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    • Martyn1981
    • By Martyn1981 5th Dec 16, 3:57 PM
    • 5,767Posts
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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.
    Just 'call me 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 11
    • Martyn1981
    • By Martyn1981 13th Sep 17, 7:01 AM
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    Martyn1981
    This looks interesting:

    10 yr warranty: good
    No reference to no. of cycles though: bad
    2.5 kW discharge rate (per module): good

    What does it actually cost to get installed? And does this cost vary with the inverter - it claims to be compatible with a few but not SE as yet.

    And how good is a warranty anyway? Will these manufacturers be around for the 10yrs and how easy will it be to claim from a company based in China?
    Originally posted by Exiled Tyke
    I assume you need to also buy a charge/discharge inverter if operating on the AC side.

    Good news is that they probably will be around for some time as BYD are massive, they are the guys building EV's in China, and buses in Europe/UK. I think BYD are bigger than Tesla and growing just as fast or faster, with their own Gigafactories.

    As the Tesla PWII is too big for me, I'm more and more convinced that a few years are needed, as I forsee a big battery battle, with a lot of fatalities in the coming years .... but ..... some very good winners.
    Just 'call me 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.
    • Cardew
    • By Cardew 13th Sep 17, 9:37 AM
    • 26,809 Posts
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    Cardew
    Unless the Government or one of its agencies act quickly to regulate this market the cowboys will soon be operating with outrageous claims of savings.
    • NigeWick
    • By NigeWick 13th Sep 17, 10:53 AM
    • 2,696 Posts
    • 1,004 Thanks
    NigeWick
    As the Tesla PWII is too big for me, I'm more and more convinced that a few years are needed, as I forsee a big battery battle, with a lot of fatalities in the coming years .... but ..... some very good winners.
    Originally posted by Martyn1981
    Tony Seba believes about four years for prices to come down far enough to make it a no brainer.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • Martyn1981
    • By Martyn1981 13th Sep 17, 3:26 PM
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    • 9,814 Thanks
    Martyn1981
    Momentum is growing in domestic market.

    Sonnen reports record solar storage sales for August
    Just 'call me 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.
    • zeupater
    • By zeupater 13th Sep 17, 4:18 PM
    • 3,696 Posts
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    zeupater
    Hi All

    Not domestic, but interesting development from a power density aspect ....

    samsung-electric-car-batteries

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    • NigeWick
    • By NigeWick 14th Sep 17, 2:02 PM
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    • 1,004 Thanks
    NigeWick
    interesting development from a power density aspect ....
    Originally posted by zeupater
    Doesn't say whether it's the Japanese, NEDC, EPA or real world distance though.

    That said, EPA says 107 per charge for my 30kWh Nissan Leaf and I get a fractsh more than that on a long journey. I also get about 150 miles per charge when tootling round town and to my allotment.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • zeupater
    • By zeupater 14th Sep 17, 2:09 PM
    • 3,696 Posts
    • 4,550 Thanks
    zeupater
    Doesn't say whether it's the Japanese, NEDC, EPA or real world distance though.

    That said, EPA says 107 per charge for my 30kWh Nissan Leaf and I get a fractsh more than that on a long journey. I also get about 150 miles per charge when tootling round town and to my allotment.
    Originally posted by NigeWick
    Hi

    I'd say it's more related to the physical size of a battery pack than anything else .... cylindrical cells aren't really volume efficient when packed together ...

