cliveb
Head Pro
I doubt the old house had a cutout switch - it even had an old fusebox with actual wire fuses before we upgraded it!
I'm guessing that perhaps the regs might have changed in the last 12 years.
Solar panels , would you ?
- Thread starter spongebob59
- Start date
I'm guessing that perhaps the regs might have changed in the last 12 years.
cliveb
Head Pro
The electrician came today to sort out as much as possible prior to National Grid installing this isolation switch, so I asked him about it.
He said that it was needed because he's not allowed to touch the 100A fuse. And National Grid have to install it because the 100A fuse needs to be removed in order to do so.
The implication being the switch is needed because he must disconnect the house from the grid while commissioning the PV system.
When I mentioned that my previous PV system (installed in 2011) didn't need an isolation switch, he speculated that perhaps they removed the 100A fuse themselves, but it's something he's not allowed to do.
So this new PV system is going to have FOUR isolation switches:
- DC between panels and inverter
- AC between inverter and generation meter
- another AC between generation meter and consumer unit
- this other one (AC) between consumer unit and import/export meter
Seems a bit OTT, but I guess electricity needs to be treated with respect.
He said that it was needed because he's not allowed to touch the 100A fuse. And National Grid have to install it because the 100A fuse needs to be removed in order to do so.
The implication being the switch is needed because he must disconnect the house from the grid while commissioning the PV system.
When I mentioned that my previous PV system (installed in 2011) didn't need an isolation switch, he speculated that perhaps they removed the 100A fuse themselves, but it's something he's not allowed to do.
So this new PV system is going to have FOUR isolation switches:
- DC between panels and inverter
- AC between inverter and generation meter
- another AC between generation meter and consumer unit
- this other one (AC) between consumer unit and import/export meter
Seems a bit OTT, but I guess electricity needs to be treated with respect.
PJ87
Journeyman Pro
Our techs installed the isolation switch themselves , same as the car charger man by pulling the fuse . It seems some are either allowed or don't worry too much about it
We have a few isolators , one on battery. One on solar, cut out switch
There is even a switch in the gateway for the battery that it switches over if the power gets cut to island me to be able to use solar and battery
Otherwise would have to go dead in that power cut
They really don't take any chances
cliveb
Head Pro
The fuse in my meter box is locked with a loop of wire and a metal "seal" that has some kind of logo on it. If someone cuts off that wire to pull the fuse, I doubt they will have the correct seal to restore it. Did your fuse have this arrangement, and did the techs replace it?
Maybe it depends where you are in the country and how controlling the DNO is. (My DNO is Western Power Distibution).
Or maybe your techs decided to take a chance and hope the DNO never spots what they've done?
larmen
Head Pro
My electrician has just cut it and pulled the fuse to change the tails and install an isolator.The fuse in my meter box is locked with a loop of wire and a metal "seal" that has some kind of logo on it. If someone cuts off that wire to pull the fuse, I doubt they will have the correct seal to restore it. Did your fuse have this arrangement, and did the techs replace it?
Maybe it depends where you are in the country and how controlling the DNO is. (My DNO is Western Power Distibution).
Or maybe your techs decided to take a chance and hope the DNO never spots what they've done?
I asked the DNO about it before and they said they don’t like it, but they understand when electricians do it to work save. So I guess it is tolerated by them.
PJ87
Journeyman Pro
The fuse in my meter box is locked with a loop of wire and a metal "seal" that has some kind of logo on it. If someone cuts off that wire to pull the fuse, I doubt they will have the correct seal to restore it. Did your fuse have this arrangement, and did the techs replace it?
Maybe it depends where you are in the country and how controlling the DNO is. (My DNO is Western Power Distibution).
Or maybe your techs decided to take a chance and hope the DNO never spots what they've done?
There is a seal sticker on mine I believe , think they have access to the stickers not sure
However I know some sparks call the dno before pulling it
When I had my consumer unit replaced (post cut out switch) we cut the switch out. Cut the battery out. Solar out etc so house is dead
He was saying he would pull the fuse anyways as extra protection
His life I guess but did seem bit much lol
Fade and Die
Medal Winner
This is it exactly, most electrician’s will just pull the fuse even though they do not have the authority to do so, but in this deregulated age who is going to do anything about it?
I always invoke the excuse that it’s done for safety reasons. No one will argue with that.
cliveb
Head Pro
OK, I guess the company that are doing my PV install are just chicken and refuse to break the rules.
Fade and Die
Medal Winner
Nothing wrong with that. The main problem with works that involve the need to pull the main fuse is coordination. (If you are changing a CCU for example) getting the dno to be there on the day you are doing the work is difficult. Plus they need to be there to pull it, and replace it when you are finished. It’s just aggro. Simpler to diy, than re-seal when you are finished.
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larmen
Head Pro
Another thing was, on the hottest day in the universe ever (Thursday 2 weeks ago) the DNO people wore a thick safety suits that looked like a nice warm sleeping bag.
My local guy wore shorts and T-shirt.
Oh, I bought a camping battery with an AC socket to keep my router alive when they come to install my 100A this Friday. They also going to change the tails on their side of the meter, so it takes a little time.
My local guy wore shorts and T-shirt.
Oh, I bought a camping battery with an AC socket to keep my router alive when they come to install my 100A this Friday. They also going to change the tails on their side of the meter, so it takes a little time.
