Solar panels plus battery storage - anyone have that?

[PetrolDave]

46 minutes ago, Phil-E said:

it just has a standard plug socket on the end.

How does that avoid generating potential harmful voltage on the plug pins when it's not plugged into anything?

[J.R.]

There will be an isolating relay that is only energised from the mains connection so that no voltage can be present on the mains plug. At least that is how I would do it.

 

It would still freak me out looking at the disconnected plug attached to the solar array.

 

When I had a back up generator for the infrequent power cuts at my UK house I begrudgingly made up a lead with a 13a plug on each end, it was a portable generator and for the times it was needed it was not worth doing the job properly with an auto changeover switch.

 

Even though it was only me living there and using the genny I kept the lead away from the genny and under lock and key, I was also religious in following my safe connection and disconnection procedure, the only drawback was a daytime power cut & not knowing from neighbours lights if the power had come back on.

[Phil-E]

Yeah it shuts off when it's not plugged into a live socket. So if there's a power cut it will also shut off etc.

 

I also just found a tutorial that runs some little command over a terminal to boost the maximum output to 800w. See if it makes a difference now we're getting some good sunshine.

[cheezemonkhai]

The Eddie question is interesting to me because I have no idea how much excess we will have.

 

going to be a 5kW inverter and 10kWh battery, plus a 70ish kWh EV attached to a zappi.

 

Options I see are:

 

1) leave as is

2) fit an eddi

3) add another 5kWh battery 

 

Battery is probably 2-3 times the cost of an eddi and wouldn’t brink the summer benefit. In winter however and extra 5kWh (to make 15kWh) charged at cheap rate would see us through a typical day with no peak useage.

 

On the balcony generator, there are a few companies advertising them in the Uk, but they look like they have the German plug on them. Some have a fancy uk box too but whilst I get the attraction I also get twitchy around double male plugs.

Edited 9 June, 2023 by cheezemonkhai

[Colin170CR]

Or 4, get an all-in-one heat pump hot water tank & use solar / battery power to heat hot water at 3 x the efficiency of an immersion heater. 

I have an Eddie at the moment which serves a vented indirected SS cylinder & immersion heater. My gas boiler boosts the HW early in the morning & the Eddi tops it up during the day with excess solar. I don't have any grid power going into the immersion at all.  

 

My long term plan is to come off gas so I need an efficient means of producing hot water once the boiler is gone which can work when there is no solar. I cannot use an air to water heat pump system cos my radiator pipes are too small (10mm microbore). I therefore plan to go for an Air to air heating / cooling system but need a separate solution for hot water. 

An immersion heater will only ever be 100% efficient & come winter will need grid power in the absence of solar. 

An all-in-one unvented Heat Pump HW cylinder heats water directly at an average efficiency of 288-350% depending on the season, & the water temp required. Example.

Vaillant HW HP

 

The only snag with these HP HW cylinders is that they they need ducting to & from outside & they make a noise (like a big fridge running) so they can't really be put in an airing cupboard or near bedrooms. Favourite locations for them are the loft (if your hatch is big enough - mine isn't) or, the garage or a utility room. 

They are quite popular on the continent but only just starting to make headway in the UK. 

There are a few YT vids on them as well.

 

Food for thought.

 

[PetrolDave]

On 08/06/2023 at 15:57, J.R. said:

There will be an isolating relay that is only energised from the mains connection so that no voltage can be present on the mains plug. At least that is how I would do it.

That's fine until the lead is unplugged after a power cut with the generator still running, as the generator output will still be connected to the plug as surely the relay will now be being energised by the generator output?

 

Needs to be made clear that the generator must be turned off before unplugging the lead?

[Phil-E]

56 minutes ago, PetrolDave said:

That's fine until the lead is unplugged after a power cut with the generator still running, as the generator output will still be connected to the plug as surely the relay will now be being energised by the generator output?

 

Needs to be made clear that the generator must be turned off before unplugging the lead?

