What green systems do you have and why? Solar, Battery, EV, Heating systems etc

Ok so I thought this might be useful to document what I have running and why and maybe it would help someone else choosing kit or at least let people know they can ask me questions about what I have and why I went for it. Can show savings in pounds or just reasons for going green.

Ok I moved into a 18 month old house Feb 2021, the house was built with an Air Source Heat Pump, 2.4kwh of East facing solar panels, triple glazing where possible, underfloor heating downstairs, oversize rads upstairs, slightly thicker insulation in walls and the roof. Smaller detached 96m2. So fairly green but turned out not cheap to run! First couple of weeks in the house I noticed it was using 35 - 40kwh per day! The previous owners kept the house at 24 - 25c in everyroom. Previous home was 150m2, gas heated. Gas and elec bill was £58 a month so I was a bit stunned at first!!

Improvements made by me. First turned the heating down to 21c downstairs, 3 separate heating zones, 20c upstrairs, single zone. Added 4.62kw of panels on the West facing roof. Added GivEnergy AC3 and the 8.2kw battery (external install). Had some issue with the battery after the first 4 weeks of install, was actually offline for over 3 weeks. Has since been fixed but it does mean my data is off as I still had to use grid energy in August.

August grid consumption 59kw cost £21.71 (no seg 100% green)
September grid 131kw cost £12.42 (Outgoing Agile 100% green)
October grid 205kw cost £18.84 (Outgoing Agile first half of the month then switched to Go and SEG 100% green)
November (as of today) 120kw cost £11.31 (no export this month 100% green)

Next plans are an EV is on order, though no delivery week has been given yet. Shortages! I went for a id.3 Life Pro Performance. A Zappi charge will be going in. Add extra 6 panels on my East facing room another 1.8kw. Second battery, maybe though I am a bit undecided. The last 2 weekends we did drain the battery by 2pm but I am not sure the cost of a second battery can be justified for maybe 4 months of the year? I am using green electricity already.

Reasons I went with givenergy was I liked the integration with Octopus Agile, though I never turned it on and instead managed it myself! Cost, hard to beat it really. I spent all Summer looking at systems, powerwall, powervault, givenergy. Had problems yes, but they have all been resolved and based on how all my issues were dealt with I am happy I went with GivEnergy.

Goal is to be green, cleaner. The savings do help but only make up 1 third of the reason the wife and I purchased all this kit.

So what do you all have? Why did you get it? Any suggestions to help me or others on the green journey? Would anyone like extra detail on my kit? Make model? Or don't worry and I will go make another cuppa and get back to work :-)

I have:

fully smart central heating system, each room with its own smart TRV with timers and profiles. That was my first step to being more efficient. That alone dropped my gas bill significantly
Every lightbulb is now smart, which also now means LED
4KW PV feeding 5KW hybrid inverter supported by 8.2kW battery,
PV diverter for the immersion ( I deliberatley didnt get rid of my hot water tank when we got a new boiler )
Loads of smart plugs for energy monitoring and logic to say when best to use the devices
Loads of sensors for temperature etc
Home Automation system running on Pi to get it all to work well

Shed has its own small PV with leisure battery for lighting etc

Summer my grid energy in minimal. Now bringing energy from the grid but generally all at off peak rates
I am lucky enough to have FIT, so if I include that I think I am about cost neutral or even negative over the year
Understanding energy consumption has allowed me to make many small changes to reduce that without actually changing my expectations re what I can do

I did all the home automation in my previous home with Hive. But done nothing smart with with this one. My hotwater tank is heated by my ASHP so no diverter, though technically my PV / Battery is doing my hot water as a coincidence my ASHP draws up to 3000w, which is the output of the AC3.

We have 10.4 kW of Givenergy batteries (2x5.2) along with 5.6 kWp of solar. I’ve been on Octopus Go since December and over 81% of our imported electricity has been at 5p, making the average unit price 6.6p. This includes charging our EV at night.
If you factor in the payment receive for exports the import unit price comes down to 2.5p! And if you include solar to battery/home, we paid 1.3p for each unit we consumed. Obviously there is the standing charge to include and the installation cost! But at this rate the repayment period will be shorter than anticipated.

We have just pushed the button on ordering a high temperature ASHP (Daikin) and new hot water cylinder (Mixergy) to replace our 35 year old gas system that is limping on only the ignition burner! We need to have 3 radiators upgraded to double panels to meet to heat demand calculations, but otherwise the existing radiators are supposed to be sufficient running the system at 40-60 degrees C. It is a slightly scary time to do this from an electricity price perspective, but getting in on the existing RHI payment scheme should be several grand better off than the next scheme for us. At the end of the day we want a comfortably warm home with lower CO2 emissions and if that costs a bit more then so be it, but hopefully there will be ASHP tariffs soon and additional levies on green electricity will be removed.

I’d like to add the Givenergy power diverter to the Mixergy tank once available, that will hopefully provide much of our hot water during the warmer months. It will reduce the amount we export therefore change the cost calculation above, but we should be able to remove our gas connection and associated costs, we’ll need to change the gas hob for an induction one too!

dcsh Hmm my ASHP tops out at 45C, there is an electric booster feature if I need more water in a hurry. But a few people I know have higher temp ASHP. The biggest change to get used to is the running schedule, the idea of leaving the heating on 24/7 felt odd at first but I've found it does save me money holding a constant 20 - 21c temp rather than cooling down to 15c or something then trying to heat up to 20.

The Eddi device is a good solar diverter too. I just checked last week if my system could have a diverter but apparently not.

