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    • Martyn1981
    • By Martyn1981 5th Dec 16, 3:57 PM
    • 9,660Posts
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    Martyn1981
    On-grid domestic battery storage
    • #1
    • 5th Dec 16, 3:57 PM
    On-grid domestic battery storage 5th Dec 16 at 3:57 PM
    Hello!

    Right, as discussed elsewhere, battery storage for self generation (typically PV) is interesting (to some), and gathering momentum in the UK. So here's a thread to discuss it, and watch it develop.

    I've called it on-grid, as off-grid is so much more specialised. And domestic as commercial scale storage, or grid scale can be chatted about on the Green & Ethical energy issues thread.

    So, where are, well this article lists about 20 systems that are available or should be available soon:-

    Introducing CleanTechnica’s New Home Battery Overview Page

    Jumping straight in with personal opinions:-

    Economical - Not yet. Prices are falling fast, the range of products is expanding fast, and large numbers are being deployed in some countries, either because the price of leccy is high (Australia & Hawaii) or because subsidy schemes exist (Sweden & Germany).

    Where are we today. My needs are a 4kWh system. That's 4kWh of useable capacity, which would mean about 8kWh of lead acid (LA), or about 5kWh of lithium ion (Li-ion). My research has found batts in the high £2k and up range. I need the price to be nearer to £1.5k.

    The Tesla Powerwall II, installed is approx £6.5k, which works out at about £2.2k for 5kWh, but of course, it doesn't work quite like that, as smaller systems will cost proportionately more.

    Environmental - Tricky one this (to say the least). Until storage is needed, it's not environmental. Renewable energy (RE) generation currently displaces gas generation, which is a demand follower. Once gas generation is pushed down to zero (at times) we need storage, but we aren't there yet.

    However, to push gas generation down to zero, we need more RE, and to ensure it is viable/economic/profitable, we will need storage - chicken and egg situation.

    The advantage of storage to the environment, is to take peaks of RE and timeshift them to peaks in electricity demand. On a domestic level, this works quite well as PV generates during the day into the afternoon (or evening) depending on the month, so any stored leccy is available for the evening peak 5pm to 7pm.

    That's the background, and now here's a thread to discuss options, prices, economics, and watch things unfold. Enjoy.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
Page 61
    • Solarchaser
    • By Solarchaser 26th Sep 19, 3:48 PM
    • 199 Posts
    • 264 Thanks
    Solarchaser
    Mmmmikey I agree with everything you say there.
    And if I'm moved to metered export at 5p and time of use at points is say 3p, then I'll be doing as you are, but while its borderline I want to self use as much as possible.

    Joe, tbh we havent had a power cut in.... about 10 years I think, so I havent even wired up the eps on my sofar, but I assumed it would continue to charge the batteries if the solar was more than the load, I'm pretty sure I read that the lux will.
    • Martyn1981
    • By Martyn1981 26th Sep 19, 3:58 PM
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    Martyn1981
    I have a very similar view - 12 to 15 years seems about right at today's prices, hence my comment of having a fighting chance but no certainty.

    One great big unknown in all of this is what happens to tariff structures. Based on other posts folks have made here pointing to official data, it seems reasonable to assume that, over the next few years, average electricity prices will remain at about today's level, with the exception of "natural" inflation which is more or less balanced out by interest rates and the opportunity cost of lost interest on any savings used to buy the battery.

    But - and it's a big but - there are a million or smart meters out there and like them or loath them it's a fair guess there are a lot more to come. This opens up the way for more and more time of use tariffs. Let's say instead of paying a flat rate of 13p per kWh you pay a rate between 5p and 20p per kWh depending on time of day. Given that energy company profits are effectively regulated this is likely to result in a bill that is about the same if you assume that average prices remain the same. Logically, you'd use the battery at a time when you were saving 20p per kWh, which makes the case much more attractive.
    Originally posted by mmmmikey
    Sorry for fussing, but having started this thread I've been paranoid not to suggest an economical return, in case I mislead anyone. But your 12-15yr suggestion seems fair, and I've done all my calcs based on warranted life, which I know is unrealistic, but again, worried about misleading.