 I can unplug the inverter under bright sunshine and touch the pins. There is no power when it's not connected to a live socket. There's obviously some sort of smart sensing if there is voltage on the pins before the inverter kicks in.

[Gaz]

On 06/06/2023 at 15:46, Gaz said:

Early days and things like panel numbers and other bits and pieces will need to be discussed, but I'm quite looking forward to delving in.

 

Well installation was finalised yesterday 👍

 

We ended up with nine panels in a 3x3 pattern due to the shape and size of our roof.

 

I'm slowly learning how everything works, but they're currently generating 3kw, the battery is at 100%, the water in the immersion tank is way too hot (plumber coming to install a controllable immersion), but I can stop the Eddi via an App on my phone so it's at least not boiling the water continuously.

 

And I'm now exporting 2.9kw to the grid:

 

 

Which, although we've got a smart meter, I'm guessing means nothing until we get our tariff (Octopus) changed, presumably to Flux.

 

One thing that's crossed my mind - should I leave it all on Eco until the tariff change?  I see I can charge the battery off peak (2am to 5am) and then export it at peak times, once on the Flux tariff, which seems financially sensible.

 

Are there any other 'top tips' people can suggest I ought to be doing?

 

Ta

 

Gaz

 

[Colin170CR]

4 hours ago, Gaz said:

 

Well installation was finalised yesterday 👍

 

We ended up with nine panels in a 3x3 pattern due to the shape and size of our roof.

 

I'm slowly learning how everything works, but they're currently generating 3kw, the battery is at 100%, the water in the immersion tank is way too hot (plumber coming to install a controllable immersion), but I can stop the Eddi via an App on my phone so it's at least not boiling the water continuously.

 

And I'm now exporting 2.9kw to the grid:

 

 

Which, although we've got a smart meter, I'm guessing means nothing until we get our tariff (Octopus) changed, presumably to Flux.

 

One thing that's crossed my mind - should I leave it all on Eco until the tariff change?  I see I can charge the battery off peak (2am to 5am) and then export it at peak times, once on the Flux tariff, which seems financially sensible.

 

Are there any other 'top tips' people can suggest I ought to be doing?

 

Ta

 

Gaz

 

I've had my system since March & I'm still fiddling with it daily. I haven't changed my tariff yet either although that I will have to do soon. Now we have an EV we are capturing more excess solar than before. Last month we used 97% of what we generated with only 3% going back to the grid. 

 

I leave my GE Inverter on ECO mode & time charge the battery overnight on "cheaper" lekky. How much to charge it up to depends on the weather forecast for the next day & it's predicted usage. There's no point charging the battery up to 100% when the sun can do it for free the next day. In good weather we get sun from 6am so the 9.5kW battery (thinking about doubling it's capacity) can get charged from 30% to 100% by 11am & then it becomes a case what can we turn on to save giving excess solar it back to the grid - currently for free!! As I said we now have an EV so when it's not being used that stays plugged into the Zappi charger to suck up any excess solar, along with the Eddi to heat up the HW tank (we're still on gas CH & Hot water). Definitely get yourself a thermostat controlled immersion heater otherwise there is a serious risk of scalding with overheated HW. Mine is set to 60c. 

My car charger is set as priority over the Eddi on the MyEnergy App so if there is excess solar it goes to the car first, if plugged in, then the Eddi. I'm still learning the GE App which has a load of fine tweaking features. I also get weekly usage reports from GE so I can see where the energy is going & what I might need to tweak.   

Obviously as we approach winter daytime generation is going to drop off & you will be need to be charging your battery overnight on cheaper rate & using it during the day to offset the high daytime rate. You will therefore not be wanting to export anything back to the grid. 

 

Below is one of the graphs from my last weeks report. 97% used & only 3% went back to the grid.

I'm thinking about adding more panels to the front of my house to catch the late afternoon sun & adding another 9.5kWh battery to give me 19kW of storage. The new GE All In One solution is another possible option. 

