Solar PV target price

Solarchaser

I have a wsw as part of my array and to be honest its probably the most relevant,  as its the one still producing in the evening at meal and dishwasher times.
Also I'd imagine a steep angle would be very helpful in the dead of winter when the sun angle is low.

Not sure how big a difference wnw would be to wsw to be honest. 
My ene array doesn't do too well, but it suffers from a lot of shading.

For the efficiency,  obviously higher is better, but only you can decide how much is worth it.
A 25 year guarantee is great... but are you likely to use it?
I'd expect the install company to have been phoenix'd a half dozen times by that point making the warranty pretty much null imo.

I guess if it was say £5k for normal panels and 5.2k for super ones, id get the super ones, but if its 6k for super, id stick with normal.

3.6kw is what most people tend to have, but personally id always advise to get more on the roof if you can.

Also as someone often woken up by the bloody pigeons cooing, id strongly advise to make pigeon proofing part of the install.

Hexane

I think my panels may be LG, can't remember. They did come with very lengthy manufacturer warranty and performance warranty. Not sure anyone would be bothering to make a complaint about that after using them for 20+ years though. I dont think I paid much extra for the panels being that make.

One company advised me against using my east roof that is rather north of east. I ignored their advice in order to get ten extra panels on. The aim being to go as big as we thought the DNO would let me, both for improving break even points, but also to make it more useful for future plans like charging an electric vehicle (not happened yet, but only a few years in).

The comment about a steep pitch roof being good for winter sun is correct, but if it's partly north facing then I don't think it will see the sun in winter. For summer evenings it will be great (my east-with-north panels generate way too much in early summer mornings before I'm even awake.)

My view generally is, if you can afford the extra panels without having to get an interest-bearing loan, then get them.

Martyn1981

The previous posts nail this, for max gen you want shallow pitch E/W rooves, as they don't see much of the sun in the winter when steep panels would benefit from a low sun angle.

I just tried my WNW (+110d) set up on PVGIS and the 30d roof gives 733kWh/kWp, but a 50d pitch is 651.

However, it's never as simple as that. You need to consider the lower generation in context with the marginal cost of the extra panels. If you are definitely doing the other roof(s) then that cost is committed, so adding panels to the WNW will be relatively cheap in comparison and may make up for the lower gen.

And as others have said, you typically want as much PV as possible, and personally west generation is really cool, at this time of year I can be exporting (not importing) well into the evening thanks to the WNW boost. I think on their own, they don't make sense, but as part of a well balanced package, you will appreciate them.

BTW PV panel degradation seems to have fallen considerably. Pre 2000 panels were about 0.8% pa, but post 2000 silicon panels were down to 0.34% (off the top of my head). That study was done about 5+yrs ago, and PV production now is very different to the early 2000's.

JKenH

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

M0ney

JKenH said:

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

Can I ask, what software do you use to monitor your generation? I bought a dongle which connects to my inverter it was something like £85 and I've never been able to get the app on my phone to connect to it.   It's called Ginlong, I think. 

JKenH

M0ney said:

JKenH said:

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

Can I ask, what software do you use to monitor your generation? I bought a dongle which connects to my inverter it was something like £85 and I've never been able to get the app on my phone to connect to it.   It's called Ginlong, I think. 

I’ve forgotten the procedure for connecting  but I have Wi-fi dongles on both my inverters and I think you enter their details when you register.  It is Ginlong software. This is the page to register
https://www.ginlongmonitoring.com/

M0ney

JKenH said:

M0ney said:

JKenH said:

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

Can I ask, what software do you use to monitor your generation? I bought a dongle which connects to my inverter it was something like £85 and I've never been able to get the app on my phone to connect to it.   It's called Ginlong, I think. 

I’ve forgotten the procedure for connecting  but I have Wi-fi dongles on both my inverters and I think you enter their details when you register.  It is Ginlong software. This is the page to register
https://www.ginlongmonitoring.com/

Yeah I did this, and I was never able to get it to work. I'll need to call them up.

JKenH

M0ney said:

JKenH said:

M0ney said:

JKenH said:

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

Can I ask, what software do you use to monitor your generation? I bought a dongle which connects to my inverter it was something like £85 and I've never been able to get the app on my phone to connect to it.   It's called Ginlong, I think. 