    Regarding those time of use rates, somewhere, way back I mentioned a package which was (I hope I get this right) 5p at night, 12p or 13p through the day, but 25p week day evenings, for four hours.

    Based on that I could see batteries being excellent, with PV in the summer covering that evening period, and night rate charging of batts to avoid it in the winter, and possibly if battery wear/cost is OK, the 12p period too.

    The downside as i recall was a pretty damn high standing charge.


    Odd question, and I'm basing this entirely on what EV'ers and EV news reports, but is it safe(r) to suggest batts will last well past 10yrs now? I'm, thinking 20 with 70% capacity remaining, or am I getting ahead of my ski's?
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
    • Solarchaser
    • By Solarchaser 26th Sep 19, 4:04 PM
    • 199 Posts
    • 264 Thanks
    Solarchaser
    I dont think anyone can give cast iron guarantees, as apart from anything, the battery chemistry keeps getting tweaks.

    I note the ovo v2g trial wont take gen 1 leafs as they dont like its battery chemistry.

    Buuuuut... all the signs are they will last waaaaay past their warranty periods as long as they are not abused
    • joefizz
    • By joefizz 26th Sep 19, 4:51 PM
    • 412 Posts
    • 365 Thanks
    joefizz
    Joe, tbh we havent had a power cut in.... about 10 years I think, so I havent even wired up the eps on my sofar, but I assumed it would continue to charge the batteries if the solar was more than the load, I'm pretty sure I read that the lux will.
    Originally posted by Solarchaser

    Dont know if we are talking about the same thing but from last weeks experience theres a 120 sec cutover time on the display (configurable) and it switches between outputs so if it senses anything on the input it disconnects the ups, although the actual physical switch time is obviously a lot less.


    Mains power goes off, pv inverter shuts down for safety, sofar battery inverter kicks into ups mode. If you isolate the whole house from the mains and plug the pv solar into the ups output the pv might kick in (timeouts etc) and when it does, if the sofar battery is not isolated from it it will switch off the ups output, switching off the pv inverter, which switches back on the ups, which... and you could go off to infinity with that one.


    Its not supposed to charge through the UPS connection (probably one of those 'this should not occur' messages on the display), it is supposed to isolate the charging/input circuit for safety... .. I did note in the past the amount of 'unrecoverable' fault codes that are listed in the manual!



    I hadnt had a power cut here in about 15 years but in the last few years they have been increasing. The local substation went bang (quite literally, needed an artic with generator running for a week) so looked like an end of life scenario, upstream one was replaced last year with a scheduled power outage and there have been a few faults/brownouts this year. Id advise attaching even a trailing socket to the ups load output, at least then if it does go dark you can attach a long extension lead and run it to the fridge/freezer/light rather than trying to do it all in the dark on an unfamiliar system with perhaps limited access. Probably doing the work is the only way to guarantee it would never be needed ;-) The old saying, better to look at it than for it.
    • joefizz
    • By joefizz 26th Sep 19, 5:07 PM
    • 412 Posts
    • 365 Thanks
    joefizz
    Sorry for fussing, but having started this thread I've been paranoid not to suggest an economical return, in case I mislead anyone. But your 12-15yr suggestion seems fair, and I've done all my calcs based on warranted life, which I know is unrealistic, but again, worried about misleading.
    Originally posted by Martyn1981

    Well since I installed the solar, the electricity prices here have jumped almost 20%... thats brought any 'payback' time down into single figures. If it goes up even half that and savings rates drop as they have been doing and rocs and export returns keep pace with inflation then by the end of the warranty period (7 years) it could have reached break even....
    ...lots of ifs ands and buts there. They could cut ROCS/export completely and then forget it or decide all this free nuclear energy should be given away to us free etc etc.


    One thing I do know though is that I get my quarterly electricity bill next week and like the last quarter should be in the order of a fiver....


    Without rocs/fit/export it is difficult to even come close to a payback in reasonable lifetime unless prices go through the roof again and savings rates go negative....



    Saying that though the economics of buying an iboost at 200 quid were never going to work for me so ymmv.


