Posted by: @misterb

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@transparent 

I am not selling the battery its an option  for them to consider. I'm sure they are adult enough to make their own judgement and enquiries as to it's suitability...

I must admit, @misterb, that I didn't take @transparent's post as a criticism of your suggestion. What you did, though, is incidentally highlight a point I for one had not considered before and that is the extent to which interoperability is practical vs a marketing box-ticking exercise.

I hadn't considered getting an extra battery for some time but with 15kWh available for just under £3k I'm at least taking a closer look. However, if the Fogstar touts its compatibility based on implementing Modbus and getting the inverter and battery to talk to each other requires just that, I may have an issue given my Growatt inverter uses a non-standard flavour of Modbus. It's another thing I have to factor in and not one I'd have noticed without @transparent's reply to the comment you made.

Perhaps my initial (and subsequent) reading of the response might have meant I have taken the comments in a manner unintended.....

But the point re people actually researching and checking that what they buy is compatible with other parts of their jigsaw BEFORE they buy it, is perhaps the most important part of this discussion.  

Measure once, cut twice could be ammended to if you don't check what you're buying, you might end up buying twice !

Posted by: @misterb

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Perhaps my initial (and subsequent) reading of the response might have meant I have taken the comments in a manner unintended.....

But the point re people actually researching and checking that what they buy is compatible with other parts of their jigsaw BEFORE they buy it, is perhaps the most important part of this discussion.  

Measure once, cut twice could be ammended to if you don't check what you're buying, you might end up buying twice !

Quite agree.

Although I might even suggest the most important part of this discussion is that there is a discussion. I've been really lucky to find a company to support us that actually knows what they're doing but the general dearth of knowledgeable and/or ethical tradespeople in this industry means a lot of people on this forum and beyond actually don't know what they don't know. Once they know the unknowns your stance on checking before buying comes into its own.

May I share with this forum the current content of the screens in front of me.

I have here the new PAS-63100 standard for storage batteries, which we've discussed over here on this forum
and also a set of email exchanges with a manufacturer of storage products based in China.

The Chinese lithium cell manufacturers are eagerly embracing a stringent new safety standard VDE2510-50 which allows them to specify products which will not cause fire, explode or emit noxious gasses.
The test involves heating cells to destruction at 380 ℃ and there are several aspects of the test which can be reported on.

The UK standard PAS-63100 also aims to prevent the spread of fire, whilst simultaneously addressing the safety of installers and customers undertaking basic maintenance, such as changing a blown fuse. It takes no account of battery chemistry, nor VDE2510-50.

There are overlaps between the two approaches, and also some interesting omissions, which I reported to BSI over the last 36-hours
BSI's staff have responded rapidly, and have escalated my comments onward to the authors.

It's of interest to me that PAS-63100 requires certain actions to occur as a result of a fault, but does not make assumptions as to which device is to implement those safety procedures.

For example, readers here might assume that a domestic storage battery will include a BMS that will create an open-circuit when measurements exceed its configured parameters.
But what if the trip/relay is actually

• incorporated within the inverter by some manufacturers, rather than their battery unit
• or is part of a separate enclosure which links multiple batteries and inverters (as I currently have under test)

Can we assume that the appropriate command to open the contacts is passed between the devices?
After all, we have read that the devices are 'compatible' and we can see the RS485 ports linked between them.

But that's actually unlikely to be the case!

I don't think there's any standard command sequence which forms part of the 'compatibility' claim.

Equally, I need to be wary of taking a battery from one manufacturer and connecting it to a 'compatible' inverter from another.
Suppose neither has actually implemented a PAS-63100 approved trip/relay?

As someone who has entered this field through hands-on (DIY) experience within a community-energy environment, I will see things differently to the professionals within DESNZ, IET and BSI who have contributed to PAS-63100.

We do need to be having these discussions on this forum.
As the last couple of days have demonstrated, there are routes through which our comments and observations can very quickly be passed upwards to those writing the official standards.

@transparent

While I am a firm believer in the need for battery storage and/or other methods of energy storage, to help smooth out the peaks and troughs of energy supply and demand, the more I hear about potential safety issues, the more concerned I become.

Just as there is concern on the forum about the problems in obtaining a good reliable heat pump installation, how would an everyday customer know if the proposed installer of a battery storage system is actually sufficiently trained and experienced?

I think that I would feel much happier if energy storage was carried out at larger scale and was actually under the control of the grid operators and DNO's. By positioning both very large scale and large scale energy storage at locations around the country it should not only help smooth out the supply and demand issues, but also help reduce the electricity system infrastructure upgrades to more manageable levels.

An idea would be to have battery storage systems next to electricity substations, such that the batteries are charged during low demand periods of the day and then are used to supplement the local supply during peak periods. The same Engineers that look after the substation could also carry out maintenance on the battery storage.

Larger scale storage could be situated where the cables from North Sea wind farms come ashore, so that when there is an abundance of supply, this can be stored rather than having to limit generation. There could even be a plant for producing Hydrogen for industrial use or electricity generation if the battery storage should become fully charged.

Posted by: @derek-m

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I think that I would feel much happier if energy storage was carried out at larger scale and was actually under the control of the grid operators and DNO's. By positioning both very large scale and large scale energy storage at locations around the country it should not only help smooth out the supply and demand issues, but also help reduce the electricity system infrastructure upgrades to more manageable levels.

Energy transport companies licensed by Ofgem to operate within defined geographical areas may not own or control any generation or storage assets.

They may, however, work in partnership with community-based organisations to create innovative technologies which can better handle grid balancing or beneficial outcomes for consumers 🙂 

As for large-scale storage...
Hold that thought. I'm just checking what data I can reasonably present here on commercial battery storage.