I’ve forgotten the procedure for connecting  but I have Wi-fi dongles on both my inverters and I think you enter their details when you register.  It is Ginlong software. This is the page to register
https://www.ginlongmonitoring.com/

Yeah I did this, and I was never able to get it to work. I'll need to call them up.

Have you tried the instructions in this link?

https://www.nuvisionenergy.co.uk/index.php?route=pavblog/blog&id=31

M0ney

JKenH said:

M0ney said:

JKenH said:

M0ney said:

JKenH said:

Apologies for digressing earlier. I have WSW and ENE slopes, about 15 degrees off the cardinal points. In terms of overall kwh generated that is a distinct disadvantage compared to a vaguely South facing roof. The six weeks either side the winter solstice are a waste of time. I have a 39* pitch and the sun never gets at a good angle to it in winter. As has been said with these orientations an almost flat roof would be ideal. The steeper the roof the more time the one of the slopes is in shade so you have a shorter window of useful generation. My ENE roof peaks around 9.30 am and in winter the sun at that time is so low in the sky that its rays have to travel through a lot of atmosphere to get there. By the time the sun is higher in the sky at noon it is only striking the roof a glancing blow.

In the summer it is a different story with 2kw for in the region of 12 hours. Great for breakfast and tea. (3kw around 6pm). Anyone with a south facing roof misses out on this early morning and evening sun. 

When it is really cloudy orientation is almost irrelevant and You just want as many panels as possible. 

If you want to use the Pv as it is generated go for an E/W split but if you have a battery you will be better with a south facing roof as you get more kwh/kwp all year round. 

Costs - aim for around £1000/kwp. My 7.8kwp installation ended up costing me £7k in 2018.

With hindsight I often wish I had gone for a solar edge system. I don’t have major shading issues except early morning but just my view in looking at generation figures achieved the solar edge system is a benefit. Others may say the additional cost isn’t worth it. 

One last thing if you have a 5kw system split E/W you would probably manage with a 3.6kw inverter or even smaller. My ENE roof inverter at 3.6 kw for 3.6kwp panels is way too big and contributes to poor efficiency in the winter. I get a sustained 4.6kw from my 7.8kwp of panels in summer with the odd short lived peak on intermittently cloudy days of 6kw. 

Edit

These are the generation curves from my ENE and WSW roofs on a clear October day.

ENE roof 3.6 kwp

WSW roof 4.2kwp

Note the difference in peak power. 2.8kw from 4.2 kwp WSW roof (0.67 kw/kwp) compared to 1.8kw from 3.6kw/kwp from ENE roof (0.5 kw/kwp). A neighbour 100 m away with a SSE facing roof  had peak generation of 3.34kw (0.835kw/kwp).

My combined generation from the 2 roofs was 18.71kwh (2.40 kWh/kwp) compared to 19.17 kwh from the 4kw SSE roof (4.79kw/kwp). The SSE roof was twice as efficient.

The previous day when it was showery my roof had generated 5.12 kwh (0.66kwh/kwp) while my neighbour generated 3.12 (0.78 kWh/kwp) so you will see the difference in efficiency is much less in poor weather.

In May this year my best day’s generation was 45.72 (5.86 kWh/kwp) compared to my neighbour’s at 28.93 (7.23 kWh/kwp). I had over 2kw from before 7am to after 7pm while my neighbour had 2kw from 8.30am to 4.15pm. My peak generation was 4.5 kw (0.58 kw/kwp) compared to my neighbour’s 3.57 kw (0.89 kw/kwp)

Can I ask, what software do you use to monitor your generation? I bought a dongle which connects to my inverter it was something like £85 and I've never been able to get the app on my phone to connect to it.   It's called Ginlong, I think. 

I’ve forgotten the procedure for connecting  but I have Wi-fi dongles on both my inverters and I think you enter their details when you register.  It is Ginlong software. This is the page to register
https://www.ginlongmonitoring.com/

Yeah I did this, and I was never able to get it to work. I'll need to call them up.

Have you tried the instructions in this link?

https://www.nuvisionenergy.co.uk/index.php?route=pavblog/blog&id=31

It looks familiar, I'm not home again until Friday, I need to get on it again because I would really like to be able to log my generation, I'm a bit of a geek that way.

M0ney

Looks like it's working after trying again, not sure what I did different this time. My question now is, will the data be sent to the app on my phone when I am not connected to my wifi, I'm regularly away from home for weeks at a time, will the data go to my phone when I'm away and if not will it refresh all the data when I get home and reconnect to the wifi at home?