    As Ive mentioned a couple of times, Ive always thought about replacing parts of the system as a matter of course but the majority of the expensive bits have been done (framing, installation, wiring, buying the physical boxes etc).
    Ive just received a new pc box from dell,my old one is almost 7 years old and is a bit like triggers broom, hd replaced 6 years ago with ssd, secondary hard drive replaced at least once, cpu fan and case fan have both been replaced by quieter versions. All the original components are still in use somewhere for some other purpose (the dell I replaced it with is in the studio and the one before that is in bits in the loft for the oft vaunted home media system Ive threatened to make every winter since.)


    Im quite heavy on rechargeable aas and although they drop off after about 3 years of use (abuse) they still are useful for the garden leds, putting in to an old rechargeable dremel, just today recharged 4 10 year old ones I use to power a sensor light under the bathroom cabinet etc etc.


    At the very least we should be able to recover most of the batteries we are all using, or sell on for spares/repair etc.

    When I was in my 20s I bought a lot of stuff with lifetime guarantee, now Im happy with the lidl 3 year ones ;-) Give it another 5 years and I wont be bothered with use by dates ;-)
    • 1961Nick
    • By 1961Nick 26th Sep 19, 5:11 PM
    • 1,129 Posts
    • 3,692 Thanks
    1961Nick
    Sorry for fussing, but having started this thread I've been paranoid not to suggest an economical return, in case I mislead anyone. But your 12-15yr suggestion seems fair, and I've done all my calcs based on warranted life, which I know is unrealistic, but again, worried about misleading.

    Regarding those time of use rates, somewhere, way back I mentioned a package which was (I hope I get this right) 5p at night, 12p or 13p through the day, but 25p week day evenings, for four hours.

    Based on that I could see batteries being excellent, with PV in the summer covering that evening period, and night rate charging of batts to avoid it in the winter, and possibly if battery wear/cost is OK, the 12p period too.

    The downside as i recall was a pretty damn high standing charge.


    Odd question, and I'm basing this entirely on what EV'ers and EV news reports, but is it safe(r) to suggest batts will last well past 10yrs now? I'm, thinking 20 with 70% capacity remaining, or am I getting ahead of my ski's?
    Originally posted by Martyn1981
    The Octopus TOU Go Tariff is geared towards EV owners but should suit anyone with a domestic battery. Prices will obviously vary depending on location, but the 5p/13.4p (25p S/C) I've been quoted seems to be very competitive ... it wouldn't be bad without a battery! Not having a punitive peak rate tariff removes any risk of having to change your habits or trying to train your other half!
    4kWp (black/black) - Sofar Inverter - SSE(141°) - 30° pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • Martyn1981
    • By Martyn1981 27th Sep 19, 8:59 AM
    • 9,660 Posts
    • 14,553 Thanks
    Martyn1981
    Oops, still fussing, wish I'd kept my mouth shut and saved the last remnants of my dignity now.

    I should have pointed out I only meant myself regarding economics and paybacks. I know that's stupid, but I worry about misleading people. Everyone else should spread the info thick and fast.

    The great news now though, is that when I started this thread I think I knew very little, but perhaps a tad more than others. Now I'm like a dog trying to comprehend a smart phone. So I appreciate all the great advice from the 'doer's' and hope info on economics keeps flowing freely.

    Mart (the worrier).
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
    • mmmmikey
    • By mmmmikey 27th Sep 19, 9:27 AM
    • 447 Posts
    • 731 Thanks
    mmmmikey
    Now I'm like a dog trying to comprehend a smart phone.
    Originally posted by Martyn1981

    I might be going a bit off topic here, but I have a cat that I've taught to use an iPad. She knows how to start the game where the mouse runs erratically across the screen and squeaks when she taps it with her paw. I have to say, though, she's not very good at remembering to plug it in and charge it up. And I expect it's going to be even harder to get her to charge it overnight using cheap rate electricity, she doesn't even seemed to have grasped the basic concepts of energy saving
    • Martyn1981
    • By Martyn1981 4th Oct 19, 4:06 PM
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    Martyn1981
    Just a news item on another storage trial:

    Residential solar and storage set to provide flexibility in local energy market trial

    Residential solar and storage is to provide flexibility to UK Power Networks (UKPN) as part of a new local energy market (LEM) trial in Brixton.

