I wrote this today to post elsewhere but thought somerats might be
interested. If not, please press NEXT.

We moved back to the UK from Italy 4 years ago and installed solar on
our SW facing roof as soon as we could. We have a reasonably well
insulated 60’s detached house and we’ve been very happy with solar. We
got in just before last Feed-In Tariff changed so we currently get just
under £400 a year payments for the electricity we export, but this is
based on the size of our installation, not what we actually supply to
the grid.

We looked at having a battery initially but we couldn’t justify the cost
of the Tesla unit that was the only one that our panel supplier would
install. We are now 75 so need a reasonable ROI 😊

However with the recent energy price crisis we looked again and I got a
big surprise. I must emphasize that this solely applies to our situation
as described above and considering that we are retired and apart from
electric hob/oven and kettle the only large appliances we have are
dishwasher and washing machine and being at home all day we can put
those on when the sun is shining and the electricity is free.

I downloaded a year’s worth of day by day usage showing what was
generated and what we used for “free” and what we imported (we also have
a “smart” switch that energises when we have excess above the set limit
and we plug into that either a space heater in the winter or a fan in
the summer so we have some “free” heating/cooling that I haven’t
considered).

I plugged that into a spreadsheet where I could vary the battery size
and then calculated what I had left over to charge a battery and how
much of that charge would be left each morning (this isn’t entirely
accurate as there’s no guarantee that you are generating before you need
it). We use around 7kWh/day average with around .1 kWh background use
24/7 from fridge/freezer and TV/Sky box. I also allowed for the
possibility of using cheaper overnight electricity to charge the battery.

The surprise was that the best battery size was 2kWh. I knew the 13kWh
Tesla was too big, but I thought the optimum would be about 6/7 to match
our usage – that wasn’t true though no matter how I juggled with
overnight charging.

When you drill down the reason is obvious. For 6 months of the year
Apr-Aug we generate far more than we use in the day and we only use less
than 1kWh overnight, so 2kWh is enough to shift the excess to when we
need it and storing more than that is of zero benefit.

For December and January we just don’t generate enough at all, so a
battery is not much use whatever the size – there are some good days
when we generate an excess, but only a couple each month and never more
than a couple of kWh. You could top up a bigger battery every night with
Economy 7, but then there are quite a few days when you are charging the
battery unnecessarily – it’s cheaper, but still a waste of money. You
could I suppose look at the forecast and what you expected to use for
the next day every night and set the Eco7 charge level accordingly, but
a lot of faff for not much benefit imo.

November and Feb are a bit better but not much, whereas October and
March are the only months where a slightly bigger battery makes more sense.

So, with a 2kWh battery I would save £227, which is about 71% of our
current bill. A 4kWh battery saves 85% (as do 11 and 13 kWh weirdly).
Counterintuitively a 7kWh saves only 80%. These are based on actual
prices. The amounts saved would increase as prices rise, but the
relative percentages will be unchanged.
2kWh batteries are available and with the inverter and kit to switch the
battery in seamlessly when there is a power cut would cost around £2.5k,
so even at current prices this is a reasonable ROI of around 10 years. A
4kWh system would be an extra £1k, but it doesn’t seem sensible to me to
spend that to save <£50pa. Even if prices double (and importantly stay
that way which I doubt will happen) it’s an ROI of 10 years.
The only problem is finding someone to install the smaller modular system ☹

So that is my analysis for our situation. We heat with a wood-burner and
have gas CH and water heating with a new combi-boiler. The results will
be different if you are all electric or have an EV or have the
possibility to sell back to the grid at surge pricing but even I CBA to
spend my life monitoring that...

BrritSki wrote:

>We moved back to the UK from Italy 4 years ago and installed solar on
>our SW facing roof as soon as we could. We have a reasonably well
>insulated 60’s detached house and we’ve been very happy with solar. We
>got in just before last Feed-In Tariff changed so we currently get just
>under £400 a year payments for the electricity we export, but this is
>based on the size of our installation, not what we actually supply to
>the grid.

[snip interesting calculations]

One factor that you might not have considered, is the effect of a
compulsory smart meter (which I think may well happen) followed
by export payments based on actual, rather than deemed, export.

Chris
--
Chris J Dixon Nottingham
'48/33 M B+ G++ A L(-) I S-- CH0(--)(p) Ar- T+ H0 ?Q
chris@cdixon.me.uk @ChrisJDixon1
Plant amazing Acers.

Chris J Dixon <chris@cdixon.me.uk> wrote:
> BrritSki wrote:
>
>> We moved back to the UK from Italy 4 years ago and installed solar on
>> our SW facing roof as soon as we could. We have a reasonably well
>> insulated 60’s detached house and we’ve been very happy with solar. We
>> got in just before last Feed-In Tariff changed so we currently get just
>> under £400 a year payments for the electricity we export, but this is
>> based on the size of our installation, not what we actually supply to
>> the grid.
>
> [snip interesting calculations]
>
> One factor that you might not have considered, is the effect of a
> compulsory smart meter (which I think may well happen) followed
> by export payments based on actual, rather than deemed, export.
>
> Chris

I doubt our situation is comparable as we have higher consumption and will
be going all electric once we have an ASHP installed for heating and hot
water. Late Sept. is showing 15-20 kW/h produced per day and when
available, a Tesla Powerwall battery will be installed. Just say if more
info would be of any use.

--
Toodle Pip, Mike McMillan

On 26/09/2022 14:30, Chris J Dixon wrote:
> BrritSki wrote:
>
>> We moved back to the UK from Italy 4 years ago and installed solar on
>> our SW facing roof as soon as we could. We have a reasonably well
>> insulated 60’s detached house and we’ve been very happy with solar. We
>> got in just before last Feed-In Tariff changed so we currently get just
>> under £400 a year payments for the electricity we export, but this is
>> based on the size of our installation, not what we actually supply to
>> the grid.
>
> [snip interesting calculations]
>
> One factor that you might not have considered, is the effect of a
> compulsory smart meter (which I think may well happen) followed
> by export payments based on actual, rather than deemed, export.

