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dangos avatar image
dangos asked

UK ESS Self-install MCS certification

Hi

I am looking to install my own ESS - Multiplus II with Pylontech US3000C batteries, solar on MPPTs on the DC side. I am happy to do all the design and install work myself, however I would ideally like to find someone who is MCS certified to sign it all off afterwards and give me a shiny certificate.

Does anyone know of anyone that would be willing to do this kind of thing in the South East of the UK?

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59 Answers
solar-sam avatar image
solar-sam answered ·

seeing some Alibarba solar battery prices at unbelievable value, but saying it can only send to EU...Saw pylontec US 5000 battery for £560 for a 5kw one. Clearly some market manipulations going on with UK sales as taking excessive profits or trying to falsely hold up prices. That's under half of what I can find cheapest retail, with some three times that price.

I'm sure battery prices will crash very soon, and it really opens the door on charging off peak and discharging at peak to the grid on a daily basis. I for one will obtain a decent bank then, not just a few for current overnight loads. Sent some wholesalers the link asking them to get some for me and got a stonewall reply.

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Craig Chamberlain avatar image Craig Chamberlain commented ·
£560 for a US5000 seems too good to be true tbh. I'd love to believe it's a true reflection on prices but I just don't. £1279 inc VAT is the cheapest I've seen online from UK suppliers and that seems about what I would expect based on what I paid for my third battery and the time that has passed since then.

I just don't see any reason why we would expect a "crash" in prices. A steady reduction yes but why expect a crash? It's a mature market.

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solar-sam avatar image
solar-sam answered ·

Octopus power saving session today 17:30-!8:30. 17/01/24

Offer is £2.25 per kw/hr.

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Craig Chamberlain avatar image Craig Chamberlain commented ·
Yeah, saw that and thankfully my Node-RED flow automatically signed me up for it. Hopefully it will also automatically start the export at 5:30pm too. Will be cooking dinner between 5pm and 5:30pm so will monitor it. :)
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daza avatar image daza Craig Chamberlain commented ·

@Craig Chamberlain nit sure if NodeRed worked or if it worked when I loaded it up on the web page but I did get signed in automagically, PS I didn’t get the Pushover notification any help with that?

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Craig Chamberlain avatar image Craig Chamberlain daza commented ·
I got the pushover notification to say it had signed me up for the session and I'm happy to report that the forced export started on cue at 5:30pm and is approaching the end of the sessions where it will hopefully go back to 0w grid export.

As for why your pushover isn't working, all I did was set up a pushover account and got an API token and User key which I entered into the appropriate node. I then installed the pushover app on my iPhone and set it up (I forget exactly what I did) to receive the notifications. Not sure if this will help but let me know how you get on.

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daza avatar image daza Craig Chamberlain commented ·
Ok cool I’ll have a look but I couldn’t get it to discharge itself either,so had to use the beta VRM to sell, but I defo need another battery. I’ll look at the discharging later but it’s probably a good job it didn’t do 5000W as now I’m in limp mode with 30% left
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Craig Chamberlain avatar image Craig Chamberlain daza commented ·
The saving session took my battery from 88% to 56% and that's with three US5000 batteries with 14.4kWh (13.68kWh at 95% DoD). But the thing is, even if I had to deplete my battery to 10% or even 5% during a saving session then I absolutely would because the income from the saving session export is much greater than the cost of even peak rate import. £2.25/kWh vs £0.30/kWh roughly. So I don't have any lower battery limit during a saving session other than the usual 10% min SOC I have set globally.
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xtopher avatar image xtopher Craig Chamberlain commented ·
Ditto! I had a good solar day so batteries were up at 80-90%, but would run it to empty (10%) if needs be.
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daza avatar image daza Craig Chamberlain commented ·
Dam it @Craig Chamberlain very true, wish I stayed on the Gas now but mine didn’t switch for some reason is there any code used when inputting the -5000W for export and the 0watts for stop session.
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solar-sam avatar image
solar-sam answered ·

im very interested in your node-red and if it works. i'm not even in the uk currently but hopefully i've also just set up conditions to aid the grid and export 4500w for an hr. so bit of a learning curve for me as well. even better i'm off to a local bar where its 1.5 euro a pint, so will return in profit from the exercise. hopefully aiding the grid like this will become the norm, even if the kw/hr isnt so lucrative its extremely worthwhile and helps prevent use of coal and gas firing and aids the grid.