    Elmore House – a block of flats in South London – is already taking part in Project CommUNITY, a peer-to-peer energy trading trial run by EDF that sees residents trade energy generated from solar and stored in batteries between each other.

    Now that project will go one step further, with an LEM to run out of the flats, testing how residents can support local power supplies by offering flexible power services to respond to supply and demand. The project, dubbed Urban Energy Club, is being run by EDF, UKPN and Repowering London.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
    • shavy65
    • By shavy65 5th Oct 19, 12:24 PM
    • 480 Posts
    • 1,463 Thanks
    shavy65
    Anyone heard of projectsolarUk ltd?
    Got a flier through the door last week, they`re working in partnership with Duracell to provide domestic battery storage.
    Not much info except: -

    Scalable up to 6 KW
    Continuous 3 KW
    10 year warranty on battery

    No mention of price, think they`re based in Staffordshire.
    3.975 kWp System, South facing, 21 degree pitch, 15 x Canadian Solar Elps, Samil Inverter, location NE Scotland (Fraserburgh) Bring on the Sun
    • Hexane
    • By Hexane 5th Oct 19, 12:46 PM
    • 156 Posts
    • 178 Thanks
    Hexane
    Anyone heard of projectsolarUk ltd?
    Originally posted by shavy65
    There was or is a company called Project Solar who have received some negative commentary on this forum:

    https://forums.moneysavingexpert.com/showthread.php?t=5257124
    https://forums.moneysavingexpert.com/showthread.php?t=5953765
    https://forums.moneysavingexpert.com/showthread.php?t=5921820
    https://forums.moneysavingexpert.com/showthread.php?t=5925262
    https://forums.moneysavingexpert.com/showthread.php?t=5923050
    https://forums.moneysavingexpert.com/showthread.php?t=5919271

    Don't know if the company you name is the same or a different company?
    7.25 kWp PV system (4.1kW WSW & 3.15kW ENE), Solis inverter, myenergi eddi & harvi for energy diversion to immersion heater. myenergi hub for Virtual Power Plant demand-side response trial.
    • shavy65
    • By shavy65 5th Oct 19, 1:56 PM
    • 480 Posts
    • 1,463 Thanks
    shavy65
    So, I had already pushed the `Enquire` here button before I posted on here.....so, yeah, regretting that now after reading the above reply!

    No harm done anyway, was only going to get a rough price to share with all interested parties on here anyway.

    As always, cheers!
    3.975 kWp System, South facing, 21 degree pitch, 15 x Canadian Solar Elps, Samil Inverter, location NE Scotland (Fraserburgh) Bring on the Sun
    • Hexane
    • By Hexane 5th Oct 19, 9:03 PM
    • 156 Posts
    • 178 Thanks
    Hexane
    So, I had already pushed the `Enquire` here button before I posted on here.....so, yeah, regretting that now after reading the above reply!
    Originally posted by shavy65
    I think we've had some posters on here who had not just enquired, not just had a quote, but actually gone ahead and signed a credit agreement or paid a deposit! But thankfully consumer protection law in this country is still (for a few more weeks at least?) fairly robust, so they were able to cancel and get their money back.
    7.25 kWp PV system (4.1kW WSW & 3.15kW ENE), Solis inverter, myenergi eddi & harvi for energy diversion to immersion heater. myenergi hub for Virtual Power Plant demand-side response trial.
    • joefizz
    • By joefizz 9th Oct 19, 5:48 PM
    • 412 Posts
    • 365 Thanks
    joefizz
    Just had this quarters electricity bill in and its 7.68. Thats down from 8.74 from the same quarter last year.
    So thats about a quid saved by being away for a month...
    • Reed_Richards
    • By Reed_Richards 9th Oct 19, 7:24 PM
    • 607 Posts
    • 372 Thanks
    Reed_Richards
    In my area the MSE Energy Club is giving me access to an E.ON tariff ("Fix 1 Year Exclusive Autumn 2019") with, for me, a 5.25p per day standing charge and 15.551p per kWh. This seems an attractive tariff for anyone who consumes only small amounts of electricity from the grid because they have a battery (or for other reasons). Of course if your electricity consumption is sufficiently small then a zero standing charge tariff will win-out.
    Reed
    • JKenH
    • By JKenH 13th Oct 19, 9:51 AM
    • 1,116 Posts
    • 3,240 Thanks
    JKenH
    I am thinking that electricity prices will become more volatile as more wind generation is rolled out (see other thread Discussion ... ASHP(Air/Air) with Solar pv). The opportunities for those with batteries to trade their electricity will therefore grow leading those who can afford them to install even bigger batteries.

