I'm a bit late to this party, and apologies if this has been covered somewhere in the past 1600 comments. But is there a go to website for figuring out what I need to do, and get for a hobby type set up? I'm thinking workshed - panels on roof to charge up some smaller batteries to power lights, and keep battery tenders on the go...
Cheers!
Not that I know of. But in essence, you need panels, a hybrid inverter and a battery compatible with your inverter. Start by thinking about how much roof area you have and want to cover. Panels vary in size and generating capacity but all are now around 20-24%. Meaning that size=power. Once you know your area and find the right size panels to get the max power out of the area you have. Use the total power to find a suitably sized hybrid inverter and use the inverter type to find a compatible and suitably sized battery. The rest is just wiring and grounding.
Not that I know of. But in essence, you need panels, a hybrid inverter and a battery compatible with your inverter. Start by thinking about how much roof area you have and want to cover. Panels vary in size and generating capacity but all are now around 20-24%. Meaning that size=power. Once you know your area and find the right size panels to get the max power out of the area you have. Use the total power to find a suitably sized hybrid inverter and use the inverter type to find a compatible and suitably sized battery. The rest is just wiring and grounding.
Many thanks! I shall measure up this weekend and make a start to this next project...
Cheers!
So Octopus are cutting their fixed export rate from 15p to 12p per kWh. I'm on IOG so charge car and house overnight at 7p which isn't changing bar the 6 hour car charging cap which isn't an issue for me.
Are there any competitors that are worth looking at? Eon have a cheaper EV tarrif but if you're on that it looks like you're limited to 6p(ish) for export so that's not viable. Good Energy have a decent export rate but their EV tarrif is at 8.5p and the cheap window is shorter than Octopus. And Octopus plays nicely with Home Assistant and predbat so that's another point in its favour.
Reminds me, I had a letter from EDF as my export tariff is about to end, have to call them to agree the next rate for some reason, will do that and report back!
Does anyone know about plug in batteries?
What I would really love is a plug in balcony solar setup, but my apartment doesn't have a balcony, so I just want to look at a plug in battery storage to charge overnight at cheap rate and release during the day as needed.
I'm not saying it's a bad idea, but I have some questions/points:
- How would you get cheap rate... Do you have an EV?
- Even assuming free electricity a 2kW "station" seems to cost about £800 on average so £800 / £0.60 = 1333 days to break even. Doesn't seem very good numbers.
- balcony PV isn't allowed in the UK yet although it's being looked at. So I think you'd need some way of isolating the house in the event of a power cut.
If the numbers were better I'd be interested though.
(I think batteries still struggle to make economic sense unless without being paid for export .... And that's reducing now.)
How would you get cheap rate... Do you have an EV?
Octopus Agile, is usually cheaper overnight and daytime away from peak time. Think you can automate battery charge based on the rate using IFTTT or go full Home Assistant on it.
Ahhh, OK.... I'm on agile too.
It's a bit cheaper but id say the average over night is about 12p is guess. Obvs not.last night 😉
One thing I would say is that the Octopus IFTTT integration is not trustworthy.
You'd be better rolling your own.
(I just run a bash script on a pi ever 30 mins to get the new price and then switch stuff on and off based on that)
It transpires my house has MCS certificate, despite being told before it does not.
I have 6x Viridian panels and Growatt inverter with estimated 1540kWh generation annually.
Currently on Octopus Intelligent Go, EV X 12k miles, a person at home all day, 4 bed/4 people house.
Getting better at using cheap overnight AND load spreading through the day to maximise any solar. We do plan to use as much as we can locally rather than export.
Is there any downside to signing up to Outgoing Octopus (flat rate) on top of Intelligent Go (which is how I understand it works...) and selling on the odd occasion we have some "spare" electricity?
That the 12p rate? If so thats what I'm on, so no downside. You're coming into right time of year now to export as much solar as you can, this is where batteries can help to store excess to use at at night and poor solar days but that's another topic.
so far this year I've generated this
January was piss poor, but its getting better now
No downside as you get paid more than it costs you overnight. That's is how we are setup except flux outgoing.
Yes, 12p rate.
I've signed up - seems that I've given free power away again today despite someone being in all day on a PC and a washing machine load done...