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daza avatar image
daza answered ·

I hope it will come down but never going to be £500 odd, possibly £1100 but I’m happy to be wrong as I do need one more

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solar-sam avatar image
solar-sam answered ·

Just one fear I do have now we are being paid for solar exports in effect exactly the same as those with MCS certs (and why not anyway), is that it was listed as a trial. Just an outside possibility, that they might return and say "trial ended, thanks very much, exports stopped", or "that's it for this year, it'll be another £200, for this costly paperwork for next year".

Apart from a flurry of complaints, it is an outsiders possibility.

Lets hope self installers will now count as equals to MCS cert holders, because of what I've seen on this forum, the work seems to be superior than most paid installs.

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xtopher avatar image xtopher commented ·
Same can be said of their beta/smart products too. Though conversations I've had with Gregg on Twitter suggests he does actually want to remove red tape in general and MCS is one of those they want out the way. He said the only reason they wouldn't offer it was because of their obligations (by OFGEM) by not having MCS (making sure the install is safe etc), so as long as OFGEM are happy with what they are doing, I'm confident they will continue to offer it. The fee is for documenting what they need to keep OFGEM happy so should be a one off.
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Craig Chamberlain avatar image Craig Chamberlain xtopher commented ·
Yeah I agree, the fee was to obtain an export tariff based on a non-standard set of documentation and circumstance and once you have the export tariff then not only do I think they can't take it away from you but I also think you could migrate to another export provider if you wanted to.

Another nice sunny winter's day today where my batteries were at 100% at 05:30 and are still at 84% at 5pm. No export today but 5kWh of solar captured from a 6.1kWh forecast to keep the batteries nicely topped up. Only 6.5 hours to go until I can charge them back up again and restart the cycle. And this is still January. I'm beyond happy at how this is all working out at this point! :)

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solar-sam avatar image solar-sam Craig Chamberlain commented ·
I believe getting onto a cheap import tariff at night is the next step forward for me. However I havn't yet purchased an EV or installed a EV charge meter. Any way around these hurdles???, certainly don't mind putting in a charge point with a view to future purchase.

Know certain tariffs req a certain EV or a certain type of charger. Or even the "number plate".

All advice most welcome.

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Craig Chamberlain avatar image Craig Chamberlain solar-sam commented ·
Hi, when I was on Octopus Go I wasn't asked for any proof that I had an EV although I could have provided it if I was asked. That might have changed these days I'm not sure. I'm not sure how Octopus could tell the difference between an EV charging and a home battery charging so I guess it comes down to what questions they ask, what evidence (if any) they require, and how far you are comfortable bending the truth.

As for Intelligent Octopus Go, that is quite a different prospect since it very closely integrates with either the charger or the EV. The preference is to integrate with the charger because it is usually either on an ethernet connection or WiFi whereas the car often depends on flaky cellular networking. We have a BMW i3 connected to a Wallbox Pulsar Plus charger (the Pulsar Max is the later version of this) and our integration could have been with either car or charger but we went with the charger. It has performed really well and uses a remote protocol called OCPP to allow Octopus to command my charger remotely. It's a bit of a leap of faith to give up control of the charger but there is a way to override it and perform a "Bump Charge" if necessary but we've not had to do that at all so far.

So, I think it's worth looking into a switch to Octopus Go but I wouldn't waste your time with IOG since you really can't progress that without a specific car and/or charger. The sign up process even does a test charge before the tariff switch is completed so even if you bought a charger, you'd need to borrow a car to complete the sign up. I wouldn't be surprised if after that, Octopus monitor the usage of the charger and will know if you aren't using it. I think the T's and C's mention this in fact. Essentially they give a better tariff in return for being able to both reduce consumption by stopping the EV charging at certain times AND increasing consumption when there is a surplus of energy in the grid. It's this second item that you would fall down on if you didn't actually have an EV connected each night.