 

Ultimately I want to ditch the gas CH & install an air to air heat pump system. An air to water HP system is no good for me because I have 10mm diameter microbore pipework to all the rads in the house & to rip them all out & upsize to 15mm or larger is not cost effective & would involve a massive amount of upheaval.

Going green ain't cheap & the pension pot has taken a bit of a hammering!!!

 

[Gaz]

19 minutes ago, Colin170CR said:

There's no point charging the battery up to 100% when the sun can do it for free the next day.

 

Thanks Colin - this was what I was thinking, but wondered if I was missing something in my naivety.  Our battery (5.2 - we went with the supplier's recommendation) was at 100% by 11:30am.

 

19 minutes ago, Colin170CR said:

Definitely get yourself a thermostat controlled immersion heater otherwise there is a serious risk of scalding with overheated HW. Mine is set to 60c. 

 

Plumber popped in today, and a thermostat immersion is being installed tomorrow 👍

 

Gaz

 

[Colin170CR]

7 minutes ago, Gaz said:

 

Thanks Colin - this was what I was thinking, but wondered if I was missing something in my naivety.  Our battery (5.2 - we went with the supplier's recommendation) was at 100% by 11:30am.

 

 

Plumber popped in today, and a thermostat immersion is being installed tomorrow 👍

 

Gaz

 

Our installer initially offered us a 5.2kW battery, I'm guessing because it made their price look cheaper against others who quoted. However, I paid extra for the 9.5kW which I now think will be too small when we hit the winter months with little or no solar to top it up during the day.

 

Ultimately I'd like to be able to run the whole house on battery power all day & evening during the winter with just an overnight recharge. The single 9.5kW batt won't do it which is why I'm looking to double its capacity or maybe even more. I think up to 4 or 5 of the GE Gen 2 9.5kW batteries can be connected to a single inverter so potentially 38-47kWh of storage is possible. 

 

Talking of inverters, ours is a 3.6kW Hybrid & it is limited to a max output of 3.6kW when in battery mode which we are finding is not really enough for everything that we may have running in the house at the same time E.g. if we have the washing machine (3kW), oven (3-5kW), kettle (2kW) & dishwasher (3kW) on all at the same time during the day (potentially a maximum 13kW load) then the inverter can only supply 3.6kW via the battery so the additional 9.4kW has to come directly from the grid at the expensive day rate. As a result we find ourselves staggering the use of appliances on timers to minimise the max load on the inverter to less than 3.6kW at any one time.

Given that I want to go to an A2A heat pump system at some point we really do need a bigger output Inverter to cover that additional load as well. This is something I wish I had known / realised when we bought our system. That said, the next size up 5.2kW GE Hybrid Inverter is still limited to only 3.6kW in battery only mode so it does not give us anything extra. To get more inverter output power we'd have to consider something like the new GE All In One battery (13.5kW)/ inverter system (max 7.2kW output) but it is not (yet) compatible with our existing 9.5kW battery! It's even more expensive & what do we do with our existing inverter & battery if we switch to the All in One? The main advantage of the AIO is that it give you whole house power supply in the event of a power cut (max 7.2kW that is).

 

I got a quote for an extra 5 panels, additional 9.5kW battery & a 5.2kW Inverter (which I wouldn't bother with now) for just over £11k with 0% VAT (because I'm having extra PV panels. No PV panels would mean adding 20% vat to everything). This includes scaffolding, DNO application, Pigeon protection & modifications to my existing system. I could knock £2.8k off that price to stick with my existing 3.6kW inverter & ditch the associated changeover work but it's still quite a chunk of change & doesn't solve the problem of extra inverter output in battery only mode that I'm looking for. 

 

I tell you, selecting the right solar / battery system for your home is a minefield. Add to that the new products that are available now that weren't available when we signed up for our system at the back end of last year makes it very frustrating & very expensive. 

 

Good luck on your Solar / Battery journey. 