Fade and Die
Medal Winner
PJ87
Journeyman Pro
Today marks the day I've patiencely been waiting for. 1 year since battery install, this completing my system (solar had gone up the may before)
Anyways on the figures as they stand today, IE price my tariff now Vs the latest price cap etc (also basing on using same electric next year. I could use less , as I have replaced washing machine and fridge this year so their more efficient)
Total electric bill for one year £837.90 including standing charge .. sounds a lot but I use a lot of electric .
Cost without would have been £2806.65
On top of that they paid me £80 for what I exported
So total saved in a year £2048, system pays for itself in under 8 years
If I adjust for leaving the money in an ISA paying 5% (generous) looking extra 3 years payback roughly
So 10 years from now (factoring in this first year.. and ignoring the solar saving from may to Oct last year)
I can live with that (in reality I didn't do that because I got a mortgage at 2.54% so payback will be a bit sooner)
Anyways on the figures as they stand today, IE price my tariff now Vs the latest price cap etc (also basing on using same electric next year. I could use less , as I have replaced washing machine and fridge this year so their more efficient)
Total electric bill for one year £837.90 including standing charge .. sounds a lot but I use a lot of electric .
Cost without would have been £2806.65
On top of that they paid me £80 for what I exported
So total saved in a year £2048, system pays for itself in under 8 years
If I adjust for leaving the money in an ISA paying 5% (generous) looking extra 3 years payback roughly
So 10 years from now (factoring in this first year.. and ignoring the solar saving from may to Oct last year)
I can live with that (in reality I didn't do that because I got a mortgage at 2.54% so payback will be a bit sooner)
ColchesterFC
Journeyman Pro
@pauljames87 I've been looking into getting solar panels and a battery for my house so looking for a bit of advice so I know what to ask if I go ahead. We've got a three bed mid terrace. How many panels (roughly) am I likely to need and what size battery should I be looking at? Obviously not expecting precise answers but trying to gauge whether I can afford it or not is difficult if I don't know whether I need 4 or 10 panels and a 3.5kw or 8kw battery. Is there any online calculators that will give me an idea without having to contact a company?
larmen
Head Pro
Fixed price solar installations | Heatable
Get a fixed, up-front price to have solar installed in your home and see potential bill savings in real-time.
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This gives you an idea of what, and you can skip the step where they ask for contact detail.
PJ87
Journeyman Pro
I contacted a few companies and they simply use Google earth to decide what we could fit up there
It does depend on your personal circumstances, what's your daily usage for example.. you want them to size your system to provide enough to cover your usage for a day if you can including storing In a battery for use late so you don't use much in summer
I'd go for a givenergy battery, various sizes available, mainly because octopus allow them on their intelligent tariff now. So basically you can charge cheap using them and they control when the battery charges cheap (you get 6 hours cheap a night plus whenever they have excess they fill your battery)
ColchesterFC
Journeyman Pro
Had a look at the link larmen posted. They recommend 8 panels which is 3.4kw. The battery options are 5kw or 10 kw. Coming in at just under £11500 for the panels and 10kw battery and says electric bill down by 32% a year. Don't think I'll be going ahead with that as it will take over 20 years to recoup my initial outlay based on our current usage.
larmen
Head Pro
Use it for how much solar you can get, but then do your own calculation, or ask other companies.
I think the savings are not accurate.
It would be interesting if their estimates matches what PaulJames installer got him, and what he measured, on his own system.
full_throttle
Tour Winner
for the month of September;
Elec 30.78kwh £8.67
Gas 103.12 £7.24
both the above is usage cost only,
export 90.56kwh £13.58
my DD has been reduced by £26pcm,
Elec 30.78kwh £8.67
Gas 103.12 £7.24
both the above is usage cost only,
export 90.56kwh £13.58
my DD has been reduced by £26pcm,
larmen
Head Pro
I had it calculate again and did so against the quote I got from another installer.
8 panels generate 3100 kWh in a year, they both agree on that (within rounding). I am going to use 4300 kWh a year, so I will always need grid energy because of the limited roof size.
Their tool says I get 7 only, but I could trick it to 8 to match the proper quote I got.
Without battery I would generate under 30% of the used energy, with battery (5 kWh) i will use 55%. (Obviously that calculation ignores export)
They must be using the same tools to do the math.
The proper quote says my payback is going to be 11 years (£9.5k). That’s rounded down by them. That quote was on electricity prices from July/August.
5 days to scaffolding. 11 days to install.
Going to see what and when we use it before deciding on tariffs. Going with regular and 15p export for the beginning. Not going to gamble on the battery for discharging.
8 panels generate 3100 kWh in a year, they both agree on that (within rounding). I am going to use 4300 kWh a year, so I will always need grid energy because of the limited roof size.
Their tool says I get 7 only, but I could trick it to 8 to match the proper quote I got.
Without battery I would generate under 30% of the used energy, with battery (5 kWh) i will use 55%. (Obviously that calculation ignores export)
They must be using the same tools to do the math.
The proper quote says my payback is going to be 11 years (£9.5k). That’s rounded down by them. That quote was on electricity prices from July/August.
5 days to scaffolding. 11 days to install.
Going to see what and when we use it before deciding on tariffs. Going with regular and 15p export for the beginning. Not going to gamble on the battery for discharging.
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Rlburnside
Challenge Tour Pro
I’ve just had 8 in roof panels installed, it took 2 days to put panels on roof and 1 and half days to put batteries and inverter in loft and wire them up.