Solar panels , would you ?

[PJ87]

had our survey done... apparently we should be able to generate 5.3kWH... all inclusive for 16 panels, inverter, 6k battery, bird proof and EV charger - it works out about 12.5k
Now the big Q is how quickly will our payback be.. i am assuming atleast 7-8 years

I can do you a copy of my payback sheet if you want using Google sheets , I can do it prob Sunday , just need to perfect it for other people's data

Btw will they wire it so the charger can use excess solar? I'm sure they can do so the battery doesn't charge the car if you need which is good because it's very inefficient to use a battery to charge a battery

 

[D-S]

had our survey done... apparently we should be able to generate 5.3kWH... all inclusive for 16 panels, inverter, 6k battery, bird proof and EV charger - it works out about 12.5k
Now the big Q is how quickly will our payback be.. i am assuming at least 7-8 years

In reality you will need to factor in potential interest earned as rates are higher. For example £12.5k at 4% for 8 years would give you £17.2k.

 

[PJ87]

In reality you will need to factor in potential interest earned as rates are higher. For example £12.5k at 4% for 8 years would give you £17.2k.

Yes but how much tax aswell ...

Also you need to factor in each year you make so much back which can be returned to the savings

In reality over 25 years panels save a lot more than interest rates

 

[D-S]

Yes but how much tax aswell ...

Also you need to factor in each year you make so much back which can be returned to the savings

In reality over 25 years panels save a lot more than interest rates

Obviously if you are already using your ISA allowance every year tax would be an issue - but talk of advantage over 25 years versus suggestions of 7-8 year pay backs are slightly different.

 

[PJ87]

Obviously if you are already using your ISA allowance every year tax would be an issue - but talk of advantage over 25 years versus suggestions of 7-8 year pay backs are slightly different.

Yes but once paid back that's not just it... It's the fact that in say 25 years you have made that 12k back plus 12k again..

Once my system pays for itself if prices did remain this stupid high I'd pay £50 pm for my high usage instead of £200

That's a massive saving

 

[Tashyboy]

had our survey done... apparently we should be able to generate 5.3kWH... all inclusive for 16 panels, inverter, 6k battery, bird proof and EV charger - it works out about 12.5k
Now the big Q is how quickly will our payback be.. i am assuming atleast 7-8 years

If anyone can give an estimate to within 1 year I will show my backside in Woolley’s.
The problem being that at how do we know what will be paid out per KW etc. how mush will electricity be in 18 months, how much sunshine will we get to generate solar. Etc etc etc.
Having said that. My panels are now generating over 66p per KW and when I started it was 40 odd pence per KW. No one in their wildest imagination thought it would be this high. It is raking in money for me. I think you should be in a very happy place.

 

[Mudball]

If anyone can give an estimate to within 1 year I will show my backside in Woolley’s.
The problem being that at how do we know what will be paid out per KW etc. how mush will electricity be in 18 months, how much sunshine will we get to generate solar. Etc etc etc.
Having said that. My panels are now generating over 66p per KW and when I started it was 40 odd pence per KW. No one in their wildest imagination thought it would be this high. It is raking in money for me. I think you should be in a very happy place.

pl dont carry out the threat of going into a Wolleys.. but i am not entirely sure how this calculation was done by the surveyor.
Our installed capacity is 6.8k... our estimated output is 5358kwh.. our annual consumption is 4227kwh

 

[PJ87]

pl dont carry out the threat of going into a Wolleys.. but i am not entirely sure how this calculation was done by the surveyor.
Our installed capacity is 6.8k... our estimated output is 5358kwh.. our annual consumption is 4227kwh

View attachment 49265

My yearly usage they estimated was spot on for first year tbh

 

[cliveb]

My yearly usage they estimated was spot on for first year tbh

When you say they estimated your yearly usage, do you mean they estimated how much of your panel generation would be used rather than exported? If they got that spot on, it's a remarkable achievement. I would guess being within 20% would be pretty good - usage patterns can vary quite a lot.

I'm about to have a modest 3.7kW system installed, and they have predicted about 4000kWh generation of which I will consume about 1600. It will be interesting to see how accurate that is.

 

[GreiginFife]

pl dont carry out the threat of going into a Wolleys.. but i am not entirely sure how this calculation was done by the surveyor.
Our installed capacity is 6.8k... our estimated output is 5358kwh.. our annual consumption is 4227kwh

View attachment 49265

Emm, I’m no mathematician but that cost saving looks a bit, how shall we say… optimistic. I think they might have a decimal point in the wrong place.

Surely they have multiplied by 29 rather than 0.29 meaning it’s nearer £932.

 

[PJ87]

When you say they estimated your yearly usage, do you mean they estimated how much of your panel generation would be used rather than exported? If they got that spot on, it's a remarkable achievement. I would guess being within 20% would be pretty good - usage patterns can vary quite a lot.

I'm about to have a modest 3.7kW system installed, and they have predicted about 4000kWh generation of which I will consume about 1600. It will be interesting to see how accurate that is.