HTH

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daza avatar image
daza answered ·

Coming back to this battery thing! ie price guys it doesn’t look good I spoke to a supplier and they said the VAT isn’t going, all that is happening is installers that can clam vat are not being charged VAT and us diyers that can’t will be charged VAT doesn’t make sense to me as those Limited companies can already claim VAT, he did say that prices will likely go down Feb but not drastically.

Very disappointing if this is what it actually is

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Craig Chamberlain avatar image Craig Chamberlain commented ·
If you're referring to the VAT cut that was introduced on solar PV installations back in April 2022 then that was never something that could be taken advantage of by a DIY installer. It was only ever applicable for the supply AND INSTALLATION of solar PV, and optionally a solar battery system at the same time, by the same company. You couldn't buy from one company and then have another company install it. That said, if you did buy the gear yourself (20% VAT paid as usual), then you could get a company to install it and only pay 5% VAT on the installation cost.


Also, this never applied to battery only installations and you couldn't do solar now and add battery later because the subsequent battery supply and installation would revert to the full VAT rate.

Companies that are VAT registered (limited or sole trader) can (generally) claim back VAT on purchases but when those companies sell to an end consumer, they have to charge VAT at the prevailing rate. Then as part of their VAT return, they declare the purchases and sales VAT and either pay the difference to HMRC or claim back money if they had more purchase VAT than sales VAT. So for a solar installer who is supplying and installing all the gear, they can charge the end consumer this special 0% rate. That in theory makes it cheaper for the end consumer but of course it's up to the installer to decide how much profit they want to make and I suspect some installers are not passing on these savings in full. And for the last few years the market has seen such high demand that competition has not really been keeping the suppliers honest. I think that will change soon if it hasn't already.

We're still living in an inflationary economy so in general prices are rising (which is actually a good thing!) so the only change in prices we can reasonably expect is due to supply meeting and exceeding demand, general production efficiency and yield improvements and market competition. None of these tend to produce step changes, only incremental changes. The only thing that could create a step change in pricing is if a new technology was imminently on the horizon that uses different materials and would render existing battery tech obsolete. Then the suppliers will want to dump inventory fast!

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daza avatar image daza Craig Chamberlain commented ·
@Craig Chamberlain yeah similar there is a VAT cut on batteries in February, yes 100% agree new battery tech is the only thing at at the mo it’s a lot of hype and nothing is market ready yet with no time frame to market.
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Craig Chamberlain avatar image Craig Chamberlain daza commented ·

Where have you seen the info about this VAT cut on batteries in February? I've seen rumours but no actual substance behind them so far.

Edit: I think I know what you're referring to now. Basically the government are dropping the requirement that batteries only qualify for the 0% VAT rate if they are installed alongside other energy saving tech such as wind turbines or solar panels. So from 1st Feb you can retrofit batteries to an existing installation or install a battery only installation and you'll get 0% VAT on the material and labour. However, you'll still need to employ the services of a company to do this work so it won't affect the prices that you or I will pay for buying the batteries themselves unfortunately.

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daza avatar image daza Craig Chamberlain commented ·
Yep us DIYers are out of luck and pointless paying someone to install a battery as it would mostly cost more to have someone install it than just paying the vat on it.
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solar-sam avatar image
solar-sam answered ·

Its really crackers just how much some installers are charging peeps to install a few solar batteries. Saw an advertisement the other day saying would you like more solar batteries to basically tick this box. I thought "well they buy in scale so might get a better deal for another one, nothing to lose". Well this well meaning chap phoned me, and was telling me exactly what he thought I needed without listening to me as to what I was after ie Another pylontec us 5000.

After I pointed it out he passed me onto his boss, who blatantly told me the cost would be £4000, for something I can buy right now for £1260. Understand some small labour charges, as they take about 30 mins to fit but goes to show what they are trying to get away with. After a short frank exchange of views he told me he couldn't buy them less than £1600 each, to which I offered to sell him 10 at 10% cheaper. Needless to say he couldn't actually get them cheaper than we can, and demonstrates that installers are really trying it on with customers still to maximise profits. Some even quoting £400-£500 per panel for 375W ones ??? With true prices less than one fifth of that I'm still seeing rubbish installs being done in many places where the installer could have easily put up more panels fort he customer if wanting to install in portrait and landscape. My fear is this installer greed will prevent the installation of a lot more uk green energy.