Yes, I think that may well happen, and would change the calculations,
although we'd still be exporting significantly with a 2kWh battery and
possibly with a higher price/kWh exported, although if it's time based
we are generating at the worst time of course.

>
> Chris

On 26/09/2022 15:05, Mike McMillan wrote:
> Chris J Dixon <chris@cdixon.me.uk> wrote:
>> BrritSki wrote:
>>
>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>> our SW facing roof as soon as we could. We have a reasonably well
>>> insulated 60’s detached house and we’ve been very happy with solar. We
>>> got in just before last Feed-In Tariff changed so we currently get just
>>> under £400 a year payments for the electricity we export, but this is
>>> based on the size of our installation, not what we actually supply to
>>> the grid.
>>
>> [snip interesting calculations]
>>
>> One factor that you might not have considered, is the effect of a
>> compulsory smart meter (which I think may well happen) followed
>> by export payments based on actual, rather than deemed, export.
>>
>> Chris
>
> I doubt our situation is comparable as we have higher consumption and will
> be going all electric once we have an ASHP installed for heating and hot
> water. Late Sept. is showing 15-20 kW/h produced per day and when
> available, a Tesla Powerwall battery will be installed.

We've been generating 10-15 kWh for the last week.

Higher consumption may make the situation worse IMO as I think some of
us have already tried to tell you.

In the summer when you are generating and possibly storing a lot you
will not need it for heating. Maybe you can sell it but will prices be
good when everyone's got power to sell ?

In the winter you probably won't generate enough to keep your battery
topped up. Below I've listed our generation for December and January
last winter by day. We only generated enough to satisfy our fairly low
usage of around 7kWh on 5 days. Even with a bigger array (I think you
have 20 panels vs our 14) this wouldn't change much if you have a bigger
demand too for all your heating.

And a bigger battery needs more time to fill up. On my calcs and usage,
you'd only have charge in yr battery from solar on 2 days in Dec and 12
in Jan and your Tesla battery wouldn't be full consistently until the
end of Feb. I imagine your usage needs are proportionally higher (If we
switched our gas kWh to electricity we'd add 250% to our usage even with
a 300% efficient ASHP [1]) than the difference in our array size, so
that would make things much worse.

I understand that you'll be topping up the battery with cheaper
overnight electricity, but even with the claimed efficiencies of an ASHP
I'm not convinced that will be much cheaper than gas [2].

Date System Production
01/12/2021 4.24
02/12/2021 10.31
03/12/2021 1.87
04/12/2021 7.85
05/12/2021 1.21
06/12/2021 0.81
07/12/2021 0.42
08/12/2021 1.92
09/12/2021 5.44
10/12/2021 8.05
11/12/2021 1.36
12/12/2021 2.22
13/12/2021 2.47
14/12/2021 1.10
15/12/2021 1.75
16/12/2021 0.50
17/12/2021 1.64
18/12/2021 0.62
19/12/2021 0.93
20/12/2021 0.91
21/12/2021 1.22
22/12/2021 1.68
23/12/2021 0.52
24/12/2021 2.53
25/12/2021 0.24
26/12/2021 0.53
27/12/2021 0.45
28/12/2021 0.71
29/12/2021 1.32
30/12/2021 0.70
31/12/2021 3.81
01/01/2022 3.11
02/01/2022 7.69
03/01/2022 1.46
04/01/2022 5.98
05/01/2022 3.94
06/01/2022 1.55
07/01/2022 1.73
08/01/2022 1.62
09/01/2022 5.18
10/01/2022 5.21
11/01/2022 1.43
12/01/2022 5.36
13/01/2022 5.47
14/01/2022 4.44
15/01/2022 1.35
16/01/2022 2.84
17/01/2022 5.61
18/01/2022 4.01
19/01/2022 4.11
20/01/2022 2.54
21/01/2022 1.77
22/01/2022 4.87
23/01/2022 0.47
24/01/2022 1.52
25/01/2022 0.25
26/01/2022 4.13
27/01/2022 3.43
28/01/2022 4.06
29/01/2022 2.84
30/01/2022 5.66
31/01/2022 7.44

[1] which is only true under ideal conditions and wouldn't apply to the
gas we use to heat water which would need to be done by means other than
and ASHP). And of course the efficiency is immaterial if it needs more
input to heat the house because it's not well insulated or draughty
(which may not apply in your case).

[2] We used around 10,000kWh of gas last year (we will endeavour to
reduce that significantly this year) which would cost around £1k at new
prices.
With an ASHP, assuming 10% of that is for hot water which would still be
needed, we'd also have 9MWh at 300% efficiency = 3000kWh + HW at 1000kWh
= 4,000kWh which even at overnight rate (can't find the figure, but it's
going to be higher than the current 18.59p rate) is going to be around
£800. So all that outlay for a saving of £200 + £90 for the standing
charge...

On 26/09/2022 17:27, BrritSki wrote:
> On 26/09/2022 15:05, Mike McMillan wrote:
>> Chris J Dixon <chris@cdixon.me.uk> wrote:
>>> BrritSki wrote:
>>>
>>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>>> our SW facing roof as soon as we could. We have a reasonably well
>>>> insulated 60’s detached house and we’ve been very happy with solar. We
>>>> got in just before last Feed-In Tariff changed so we currently get just
>>>> under £400 a year payments for the electricity we export, but this is
>>>> based on the size of our installation, not what we actually supply to
>>>> the grid.
>>>

(snip loads of data and analysis)

Having looked briefly into this, if you are in a FIT scheme, you may
need to be careful that modifications to your system do not cause you to
loose your FIT payment.