It's pretty easy to work out now. They put into computer software and how many panels , the angle, direction then compare to previous years sunlight

They were within 200 kw for production.. as in I went over what they told me they would

 

[larmen]

It's pretty easy to work out now. They put into computer software and how many panels , the angle, direction then compare to previous years sunlight

They were within 200 kw for production.. as in I went over what they told me they would

A work colleague got solar and thinks they have to low ball their estimate. Is there a regulator who gives them the formulas for a bad weather year?
She says they were ahead last year on a good year, and this year so far they are on it on a bad summer.

We get their company to come around check out ours. From a preliminary I think they could fit 7 easily, they think they can fit 8 panels. Roof is too short to stack 2 over each other.

Putting the stuff in their software, we got a 33 pitch and a 35 degree to south west we can’t quite 100% fulfil ours, but we get quite close.

Btw, just checking our dailies on Octopus, and on days we are not in at all we use 5.2 kWh of electricity, on days we peak we use 15 kWh.
Is our base load too high? It seems so to me.

 

[PJ87]

A work colleague got solar and thinks they have to low ball their estimate. Is there a regulator who gives them the formulas for a bad weather year?
She says they were ahead last year on a good year, and this year so far they are on it on a bad summer.

We get their company to come around check out ours. From a preliminary I think they could fit 7 easily, they think they can fit 8 panels. Roof is too short to stack 2 over each other.

Putting the stuff in their software, we got a 33 pitch and a 35 degree to south west we can’t quite 100% fulfil ours, but we get quite close.

Btw, just checking our dailies on Octopus, and on days we are not in at all we use 5.2 kWh of electricity, on days we peak we use 15 kWh.
Is our base load too high? It seems so to me.

My base load is 8kw a day which is high

They low ball I believe as it's better to predict too low than too high and not meet it

I mean they do lots of things to make sure they meet

I know my panel can produce more than my micro inverters can convert but the idea is when the panel ages even at 80% efficient it's producing the same amount as day one

You don't want to predict really high and not deliver

 

[cliveb]

It's pretty easy to work out now. They put into computer software and how many panels , the angle, direction then compare to previous years sunlight

They were within 200 kw for production.. as in I went over what they told me they would

Ah right, so they were predicting your yearly generation. Yes, that's easy.

What's not easy is to predict how much of that generation you get to use (with to the rest being exported).

 

[PJ87]

Ah right, so they were predicting your yearly generation. Yes, that's easy.

What's not easy is to predict how much of that generation you get to use (with to the rest being exported).

Yes they predicted I would use all but 100kw of it I think

Have to admit now I have the battery my export is very low so their predictions are closer altho I am still wasting export

If I ran down the battery more and left space for excess solar then wouldn't export but it's more cost efficient to leave it full up and save ever paying that high rate

Another example in the summer months running the tumble unless it's using solar it's more cost efficient to run it in the cheap hours as whilst you recharge the same energy there is a say 10% drop off in efficiency compared to just using it

 

[larmen]

Have you considered a solar converter for your hot water? Eddie(?)

I saw a YouTube video that it might not be worth it at certain export tariffs and only marginally on others.

 

[cliveb]

Another example in the summer months running the tumble unless it's using solar it's more cost efficient to run it in the cheap hours as whilst you recharge the same energy there is a say 10% drop off in efficiency compared to just using it

Wouldn't the most efficient use of solar in the summer to dry your washing be to hang it on the line?

 

[PJ87]

Wouldn't the most efficient use of solar in the summer to dry your washing be to hang it on the line?

The system has its holes but she likes to do washing 7pm every night and dry for morning to put away before work

 

[full_throttle]

September update,

August bill is
Elec £18.25
Gas £18.57

Exported 1/7 - 31/7 £25.73
Exported 1/8 - 31/8 £24.45

So far I have exported £86.76 and the two above, about £135 since late April £

I think that means after exporting, I am being charged about £13 for the months usage of gas and electric inc daily standing charge,

I have a long way to go until the panels are paid off but I'm quite happy I made the decision to go Solar

 

[PJ87]

September update,

August bill is
Elec £18.25
Gas £18.57

Exported 1/7 - 31/7 £25.73
Exported 1/8 - 31/8 £24.45

So far I have exported £86.76 and the two above, about £135 since late April £

I think that means after exporting, I am being charged about £13 for the months usage of gas and electric inc daily standing charge,

I have a long way to go until the panels are paid off but I'm quite happy I made the decision to go Solar

We went away in August for a week so I set the powerwall to self power mode. No grid charging at all for a week

Litterally just charged 42p a day for standing charge and made a bit in export (not enough to cover all the standing)

Anyways Augusts bill was as follows

Bill £52.52
Export £5.59

Total usage 784.9 kw

Cost without set up £241.12

£194.19 saved this month

Year 1 saving (may to april) was £1258

Year 2 saving (may to August) stands at £922

£13140 left until break even , approx 7 years from now .. 8 year total