We've had our solar / battery for about 15 months. We are on Agile import and fixed export. 5.3kW of panels on a SE facing roof and a 13.5kW battery. We are allowed to export up to 7.3Kw to the grid. In hindsight I would have filled the other roof with NW facing panels to give greater generation throughout the day. An excellent source of info is " Gary Does Solar " on YouTube. I would recommend taking a look, so much useful information and extremely well presented and reasoned.
Solar Panels
- Thread starter Marchrider
- Start date
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OP
OP
Marchrider
Über Member
oh thats interesting, being able to have fixed for export and agile for import, that would be perfect for me
don't understand why agile export is such a poor deal - I'm sure there is something I'm not understanding
ebikeerwidnes
Guru
- Location
- Z’ha’dum
One of the things about solar is that you get data for imports export and energy used in detail
so you can spend ages on spreadsheets working out tariffs and stuff
Although - in my case - my wife never appreciates the charts and tables that I try to show her
dunno why - maybe a PowerPoint would help???
I was on Agile export for a while before switching to fixed. Agile export can be beneficial as the rates tend to be very good in the early evening when import rates are higher, but not so favourable during the rest of the day. There's not as much solar in the winter months when the daylight hours are shorter and so less generation / surplus to export ( if any ) to export at the peak rates.
With battery and solar our electricity costs last year were negative £235 -ish. We still have gas CH/HW ( though we made a conscious effort to use our electric oven / immersion etc ) This electricity credit offset a big chunk of our gas bill, so the annual cost of energy in our 3 bed mid terrace, with two pensioners usually at home for a great part of the day was a little over £200-ish.
( there's always the discussion about the initial investement and " pay back time " which I suppose is valid, but for some reason is seldom applied to other items such as gas boilers and kitchen appliances )
One final observation " fill your roof " while the scaffolding is up, as adding more panels later will be more expensive.
ebikeerwidnes
Guru
- Location
- Z’ha’dum
We have reached the time of year when I put the kettle on in the morning and the smart meter registers
32W
then zero a few seconds later
In winter - 3kW
its nice to see
32W
then zero a few seconds later
In winter - 3kW
its nice to see
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
No point for us, the roof pitch is in the wrong direction !
ebikeerwidnes
Guru
- Location
- Z’ha’dum
We had problems - the company we used managed to fit 4 facing backwards that work in the morning
and 3 more on the side which generate more as they are in Sun for longer
works well - just wish the sycamore tree out the back would fall down!!!!
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
We get sun either in the morning or afternoon - roughly east west facing roof, not south.
It may well be still worth it. The sun doesn't always shine ( especially in the UK ) and the panels generate in ambient light. PV panels are a more accurate description than " Solar Panels ". I'm in the process of evaluating the cost effectiveness of adding a further 10 panels to our NNW facing roof, It's the install cost of scaffolding etc that I'm weighing up. Good quality Solar Panels are available over the counter from places such as City Plumbing for about £60, and getting cheaper.
There's a Solar / PV forum that I'm a member of, some of the members are quite " geeky " and have quite sophisticated monitoring kit. In one recent discussion they were talking about voltage generation being seen when there was a particularly bright moon. Obviously only a very small voltage and not in anyway useable, but still present.
Alex321
Guru
- Location
- South Wales
That 10p average is the average for TODAY. It varies considerably during the year, and will often be more than the 15p you get on the fixed export tariff.
And the rates are usually higher than the daily average during the period you are most likely to be exporting - you won't be feeding to the grid in the middle of the night.
Legs
usually riding on Zwift...
- Location
- Staffordshire
We’ve got 14no 450W panels - 4no facing east (100) and 10no facing west (280). It works well because we get good production well into the late afternoon in summertime.
This was our production trace from last Tuesday.
We’ve got 10kWh of battery storage. Having an EV and a PHEV means we get to buy our electricity overnight at 7p/kWh and we sell our surplus energy at 15p/kWh. Octopus even reduced our standing charge in their latest tariff changes!
OP
OP
Marchrider
Über Member
Inverters ?
in the original proposal for 15 panels at 450w (6.75 kw) it specified a 3680w inverter,
I have now suggested 20 panels (20 * 450 = 9 kw) and he has said I will need a bigger inverter a 6000w one
why in both cases is the inverter capacity less than the possible output ?
and would an inverters lifespan likely to be longer if it was working no where near its capacity
in the original proposal for 15 panels at 450w (6.75 kw) it specified a 3680w inverter,
I have now suggested 20 panels (20 * 450 = 9 kw) and he has said I will need a bigger inverter a 6000w one
why in both cases is the inverter capacity less than the possible output ?
and would an inverters lifespan likely to be longer if it was working no where near its capacity
chris-suffolk
Über Member
Over 450 kwh so far for March - so that's about £330 I'll be paid for the month. Still 3 days to go, so may hit 500 kwh, which would be about £370. Currently get about £3200 per year so that gave me a payback of about 4 years. Just profit ever since.
ebikeerwidnes
Guru
- Location
- Z’ha’dum
That's a lot of panels
I was rather disappointed that we could only manage 7 - and then 4 facing one way and 3 another
still - you can only work with what you have got!
Alex321
Guru
- Location
- South Wales
Don't know. We have a 10kW inverter, for a 10.14kW system.
