one last week where we only generated around 9kWh. Same applies in winter, but with levels that are around one quarter of those in midsummer.

[Fintray]

I've had a look at the APS facility in the Solaredge inverters (the firmware version in my Solaredge inverters precedes that change) and how it can be used with the Victron units but noticed that there is a limit on the connected PV see https://www.victronenergy.com/live/ac_coupling:start.
Personally I would look at getting started on the roof asap an end up with the system as you want it without going through a few stages.

[Heliox]

The PVGIS plot looks about right. 402kWh for December compares reasonably well with our figure of 195kWh for December from a smaller system. I know for sure that we have loads of days in winter when we struggle to get above about 500W all day, so using the ratio of December generation for the two systems I would say that you will have lots of winter days when you struggle to get above about 1kW. I think 2kW is very much a pipe dream for any sort of guaranteed output in winter, TBH. May be some days in winter when you see way more than 1kW, but equally there will be days when you probably see less. The ratio between good and bad days can easily be three or four to one in terms of output. For example our best summer day can deliver around 40kWh, but we can easily get days like one last week where we only generated around 9kWh. Same applies in winter, but with levels that are around one quarter of those in midsummer.

I think from your clear ''at the coal face'' experience shows a good argument for battery storage so that at least what you get is useable even if stored in a battery for use later rather than fed to the grid.

[Heliox]

I've had a look at the APS facility in the Solaredge inverters (the firmware version in my Solaredge inverters precedes that change) and how it can be used with the Victron units but noticed that there is a limit on the connected PV see https://www.victronenergy.com/live/ac_coupling:start.
Personally I would look at getting started on the roof asap an end up with the system as you want it without going through a few stages.

Thanks for your post, very helpful, I had to find out what 'APS facility' was first?
Which actually led me to this:

https://www.victronenergy.com/live/venu ... _solaredge

Eureka! seems like Victron and Solaredge have already ticked these boxes for what I am looking for