My only evidence for this suggestion is the discussion on this thread

https://electricianforum.co.uk/threads/batteries-and-fit-payment.54847/

It might be something you need to check before going too far down the road.

>

--
Chris B (News)

On 27/09/2022 12:53, Chris B wrote:
> On 26/09/2022 17:27, BrritSki wrote:
>> On 26/09/2022 15:05, Mike McMillan wrote:
>>> Chris J Dixon <chris@cdixon.me.uk> wrote:
>>>> BrritSki wrote:
>>>>
>>>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>>>> our SW facing roof as soon as we could. We have a reasonably well
>>>>> insulated 60’s detached house and we’ve been very happy with solar. We
>>>>> got in just before last Feed-In Tariff changed so we currently get
>>>>> just
>>>>> under £400 a year payments for the electricity we export, but this is
>>>>> based on the size of our installation, not what we actually supply to
>>>>> the grid.
>>>>
>
>
> (snip loads of data and analysis)
>
> Having looked briefly into this, if you are in a FIT scheme, you may
> need to be careful that modifications to your system do not cause you to
> loose your FIT payment.
>
> My only evidence for this suggestion is the discussion on this thread
>
> https://electricianforum.co.uk/threads/batteries-and-fit-payment.54847/
>
>
> It might be something you need to check before going too far down the road.
>
Thanks for that, it certainly needs looking into. I can see why they
would do it too - the FIT payment is based entirely on the size of my
array and has nothing to do with how much I actually feed back to the grid.

The question is moot though as I cannot find anyone to supply and fit a
small battery !

On Tue, 27 Sep 2022 13:17:56 +0100, BrritSki <rtilburyTAKEAWAY@gmail.com>
scrawled in the dust...

>On 27/09/2022 12:53, Chris B wrote:
>> On 26/09/2022 17:27, BrritSki wrote:
>>> On 26/09/2022 15:05, Mike McMillan wrote:
>>>> Chris J Dixon <chris@cdixon.me.uk> wrote:
>>>>> BrritSki wrote:
>>>>>
>>>>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>>>>> our SW facing roof as soon as we could. We have a reasonably well
>>>>>> insulated 60?s detached house and we?ve been very happy with solar. We
>>>>>> got in just before last Feed-In Tariff changed so we currently get
>>>>>> just
>>>>>> under £400 a year payments for the electricity we export, but this is
>>>>>> based on the size of our installation, not what we actually supply to
>>>>>> the grid.
>>>>>
>>
>>
>> (snip loads of data and analysis)
>>
>> Having looked briefly into this, if you are in a FIT scheme, you may
>> need to be careful that modifications to your system do not cause you to
>> loose your FIT payment.
>>
>> My only evidence for this suggestion is the discussion on this thread
>>
>> https://electricianforum.co.uk/threads/batteries-and-fit-payment.54847/
>>
>>
>> It might be something you need to check before going too far down the road.
>>
>Thanks for that, it certainly needs looking into. I can see why they
>would do it too - the FIT payment is based entirely on the size of my
>array and has nothing to do with how much I actually feed back to the grid.

FIT payments have obviously changed a lot since I registered for mine,
which is entirely based upon how much I generate. I only get a tiny amount
for what they reckon I export - 50% of generated at £0.04/unit. I get a
fair whack for generated though, which will presumably go up in April.
Whether it will still cover all my energy bills remains to be seen.

>The question is moot though as I cannot find anyone to supply and fit a
>small battery !

That's a shame, it sounded like a cunning plan.

--
Penny
Annoyed by The Archers since 1959

On Tue, 27 Sep 2022 13:17:56 +0100, BrritSki
<rtilburyTAKEAWAY@gmail.com> wrote:

>On 27/09/2022 12:53, Chris B wrote:
>> On 26/09/2022 17:27, BrritSki wrote:
>>> On 26/09/2022 15:05, Mike McMillan wrote:
>>>> Chris J Dixon <chris@cdixon.me.uk> wrote:
>>>>> BrritSki wrote:
>>>>>
>>>>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>>>>> our SW facing roof as soon as we could. We have a reasonably well
>>>>>> insulated 60?s detached house and we?ve been very happy with solar. We
>>>>>> got in just before last Feed-In Tariff changed so we currently get
>>>>>> just
>>>>>> under £400 a year payments for the electricity we export, but this is
>>>>>> based on the size of our installation, not what we actually supply to
>>>>>> the grid.
>>>>>
>>
>>
>> (snip loads of data and analysis)
>>
>> Having looked briefly into this, if you are in a FIT scheme, you may
>> need to be careful that modifications to your system do not cause you to
>> loose your FIT payment.
>>
>> My only evidence for this suggestion is the discussion on this thread
>>
>> https://electricianforum.co.uk/threads/batteries-and-fit-payment.54847/
>>
>>
>> It might be something you need to check before going too far down the road.
>>
>Thanks for that, it certainly needs looking into. I can see why they
>would do it too - the FIT payment is based entirely on the size of my
>array and has nothing to do with how much I actually feed back to the grid.
>
>The question is moot though as I cannot find anyone to supply and fit a
>small battery !
>
I'm going to display my complete ignorance about big batteries: good
thing I'm not relying on one to power my house then.

The advice with normal, rechargeable lithium batteries seem to be not
to keep them at 100% charge if you can avoid it and not to let them
become fully discharged. Can the battery circuits of a solar energy
system be set to stop charging at a pre-determined limit and to stop
delivering power at a separate, lower level?

In which case, if 2kWh is the optimum amount of storage capacity,
would a 4kWh battery which has been programmed to stop charging at 75%
capacity and also to stop supplying electricity if the capacity falls
below 25% last longer and in better condition than a 2kWh battery
regularly cycled between 0% and 100% together with its 2kWh
replacement when the first one becomes clapped out?