Usually just lurk in the shadows but here goes:
Worked for years on coal power plants so thought I should atone a bit with PV and Batteries.
6.2KW PV with 5KW Hybrid + 8.2Kwh (Gen1) battery.
Solic 200 Solar Hot Water Diverter
2 EV Chargers

Almost all of it linked back to a DakBoard Screen to keep an eye on it & make sure we are using everything with the least impact to the grid/planet in mind. I also shared select parts of our system data live for others to help get a feel for how much output to expect here

Side project of live mapping the entire power output of every UK power station should that be of any interest: TerraVolt
Further side project is to annoy Simon regularly with ideas although he does one up me on most things Smart Home :-P

I have had a 30 Tube Solar Hot Water System since 2008. Means that my gas usage in summer 4-5 months is minimal, and reduced most of the rest of the year. it was got when I had paid the voluntary Carbon Offset charge on a Easyject flight to Scotland and I could not answer my wife's reasonable question asking how did I know what I paid was actually being used to effectively offset the carbon of the flight and who actually got the money! So that was my own Carbon Offset. This system ihas some problems and it is proving difficult to get support.
At the end of October last year I had an eight panel PV (2.8kW) system installed with a 3.6 kW GivEnergy Hybrid Inverter and two 2.6kWh GivEnergy Battery Packs (so a nominal 5.2kWh storage capacity).
Having just completed our first year's operation, we generated 2.582 MWh of PV power, with 46% of our first year's consumption coming directly from our system (PV and batteries - not currently charged at night). We only exported 0.8MWh of the generated power thanks to the batteries. If the exported power is offset against our imports, it means we produced 69% of our year's electricity consumption.
I am on the SEG as opposed to FIT, so get very little value from my exports (a big gripe of mine - only 2p unit). However in direct savings of power, the batteries contribute pretty much exactly 50% of our direct savings (ie the cost of power not imported). I have however only saved approximately £300 on my electricity Bill and made a further (miserly) £18 in SEG. So at current performance, the pay back time would be just under 20 years (!) however as electricity prices increase this will reduce.
Our motivation? We read David Attenborough's latest very sobering book which spured us on to make finally the investment! Part Two of my Carbon Offset!
I am very disappointed with the SEG arrangements our government have set up. In fact their appauling handling of the removal of FIT delayed and the delay to impliment its very poor replacement in turn delayed our decision to invest by a year (having just missed the FIT window) and lead directly to us including the battery packs.
I would dearly love to add another panel, taking us to a 3.1KW PV installation, but dont really have the roof space to do so.
Our Town lead with an initiative called Solar Streets to promote Solar PV, where they were in co-operation with a local Solar installer to provide an affordable solution through grouping individual house orders.
Where next? - Possibly to reduce my heating load through ASHPs? Maybe find a way to add that 9th or 10th panel?

Our house was built in 2000 and has gas CH to radiators and for hot water (old-school non-condensing boiler). I added solar thermal in 2009 (helped with an LCBP grant) and 2kW of solar PV in 2010 (with the FIT and savings, this paid for itself after just over 10 years) I've been using LEDs since 2010 too, and by now most bulbs are LED (there are still a few low energy bulbs running).
The living room and main bedroom have always been pretty cold, so at the end of 2020 we replaced the Drayton boiler controller with a smart one (Wiser - this was really easy to swap) and put iTRVs in 3 rooms (main bedroom, office, and dining room - which my son is using as a games room). I added a couple of Drayton smart plugs primarily to improve the Zigbee signal. The living room has the room stat and it's made a big difference to the comfort level there; the main bedroom iTRV sometimes demands heat at night, so it no longer gets so cold (it's over the garage); gas usage seems to have gone up slightly but not hugely, and the house is much more comfortable.
I added a GivEnergy AC3 and 8.2kWh battery in April after quite a bit of research - I chose GivEnergy over Tesla/Powervault for cost/management reasons, and over Lux because I liked the products better and the direction GE seemed to be going. I predicted a 10-15 year ROI for the battery, and so far it's looking like I should easily beat that; this may depend on which tariff we get going forward - currently we're on Octopus GoFaster (I was on Agile for a while but that's no longer economic); we don't have an EV at the moment so I'm not sure what will happen at renewal (I'm hoping that Octopus will announce a tariff aimed at battery owners before that).
Next steps are probably to look at getting an energy survey done - I've added more loft insulation, but I'm pretty sure there are issues with cold bridges, etc, also the conservatory is not really usable in the winter and even just using the electric panels for frost protection uses significant kWh, so I'm interested to improve that if possible (on that topic, does anyone know if far-IR panels would work for frost protection?)
In summer the PV+battery on GoFaster (3h charge from 22:30) works pretty well, but now the sun is lower the battery is running out during the day, so we end up importing at the higher rate (I also wonder about getting a 2nd battery, but will probably monitor for a bit longer before deciding). We might also get an EV, though I'm not convinced by the economics for that yet.

Please see the message titled 'Trying to come off-grid' but also I have an electric vehicle with a difference. It is a battery powered trike that is designed for off-road use and is in fact a vehicle for people with limited ability. (no road tax) See the web page https://www.tramper.co.uk/products/scooter.

As it is designed to be re-charged and I have a system here that powers the house and shed (garage), I have free fuel and can travel anywhere within 50 miles. (Never been over 25 miles as I don't need to and don't want to, and can't, re-charge if I do 50 miles.) Regularly do, whatever the weather decides to do. (I've got the kit to do it so why not?)

I have great fun with this and people are always smiling and waving at me.

I love 'green' energy and trying to do good for this planet and all that is on it.

Best wishes all.

Geoff.

Having a large, south-facing roof, we decided to augment our extant 4kW array, with another 10.5kWP one. With so much potential PV it made sense to look at other uses of electricity at the same time.
Having carried out considerable research, GE came out on top, for bang-for-buck.
We also looked at an EV & charger.
The last bit of the jigsaw, was heating. Once again, electricity made sense - as long as we could bring it in cheaply enough, when the PV wasn’t producing, and batteries had depleted. We decided that if we went down the ASHP route, we’d want to retrofit overlay underfloor heating, and this meant moving out, as the disturbance would be considerable. It would also provide the ideal opportunity for the long-overdue refurb / redecoration.