If you have a hot water cylinder then you're probably better off using spare power to heat that [using a diverter].
If you have a hot water cylinder then you're probably better off using spare power to heat that [using a diverter].
I need to properly do maths on electric use, selling solar at 12p Vs gas unit cost and efficiency.
First glance seems use gas for hot water, use as much solar as you can buy oad spreading through the day, sell at 12p what is spare, charge car and big loads overnight at 3.5p...
That may change if I look at a battery. 🤔
i have a PV diverter - we never use it.
Charge the batteries , sell the excess.
There is never excess at a points in the year where id need to be heating water.
Charge the batteries , sell the excess.
He's not got batteries - but he does have a bit water tank.
So he's have to spend a fair chunk before he start selling those units for 12p.
Also, maybe he wants to reduce his carbon emissions (rather than make a few quid) which using the power to heat water will do.
Even assuming free electricity a 2kW "station" seems to cost about £800 on average so £800 / £0.60 = 1333 days to break even. Doesn't seem very good numbers.
certainly no expert but that works out at about 4 years no? how much do the regular rooftop installs take to break even? 12 years?
I really need to sit down and go through this thread to see what we are best doing. (Moving into a smallish (110m2) 4 bed house in East Yorkshire, built in 2003. EPC C. Gas heating, electric water heater faces ENE and WSW) It would seem daft to wait a year or three before acting rather than crack on and start saving money and investing in the property straight away.
certainly no expert but that works out at about 4 years no?
Not really.
Because the only way to get that free electricity is through solar - and there won't be enough spare generation for 6 months of the year so that 4 years then becomes around 8.
And I don't think the batteries are expected to last that long if used in that way.
Solar panels are guaranteed for around 25 years (and I believe their payback is now around 7 years)
Apologies as I'm sure this has all been covered, but does the cost of a new solar install ever stack up on a modern new build?
We just had a bit of a hard sell from a company we contacted for a quote.
£13,500 bought us 8 x 450W panels, invertor and 5.76kWhr battery, this would supplement the 6 x 300W panels (no battery) that came with the house.
Predicted annual generation is 5400kWhr including existing panels (I checked this against other, independent calculators such as this one https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html&source=gmail&ust=1774512820560000&usg=AOvVaw2e0hqTBW5Bh6uqU9_Pr-z e"> https://re.jrc.ec.europa.eu/
This easily covers our electrical consumption for the year, saving us £40-£50 (I haven't figured out what component of our bill is standing charge which presumably we still pay!). Salesperson was adamant that we would recoup a significant extra sum from SEG but even his calcs (and the other independent calcs I did) only suggest £300/yr SEG, assuming we get 15p/kWhr which is sounds might not be guaranteed.
At ~£162/month for ten years on finance to pay for the installation, AND since we would still be paying for gas fired central heating and hot water (~£60/month) we're basically out of pocket for the lifespan of the install. Salespersons calcs (appended at the back of the quote) actually show break-even at yr 25 🙄.
I would have liked to do it just for energy independence and because it feels like the right thing to do, but I just can't square the figures. Am I missing something? Is SEG the cash-cow the sales guy suggested it might be? I'm wondering if we would be better off just sticking a hot water cylinder on to our existing install and using a smart tarrif to top it up overnight...
Batteries make a lot of sense to shift usage from day to evening for example or, in our case, to power our ASHP using cheaper periods through tarifs such as Cosy.
£13,500 bought us 8 x 450W panels, invertor and 5.76kWhr battery, this would supplement the 6 x 300W panels (no battery) that came with the house.
No, you're being ripped off. I paid £7,500 for 12 panels, inverter, and a 5kWh battery, and £1,500 of that was the scaffolding.
No, you're being ripped off. I paid £7,500 for 12 panels, inverter, and a 5kWh battery, and £1,500 of that was the scaffolding.
Funny, I just received another quote, should have checked my email before posting 😂
Quote from a local electrical contractor with a good reputation for PV, £8,600 for 14 panels and a 10kWhr battery.
Still a long way off paying for itself sadly, £60 a month in consumption and SEG doesn't seem to cover the ~£100/month on a 10yr loan.