 

[Gaz]

I know I'm in the beginning of the honeymoon period, but as the evening quietens down, 15 minutes ago we were at:

 

 

So unless it's all tosh, our panels have generated, on a day with more cloud than sun, 6.3Kwh more than we've used.  The HW's been off since midday, and is still too hot.

 

It'll change of course as the days shorten, but at the moment it's hard to feel sceptical.  Heaven forbid, I'm now wondering if I should swap the GTI for an EV 😳

 

G

[Colin170CR]

3 minutes ago, Gaz said:

I know I'm in the beginning of the honeymoon period, but as the evening quietens down, 15 minutes ago we were at:

 

 

So unless it's all tosh, our panels have generated, on a day with more cloud than sun, 6.3Kwh more than we've used.  The HW's been off since midday, and is still too hot.

 

It'll change of course as the days shorten, but at the moment it's hard to feel sceptical.  Heaven forbid, I'm now wondering if I should swap the GTI for an EV 😳

 

G

Ha Ha.

I had always planned to get an EV  to make the most of the solar system during the summer & to only charge the car from home. It was sad to let my wife's Karoq Edition go to make way for the EV but I have to say the little Kona (used car purchase) is a bit of a pocket rocket & will see off many a GTi quite easily. 201Bhp & instant torque makes it a hoot to drive briskly. Granted it's not as plush inside as the Karoq & the ride is a bit bumpy on uneven roads but SWMBO loves it so that's all that matters. If Skoda had something similar we would have considered it but the Enyaq is far too big for what we need. 

Also, I reckon we've already saved around £350 in 3 months on fuel against the old old Karoq & my Superb which I haven't used as much as a result of having the EV which is now our go to vehicle for all local trips. Our longest trip so far in the EV was a 160 mile round trip to Surrey without having to charge en-route or at our destination & it still had approx 120 miles of range left when we returned. It's averaging 4.8miles/kWhr or, over 160mpg as a petrol equivalent. I have to say I am enjoying the EV driving experience but every now & again I need a blast in my 280 Superb to satisfy my inner petrol head.  

[robt100]

On 11/09/2023 at 20:48, Gaz said:

I know I'm in the beginning of the honeymoon period, but as the evening quietens down, 15 minutes ago we were at:

 

 

So unless it's all tosh, our panels have generated, on a day with more cloud than sun, 6.3Kwh more than we've used.  The HW's been off since midday, and is still too hot.

 

It'll change of course as the days shorten, but at the moment it's hard to feel sceptical.  Heaven forbid, I'm now wondering if I should swap the GTI for an EV 😳

 

G

Looking good Gaz. Been pondering over getting solar in the next year or so, seeing your generation vs consumption (which is close to what we use, albeit slightly higher than us) does make me think it'd be worth it with a decent battery. Would be stuck with a 3.6kw inverter though as a lot of homes here have solar and i reckon if i go anything bigger, then its gets into that nasty "upgrade the power network" situation to feed back to the grid at over 3.6kwh😬

[Gaz]

38 minutes ago, robt100 said:

Looking good Gaz. Been pondering over getting solar in the next year or so......

 

Ta rob.  I'd pondered, dithered, pussyfooted and been generally sceptical for a fair while.  Now we've done it, I wish I'd done it sooner, even being as overly cautious as I am.

 

I asked advice from the installer on battery size, and they said we'd be fine with a 5.2, so that's what we did.  We can always upgrade capacity at a later date, and given Colin's comments it's certainly something to consider.

 

We can't change tariff just yet, but will asap, so we can 'sell' what's being exported.  In the meantime, I had cheese on toast yesterday - toaster on for frozen bread, then grilling the CoT, boiling the kettle for a cup of tea, and I used no electricity other than what the panels were providing 👍😎

 

Gaz

 

[Gaz]

On 11/09/2023 at 19:32, Gaz said:

Plumber popped in today, and a thermostat immersion is being installed tomorrow 👍

 

Immersion fitted yesterday 👍  Plumber said the immersion end cabling was unsafe, and he was taking the old immersion to the National History Museum, because it was older than him! 🤣

 

Sparky came today and installed a new cable.  He confirmed the old cable was a bit worse for wear:

 

 

Absolutely no insulation left on the immersion end 😱

 

Scaffolding went today, so hopefully that's us sorted for a good while.