We’ve now done all of the electrical side, and are still planning/mulling over the heating installation - which will need to be completed by 31st March, as RHI applications won’t be considered after that date.

Our system comprises:
4kWP array on the original FiT (Yay! 😃 )
10.5 kWP array not yet on SEG.
New home electrical check, with new consumer units for everything.
Myenergi Zappi.
Peugeot e2008.
2 X GE 8.2 kWh batteries.
2 X GE AC Coupled 3.0 (one on each battery). *
Upgraded DNO fuse (80amp).
SMETS 2 meter.
Octopus Go Faster (great product!). Use this referral link for a £50 credit each.
Motivation for me, personally, was to be more considerate of our environment, and the fact that I love the technology.
Moving forward, I’d eventually like to learn more Python, build my own UI to control all the kit from one place, and host it all locally on a NAS. Long way off that one, yet!

Very happy to help / advise anyone just starting the journey.
If I were to offer only one piece of advice, it would be to get as much PV on the roof / in the garden / on the cat & dog that you can physically & financially afford; THEN consider all of the other goodies.

• Reason for an AC 3.0 on each battery, is to get 6kW instantaneous delivered, otherwise, no matter how much storage you have, with only one AC 3.0, the most that can be instantaneously delivered, is only 3kW, which will only do a kettle!

I'm looking to avoid a heat pump for my own reasons but the main one is 300% efficiency at 20p peak rate vs 100% efficiency at 5p for direct offpeak heating make sense for me.

Lots of systems on the way including https://mcdonaldwaterstorage.com/products/thermal-store/electric-wet-central-heating/

hamilton I do not think Heat Pumps will be the answer for every household, there are better options. SunAmp as an example. But I would entertain Heat Pump's on new we insulated homes. I am lucky that my ASHP draws 3000w and my AC3 discharges 3000w so I am covered. But yeah Heat Pump did not save me money moving from a Gas heated 4 bed detached to a ASHP heated 3 bed detached. The bills were much higher. But with a storage battery of decent size the costs have plummeted..

Opted to not have anything to do with heat pumps of any sort. Reason? They freeze up in the winter - right when you need them most, they use a HUGE amount of electricity to run and they are not really suitable for domestic environments as they make a lot of noise - not good for when you are trying to sleep. Otherwise, hoping to be off-grid soon with the PV array on the roof and batteries in 'the shed'.

Interesting to read about other people's heating refurbs. Currently have gas combi for space and hot water heating. Was installed when I bought the place 4 years a go. When the gas combi dies, I am thinking of replacing with an electric version of the gas combi. Anybody got any ideas please?

Geoff-Bell I keep seeing reviews in the news papers and why Heat Pumps will not work, will cost more, be loud etc. But as someone who has a low heat heat pump air source, it is nothing like the reviewers are making out. The new higher heat ones should be even better. But I can say they are not that loud, it is no louder than having a fan running in the bed room during the height of Summer. You get a low hum in the winter when the window is shut for up to 30 minutes with the current weather (5 - 10c). Electricity wise my unit sucks in up to 3000w but it scales up to that, if it is just heating the hot water tank I see it draw 1600w ish sometimes 2400w. But not for very long periods, a few nights back temps dropped to 2c and the pump came on for just over 30 minutes at 4 in the morning. It did not wake anyone.

Don't get me wrong, they wont work for everyone and other solutions will work better especially in older properties. But for anyone considering a revamp for better insulation, underfloor heating then a heatpump is great. You get more out than you put in. When I first moved in I set the system to run like a gas boiler house, heating on in the morning then timed again to come on before getting home to keep running costs low. But that didn't work very well, took too long to heat up, then costs get high. I now leave the system set for 20c in 3 zones downstairs and 19c up to run 24/7, works a treat.

Yes they can freeze up if not serviced/maintained. But for the most they should defrost themselves and be fine, the only thing I should need to do is dig it out if it gets buried by snow to keep a clear airflow. But it is in a fairly shelted corner of my garden but I have only been in the house 10 months so not had a hard winter yet so I might change my mind on all this lol. But so far my hotwater has been free for at least 6 months this year.

Costs, so today 19th, 19 days into this months bill, its a cold month and my electric has come to £19.66 so far. That is heating, hotwater both via the ASHP, cooking etc etc everything in my place is electric. But heatpumps are worth looking into in my opinion, depending on the condition/insulation of your home. Some might be noisy but they wont all be.

Oh and service costs for ASHP, £75 per year. That includes refrigerant top-up or replacement if needed.

Geoff-Bell
Have a look at the tepeo system. There are many companies starting to do alternatives to heat pumps.
https://tepeo.com/

Recently fitted 6kw of PV facing south in a single array, suffers from a spot of shading in the winter sun on the lower PV string. 8.2kwh GivEnergy battery and HY5.0 inverter setup with a Zappi and Eddi. Some of usual smart home stuff, HIve, Hue etc and won't touch a light that isn't LED. Been running an Peugeot E208 since May averaging around 1000 miles a month on top of all of that.

Aim was to get electricity costs down as low as possible, staying in the house for at least the next 15 years so it made the rough maths a bit easier. I'd looked at a Powerwall and having done the usual YouTube based research (thanks Fully Charged, EVM and the EV puzzle for their insights) settled on the GivEnergy setup. Secondary aspect was green energy usage but it did need to pay for itself.

Prior to EV ownership household usage was around 6-10 kwh per day depending, didn't really 100% know as was still on a mechanical meter but I had monthly usage numbers. It also made working out peak loading difficult and I think this is one of the most important aspects of a battery system - if you bust the limit you will always end up pulling from the grid albeit at a reduced rate.

I could have got up closer to the maximum of the inverter in terms of PV (6.5kw) but I can't see the point in adding more stress to the inverter but running it at the top end and potentially above during summer (odd days where the UK sees above the 1000w/m2 most panels are tested at) just seems a bit silly.