Nick

On 27/09/2022 20:16, Nick Odell wrote:
> On Tue, 27 Sep 2022 13:17:56 +0100, BrritSki
> <rtilburyTAKEAWAY@gmail.com> wrote:
>
>> On 27/09/2022 12:53, Chris B wrote:
>>> On 26/09/2022 17:27, BrritSki wrote:
>>>> On 26/09/2022 15:05, Mike McMillan wrote:
>>>>> Chris J Dixon <chris@cdixon.me.uk> wrote:
>>>>>> BrritSki wrote:
>>>>>>
>>>>>>> We moved back to the UK from Italy 4 years ago and installed solar on
>>>>>>> our SW facing roof as soon as we could. We have a reasonably well
>>>>>>> insulated 60?s detached house and we?ve been very happy with solar. We
>>>>>>> got in just before last Feed-In Tariff changed so we currently get
>>>>>>> just
>>>>>>> under £400 a year payments for the electricity we export, but this is
>>>>>>> based on the size of our installation, not what we actually supply to
>>>>>>> the grid.
>>>>>>
>>>
>>>
>>> (snip loads of data and analysis)
>>>
>>> Having looked briefly into this, if you are in a FIT scheme, you may
>>> need to be careful that modifications to your system do not cause you to
>>> loose your FIT payment.
>>>
>>> My only evidence for this suggestion is the discussion on this thread
>>>
>>> https://electricianforum.co.uk/threads/batteries-and-fit-payment.54847/
>>>
>>>
>>> It might be something you need to check before going too far down the road.
>>>
>> Thanks for that, it certainly needs looking into. I can see why they
>> would do it too - the FIT payment is based entirely on the size of my
>> array and has nothing to do with how much I actually feed back to the grid.
>>
>> The question is moot though as I cannot find anyone to supply and fit a
>> small battery !
>>
> I'm going to display my complete ignorance about big batteries: good
> thing I'm not relying on one to power my house then.
>
> The advice with normal, rechargeable lithium batteries seem to be not
> to keep them at 100% charge if you can avoid it and not to let them
> become fully discharged. Can the battery circuits of a solar energy
> system be set to stop charging at a pre-determined limit and to stop
> delivering power at a separate, lower level?

Yes.
>
> In which case, if 2kWh is the optimum amount of storage capacity,
> would a 4kWh battery which has been programmed to stop charging at 75%
> capacity and also to stop supplying electricity if the capacity falls
> below 25% last longer and in better condition than a 2kWh battery
> regularly cycled between 0% and 100% together with its 2kWh
> replacement when the first one becomes clapped out?
>

The difference between one that is "abused" and one that is looked after
is 4500 cycles versus 6000 cycles I think I read yesterday. Either will
see us out !

And anyway the real size of the battery is 2.4 kWh and the limits are
10% and 80% depending on the technology, so would still be adequate.

On 27/09/2022 20:16, Nick Odell wrote:

> I'm going to display my complete ignorance about big batteries: good
> thing I'm not relying on one to power my house then.
>
> The advice with normal, rechargeable lithium batteries seem to be not
> to keep them at 100% charge if you can avoid it and not to let them
> become fully discharged. Can the battery circuits of a solar energy
> system be set to stop charging at a pre-determined limit and to stop
> delivering power at a separate, lower level?

There are many different chemistries for all sorts of batteries Compare
the "deep cycle" leisure battery aimed at caravans which is much more
tolerant of low charge>high charge cycles than a standard car battery.

What you say about charge levels is definitely the advice given for
Phones and laptops but some solar storage units are starting to use
The lithium iron phosphate battery
------
From Wiki (abbreviated as Li-IP, LFP (lithium ferro-phosphate) or
LiFePO4 battery its a type of lithium-ion battery using lithium iron
phosphate (LiFePO4) as the cathode material,).....

LFP chemistry offers a considerably longer cycle life than other
lithium-ion chemistries. Under most conditions it supports more than
3,000 cycles, and under optimal conditions it supports more than 10,000
cycles.
-----
Its downside is that it has a lower energy density which might be a
problem for phones and laptops but not for solar power storage

(Small ones are often found in the upmarket solar lights (AA size at
~3.5v each) where the 350 full cycles per year can soon kill the
cheaper NiMH)

again from wiki
Single "14500" (AA battery–sized) LFP cells are now used in some
solar-powered landscape lighting instead of 1.2 V NiCd/NiMH.[citation
needed]

LFP's higher (3.2 V) working voltage lets a single cell drive an LED
without circuitry to step up the voltage. Its increased tolerance to
modest overcharging (compared to other Li cell types) means that LiFePO
4 can be connected to photovoltaic cells without circuitry to halt the
recharge cycle. The ability to drive an LED from a single LFP cell also
obviates battery holders, and thus the corrosion, condensation and dirt
issues associated with products using multiple removable rechargeable
batteries.[citation needed]

>
> In which case, if 2kWh is the optimum amount of storage capacity,
> would a 4kWh battery which has been programmed to stop charging at 75%
> capacity and also to stop supplying electricity if the capacity falls
> below 25% last longer and in better condition than a 2kWh battery
> regularly cycled between 0% and 100% together with its 2kWh
> replacement when the first one becomes clapped out?
>
> Nick

--
Chris B (News)

On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:

>On 27/09/2022 20:16, Nick Odell wrote:
>
>> I'm going to display my complete ignorance about big batteries: good
>> thing I'm not relying on one to power my house then.
>>
>> The advice with normal, rechargeable lithium batteries seem to be not
>> to keep them at 100% charge if you can avoid it and not to let them
>> become fully discharged. Can the battery circuits of a solar energy
>> system be set to stop charging at a pre-determined limit and to stop
>> delivering power at a separate, lower level?
>
>There are many different chemistries for all sorts of batteries Compare
>the "deep cycle" leisure battery aimed at caravans which is much more
>tolerant of low charge>high charge cycles than a standard car battery.
>
>What you say about charge levels is definitely the advice given for
>Phones and laptops but some solar storage units are starting to use
>The lithium iron phosphate battery
>------
> From Wiki (abbreviated as Li-IP, LFP (lithium ferro-phosphate) or
>LiFePO4 battery its a type of lithium-ion battery using lithium iron
>phosphate (LiFePO4) as the cathode material,).....
>
>LFP chemistry offers a considerably longer cycle life than other
>lithium-ion chemistries. Under most conditions it supports more than
>3,000 cycles, and under optimal conditions it supports more than 10,000
>cycles.
>-----
>Its downside is that it has a lower energy density which might be a
>problem for phones and laptops but not for solar power storage
>
>
>(Small ones are often found in the upmarket solar lights (AA size at
>~3.5v each) where the 350 full cycles per year can soon kill the
>cheaper NiMH)
>
>again from wiki
>Single "14500" (AA battery–sized) LFP cells are now used in some
>solar-powered landscape lighting instead of 1.2 V NiCd/NiMH.[citation
>needed]
>
>LFP's higher (3.2 V) working voltage lets a single cell drive an LED
>without circuitry to step up the voltage. Its increased tolerance to
>modest overcharging (compared to other Li cell types) means that LiFePO
>4 can be connected to photovoltaic cells without circuitry to halt the
>recharge cycle. The ability to drive an LED from a single LFP cell also
>obviates battery holders, and thus the corrosion, condensation and dirt
>issues associated with products using multiple removable rechargeable
>batteries.[citation needed]
>
>
>
>
>
>>
>> In which case, if 2kWh is the optimum amount of storage capacity,
>> would a 4kWh battery which has been programmed to stop charging at 75%
>> capacity and also to stop supplying electricity if the capacity falls
>> below 25% last longer and in better condition than a 2kWh battery
>> regularly cycled between 0% and 100% together with its 2kWh
>> replacement when the first one becomes clapped out?
>>
Thanks Chris, that's interesting. Bearing in mind my depth of insight
into battery technologies (I was roasted on uk.d-i-y for believing the
printing on the side of a rechargeable, lithium 16340 battery
(2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
leaves me wondering why, if leisure batteries are so capable of coping
with extremes and lithium has all these supply-side issues, more solar
systems aren't designed to take advantage of that older technology?

Nick

On 28/09/2022 13:41, Nick Odell wrote:
> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>
>> On 27/09/2022 20:16, Nick Odell wrote:
>>

>>>
> Thanks Chris, that's interesting. Bearing in mind my depth of insight
> into battery technologies (I was roasted on uk.d-i-y for believing the
> printing on the side of a rechargeable, lithium 16340 battery
> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
> leaves me wondering why, if leisure batteries are so capable of coping
> with extremes and lithium has all these supply-side issues, more solar
> systems aren't designed to take advantage of that older technology?

I think its that usual juggling match with various conflicting design
requirements - what is that old project management saying -
good/cheap/fast - pick two

I think that comparing Lithium with lead acid for solar storage Lithium
batteries are smaller (so can look neater strapped to the side of your
house) Less maintenance, slightly longer life, better performance in
extremes of temperature but more expensive.

This website (US based)

https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage

does a comparison and concludes

For example, a lithium ion battery like the Tesla Powerwall takes up
just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
energy, and has a warranty that says it will last for at least 10 years
while still being able to store 70% of its initial capacity. With daily
discharge of up to 80%, that’s something like 33,000 kWh served.

Whereas a deep cycle battery bank made up of flooded lead acid batteries
that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
on the floor, require regular maintenance, and last for about 7 years
total, serving about 28,000 kWh.

Dividing the cost by the expected lifetimes, the lead acid costs $750
per year of service, and the Powerwall would cost $840 per year, or 12%
more.

However with major competition for the rare earth materials for EV
batteries that cost equation may change radically in the future.

--
Chris B (News)

On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:

>On 28/09/2022 13:41, Nick Odell wrote:
>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>
>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>
>
>>>>
>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>> into battery technologies (I was roasted on uk.d-i-y for believing the
>> printing on the side of a rechargeable, lithium 16340 battery
>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>> leaves me wondering why, if leisure batteries are so capable of coping
>> with extremes and lithium has all these supply-side issues, more solar
>> systems aren't designed to take advantage of that older technology?
>
>I think its that usual juggling match with various conflicting design
>requirements - what is that old project management saying -
>good/cheap/fast - pick two
>
>I think that comparing Lithium with lead acid for solar storage Lithium
>batteries are smaller (so can look neater strapped to the side of your
>house) Less maintenance, slightly longer life, better performance in
>extremes of temperature but more expensive.
>
>This website (US based)
>
>https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>
>does a comparison and concludes
>
>For example, a lithium ion battery like the Tesla Powerwall takes up
>just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>energy, and has a warranty that says it will last for at least 10 years
>while still being able to store 70% of its initial capacity. With daily
>discharge of up to 80%, that’s something like 33,000 kWh served.
>
>Whereas a deep cycle battery bank made up of flooded lead acid batteries
>that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>on the floor, require regular maintenance, and last for about 7 years
>total, serving about 28,000 kWh.
>
>Dividing the cost by the expected lifetimes, the lead acid costs $750
>per year of service, and the Powerwall would cost $840 per year, or 12%
>more.
>
>
>However with major competition for the rare earth materials for EV
>batteries that cost equation may change radically in the future.

Bring back the Enfield 8000 and embrace lead acid batteries in EVs!