 

Gaz

 

 

 

[Warrior193]

19 minutes ago, Gaz said:

 

Immersion fitted yesterday 👍  Plumber said the immersion end cabling was unsafe, and he was taking the old immersion to the National History Museum, because it was older than him! 🤣

 

Sparky came today and installed a new cable.  He confirmed the old cable was a bit worse for wear:

 

 

Absolutely no insulation left on the immersion end 😱

 

Scaffolding went today, so hopefully that's us sorted for a good while.

 

Gaz

 

 

 

Yep, that's what we call in the trade, Fubar.

[Colin170CR]

44 minutes ago, Gaz said:

 

Immersion fitted yesterday 👍  Plumber said the immersion end cabling was unsafe, and he was taking the old immersion to the National History Museum, because it was older than him! 🤣

 

Sparky came today and installed a new cable.  He confirmed the old cable was a bit worse for wear:

 

 

Absolutely no insulation left on the immersion end 😱

 

Scaffolding went today, so hopefully that's us sorted for a good while.

 

Gaz

 

 

 

Yikes. How did that not blow a fuse / trip a breaker?  

[Gaz]

42 minutes ago, Colin170CR said:

Yikes. How did that not blow a fuse / trip a breaker?  

 

I think that's known as there but for the grace of God...

 

Sparky said he was surprised nothing had blown.  In reality, I think the insulation had crumbled to now't, but because there wasn't any movement, there was space left (just) between the wires.  The plumber had taped it up with electrical tape, but we left it all switched off to be on the safe side.  Spark said it was good we had a new consumer unit (installed 2021) so had a layer of protection there too.

 

G

[Colin170CR]

2 minutes ago, Gaz said:

 

I think that's known as there but for the grace of God...

 

Sparky said he was surprised nothing had blown.  In reality, I think the insulation had crumbled to now't, but because there wasn't any movement, there was space left (just) between the wires.  The plumber had taped it up with electrical tape, but we left it all switched off to be on the safe side.  Spark said it was good we had a new consumer unit (installed 2021) so had a layer of protection there too.

 

G

I'm surprised the sparks didn't pick it up when you had the new consumer unit installed in 2021. 

I had a new CU when we had the solar put in & the electrician tested & visually checked every single electrical connection in the house & loft before they would / could sign it off. 

[Gaz]

On 14/09/2023 at 20:12, Colin170CR said:

I'm surprised the sparks didn't pick it up when you had the new consumer unit installed in 2021. 

 

And we had to have bathroom and kitchen lights changed in order to pass the full house inspection/sign off that happened after the CU was moved and updated 🙄

 

 

We really need the MCS Certificate so we can change tariff.  We've already exported more than we use, and we're not far short of having generated double that.

 

Gaz

 

 

[Colin170CR]

3 hours ago, Gaz said:

 

And we had to have bathroom and kitchen lights changed in order to pass the full house inspection/sign off that happened after the CU was moved and updated 🙄

 

 

We really need the MCS Certificate so we can change tariff.  We've already exported more than we use, and we're not far short of having generated double that.

 

Gaz

 

 

Why did you not get an MCS certificate?  

Think I have one somewhere in my handover pack.

 

You need an EV to suck up some of that excess solar🚗

Don't worry though with the shorter days & winter weather coming your solar generation will drop off considerably so you'll need everything you can generate. 