Household wise is where it gets a bit harder, early 1970s detached house so it needed some work to help improve its efficiency from when we moved in - now up to at least 270mm of insulation in the roof, it had a modern condenser gas boiler in the airing cupboard with the hot water tank below it. Still waiting on new windows and doors to replaced the 25 year old double glazing which will definitely help with the heating. Cavity wall insulation was already there and I'm in the process of adding radstats to the radiators which are enormous (designed for single glazing I guess) which could be a benefit on the heat pump front.

Everything in the house bar heating and hot water are electric, modern induction hub and electric oven etc, 10.5kw shower etc. Sadly the British Gas 'engineer' who moved the boiler into the airing cupboard instead of the kitchen and replaced the hot water tank fitted one that's really too small for a 3 bed house. That's annoying as it prevented me from fitting a power shower, especially as my DHW heating losses are so small.

I've got some better data after 2 and half months of having the system installed so my electrical consumption planning is below, please note this does not include any PV generation.

23 kwh used per day as an average, 10kwh for the EV, 10kwh to charge the battery from AC and 3kwh 'extra'
Cost on 'Go' is £1 to charge the EV and battery, £0.74 for the 3 on peak units and another £0.19 standing charge.
Total electricity for the year based on this model is £705 before any PV, add in gas at £500 per year and I'm looking at a total of £1200 for the year or £100 a month.
8400 kwh per year used, if we take the best rate I can find today per kwh its 20.68p variable plus 23.16p a day standing charge. £1736 for the electricity plus £84.50 standing charge for a total of £1820 just for electricity or a combined bill of £2320.
So without any PV its £1100 a year cheaper for me or a payback period of 11 years - assuming any cost rises between the on peak and off peak rates of 'Go' remain.
With regards to the PV I'm expecting to spend 4 months of they year using a lot less of the 20 units put into the battery can car daily so I think I can remove another £120 or so from the electricity bill.
Finally SEG tariff rates, looking today some are offering above 5p a unit without needing to be on their supply tariff - I've seen some 30kwh plus generation days in mid September already so assuming 5 units of export for 181 days that's a further £45 off the bill as a conservative estimate.
So potential further bill reduction of £165 bring the total costs down to £1035 including gas or £86 a month.

Be interesting to see how the numbers above translate over the course of the next 12 months.

Most useless device is the Eddi, I'm actually better off exporting the generation and using the gas boiler at the moment.
Future plans are a spot more integration probably Home Assistant but I need to upgrade my old NAS first, better heating control, mostly smart rad stat valves and further insulation improvements - lifting some floor boards to get some pipe insulation on the CH plumbing, sadly downstairs pipework is in concrete. Battery and inverter are in the roof so want to stick PIR board between the eaves to stabilise the winter/summer temp extremes, obviously ensuring sufficient ventilation at the same time.

For the TL: DR types, £11k outlay saves between £1100-1285 per year conservatively but how your house is configured is key and an EV makes that relative return even faster. Or my total fuel bill for both house and a car doing 12k miles a year is under £100 a month.

Well, hello everyone.
Since moving into our 3 Bed semi 5 years ago we have been biding our time making do until about 2019 when I started getting itchy to get a new car. Our Corsa was really not fir for our needs any more and ongoing maintenence was starting to bite. Decided to keep it on the road as long as possible until the electric corsa came out. Thought the idea of driving on electric was great. Alleviating some of my eco anxiety for every time I had to use the diesel to get around, even if it did get 60mpg, I still didn't like that I was chucking co2 out every journey, plus electric would give me free electric when I used the brakes! The idea of a Hybrid didn't make sense for my usage, like a washer dryer, more parts to service and go wrong, more weight unnecessarily. I suddenly had to deal with the distressed purchase of my EV as the Corsa was clapping out. Ended up deciding on the Leaf 40. Couldn't wait for the Corsa release and after testing the near identical e-208 thought it wouldn't suit size wise so probably best. Managed to get the Home Energy Scotland loan to help with the cost of the car.
That was only the start. Unfortunatley after the passing of my MIL my wife had some inheritance burning a hole, and through lockdown set her sights on the kitchen. This led to us decanting from the house, full rewire (I'd been angling this to better set up my future eco interests) as the house still had cartridge fuses so show how long it hadn't been upgraded. Following walls coming down, new bathroom and kitchen with induction hob this time, (all starting because the wife wanted a dishwasher and a bath instead of shower) we had external installation and render put on the house, handily got recommended a scheme for this when applying for the car loan with EST. This has cut our heating bill by a chunk but we are still on GCH.
Queue this year where I've finally managed to get a split 3.7kW Solar PV, 1.7kW-South & 2kW-West. We got this tied to a Hybrid Givenergy 3.6 and 8.2 Battery. This looks to be able to help us meet about half of our yearly house electric demand. Managed to get on to Octopus GO with a newly installed smart meter so have been able to get our average to approx 7p/kWh but we have only had the complete system in for about a month now, delays with inverter, battery etc.
Setting my sights on our heating now since the only thing we didn't touch at our renovation, the heating, is on its last legs with a condensing combi which will be BER when it finally conks out totally.
Need to get about 10.5MWh of heat demand met per year so am seriously looking at an ASHP before the RHI finishes. Looking at pairing it to some sort of storage like a Sunamp, but may end up just getting an additional 8.2kW battery in the loft to the existing inverter. Not sure yet, any thoughts?

Salibaba Not sure any installer will put a 8.2kw battery in the loft. Because they weight 94Kg I was advised ground floor install only. But you already have a battery so I am assuming your installer did put it in the loft?

As far as I know it was fine, installer had a job getting it up there though even after I asked if it would be do-able. Was the easiest place to put it, could be secured without issue, and meant a short DC run for the PV. The missus commented there was much grunting, and partial disassembly of the ladders 😅 .
I have seen similar Givenergy kit wall mounted on the side of buildings externally on the ecobubbl channel on YT.
I do know it couldn't go in the same cupboard as my boiler due to space constraints, Givenergy requires certain spacing either side of the kit and between the battery and inverter.