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daza avatar image daza commented ·
Totally agree mate this is just a kin to double glazing raking it hand over fist as more shakes pop up that are not planning to be around for long just making the quick buck
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dmsims avatar image dmsims daza commented ·

I see Fogstar rack batteries have gone down to £1049

https://www.fogstar.co.uk/collections/server-rack-batteries/products/server-rack-battery-48v-5-12kwh

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Craig Chamberlain avatar image Craig Chamberlain dmsims commented ·
Worth noting that the fogstar batteries are only rated to 4000 cycles at 80% DoD whereas Pylontech are 6000 cycles at 95% DoD. Whether these figures are accurate or not is anyone’s guess of course.

They do have onboard heaters though, which is a nice feature.

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daza avatar image daza Craig Chamberlain commented ·

@Craig Chamberlain you are right but they do the test at 1C compared to pylontechs 25C but then again pylontechs spec says >8000 cycles at that temp and with a design life of 15plus years. The Fogstar does say that it has full depth of discharge but displays 80% DOD but that could be that because they do it at 1C it’s hard to compare but yeah still appares weaker 15% of the battery missing and only 4000cycles I’ll stick with pylontech

https://en.pylontech.com.cn/view_pdf/web/viewer.html?file=/A_UpLoad/upload_file/20230629201336_0215.pdf&fname=Residential+BESS-rack+mounted+type+EN+US+5000.pdf



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Craig Chamberlain avatar image Craig Chamberlain daza commented ·

Where do you see it saying the Pylontech's are tested at 25C. I'm pretty sure that's a mistake because that would mean a 2500A charge/discharge current. FogStart do indeed specify 1C which for a 100Ah battery means a 100A test current which is reasonable if a little unrealistic for an ESS system but I don't see the test current in the Pylontech spec. I very much doubt that Pylontech even test at 1C because that is above the 80A "recommended" max current. More like they test at 0.5C (50A) or maybe even lower. Could the 25 you mentioned be 0.25C perhaps (25A)?

The >8000 cycle figure from Pylontech seems to have gone up from the spec of >6000 cycles that came on the printed spec sheet with mine. Maybe they are finding that they are easily exceeding the 6000 cycles in operation and so are upping the spec.

Edit: I just double checked in case my memory was playing tricks on me and sure enough, the manual I got with my batteries says >6000 cycles at 25 degrees C (temperature) which I think is where you have seen the 25C. In the link you attached above the degrees symbol is missing. You can also see where it says 25 / 77 which is actually 25 C / 77 F.

So with a design life of 15 years and now >8000 cycles, that's 8000 / 15 / 365 = around 1.5 cycles per day which is pretty generous. It does say in the spec that the design life depends on the "specific operating conditions" and to "please check with Pylontech service team" for more details.

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dmsims avatar image dmsims Craig Chamberlain commented ·

Actually the rating for Pylontech just says >6000 25C with no DoD specified!

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daza avatar image daza dmsims commented ·
Is that the manual as mine says the same but they have updated the spec on there website that’s where I have noticed the difference in cycles might reach out for change confirmation on that.
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daza avatar image
daza answered ·

@dmsims i reached out to pylontech and it is what I thought they have increased the battery cycle limit after testing. So all US5000’s have been increased in cycles. Good new all round as I wait for the last US5000 to arrive to take me to 4

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dmsims avatar image dmsims commented ·

Yes but what DoD are they using ?

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Craig Chamberlain avatar image Craig Chamberlain dmsims commented ·

They state 95% DoD on the same specification page as they specify the cycle count and design life amongst other things so I think it's fair to assume that is also the DoD they are tested at.

Also, I'm pretty sure the definition of a "cycle" is from fully charged to min SOC and back to fully charged again. If you only went from 100 to 52.5 and back to 100% then that would only be half a cycle.

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daza avatar image
daza answered ·

Cheers mate. @Craig Chamberlain as for the Pylontech query it is @95% depth of discharge so the same. @dmsims

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Craig Chamberlain avatar image Craig Chamberlain commented ·
Thanks for following this up. I was pretty sure that would be the answer but it's good to have that confirmed.
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