 

I switched to Octopus Go a week ago (electric only, Gas stays on variable rate) to get a better night time tariff - 9p/kWh instead of the 15p I was on previously. The only snag is the lower rate night tariff only lasts from 00.30 to 04.30am which is not really long enough to charge the car right up if it's less than a 1/3 full. The house battery charges in about 2hrs  so that's not a problem. I looked at Intelligent Octopus but our car (Kona) & charger (Zappi) weren't compatible yet? Don't know what that's all about because the car & charger are both very popular. Not everyone wants or can afford a Tesla.    

[Gaz]

16 minutes ago, Colin170CR said:

Why did you not get an MCS certificate?  

 

All part of a process, or so we're told.  After a second chaser, we got it this afternoon.  It seems we now wait to be contacted by our DNO with our MPAN number.  I don't understand all the mumbo jumbo.

 

Had a minor panic yesterday as I changed our wi-fi log-in, which kicked a lot of things out, including the Eddi and Inverter.  Got the Eddi linked up, but none of the password or log-in details for the Inverter worked 😢  As it turned out, our step-grandson had told a pack of lies about using our wi-fi (which he doesn't have access to), little sod, and when I changed the router password back, the Inverter connected straight back up.  Phew! (The Inverter goes dormant without a Wi-fi connection).

 

G

[Colin170CR]

22 minutes ago, Gaz said:

 

All part of a process, or so we're told.  After a second chaser, we got it this afternoon.  It seems we now wait to be contacted by our DNO with our MPAN number.  I don't understand all the mumbo jumbo.

 

Had a minor panic yesterday as I changed our wi-fi log-in, which kicked a lot of things out, including the Eddi and Inverter.  Got the Eddi linked up, but none of the password or log-in details for the Inverter worked 😢  As it turned out, our step-grandson had told a pack of lies about using our wi-fi (which he doesn't have access to), little sod, and when I changed the router password back, the Inverter connected straight back up.  Phew! (The Inverter goes dormant without a Wi-fi connection).

 

G

Inverter - yes it goes dormant with no wifi. Our stopped working a few weeks ago. Wifi was fine so that was not the problem. After checking online forums I rebooted my router & hey presto the inverter came back into life. It seems the inverter / router may loose connection from time to time but neither is able of reconnecting automatically? Not sure why this is & it certainly ain't progress in my book.

All this tech is great but it's prone to having tantrums & seems to me to need constant attention. 🤞since then ours has behaved OK. 

I'm still wondering about getting more panels & another battery. 🤔

[Colin170CR]

Fast forward 6 months & I was right.

Our 9.5kWh house battery is not big enough in winter. Not helped by my wife who seems to have the washing machine, HP Tumble dryer, floor steam cleaner & just about every other electrical appliance in permanent use!!!

As a result I'm adding another 9.5kWh GivEnergy battery (19kWh in total) & 5 extra 425watt Perlight panels (15 in total) which will go on our NW roof to get the afternoon & evening solar that our existing ESE array misses. 

The scaffolding went up today & the rest gets done next week🤞.

 

Based on 1 year of data I reckon we've saved around £2,200 on electric & that includes the additional needed to charge our EV overnight every other night & fuel saving on the old ICE car. Extra panels & battery should improve on this going forward.

I switched to Octopus Intelligent Go a few weeks ago so now we get 6hrs @7.5p/kWhr overnight for charging the EV, batteries & running time delayed household appliances.

 

I'm also looking at Heat Pump Hot Water cylinders (Mixergy iHP) or, a Sunamp Thermal battery for hot water. This would replace our existing indirect gravity fed HW cylinder. Only snag with this is that we will have to convert to mains pressure hot water which will involve ripping out booster pumps & re-plumbing some areas. The upside is that I should be able to get rid of the cold water tank in the loft - but not the boiler F&E tank. The existing gas boiler will stay for now because it's only 5 years old & also because I can't yet come to terms with the amount of upheaval & mess installing an A2W heat pump will generate (10mm microbore pipework to all radiators). I may eventually go for an Air to Air HP system which gives us cooling as well as heating. No grants available for these at present but they are easier to install & cheaper than A2W systems.

 

Slowly slowly catchy monkey.