THALL Salibaba I had mine installed in the loft, 4 of us shoved it up there using some lifting strops etc, probably helped I have a proper loft ladder and its fully boarded out. Made massive sense for me as it was an easy empty space to install it and I could run the AC side stuff down through the airing cupboard direct to the metering unit.

My only concern is temperatures in summer but with panels now covering most of the south aspect it'll reduce a lot of the direct heating - coupled with the planned PIR board install between the roof trusses will sort that.

If you really wanted to do it then a ratchet winch and some strops would work without being a slight H&S nightmare - you'll never get the likes of EON etc to install one in the roof.

Sykes
Hi your systems sound great, do have you 3 phase, if not can you tell me how you got your DNO to agree to having 2 x 3kW inverters plus your original PV system on a 80A supply (let alone for the extra 10 kW)? did you apply via the G99 form as it obviously exceeds the G98 limits.
I have 2 x 8.2kWh batteries on a single inverter and 3.8kWp solar, all agreed on the G98, also DNO upgraded my cutout fuse to 80A.
When I applied to extend my solar by G99 they begrudgingly agreed to an extra 3kW on my roof plus an inverter which compied to the G100 standard and was limited to zero export!!
I would love to have a setup like yours, it would be nice to know how you achieved this.
Many Thanks Pete

Guzz For my systems the DNO capped my export to 3.68kw. But everything generated is available to my house. I am adding another 2.4kw soon which will give me 4.8kw East facing, 4.62Kw West and 3k from the battery. DNO has already capped me at 3.68kw export so the installer says the extra panels wont be an issue. The extra power is to charge my EV more.

In fact I have my reply letter from the DNO which says 9kW installation (2kw existing + 4kw pc + 3kw battery) limited to 3.68kw export capacity.

Hi @Guzz
The system's not long been installed, and I'm still waiting for the installer to supply the paperwork.
Most of the PV is used locally - charging the batteries EV.

Guzz It just depends on your DNO, how many people around have solar, load on substations etc in the area.

I'm capped at 5kw export on a 6kwp array with a single inverter - it's still quite a way under my DNO fuse at 100A (its an old one and is confirmed as 100A when my meter was replaced recently). I've got a 10.5kw shower on a 45A CB to give a representative idea of kw vs Amp demands but any household consumption comes isn't going out via the DNO fuse regardless. So even on a day when you are exporting everything you generate back to the grid with a 14kw PV array its still under the 60A fuse value (58.4A)

A lot of arrays are going to drift into G99 territory as its not that difficult to get there anymore, I know a few quotes I had were trying to sell a 3.6kwp PV array as a solution as its keeps it under the G99 limit so automatic DNO approval and a lot less mucking around. My G99 was applied for with the installer and the faff has been on the DNO end, had a site visit to confirm correct fitment of safety devices etc last week.

yandards
Hi Sykes yes I understand the maths just wondering how the G99 form was completed. I know the main fuse is not really a factor but if you do a quick add up of the PGM's, 2 x 3kW inverters, a 4kW existing PV system and an additional 10.5kW PV thats 20.5 kW. That's getting on for 90 Amps. I know that's never going to happen in reality but that's the way the DNO will view it.
I was curious as I have a similar incoming supply, I have a single 3kW battery inverter plus 3.8kW PV and my DNO will only agree to an extra 3kW PV with export limited to zero with a G100 compliant inverter! I'm jealous!!
What was your "safety device" that was inspected at the site visit was that some form of export limitation?

Hi all, really liking this community - a lot of questions I had have been answered reading other user's posts already.

Our set-up (installed Friday last week):

4.38kWh PV (12 x Canadian Solar 370W)
8.2kWh GivEnergy battery
3.6kWh GivEnergy inverter

We have a 4 bedroom detached house with the PV pointing in a south-south-west direction. I've always wanted to go solar but knew the house we lived wouldn't be the one we stayed in for long enough. So when we moved early last year we knew this would be ours for at least 20 years so started to look closer at the set-up. Eon quoted £9,300 for a similar set-up as above (but with 5kWh battery) and then a local installer quoted nearly £2,000 less with the 8.2kWh battery.

So far I'm pleased with how it has gone. Today will be the first day after the full commissioning, battery was fully drained and charged yesterday so I'll be checking our meter etc. Unfortunately we can't have smart meters, they tried to fit them last year but the distance between the gas meter and electric meter is too far and they cannot communicate (found out the electric does the reporting of the values to the energy supplier and the gas one just tells the electric one what to report). Hopefully that can be sorted soon as I'm told it will be needed for the SEG Export?

chris_p I am a bit surprised by that EON quote. I went with EON this Summer for a 4.62kw 14 panels with solis inverter, GivEnergy AC3, 8.2kw battery and my previous solar linked to the AC3 as well and that came to £8200 which was the same as a local quote. Big difference was 0% finance so I got to keep a bit of cash in the bank.

Yes you will need a smart meter that is capable of showing export to register for SEG.

THALL Thanks for confirming the smart meter. I wonder if because the demand is increasing they are doing a bit of profiteering? But then also my supplier said kit was getting hard to source, especially panels. He originally quoted for one type of panel, over 1,500 showing in stock, we agreed the quote two days later and all 1,500 were gone. So we had to switch to another panel brand or wait until February.

chris_p Maybe. I expect their sales people start as high as they feel they can then barter down. I have EON quoting for a second 8.2kw battery December 8th and the guy has already suggested I wait until April when they expect prices to drop which I found rather refreshing!

THALL Yeah that's decent of them, good to hear that kind of thing.

Hi @chris_p
Welcome to the forum!
Yes - great to be able to discuss stuff with other, like-minded folk, isn't it?
Bet you're like a kid with a new toy - I should know, I still am!
Lovely day here - the PV's chucking out the kWs, and the controllers are a-buzzin' . Should have full batteries again, within an hour or 2 - after which I'll get some electric heating on...
Enjoy!