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    • David RC
    • By David RC 14th Sep 17, 3:59 PM
    • 3 Posts
    • 1 Thanks
    David RC
    PV output loss from 'Grid instability' - battery cure?
    I have a 3.8 kWh nominal PV ground based array 100m from my house which is at the end of a long country lane. Many of my neighbours now have PV systems. On sunny days I often get a message on my SunnyBoy inverter saying that it has shut down owing to grid instability. I note that the output voltage is often at 260V or above and assume my inverter is programmed to shut down at above about 260/265V.
    The problem is most likely that the local grid line cannot take the generation load from the group of houses if local usage is low. I'm interested in possible cures for this problem since I'm one of the very fortunate PV generators currently receiving 50.67p/kWh (that includes the assumed 50% export tariff element) on all my output whether or not I use that output in my home. I started generating in 2012. Initial annual output was about 3.9MWh but after three years has fallen to about 3.5MWh as more local generation has come on stream. My panels remain efficient - the inverter was reading 4.1kWh yesterday for a brief period. My annual usage after the PV array installation was initially 2.9MWh but has risen to about 3.2MWh recently, I suspect because of the lag in inverter start up following a grid instability outage when my house load increases.
    I am considering buying a battery pack to take the output from my array when the AC output voltage rises above the grid-acceptable level. The economics don't work yet, but the possibility of time dependent pricing of mains supply electricity is a factor to bear in mind.
    My technical question is can a battery take the DC output from my array and store it before it goes through the inverter, and then discharge through the inverter at a later time so as to give a total generated output back at the level I enjoyed before the grid instability problem? Can the battery be made to start and stop storing at specified times or automatically if my inverter AC output voltage rises above a set trigger voltage so as to stop the inverter shutting down?
    Thanks for your help.
    • Martyn1981
    • By Martyn1981 14th Sep 17, 5:35 PM
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    • 9,814 Thanks
    Martyn1981
    My technical question is can a battery take the DC output from my array and store it before it goes through the inverter, and then discharge through the inverter at a later time so as to give a total generated output back at the level I enjoyed before the grid instability problem? Can the battery be made to start and stop storing at specified times or automatically if my inverter AC output voltage rises above a set trigger voltage so as to stop the inverter shutting down?
    Thanks for your help.
    Originally posted by David RC
    Hiya and welcome. Some batteries are designed to work on the DC side, this can even be used to allow generation above 3.68kW without exceeding the DNO limits.

    However, you will need an inverter that can do this, plus you may find that the inverter still has to shutdown if it sees grid voltage exceed 253V, as that's the max allowed and any PV gen will push it higher. [Some older inverters may go higher depending on when they were installed and the rules then, but not now.] There are also islanding inverters that can operate with the grid down but this gets even more complicated and regulatory.

    Your DNO is required to maintain the voltage at 230V (-6% / +10%) but more importantly they are required to maintain this level even with SSEG's (small scale electricity generators) on that line. So worth speaking to them so they can monitor how often it happens and see if it can be resolved simply by changing the tappings, or by other works.
    Just 'call me 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.
    • David RC
    • By David RC 14th Sep 17, 6:27 PM
    • 3 Posts
    • 1 Thanks
    David RC
    Martyn
    Thanks for the reply to my post which seems to have vanished. What is the DNO that I should contact to discuss the high voltage at my inverter and how do I find their contact details? As you can see I'm new to posting on this site and to electricity generation.
    Thanks
    David RC
    • Martyn1981
    • By Martyn1981 14th Sep 17, 6:36 PM
    • 5,767 Posts
    • 9,814 Thanks
    Martyn1981
    Martyn
    Thanks for the reply to my post which seems to have vanished. What is the DNO that I should contact to discuss the high voltage at my inverter and how do I find their contact details? As you can see I'm new to posting on this site and to electricity generation.
    Thanks
    David RC
    Originally posted by David RC
    Hiya David, sorry I went straight into acronym mode, very rude of me.

    The high voltage network is run by the National Grid, then the low voltage network is run by about 10(?) companies known as the district network operators. Mine in the south west is Western Power Distribution. You can Google yours, or it may be mentioned on your leccy bill as a contact number for problems.

    Hopefully they will be helpful and install a monitor to see how high the voltage is, and how often it goes too high. Mine tends to sit around 238-241V but it will vary all day. I had one inverter shutdown, but that was about 3 years ago and on a sunny Sunday afternoon when demand will be light and voltage can be expected to rise.

    Your inverter might display grid voltage so you can keep an eye too. Whilst 230V is technically the UK voltage this is really an attempt to move closer to the European 220V but I believe in name only, hence the revealing -6%/+10% range.
    Just 'call me 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.
    • Martyn1981
    • By Martyn1981 16th Sep 17, 10:13 AM
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    • 9,814 Thanks
    Martyn1981

    Clearly I'm easily pleased, but I'm actually getting a little excited about the second half of 2017, we could see:

    3. Off-shore wind contract announcements at sub HPC 2012 prices, so below £92.50, hopefully in the £80's and even a slim chance of a deal that starts with a 7.
    Originally posted by Martyn1981
    Just sharing a chuckle as I spotted this whilst looking for an old article, I was miles out ..... though to be fair £57.50 does have a 7 in it.
    Just 'call me 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.
    • NigeWick
    • By NigeWick 17th Sep 17, 10:03 AM
    • 2,696 Posts
    • 1,004 Thanks
    NigeWick
    Ordered my Tesla Powerwall 2 yesterday. I looked at the generation from my 4kW system and decided I do not need any extra solar. The battery is going to be fitted by an electrician who does solar & batteries and when he came for a site visit we discussed costs. The battery is £5,000 plus VAT. If I have some more solar generation it is 5%. If I don't have any extra solar is it 20%. I am therefore having two of the cheapest available panels fitted complete with their own inverter etc. With labour costs, I'll be paying roughly the same as I would for just the battery. He is also going to fit a Zappi vehicle charger at the same time so that when there's enough solar the car will get charged too.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • David RC
    • By David RC 18th Sep 17, 10:13 AM
    • 3 Posts
    • 1 Thanks
    David RC
    PV output from grid instability
    Martyn
    Thanks. I've contacted SSE, my local DNO, and will let you know the result of my complaint. I suspect there are other PV panel owners at the end of country lanes where their output is being rejected because of lack of local load in the middle of the day. They wouldn't know this unless they monitored their output closely.
    • theboylard
    • By theboylard 18th Sep 17, 12:25 PM
    • 1,118 Posts
    • 2,734 Thanks
    theboylard
    Ordered my Tesla Powerwall 2 yesterday. I looked at the generation from my 4kW system and decided I do not need any extra solar. The battery is going to be fitted by an electrician who does solar & batteries and when he came for a site visit we discussed costs. The battery is £5,000 plus VAT. If I have some more solar generation it is 5%. If I don't have any extra solar is it 20%. I am therefore having two of the cheapest available panels fitted complete with their own inverter etc. With labour costs, I'll be paying roughly the same as I would for just the battery. He is also going to fit a Zappi vehicle charger at the same time so that when there's enough solar the car will get charged too.
    Originally posted by NigeWick
    Any pics when installed would be appreciated Nige Don't forget banana for scale
    Llike most I'm following news of batts closely so more real world examples would be greatly appreciated, its' folks like you taking the plunge that motivate us sitting on the fence!!
    4kWp, SSE, 16 x 250w EcoFuture BoB with retro-fitted SolarEdge P300 optimisers & SE3500 Inverter, in occasionally sunny Corby, Northants.
    • NigeWick
    • By NigeWick 19th Sep 17, 8:34 AM
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    NigeWick
    Any pics when installed would be appreciated Nige Don't forget banana for scale
    Originally posted by theboylard
    Will do. What size banana?

    The battery is going on the outside wall of the garage which will mean less wiring and saving room for the car, and, all the detritus from 21 years living here.....

    The electrician said that the battery location would be alright as the wall is East facing & in a narrow passage between it and a 6ft fence. Plus, our weather tends to come from the West.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • Cardew
    • By Cardew 19th Sep 17, 10:34 AM
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    Cardew
    When electric cars become mandatory, it is going to be a logistic nightmare for those in flats/houses without parking to have charging facilities. Especially as, I suspect, the majority of owners will wish to charge overnight, and 2 car households are common these days.
    • EricMears
    • By EricMears 19th Sep 17, 10:42 AM
    • 2,256 Posts
    • 3,962 Thanks
    EricMears
    When electric cars become mandatory, it is going to be a logistic nightmare for those in flats/houses without parking to have charging facilities. Especially as, I suspect, the majority of owners will wish to charge overnight, and 2 car households are common these days.
    Originally posted by Cardew
    I don't think two car households would be a problem : I've only got one EV and almost always charge it overnight but don't usually need to charge it every night. Hopefully new EVs will have better range than mine so might only need charging once or twice a week. (of course in the unusual situation where a household has two or more EVs and uses up all the range on both of them every day they could always fit a second charging point).

    For people without their own garage /parking space there is always the possibility of 'destination charging'.
    N Derbyshire.
    4kwp S Facing 17.5deg slope (dormer roof).
    • snecker
    • By snecker 19th Sep 17, 12:53 PM
    • 2 Posts
    • 3 Thanks
    snecker
    When electric cars become mandatory, it is going to be a logistic nightmare for those in flats/houses without parking to have charging facilities. Especially as, I suspect, the majority of owners will wish to charge overnight, and 2 car households are common these days.
    Originally posted by Cardew
    I don't think so. Charging infrastructure is rapidly expanding and see Tesla's recent mobile battery swap patent application. I'm too new to post links but google for more info if interested. In most EVs, the battery sits at the lowest point and is usually pretty trivial to swap.
    Last edited by snecker; Today at 12:59 PM.
    • snecker
    • By snecker 19th Sep 17, 12:57 PM
    • 2 Posts
    • 3 Thanks
    snecker
    Just wanted to say hello and thanks for this fascinating thread. I am hoping to get a PV with battery scheme but as costs seem to be heading downwards so quickly, it looks like the best thing to do at the moment is wait.

    EON are quoting me £7.5k for solar and battery for my place. The battery just doesn't seem to make sense for me at the moment.
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