Nick

Nick Odell <nick@themusicworkshop.plus.com> wrote:
> On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:
>
>> On 28/09/2022 13:41, Nick Odell wrote:
>>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>>
>>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>>
>>
>>>>>
>>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>>> into battery technologies (I was roasted on uk.d-i-y for believing the
>>> printing on the side of a rechargeable, lithium 16340 battery
>>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>>> leaves me wondering why, if leisure batteries are so capable of coping
>>> with extremes and lithium has all these supply-side issues, more solar
>>> systems aren't designed to take advantage of that older technology?
>>
>> I think its that usual juggling match with various conflicting design
>> requirements - what is that old project management saying -
>> good/cheap/fast - pick two
>>
>> I think that comparing Lithium with lead acid for solar storage Lithium
>> batteries are smaller (so can look neater strapped to the side of your
>> house) Less maintenance, slightly longer life, better performance in
>> extremes of temperature but more expensive.
>>
>> This website (US based)
>>
>> https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>>
>> does a comparison and concludes
>>
>> For example, a lithium ion battery like the Tesla Powerwall takes up
>> just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>> energy, and has a warranty that says it will last for at least 10 years
>> while still being able to store 70% of its initial capacity. With daily
>> discharge of up to 80%, that’s something like 33,000 kWh served.
>>
>> Whereas a deep cycle battery bank made up of flooded lead acid batteries
>> that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>> on the floor, require regular maintenance, and last for about 7 years
>> total, serving about 28,000 kWh.
>>
>> Dividing the cost by the expected lifetimes, the lead acid costs $750
>> per year of service, and the Powerwall would cost $840 per year, or 12%
>> more.
>>
>>
>> However with major competition for the rare earth materials for EV
>> batteries that cost equation may change radically in the future.
>
> Bring back the Enfield 8000 and embrace lead acid batteries in EVs!
>
> Nick
>

Nick, are you on Facebook? Some interesting relevant groups there which I'm
a member of, eg Solar and Battery UK. Our solar system is due to be
installed at the end of October, so I've been doing quite a bit of
research.

--
Sally in Shropshire, UK

Sally Thompson <thompson.stonybrook@gmail.com.invalid> wrote:
> Nick Odell <nick@themusicworkshop.plus.com> wrote:
>> On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:
>>
>>> On 28/09/2022 13:41, Nick Odell wrote:
>>>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>>>
>>>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>>>
>>>
>>>>>>
>>>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>>>> into battery technologies (I was roasted on uk.d-i-y for believing the
>>>> printing on the side of a rechargeable, lithium 16340 battery
>>>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>>>> leaves me wondering why, if leisure batteries are so capable of coping
>>>> with extremes and lithium has all these supply-side issues, more solar
>>>> systems aren't designed to take advantage of that older technology?
>>>
>>> I think its that usual juggling match with various conflicting design
>>> requirements - what is that old project management saying -
>>> good/cheap/fast - pick two
>>>
>>> I think that comparing Lithium with lead acid for solar storage Lithium
>>> batteries are smaller (so can look neater strapped to the side of your
>>> house) Less maintenance, slightly longer life, better performance in
>>> extremes of temperature but more expensive.
>>>
>>> This website (US based)
>>>
>>> https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>>>
>>> does a comparison and concludes
>>>
>>> For example, a lithium ion battery like the Tesla Powerwall takes up
>>> just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>>> energy, and has a warranty that says it will last for at least 10 years
>>> while still being able to store 70% of its initial capacity. With daily
>>> discharge of up to 80%, that’s something like 33,000 kWh served.
>>>
>>> Whereas a deep cycle battery bank made up of flooded lead acid batteries
>>> that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>>> on the floor, require regular maintenance, and last for about 7 years
>>> total, serving about 28,000 kWh.
>>>
>>> Dividing the cost by the expected lifetimes, the lead acid costs $750
>>> per year of service, and the Powerwall would cost $840 per year, or 12%
>>> more.
>>>
>>>
>>> However with major competition for the rare earth materials for EV
>>> batteries that cost equation may change radically in the future.
>>
>> Bring back the Enfield 8000 and embrace lead acid batteries in EVs!
>>
>> Nick
>>
>
> Nick, are you on Facebook? Some interesting relevant groups there which I'm
> a member of, eg Solar and Battery UK. Our solar system is due to be
> installed at the end of October, so I've been doing quite a bit of
> research.
>

Hello Sally,
I have done a fair bit of research but being a coward and (maybe, over)
cautious, I have steered clear of any social media from the start; I must
have looked at hundreds of websites however and found some companies very
helpful and the likes of Ecobubl have put up many a video on YouTube that
have been watched and found to be very informative (that is the closest I
ever go to SM and have never joined or pressed the comment buttons or
whatever). We are going out on Saturday to celebrate Mrs. McToodle’s 21st
birthday and it will also be our ‘Megawatt Hour of solar production’
celebration as we recently clocked up our first MW/h. ;-)))

--
Toodle Pip, Mike McMillan

On 29 Sep 2022 13:37:59 GMT, Sally Thompson
<thompson.stonybrook@gmail.com.invalid> wrote:

>Nick Odell <nick@themusicworkshop.plus.com> wrote:
>> On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:
>>
>>> On 28/09/2022 13:41, Nick Odell wrote:
>>>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>>>
>>>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>>>
>>>
>>>>>>
>>>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>>>> into battery technologies (I was roasted on uk.d-i-y for believing the
>>>> printing on the side of a rechargeable, lithium 16340 battery
>>>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>>>> leaves me wondering why, if leisure batteries are so capable of coping
>>>> with extremes and lithium has all these supply-side issues, more solar
>>>> systems aren't designed to take advantage of that older technology?
>>>
>>> I think its that usual juggling match with various conflicting design
>>> requirements - what is that old project management saying -
>>> good/cheap/fast - pick two
>>>
>>> I think that comparing Lithium with lead acid for solar storage Lithium
>>> batteries are smaller (so can look neater strapped to the side of your
>>> house) Less maintenance, slightly longer life, better performance in
>>> extremes of temperature but more expensive.
>>>
>>> This website (US based)
>>>
>>> https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>>>
>>> does a comparison and concludes
>>>
>>> For example, a lithium ion battery like the Tesla Powerwall takes up
>>> just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>>> energy, and has a warranty that says it will last for at least 10 years
>>> while still being able to store 70% of its initial capacity. With daily
>>> discharge of up to 80%, that?s something like 33,000 kWh served.
>>>
>>> Whereas a deep cycle battery bank made up of flooded lead acid batteries
>>> that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>>> on the floor, require regular maintenance, and last for about 7 years
>>> total, serving about 28,000 kWh.
>>>
>>> Dividing the cost by the expected lifetimes, the lead acid costs $750
>>> per year of service, and the Powerwall would cost $840 per year, or 12%
>>> more.
>>>
>>>
>>> However with major competition for the rare earth materials for EV
>>> batteries that cost equation may change radically in the future.
>>
>> Bring back the Enfield 8000 and embrace lead acid batteries in EVs!
>>
>> Nick
>>
>
>Nick, are you on Facebook? Some interesting relevant groups there which I'm
>a member of, eg Solar and Battery UK. Our solar system is due to be
>installed at the end of October, so I've been doing quite a bit of
>research.