Sykes Haha! I sure am! I think my partner is going to kill me if I say "killowatt hour" again 🤣 Wow, I wish ours was - it is quite gloomy here in North Lincolnshire so only 600w-800w at the moment. Keep looking at the sky for breaks in the clouds but not looking great sadly.

chris_p Sykes both doing better than me. My 7kw array is currently generating 81watts in Norfolk. Heavily overcast here. I expect my batter will be empty by the time i get home in 5 hours time.

chris_p I think my partner is going to kill me if I say "killowatt hour" again

Yes - bit of a passion-killer, that one! Nothing like a bit of tech-talk to rile the other halves!

THALL both doing better than me. My 7kw array is currently generating 81watts

Nothing more depressing than that - thick cloud, and dark underneath; trouble is, it makes you look at the output even more, doesn't it? I think it brings out the sadism streak in us!
If it makes you feel any better, we've had the best of it up t'north now, too.
Both 8.2s have just finished topping-up, though. Sorry. 😆

Sykes Wow, how large is your PV array? We have 4.38kW and only generated 2kW today so far (like anything more will happen now 🤣 )

Sykes Hmm well its not all gloom, just had my SEG application approved so I am now on Octopus SEG rather than Octopus Outgoing which means I can finally switch to Octopus Go Faster instead of just Go. So 5 hours from 0330 instead of 4 hours from 0030. Should be able to pre warm the car and put some appliances on first thing in the morning so win win. Would rather have some sunlight though!!

yandards yea, we were pretty much the same, not so professionally boarded out but it does the job and has been extra secured by our installer. Got space if we decide to add another battery, i don't think that would be on the cards at the moment unless / until I get my heat pump installed (watch this space). We wouldn't often drain more than the existing 8.2 battery. Unless like today I tell the wife, yea plenty in the battery if you get cold just use the oil radiator. Home office was a hot house! oops she says. 😅
THALL Where are you located, I'm more than happy to swing by and take that free curtailed excess off you 😆 .
chris_p Wow thats a decent price for your system. Cheaper than mine, though prices between parts of the country and the "PITA" factor with a loft install probably come into play. We got a 11x345w panels with a 3.6 Hybrid and 8.2 battery for about £8500 installed, though we did also have optimisers fitted to the 5 panels on the south string. I don't think EON would have been interested tbh. Much prefer to use local where I can, got a good price from my installer for a Zappi to go in too, they were great sorting all the grant stuff so I was pretty happy with them. The only pain I found was Home Energy Scotland due to the process of having to get quotes approved for loan funding. Installer was pretty decent knowing that they were the delay not me so weren't banging my door down for invoice payment.
My wife is happy I've found like minded people too, "Thank god, go talk to them about your import / export and give me peace!"
SEG is nice to have but when you realise that with a battery the SEG payment comes to about £1 a month with the battery catching almost every bit, it kind of becomes pointless comparing 3p, 4p, 5p.
@THALL how did you get onto Faster? Did you ring or email? I'm currently on GO but don't know if they would be keen to let me change.

1950 farmers cottage with a mansard roof. 9 year old 3.2kwh PV (great FITS rate) SE facing on the garage roof (Azimuth 138, Tilt 35) originally on an SMA Sunny boy 3kw inverter Last week upgraded to solar edge (major difference 30% ish more). The house & chimneys shadows the garage roof quite a bit from October. At the same time we fitted an AC coupled 8.3kwh GivEnergy by iVoltz. The battery and inverter had to be fitted on the side of the house because of the cable gauge to the garage. Could have replaced it for £1500 but saw no point.

Octopus Go faster 2030:00:30 at 5p. I use an app called Octopus Comparison too keep an eye on what I am using & the cost.

We have a Kia eNiro EV with a MyEnergi Zappi charger, hub and Harvi with CT clamps on the PV, garage grid (restricted due to 6mm UG Garage cable feed which is 14m in length from the house consumer unit.). Harvi CT fitted to the main grid and a new clamp on the inverter battery +ve. Electric cookers with some underfloor heating. Combi Bolier utilising a Hive system with 8 TRVs.

Low wattage bulbs around the house, CCTV & security lights. Baseload is about 100w down from 230w. Average unit cost is down to 7.72 p/kWh from 13p/kWh over the last 14 days since install. Wood stove also fitted so far not used it this year.

Now as to why! Let me be honest Mainly to save money with a hefty dose of helping the environment. The ROI on my PV was last year so I am pleased with that.

THALL Interestingly I went with the Go faster 20:30-00:30 to allow for the extra cost of the lights, tv's, ps5, x box grandchildren etc etc. Saved me a few bob that move. I also charge the battery between that time and it happily powers overnight taking 15%-20% for the stuff that is always on. Routers, fridge CCTV

chris_p Just had mouthful from the long haired general for suggesting she put on the dishwasher at 19:30 to use the last of the battery before the nightly charge kicks in. 🤣

That language 😀

THALL EON couldn't quote me. They couldn't get a salesman/surveyor too me for 4 weeks.

Salibaba You have to email to get an invite to go faster, smart@octoenergy.com you can request to switch to a 4 or 5 hour tariff with time frames of 2130 2230 2330 0030 0130 0230 0330 Though it has taken many emails to get this sorted out. Also check the agreement they send you, I asked for 0330 but they are trying to join me to 2130. They do say if the slot you request is not available they will offer the next nearest time but none of their emails say 0330 wasn;t available.....

mjkelly5a I did want the 2030 option, but it has since been removed. 2130 is the earliest available now

mjkelly5a yeah they are busy, my mate works for EON as a gas boiler fitter and he is being sent all over the country at the moment covering people or rush jobs.

THALL I am now on Octopus SEG rather than Octopus Outgoing which means I can finally switch to Octopus Go Faster instead of just Go.

