Forum Home» Green & Ethical MoneySaving

On-grid domestic battery storage - Page 40

New Post Advanced Search

On-grid domestic battery storage

edited 30 November -1 at 1:00AM in Green & Ethical MoneySaving
1.8K replies 199.3K views
13738404243185

Replies

  • JKenHJKenH Forumite
    1.5K posts
    1,000 Posts Second Anniversary Name Dropper
    ✭✭✭
    orrery wrote: »
    Oh, me too. I think that I'd like to see 3kW discharge though - with washing machines and dishwashers and kettles taking 2.2kW and a level of background for the house, I'd say that was a minimum.


    Similarly, the graphs (which were very helpful) we have seen recently indicate the need for a charge level of 3kW too - again that for me (with a 4kWp PV system), less the background consumption, would seem the minimum.


    Further, with 3kW charge rate and economy 7, the ideal battery capacity would seem to be at least 21kWh minimum - roughly the same figure would be indicated for sinking (almost) a full day's PV generation.


    Sounds expensive.

    When I first started looking at Solar and batteries I thought a massive battery would be a great idea. However the reality is that if you are going to charge it from solar you will end up with far more energy stored than you can use in summer and unable to generate enough to fill the battery anywhere near your needs in winter.

    I would suggest you base your battery around what spare generation you have in February, March, September and October. I have a 7.8kwp and am nowhere near filling the battery on this so far gloomy day.

    I can see that I will be charging it from Economy7 in the winter.
    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:) )
  • Martyn1981Martyn1981 Forumite
    10.9K posts
    Part of the Furniture 10,000 Posts Name Dropper Photogenic
    ✭✭✭✭✭
    JKenH wrote: »
    I would suggest you base your battery around what spare generation you have in February, March, September and October. I have a 7.8kwp and am nowhere near filling the battery on this so far gloomy day.

    Yep, that's exactly what my position was, but I've changed my view now looking forward as a battery that could hold enough to charge an EV each day, say 20-40 miles per day in the summer, and hold a days worth of E7 for the winter, now seems to make more sense. Also some capacity for a few extra ASHP kWh's for the spring/autumn months.

    Still mentally revising what's best, but now think 10+ kWh's rather than 4-5kWh's (useable) would be a better figure.

    I'm hoping / expecting that prices and options will improve from 2020 onwards!
    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.
  • ASavvyBuyerASavvyBuyer Forumite
    1.3K posts
    1,000 Posts Fourth Anniversary Name Dropper
    ✭✭✭
    JKenH wrote: »
    I don t actually know exactly how much my battery cost as it was part of a system. If someone can tell me how much a 7.8 kw system (26 x 300w mono panels) on two roofs with 2 inverters and IBoost should cost then I can work out the true cost of the battery.
    From what others have said they have paid for a similar size solar PV system without batteries, I would estimate between £8-10k.
    4kWp, W roof, 30° pitch, Solar Edge Inverter + Optimisers. South Wales Valleys, Installed Aug 2015. Octopus Agile Electric Tariff.
    Solic 200 Diverter, Toshiba Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul & Renault Zoe EV's.
  • ASavvyBuyerASavvyBuyer Forumite
    1.3K posts
    1,000 Posts Fourth Anniversary Name Dropper
    ✭✭✭
    I have started researching EV's & PHEV's for when we change our clean diesel car in the next couple of years. Had a look at a few yesterday to assess size, range, etc.

    In one of the reviews I found for the new Nissan Leaf it mentions: "Other green features include vehicle-to-grid (V2G) connectivity for all new Leafs, which opens up the possibility of using the Nissan as a portable energy storage unit for peak demand, and/or selling power back to the grid."

    Also found this when looking up info for the new Nissan Leaf:

    "Vehicle-to-Grid (V2G) technology combines two-way charging allowing electric vehicles to be fully integrated into the electricity grid. It helps improve the capability to handle non-programmable renewable energy flows, making renewable sources even more widely integrated and affordable. The system works by allowing Nissan EV owners to connect to the grid to play an active role in grid services, while providing the opportunity for an alternate source of income. Once scaled up, the V2G technology will be a game-changer for owners of Nissan electric vehicles as they become active participants in the energy market."

    For those that already have a new Nissan Leaf, is V2G/V2H already available, or have you been told when it will be available to use in the UK?
    4kWp, W roof, 30° pitch, Solar Edge Inverter + Optimisers. South Wales Valleys, Installed Aug 2015. Octopus Agile Electric Tariff.
    Solic 200 Diverter, Toshiba Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul & Renault Zoe EV's.
  • CoastalwatchCoastalwatch Forumite
    1.2K posts
    1,000 Posts Second Anniversary Name Dropper
    ✭✭✭
    I have started researching EV's & PHEV's for when we change our clean diesel car in the next couple of years. Had a look at a few yesterday to assess size, range, etc.

    In one of the reviews I found for the new Nissan Leaf it mentions: "Other green features include vehicle-to-grid (V2G) connectivity for all new Leafs, which opens up the possibility of using the Nissan as a portable energy storage unit for peak demand, and/or selling power back to the grid."