Do you know something the rest of us don't know? I thought our solar
system had already been installed just over 4.5 billion years ago but
if it isn't going to be finished until the end of October then I
reckon that's a heck of a long wait for the missing parts.

Seriously, thanks for the tips but I don't use Facebook and I'm only
really interested because it seems an interesting subject. I've no
plans to go down that route myself.

Nick

On 29-Sep-22 19:59, Nick Odell wrote:
> On 29 Sep 2022 13:37:59 GMT, Sally Thompson
> <thompson.stonybrook@gmail.com.invalid> wrote:
>
>> Nick Odell <nick@themusicworkshop.plus.com> wrote:
>>> On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:
>>>
>>>> On 28/09/2022 13:41, Nick Odell wrote:
>>>>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>>>>
>>>>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>>>>
>>>>
>>>>>>>
>>>>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>>>>> into battery technologies (I was roasted on uk.d-i-y for believing the
>>>>> printing on the side of a rechargeable, lithium 16340 battery
>>>>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>>>>> leaves me wondering why, if leisure batteries are so capable of coping
>>>>> with extremes and lithium has all these supply-side issues, more solar
>>>>> systems aren't designed to take advantage of that older technology?
>>>>
>>>> I think its that usual juggling match with various conflicting design
>>>> requirements - what is that old project management saying -
>>>> good/cheap/fast - pick two
>>>>
>>>> I think that comparing Lithium with lead acid for solar storage Lithium
>>>> batteries are smaller (so can look neater strapped to the side of your
>>>> house) Less maintenance, slightly longer life, better performance in
>>>> extremes of temperature but more expensive.
>>>>
>>>> This website (US based)
>>>>
>>>> https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>>>>
>>>> does a comparison and concludes
>>>>
>>>> For example, a lithium ion battery like the Tesla Powerwall takes up
>>>> just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>>>> energy, and has a warranty that says it will last for at least 10 years
>>>> while still being able to store 70% of its initial capacity. With daily
>>>> discharge of up to 80%, that?s something like 33,000 kWh served.
>>>>
>>>> Whereas a deep cycle battery bank made up of flooded lead acid batteries
>>>> that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>>>> on the floor, require regular maintenance, and last for about 7 years
>>>> total, serving about 28,000 kWh.
>>>>
>>>> Dividing the cost by the expected lifetimes, the lead acid costs $750
>>>> per year of service, and the Powerwall would cost $840 per year, or 12%
>>>> more.
>>>>
>>>>
>>>> However with major competition for the rare earth materials for EV
>>>> batteries that cost equation may change radically in the future.
>>>
>>> Bring back the Enfield 8000 and embrace lead acid batteries in EVs!
>>>
>>> Nick
>>>
>>
>> Nick, are you on Facebook? Some interesting relevant groups there which I'm
>> a member of, eg Solar and Battery UK. Our solar system is due to be
>> installed at the end of October, so I've been doing quite a bit of
>> research.
>
> Do you know something the rest of us don't know? I thought our solar
> system had already been installed just over 4.5 billion years ago but
> if it isn't going to be finished until the end of October then I
> reckon that's a heck of a long wait for the missing parts.

It's called Privatisation Nick.
Sally put in the highest bid whilst we were all busy worrying about TA.

I hope she will allow us a decent interval in which to find somewhere
else to live.

Don't it always seem to go
That you don't know what you got
'Till it's gone.

--
Sam Plusnet

On 29/09/2022 22:55, Sam Plusnet wrote:
<snip>

> 'Till

Wot?