I thought you had to be on SEG tariff on Go as well as Go Faster?

Martyn Yes, but you can switch to Go and get nothing for export while applying for SEG. To have Go Faster I had to already have SEG setup. Which I find off because I could join Outgoing Agile without applying for SEG etc.

@THALL thanks for that, I'm swithering at the moment. It's only because if I want to run high consumers such as the 8.5kW electric shower, or the missus decides to go mental and run 2 ovens, 3 rings and a kettle at once, the givenergy system only fulfils the first 2.5kW anything over has to be imported at 14.2p. My night rate being 5p is working handy ATM to fill the battery for a slow burn the following day. Missus has even gone out and got a whistling kettle for the induction hob, she only wanted it for the look. I'm lovin that I can stick it on a 1.2kW ring 🤣 .

I get the feeling If I change to Go Faster to get a better favourable time for showers, late night heaters etc, just to lower the gas usage, i'll end up with a day rate of 25p+

Also deffo something iffy there with the SEG stipulation, what about all the people who have an EV & no solar, how are they supposed to get SEG, their logic be a little flawed methinks. Agile outgoing as I'm sure you realise would be superfluous being that it, like the "Octopus SEG tariff", "Outgoing Agile" is an export "SEG" tariff. 😕

Salibaba Totally understand the running costs at the moment. Everything in my home is electric, no gas etc. But for the most part the 3kw limit from my ac3 does what I need apart from meal times when the oven, and a hob or 2 sucks around 5.5kw but thankfully they not a constant draw and go up and down. But I am running out of battery earlier and earlier. Batter starts giving at 0430 and yesterday was empty at 3:30pm. But my master plan is to get the go faster 5 hour 0330 start so I can charge the EV (when it arrives!) and even pre-condition it on cold mornings at 5.5p rather than drain the ev. Plus 7am is ok to turn on the white goods as my lot are all early risers. So 5.5p for 5 hours then the battery takes over. Hopefully second battery soon still only 1 inverter, and more solar soon. But yeah the bills are creeping up slow. Might break £30 for electric this month 🤣

THALL I've had EV for 5 years. I was also of the mindset initially that the pre heat was a major issue that I'd want on cheaper rate. I presume you are talking about climate control.

My mind is not there anymore with experience. My Kia e Niro pulls about 600wh on pre heat, my Tesla was not much more. So pulling it from the car for 15 mins is not really an issue: the 1st couple of regens will put it back.

I'm more concerned about it pulling it from the battery 😆

mjkelly5a I am due an id3, I have no idea how much power it needs for battery warming (I can google it to remind myself), but I did see the suggestion online to leave it tethered if possible.

Out of interest, anyone here have an ASHP, what sqft are you covering, what is the rough draw (I don't know if it tends to be fixed, clicking on and off or variable depending on heat demand), and what would you say is an average daily consumption figure for a coldish day; 0-5c?

Interested to know as now that I'm considering a new ASHP I'll need to factor in my GE battery, I would obviously benefit with it but I might end up considering an additional 8.2 battery VS costing a heat battery If I can configure it in.

Salibaba ME!

96m2, 3000watts when running flat out, it does take a while to get up to that draw. Often sits between 1600 and 2400w. When I get home I will check the data logger on the system and let you know. It shows me kwh for hotwater and heating separately.

What I can say is have a really well insulated home, if you already have underfloor then great. I have a low heat ASHP but I know there are higher heat output ones now.

THALL thanks very much, I was unsure if they only have a single speed or if they can ramp down / up. We got solid wall insulation at the start of the year so are fairly well wrapped up. Will at least need new rads downstairs whatever system we get, we changed to silly little ones during the refurb and the output is pathetic. We didn't know then what we know now. We may consider underfloor since I'll want to insulate under the suspended floor anyway. On our higher days we tend to use about 35-40kWh for gas. Most of that will be the heating system for sure as we don't use very much hot water with having the electric shower and dishwasher. I figure if during the winter we get a COP of 3 then for the same type of average day above, the heating will use around 10-12kWh of electricity. Hard to tell though as we don't currently run heating 24/7.

Salibaba Running the heating 24/7 does take a little getting used to, seems wrong. But it is saving me money and energy so far.

Guzz DNO was interested in the safety cut out wiring, ie PV isolation switches, main AC isolation and interestingly the G99 export limit as setup in the inverter - which I couldn't demonstrate as an end user.

yandards Thanks for that, I'm going down the G99 route too. Which inverter did you go for and I'd be interested in which DNO?

Guzz went for a full GivEnergy setup so their HY 5.0 inverter which can cope with the 6kw of PV I have coupled with the 8.2kwh battery. Figured DC coupled battery PV is the way forward as it only suffers from losses when supporting AC use.

DNO was SSE, chatting to the installer they are not the best to work with and quite slow to respond compared to others they work with.

Installer handled all the G99 stuff as it needs site drawings, circuit layout with safety cutouts etc - should be routine stuff for any MCS approved installer really.

yandards thanks, sounds like a great setup.

THALL Leaving it tethered is the best option to be sure but it really is negligible on the power use in the scheme of things.

The ID3 would power my house for 4.5 days!

What charger are you getting? GivEnergy are working very closely with MyEnergi for Zappi charger integration. Ivoltz spoke to GE support and there is a new module due anytime that'll integrate the lot.

It's not the cheapest but I rarely charged my car from the grid in the summer the solar did most of it. Average monthly bill, doing about 500 miles in the car was £35 no battery.

But there again I mainly use my ebike in the summer.

Salibaba If you have solar Have a good look at MyEnergi systems and their Eddi system to control it all.

mjkelly5a I will be getting a Zappi but I can't order it until VW factory confirm a delivery date. I ordered the car 18th October and the order was accepted by the factory but as yet no delivery date. When I ordered the car the estimate was first week of March.

