Solar panels , would you ?

[Mudball]

I like this. But one question. How much to install the things. Will you get your money back?

Assume that you wont get your money back in short term... once you set your expectations low.... it feels like it is paying back every single day.
We are in April and this week might be the first week of the year where export > import ... it feels like a win.

 

[larmen]

Then payback depends on how much you produce , sell back, use etc. what tariff used etc

I think with current tariffs, import and export, the usage is largely irrelevant a just production is telling us when we made the money back?
We don't generate 'free energy', we generate at the export rate which we either export, or use. So it all falls out of the equation and we are left with generation only.

 

[PJ87]

I think with current tariffs, import and export, the usage is largely irrelevant a just production is telling us when we made the money back?
We don't generate 'free energy', we generate at the export rate which we either export, or use. So it all falls out of the equation and we are left with generation only.

Depends, if your usage during the day rate which is say 26p a kw that usage is worth 26p to you, where as If you sell for 15p it's worth more to use it than export it

 

[larmen]

My savings are pretty much on generation x basic rate.

We sell and buy at about 15p, but generation times 29p is the amount that matches my savings. With some rounding and tariff changes for the last 2 weeks.
That's on flux. Might be different when imo]orting at go values.

 

[PJ87]

My savings are pretty much on generation x basic rate.

We sell and buy at about 15p, but generation times 29p is the amount that matches my savings. With some rounding and tariff changes for the last 2 weeks.
That's on flux. Might be different when imo]orting at go values.

Yeah my savings are worked out on full usage times basic rate

Then I take off what I actually paid / been paid

 

[larmen]

Pretty much the same.

load: 804 kWh -> £236 this is what I would have paid at base rates
net import: 191 kWh for £42 (and falling)
saving: 613 kWh for £194

generation: 665 kwH, and at 29p that gives me the same numbers as the savings are.

Somewhere at my tariff on flux and avoiding peak time import the numbers simplify down to generation x base rate.
This could get better when exporting at peak over summer.

But I like to think that ion the battery is large enough for the peak and most of the night then it is a basic calculation.

 

[PJ87]

Pretty much the same.

load: 804 kWh -> £236 this is what I would have paid at base rates
net import: 191 kWh for £42 (and falling)
saving: 613 kWh for £194

generation: 665 kwH, and at 29p that gives me the same numbers as the savings are.

Somewhere at my tariff on flux and avoiding peak time import the numbers simplify down to generation x base rate.
This could get better when exporting at peak over summer.

But I like to think that ion the battery is large enough for the peak and most of the night then it is a basic calculation.

Another month should do it for us

I turned the heating off a couple of weeks ago. However we use the air cons to heat downstairs now for 1 hour 20 mins so that does push usage up which with a day like today means we won't export. Where as yesterday we exported 10kw (covering our import)

About may time we should at least export enough to cover usage. (Not standing charge probs but shall see, kids are at home less now so no need to cool the house for them during day)

 

[larmen]

This might be a weird question, but next road down about 15 houses got new roofs and all have these hooks on there, north and south.
Is that a mass solar install?

 

[cliveb]

Yesterday was the first day since install we had a full day of unbroken sunshine:

Interestingly, no clipping. On other days there has been obvious clipping:

I'm guessing that because of the constant sunshine, the panels got hot and became less efficient. Any other theories?

 

[Mudball]

This might be a weird question, but next road down about 15 houses got new roofs and all have these hooks on there, north and south.
Is that a mass solar install?

This should be made a standard in new builds.. in this case it might just be everyone signing via some community scheme

 

[Mudball]

Yesterday was the first day since install we had a full day of unbroken sunshine:
View attachment 52909
Interestingly, no clipping. On other days there has been obvious clipping:
View attachment 52910
I'm guessing that because of the constant sunshine, the panels got hot and became less efficient. Any other theories?

I must admit I had never heard about Solar clipping..

Possible 1: Is your Inverter size big enuf to convert ? We had to get permission to install a 5k invertor due to 16 panel .. something to check out .. https://thriftenergy.co.uk/blog/solar-clipping-what-is-it-and-how-can-you-avoid-it/

…and when I read about it, I thought it would never happen to me. So I had to investigate. Looks like I have the same issue!! My theory is slightly different… unfortunately due to the orientation of our roof, we hit partial shade due to some tall tree from our neighbors garden. Prior to the install, I never thought about how much shade the roof gets. Unbroken sunlight may not mean your roof is soaking in it… This might explain why our output drops (but I could be wrong)

 

[cliveb]

I must admit I had never heard about Solar clipping..