Adding the cost of a hot water cylinder would offset a lot of our gas use but presumably also eat into our export, but I imagine we would still recoup more this way, still not sure it makes financial sense sadly...
Edit- in reply to your initial post, not the update. Sounds expensive. We were very pleased we upped the storage to 10kwh from our initial planned 5, with a flexible tariff we can minimise what we buy electricity for when not producing all we need, and can also program to dump electric to the grid at best price when we have surplus. I’d get some more quotes…..
I think ours was about 14k 3 years ago for 15 panels and 10kWh battery though that is solaredge which is more expensive (the battery especially). Last year our total electricity bill was around £40. Before installation we were spending over £1500 a year on electricity. That gives a rough 9 year payback except it doesn't account for the fact that the £40 cost includes charging 2 cars.
My regret is not adding more panels on our other roof side and a bigger inverter (out export is limited to 3.2). I'm hoping soon there will be some V2G car chargers so we can 100% load shift and export all day.
Last year our total electricity bill was around £40
Presumably that's just consumption and not standing charges? We're paying £208/yr just in standing charges!
Sounds spendy to me. We had ours installed in Nov 22. We have 5.6kWh of PV and an 8.7kWh battery (included an iBoost as well but redundant now we have an ASHP) and that came in at £12,540. I would expect that price to be lower now given the reduction in panel and battery costs. I got quotes from 5 companies and they varied quite significantly. The company I used was very good and I would recommend them.
Payback is impossible to estimate given fluctuations in Kw prices and amount solar of course but ive just checked and my inverter tells me that since installation my PV has generated 17.93MGw, at 25p per Kw (roughly the average market rate through 2025) thats a return of £4482. so roughly a payback of around 8 years. Solar panels last decades with only light degradation and my home battery is guaranteed for 10 years so quite comfortable with the decision, particularly as it was as much based on reducing our carbon footprint.
No, you're being ripped off. I paid £7,500 for 12 panels, inverter, and a 5kWh battery, and £1,500 of that was the scaffolding.
when.
Costs for the components appear to be on the rise. Panels i have on my spreadsheet as i was looking at expanding my array were sitting at 40-47quid inc vat last year are now 70-75 quid.
likewise batteries are about 20% up.
Presumably that's just consumption and not standing charges? We're paying £208/yr just in standing charges!
No that's the whole bill for the year. (Consumption + standing charge) - export
I've been considering getting panels for a while. Assuming Google Maps has North oriented correctly, is my roof (#43) a good angle to make them worthwhile?
The east facing ones are in bright sunlight all morning, but less-so in the afternoon, the south facing one has less capacity, but I assume gets sun for more of the day.
I should elaborate a little...
I used this online calculator and it suggests a payback time of 19 years for NE facing roof, and 16 years for Easterly! Seems excessive - I just wondered if real world experience might be different to an online calculator.
https://energysavingtrust.org.uk/energy-at-home/energy-tools-and-calculators/
the east will get first thing in morning and as the sun climbs, but you'll potentially get shading on the most northerly section of roof mid morning? so you may need a triple array to make it work? or panel optimizer doo dahs
South will work till mid / late noon?
im thinking how mine works, your south roof is a very similar angle to mine
The big savings would be with a battery and time of use tariff
The quote our salesperson provided suggested 25 years! We are 'low consumers' in a modern house which probably increases the payback period...
likewise batteries are about 20% up.
I think the other way around. My understanding is around a 20-40% drop in battery prices over the last 12 months. I have been tracking the price of a modular upgrade to mine and at the moment I can get circa 4kWh for a similar price to 2.8kWh about a year ago. Just holding out to see if they drop further plus don't need it until Autumn/winter
Just to PSA this again - Axle energy VPP is worth looking at if your inverter is supported (Fox, Solax, Givenergy, Solis, sigenergy). They've just confirmed they're continuing with the £10/month minimum payout beyond the original beta date of 31/3. Basically they tell you when an "event" is happening, and during the event they control your inverter to export to the grid and you get £1/kWh on top of your normal export tarrif. Events have been 1hr so far, around morning or evening peak. They play nicely with HA and you can integrate the setup into predbat.
I'm £70 up since signing up in December and they even do signing on bonuses with a referral code if you knew anyone who had one...