--
Cheers
Clive

Sam Plusnet <not@home.com> wrote:
> On 29-Sep-22 19:59, Nick Odell wrote:
>> On 29 Sep 2022 13:37:59 GMT, Sally Thompson
>> <thompson.stonybrook@gmail.com.invalid> wrote:
>>
>>> Nick Odell <nick@themusicworkshop.plus.com> wrote:
>>>> On Wed, 28 Sep 2022 17:57:50 +0100, Chris B <news@salis.co.uk> wrote:
>>>>
>>>>> On 28/09/2022 13:41, Nick Odell wrote:
>>>>>> On Wed, 28 Sep 2022 09:54:06 +0100, Chris B <news@salis.co.uk> wrote:
>>>>>>
>>>>>>> On 27/09/2022 20:16, Nick Odell wrote:
>>>>>>>
>>>>>
>>>>>>>>
>>>>>> Thanks Chris, that's interesting. Bearing in mind my depth of insight
>>>>>> into battery technologies (I was roasted on uk.d-i-y for believing the
>>>>>> printing on the side of a rechargeable, lithium 16340 battery
>>>>>> (2400mAh? How much does it weigh? Well it's not 2400mAh then.)) that
>>>>>> leaves me wondering why, if leisure batteries are so capable of coping
>>>>>> with extremes and lithium has all these supply-side issues, more solar
>>>>>> systems aren't designed to take advantage of that older technology?
>>>>>
>>>>> I think its that usual juggling match with various conflicting design
>>>>> requirements - what is that old project management saying -
>>>>> good/cheap/fast - pick two
>>>>>
>>>>> I think that comparing Lithium with lead acid for solar storage Lithium
>>>>> batteries are smaller (so can look neater strapped to the side of your
>>>>> house) Less maintenance, slightly longer life, better performance in
>>>>> extremes of temperature but more expensive.
>>>>>
>>>>> This website (US based)
>>>>>
>>>>> https://www.solarreviews.com/blog/lead-acid-batteries-for-solar-storage
>>>>>
>>>>> does a comparison and concludes
>>>>>
>>>>> For example, a lithium ion battery like the Tesla Powerwall takes up
>>>>> just about 4.5 cubic feet, hangs on a wall, stores 13.5 kWh of usable
>>>>> energy, and has a warranty that says it will last for at least 10 years
>>>>> while still being able to store 70% of its initial capacity. With daily
>>>>> discharge of up to 80%, that?s something like 33,000 kWh served.
>>>>>
>>>>> Whereas a deep cycle battery bank made up of flooded lead acid batteries
>>>>> that could discharge up to 10.4 kWh per day would take up 8.2 cubic feet
>>>>> on the floor, require regular maintenance, and last for about 7 years
>>>>> total, serving about 28,000 kWh.
>>>>>
>>>>> Dividing the cost by the expected lifetimes, the lead acid costs $750
>>>>> per year of service, and the Powerwall would cost $840 per year, or 12%
>>>>> more.
>>>>>
>>>>>
>>>>> However with major competition for the rare earth materials for EV
>>>>> batteries that cost equation may change radically in the future.
>>>>
>>>> Bring back the Enfield 8000 and embrace lead acid batteries in EVs!
>>>>
>>>> Nick
>>>>
>>>
>>> Nick, are you on Facebook? Some interesting relevant groups there which I'm
>>> a member of, eg Solar and Battery UK. Our solar system is due to be
>>> installed at the end of October, so I've been doing quite a bit of
>>> research.
>>
>> Do you know something the rest of us don't know? I thought our solar
>> system had already been installed just over 4.5 billion years ago but
>> if it isn't going to be finished until the end of October then I
>> reckon that's a heck of a long wait for the missing parts.
>
> It's called Privatisation Nick.
> Sally put in the highest bid whilst we were all busy worrying about TA.
>
> I hope she will allow us a decent interval in which to find somewhere
> else to live.
>
> Don't it always seem to go
> That you don't know what you got
> 'Till it's gone.
>

Where’s that yellow taxi come from?!

--
Toodle Pip, Mike McMillan

On 29/09/2022 14:37, Sally Thompson wrote:
> ... Some interesting relevant groups there which I'm
> a member of, eg Solar and Battery UK. Our solar system is due to be
> installed at the end of October, so I've been doing quite a bit of
> research.
>
Thanks for the link Sally. I have requested to join and will post my
analysis there too for comment as I keep thinking I have forgotten
something as everyone seems to be installing much bigger systems.

What system have you decided to go with in terms of panels and battery
size ?

BrritSki <rtilburyTAKEAWAY@gmail.com> wrote:
> On 29/09/2022 14:37, Sally Thompson wrote:
>> ... Some interesting relevant groups there which I'm
>> a member of, eg Solar and Battery UK. Our solar system is due to be
>> installed at the end of October, so I've been doing quite a bit of
>> research.
>>
> Thanks for the link Sally. I have requested to join and will post my
> analysis there too for comment as I keep thinking I have forgotten
> something as everyone seems to be installing much bigger systems.
>
> What system have you decided to go with in terms of panels and battery
> size ?
>
>
>
>

12 390W panels but we are delaying battery on grounds of cost. We are told
we can add that on later, and since it's on the DC side it won't incur VAT.
We trust the company; they are fairly local, have been in the business for
many years, and installed our ASHP some years ago.

--
Sally in Shropshire, UK

On 30/09/2022 10:07, Sally Thompson wrote:
> BrritSki <rtilburyTAKEAWAY@gmail.com> wrote:
>> On 29/09/2022 14:37, Sally Thompson wrote:
>>> ... Some interesting relevant groups there which I'm
>>> a member of, eg Solar and Battery UK. Our solar system is due to be
>>> installed at the end of October, so I've been doing quite a bit of
>>> research.
>>>
>> Thanks for the link Sally. I have requested to join and will post my
>> analysis there too for comment as I keep thinking I have forgotten
>> something as everyone seems to be installing much bigger systems.
>>
>> What system have you decided to go with in terms of panels and battery
>> size ?
>>
>>
>>
>>
>
> 12 390W panels but we are delaying battery on grounds of cost. We are told
> we can add that on later, and since it's on the DC side it won't incur VAT.
> We trust the company; they are fairly local, have been in the business for
> many years, and installed our ASHP some years ago.
>
Sounds good. We are very pleased with our similar size system (a couple
more panels but they're older and less efficient).

Good luck with the installation.

BrritSki <rtilburyTAKEAWAY@gmail.com> wrote:
> On 29/09/2022 14:37, Sally Thompson wrote:
>> ... Some interesting relevant groups there which I'm
>> a member of, eg Solar and Battery UK. Our solar system is due to be
>> installed at the end of October, so I've been doing quite a bit of
>> research.
>>
> Thanks for the link Sally. I have requested to join and will post my
> analysis there too for comment as I keep thinking I have forgotten
> something as everyone seems to be installing much bigger systems.
>
> What system have you decided to go with in terms of panels and battery
> size ?
>
I've also invited you. Couldn't work out how to put a direct link to the
group.

--
Sally in Shropshire, UK

On 30/09/2022 10:23, Sally Thompson wrote:
>>>
> I've also invited you. Couldn't work out how to put a direct link to
> the group.
>
Thanks