Possible 1: Is your Inverter size big enuf to convert ? We had to get permission to install a 5k invertor due to 16 panel .. something to check out .. https://thriftenergy.co.uk/blog/solar-clipping-what-is-it-and-how-can-you-avoid-it/

I have a 3.6kW inverter. That's (close to?) the maximum allowed without special permission. There are 9 x 415W panels, so up to 3.735kW potential, hence the clipping. The fact I have occasional clipping isn't a surprise. What was a surprise was that the peak output yesterday was 3.45 kW. Plenty of clipping again today (which has had periods of cloud as well as full sun).

My theory is slightly different… unfortunately due to the orientation of our roof, we hit partial shade due to some tall tree from our neighbors garden.

I have a very small amount of shading on the early morning before the sun gets high enough to peek over part of the roof, but no other shading at all.
In any case, clipping happens when the panels are generating more than the inverter can handle, so shading isn't anything to do with it.

Edit: just took a closer look at your graph. You appear to have some clipping at a lower total output (around 2.6kW) than at other times (output close to 2.9kW). That's weird. Can't fathom why that happens.

 

[Mudball]

I have a 3.6kW inverter. That's (close to?) the maximum allowed without special permission. There are 9 x 415W panels, so up to 3.735kW potential, hence the clipping. The fact I have occasional clipping isn't a surprise. What was a surprise was that the peak output yesterday was 3.45 kW. Plenty of clipping again today (which has had periods of cloud as well as full sun).

I have a very small amount of shading on the early morning before the sun gets high enough to peek over part of the roof, but no other shading at all.
In any case, clipping happens when the panels are generating more than the inverter can handle, so shading isn't anything to do with it.

Edit: just took a closer look at your graph. You appear to have some clipping at a lower total output (around 2.6kW) than at other times (output close to 2.9kW). That's weird. Can't fathom why that happens.

I need to first investigate how to investigate I have some serious shade from neighbors trees. Maybe the sun peeks out between the leaves and shoots the output.. I will post some more readings. I have a 5.x Invertor

 

[cliveb]

I need to first investigate how to investigate I have some serious shade from neighbors trees. Maybe the sun peeks out between the leaves and shoots the output.. I will post some more readings. I have a 5.x Invertor

Do you have two separate strings of panels? Perhaps the graph is for one string, and where it's clipping (at only 2.6kW) the total of both strings has reached the maximum for the whole inverter, while where it goes up to 2.9kW is when the other string isn't generating enough to max out the total capacity?

 

[Mudball]

Do you have two separate strings of panels? Perhaps the graph is for one string, and where it's clipping (at only 2.6kW) the total of both strings has reached the maximum for the whole inverter, while where it goes up to 2.9kW is when the other string isn't generating enough to max out the total capacity?

yes i do.. it shows up as PV1 and PV2... but both go into the same invertor. When we were installing, i was trying to see if we could get some panels on the south-west facing slow - it gets max sun after 3pmish. but they turned it down. Apparently it would need new invertor and would not feed our battery bank.

 

[Mudball]

Do you have two separate strings of panels? Perhaps the graph is for one string, and where it's clipping (at only 2.6kW) the total of both strings has reached the maximum for the whole inverter, while where it goes up to 2.9kW is when the other string isn't generating enough to max out the total capacity?

I was looking at this from a production pov.. from the website data.

 

[Robster59]

Costco have various offers on Solar panels.
Knowing nothing about this sector, I just wondered if these were good deals or not?
Costco Solar Panels

 

[PJ87]

Costco have various offers on Solar panels.
Knowing nothing about this sector, I just wondered if these were good deals or not?
Costco Solar Panels

Costco price wise will be very good however what's key in this sector (much like heat pumps) is the install side. Too many cowboys out there and Costco will be subcontracted

For example my Costco might have excellent people but yours could be rubbish etc

I'd look at companies that specialise in them and ask for examples of their work

 

[Robster59]

Costco price wise will be very good however what's key in this sector (much like heat pumps) is the install side. Too many cowboys out there and Costco will be subcontracted

For example my Costco might have excellent people but yours could be rubbish etc

I'd look at companies that specialise in them and ask for examples of their work

Well the price says "fully installed" and it says "Installed, commissioned and tested by a fully qualified team to ensure MCS compliance" so that should cover those concerns.
Mind you, they are charging an additional £430 to deliver into Scotland.

 

[Mudball]

Well the price says "fully installed" and it says "Installed, commissioned and tested by a fully qualified team to ensure MCS compliance" so that should cover those concerns.
Mind you, they are charging an additional £430 to deliver into Scotland.

Is that to offset the lack of sun in Scotland?