Salibaba So my data logger for my ASHP only logs data for "months" So October as an example, Heating used 10kwh and Hotwater used 68kwh Last month I used 205kwh from the grid and the rest was from solar. The heating now kicks in more often, last night was minus 1c and I noticed for the 4 hours cheap rate the house sucked down just over 15kw to charge the battery and do hotwater and heating. That is 5kw more than yesterday but it was very cold very windy and wet.

yandards I was re-reading you first post also and you mentioned shading on the lower half of your panels. I assume you have 2 strings across them. Lower and upper string?

mjkelly5a already WAY ahead there 😉 . We have the zappi installed already. Met with a gent at a Daikin centre today actually and was discussing adding a Sunamp to my prospective system, mainly as I know it would be perfect for me in terms of footprint and capacity, but would also 100% be diverter compatable. Eddi was the one I had in mind. I'll probably let the Givenergy battery take priority for charging most of the year and only dump into the heat storage when the GE is full. Come winter I'll probably be charging the heat battery overnight anyway due to low solar output.
THALL I stuck pre-heat on in the leaf this morning for about 10 mins before I left. Though this only does the cabin it would probably chomp about the same down regardless if it was for battery or cabin I imagine. It only took out 0.5kW from the house supply, plus that was it also topping the battery up a little while it was at it, it had been at 75% before I started remote heating. It had cut off charging at the end of my GO cycle last night. Was 76% when I got in the car so only added ₀.3kW to the battery. 0.2 would have been the heating which chimes with what I've seen when the battery has been full and preheating the cabin. Been a while though.

Also thanks for letting me know those figures. Would that be 10&68kW of electrical energy used or heat energy?

@simon_swinburne Hey any chance we could have a countdown timer battery hold feature, added either to the dashboard or future app release? App would be preferable. I'd rather if i'm going to be drawing a large amount from the grid, that I don't chomp my GE battery, eg. electric shower, boosting the car during the day etc. I'd prefer this than having to manually set up a new timer to then have to delete it when I'm done. At the moment it would be more convenient to turn off the whole system at the switch (which i wouldn't want to do)

andrew_bond could you put a radiator in the conservatory?

Salibaba Electrical energy. I will let you know in a couple of days the energy use for November, had a couple of nights at 1c and lower now so energy use will be interesting to see!

@Salibaba yep 2 strings, 8 panels a string with 3kwp on each string - made sense to wire it up as an upper and lower string.

Optimisers are only really going to make a real difference for the 3 months of the year when the sun is really low and we see little of it at those times so its potentially a cost that wont see a decent return.

I've attached the last weeks solcast data and a day of the PV trace when it was nice and sunny - compared to when the solcast card came online when my array vs the forecast tended to track pretty close together. You can clearly see the lower generation on PV string 2 and I'm even getting some shading on the upper array as the sun tracks at this time of year. Another factor is I removed my chimney when the PV went on but my neighbour still has hers - that'll produce yet more spots of shading again reducing potential generation at the time of year I really need it!

PV String
Solcast

wow that's some nice generation.☀️ I'm lucky to peak at 1kW now for this time of the year.

I had the same rationale for our west array. it only gets about 20% of the annual solar irradiance hitting my house so even though it is 6 panels vs 5 on my south they wouldn't make sense to put optimisers on. They are on their own string and would be shaded by an entire neighbouring roof from low sun as a whole string instead of one panel at a time. Murder when other people stuff blocks the sun. How do you hint to a neighbour to trim their tree LMAO. 😆

Pretty much direct south facing at a 45 degree roof angle with 6kwp of panels. As you ideally want a panel angle around 70 degrees of tilt at this time of year I suspect the extra 10 degrees above normal roof pitch is helping.

It's that potential couple of lost kWhs at this time of year that really make the difference to making it through a high usage day just on battery and Go based charging.

I can see my post in here from 5 days ago about my setup but instead of showing my name it showing [deleted] whats that about @simon_swinburne 😆

98.6% imported energy at 5p
1x 3.0 inverter with a 8.2 and a 5.2
2kw solar
1 Quazar V2G.

The V2G is clunky and delayed and fragile. Givenergy makes it work. Without Givenergy it would not be a usable system.

AndrewHolmes I assume you mean extend the gas CH into the conservatory - I could do that, but for now I've switched to using the underfloor electric heating (set to 5C, and 9C during the cheap GoFaster period - it seems to have a more accurate thermostat so doesn't come on until the air temp is under 5C, whereas the panels come on at _10C). So far this looks more cost-effective as a frost protection measure (though not to make the room usable now).

I'm considering getting an energy assessment for the house - if I go ahead with that, no doubt they will have suggestions!

Well to put in my two pennies worth, just had 5.8kw of east facing panels installed at the start of September along with a dual AC3.0/8.2kw GE system. Currently have an Zappi charger installed and awaiting the Harvi/Eddi installation once they turn up with the installer along with the GE EMS.

Long term obviously looking at getting rid of the Gas boiler, but not right this second as don’t have the funds. What we do whether ASHP or something like a tepeo I’m unsure yet. Whilst I’m sure an ASHP would probably be cheaper to run, we have micro bore all through the house (but 22/28mm main runs), and although ive upgraded the rads to type 21s all through, I wouldn’t be suprised the pipe work would need upgrading eventually, which would significantly add to the install costs and disruption. So maybe something like a tepeo if suitable might be better as I wouldn’t have to change anything else and could part charge it using solar/charge at cheap rate overnight to offset the higher cost.

Probably next install will be a mixergy tank if I can persuade SWMBO, although as she rightly points out the current one is only a few years old so might have to wait a bit for that.

In the meantime will check my insulation and windows…

32x395w panels East-West split across 2x 5kw gen1 hybrid inverters each with a 8.2.
Following the PV install I've put both feet in and now have:
Whole home air-to-air heat pump (5kw downstairs, 5kw ducted and 1.5 for office)
Sunamp heat battery
Gas supply capped off and all radiators removed.