    Also found this when looking up info for the new Nissan Leaf:

    "Vehicle-to-Grid (V2G) technology combines two-way charging allowing electric vehicles to be fully integrated into the electricity grid. It helps improve the capability to handle non-programmable renewable energy flows, making renewable sources even more widely integrated and affordable. The system works by allowing Nissan EV owners to connect to the grid to play an active role in grid services, while providing the opportunity for an alternate source of income. Once scaled up, the V2G technology will be a game-changer for owners of Nissan electric vehicles as they become active participants in the energy market."

    For those that already have a new Nissan Leaf, is V2G/V2H already available, or have you been told when it will be available to use in the UK?
    Hi ASB, the V2G aspect and range of the new Leaf were the two main reasons we went for one. Unfortunately the V2G aspect is not yet available although OVO are currently seeking participants to take part in a trial for this. I believe it includes a free installation, those already with solar can be included although you may need to be an OVO customer. They also require your post code so it may just be a regional trial! Maybe worth checking out!
    https://www.ovoenergy.com/electric-cars/vehicle-to-grid-charger
    Personally I merely require V2H as opposed to V2G so not sure if I wish expose my new car to it, although I understand it is being conducted with Nissans approval regarding battery lifetime and warranty.
    East coast, lat 51.97. 8.26kw SSE, 23° pitch + 0.59kw WSW vertical. Nissan Leaf plus one dirty diesel. Still waiting for V2H and home storage to become available at sensible cost.
  • gefnewgefnew Forumite
    170 posts
    Tenth Anniversary 100 Posts
    Hi Savvy
    On a side note a smets2 smart meter will help as this does import as well as export in real time.
  • Dave_FowlerDave_Fowler Forumite
    553 posts
    Part of the Furniture 500 Posts Name Dropper
    ✭✭
    A point to take into consideration is that every charge / discharge cycle for the battery slowly reduces its capacity, particularly if the discharge cycle is deep.

    If you are using the car as a battery store then you need to consider what effect the daily charging cycle will have. If replacing a stand-alone battery is required every 5 years, it is likely the car battery will not be in a good condition after a similar length of time. What will be the effect on the car battery and the selling price of a 5 year old car which has been used as a V2G source?


    Dave F
    Solar PV System 1: 2.96kWp South+8 degrees. Roof 38 degrees. 'Normal' system
    Solar PV System 2: 3.00kWp South-4 degrees. Roof 28 degrees. SolarEdge system
    EV car
    Location: Bedfordshire
  • edited 31 July 2018 at 2:05PM
    ASavvyBuyerASavvyBuyer Forumite
    1.3K posts
    1,000 Posts Fourth Anniversary Name Dropper
    ✭✭✭
    edited 31 July 2018 at 2:05PM
    Hi ASB, the V2G aspect and range of the new Leaf were the two main reasons we went for one. Unfortunately the V2G aspect is not yet available although OVO are currently seeking participants to take part in a trial for this. I believe it includes a free installation, those already with solar can be included although you may need to be an OVO customer. They also require your post code so it may just be a regional trial! Maybe worth checking out!
    https://www.ovoenergy.com/electric-cars/vehicle-to-grid-charger
    Personally I merely require V2H as opposed to V2G so not sure if I wish expose my new car to it, although I understand it is being conducted with Nissans approval regarding battery lifetime and warranty.

    Thanks for the link; very interesting. However, same as you, I would only really be interested in V2H so that I had some control over how much of the car storage was being used. Mainly to cover evening and overnight low use, and to stop importing when a cloud comes across when the washing machine is on.

    Also, I may have misunderstood the figures, but it appears that OVO would charge you at normal rate to charge up the car, but only pay you about half of that when they export power from your car battery (and as Dave says, shortening the life of the battery).
    4kWp, W roof, 30° pitch, Solar Edge Inverter + Optimisers. South Wales Valleys, Installed Aug 2015. Octopus Agile Electric Tariff.
    Solic 200 Diverter, Toshiba Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul & Renault Zoe EV's.
  • ASavvyBuyerASavvyBuyer Forumite
    1.3K posts
    1,000 Posts Fourth Anniversary Name Dropper
    ✭✭✭
    gefnew wrote: »

    Thanks for the link. That looks very expensive, just for the charger (predicted to be £8-9k!). Might as well buy a battery system for that money.

    But useful to know which other cars currently have the right interface to make it possible.
    4kWp, W roof, 30° pitch, Solar Edge Inverter + Optimisers. South Wales Valleys, Installed Aug 2015. Octopus Agile Electric Tariff.
    Solic 200 Diverter, Toshiba Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul & Renault Zoe EV's.
Sign In or Register to comment.

Quick links

Essential Money | Who & Where are you? | Work & Benefits | Household and travel | Shopping & Freebies | About MSE | The MoneySavers Arms | Covid-19 & Coronavirus Support