    At what point will HMRC decide this is a business or local authorities and insurance companies decide you are running a business from home?
    Northern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps, Nissan Leaf (plus some ICEs )
    • Reed_Richards
    • By Reed_Richards 13th Oct 19, 11:18 AM
    • 607 Posts
    • 372 Thanks
    Reed_Richards
    Given the thinking on taxation of FIT payments
    http://www.yougen.co.uk/blog-entry/3009/Are+payments+for+domestic+microgeneration+liable+t o+income+tax'3F/
    I think it is likely you would find yourself liable to income tax on electricity trading profits.

    If electricity trading were deemed to be a business then you could offset the cost of the battery against profits which would ensure that you wouldn't make any profits until you had paid-off the cost of the battery. That would be a considerable advantage over simply declaring any profits as part of your income.
    Reed
    • Heedtheadvice
    • By Heedtheadvice 15th Oct 19, 10:53 AM
    • 1,355 Posts
    • 656 Thanks
    Heedtheadvice
    Suggestion for Joefizz....


    Considering what you wrote about your backup freezers being 'offline' for a period owing to trips:


    Have you considered having a mains monitoring circuit that would switch on a sounder if there was a failure? Does not prevent issues but may draw them to your attention!



    Could also be of use for anyone who needs warning of lack of power to any circuit!
    • joefizz
    • By joefizz 15th Oct 19, 12:07 PM
    • 412 Posts
    • 365 Thanks
    joefizz
    Suggestion for Joefizz....


    Considering what you wrote about your backup freezers being 'offline' for a period owing to trips:


    Have you considered having a mains monitoring circuit that would switch on a sounder if there was a failure? Does not prevent issues but may draw them to your attention!
    Originally posted by Heedtheadvice

    Thanks for the reminder, must get back to sorting out the audible alarm! I did have other notifications set up but it was only one tripped RCD in an outbuilding. Im going to be working on the garden lighting system next week so might tie that in as well.



    Ive since redesigned it as I hadnt considered that just one RCD would go and had primarily thought about total mains loss.


    On doing further research (my supplier denied there was any problem) I found a brownout in my inverter stats the day after I left. Neighbours were also on holiday and as I was away for a month it really wouldnt have helped but Ive since split them across circuits so a similar loss wont be as great (and will time running down the freezers better before I go away!)
    Probably just unlucky with the brownout, high ambient temperatures that day and the large freezer (or both) kicking in at the same time.


    Timely post as over the weekend I updated my battery inverter firmware. The manufacturer did ask why I needed to do it because generally if its working, leave well alone (which I agree with) but I said Id prefer any bug fixes included.
    The latest version of the software has some changed screen layouts and finally I can set the battery reserve down to 15% (which for some reason would never stick for me before). Of course its now out of step with the published manual and I havent had enough sun the last few days to test if it works better or not ;-)
    Schoolboy error though in that the update firmware micro sd card also had some date named directories which I assume is the legacy stats reporting and got distracted and didnt download those to the pc before updating, will look at those later.


    The reminder also reminds me to go out and check the oil level as well, normally fill up this time of year with a years worth so when/if it ever stops raining I'll go out and take a look.
    • Martyn1981
    • By Martyn1981 22nd Oct 19, 8:50 AM
    • 9,660 Posts
    • 14,553 Thanks
    Martyn1981
    Here's something funny(ish), if you watch this episode of Tesla Time News at approx 45min 40secs they experience a powercut (falling tree outside), and the house switches to Tesla Powerwalls very smoothly.

    This may be old news to the battery geeks, but I was quite impressed.

    Tesla Time News - Model Y Spotted!
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
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