If anyone reading this is aware of a Planning Application to install large-scale battery storage in their area, then please say so here (or DM me).
I would like to submit evidence during the public-consultation phase for that Application.

Thanks.

@transparent

I am fully aware that the grid operators and DNO's are not allowed by law to operate generation facilities, but I would claim that battery storage is in fact storage rather than generation.

The major problem with commercial battery storage is that I suspect it will be operated more for profit rather than for the benefit of electricity supply customers, and may therefore not be fully utilised in the most efficient and effective manner.

I don't believe it is claimed that the gas and oil suppliers also produce these energy sources, when they merely store them during the supply process.

It is about time that we had some common sense grown-up thinking concerning how best to implement the energy transition in the most effective and efficient manner.

Posted by: @derek-m

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Larger scale storage could be situated where the cables from North Sea wind farms come ashore

The following diagram describes just such a scenario.
We're looking at a marine cable bringing electricity from a wind farm into the grid where a large commercial storage battery will be co-located.

I've anonymised it, but the charts to the right describe actual results, based on three alternative strategies to get the electricity to the National Grid 400kV lines at Point A (and beyond).

The grid has insufficient capacity to accept whatever the company wishes to export from the Battery Electricity Storage System (BESS).

The three charts show the effects of Active Network Management (ANM), which would be imposed by the DNO.

ANM is a grid-protection mechanism which restricts the BESS output... effectively discarding electricity which the battery could supply.
The charts describe the amounts of electricity (in Megawatt/hours) which would be rejected due to existing wind or solar generation in that area.

Most of the generation which already connects to the transformer at Point P is from solar farms.
Export from the BESS would therefore be constrained predominantly during daytime in summer months.

In contrast, most of the generation around the Grid Supply Point Q is from other wind-farms.
That takes precedence over a proposed new connection, two transformers distant, at Point S.

Export limitation from a battery connected at Point-S therefore looks quite different.
The ANM system would reject more electricity during April/May and October.
That's when output from other wind farms is already expected to reach the permitted capacity of the local grid.

The size (total storage capacity in MWh) of the BESS in each of the three locations isn't stated here.

What matters is the amount of electricity the company wishes to export to the grid at a given point in time, measured in MW.

@transparent

Obviously the location and size of battery storage system would need to be carefully planned to achieve maximum benefit for the consumers, though I doubt that will be the case. Commercial companies are in business to make profits for their investors and/or shareholders, which is why at least some of the battery storage systems should be under the control and operation of the grid controllers directly.

The following basic explanations are given here in order to better inform forum members of the benefits of home battery installation.
They are not aimed at @derek-m who has lifetime professional experience of this subject matter!

Posted by: @derek-m

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Obviously the location and size of battery storage system would need to be carefully planned to achieve maximum benefit for the consumers, though I doubt that will be the case.

You are correct. Companies are applying for planning permission to install large-scale BESS at locations which are financially of greatest value to themselves.

It doesn't matter to them if

a: their chosen location necessitates extensive grid upgrades, because DNOs are prohibited from seeking any contribution towards this

b: the combination of capacity and location increases the risk of grid outages, because that's the responsibility of National Grid ESO to resolve

Posted by: @derek-m

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... at least some of the battery storage systems should be under the control and operation of the grid controllers directly.

... Who are also commercial companies, with shareholders seeking large dividends.

This situation will change during 2024, when control of all energy networks passes to the new Independent System Operator and Planner (ISOP).
But DNOs, NGET and gas network operators still remain privately owned.

From the viewpoint of energy security, the most resilient option remains widely-distributed local battery storage.... the subject of this topic!
There are benefits to the grid, not just the ROI for the home-owner.

Resilience of supply is becoming ever more important as the generation assets become more widely spread.

The frequency and permitted voltage ranges are stipulated by The Electricity Quality and Continuity Regulations (2002) Section 27.2 & 3

If a grid-tied inverter detects the supply deviates from those parameters, then it must disconnect itself from the grid (EREC G98 & G99 requirements).

The sudden failure of a large commercial BESS will cause a corresponding rise or fall of the grid voltage, depending on whether the battery was charging or exporting at the time.
That rapid change will also be detected by other inverters in the locality, which can mean that they too disconnect from the grid.
There is a domino-effect, radiating out from the point of the initial battery failure.

The threat-level is greatest for the (50Hz) grid frequency. It is the most stringent of the regulated parameters.
A drop in the grid voltage will increase the load on turbines, which should rotate at 3000rpm to maintain 50Hz.
That increased load causes a corresponding speed reduction.

If the 50Hz frequency deviates too far, then it becomes impossible to bring additional generation-plants on stream.

Since 2021, an annual assessment of the threat level to the grid is produced.
The latest copy of the Frequency Risk & Control Report is published for consultation today (Thur 11th April 2024). 😎 

@transparent

Let me first of all state that I am a firm believer in the need for energy storage to smooth out the peaks and troughs of energy demand. In the past, and even the present, bulk energy storage is in the form of petrol, diesel, gas, oil, nuclear fuel, water, wood and coal, with the supply of electrical energy being dependent upon the storage of one or more of the aforementioned at the power stations.

With the continuing move to more and more energy demand being in the form of electrical energy, coupled with the increasing reduction in controllable conventional electrical power generation to inconsistent renewable electrical power generation, the need for alternative methods of energy storage becomes ever more acute.

In an ideal world all homes would have at least 10kWh of battery storage, which could be gradually charged during lower demand periods of the day to help supply demand during the peak periods. This would help smooth out the demand on the electrical supply systems at high, medium and low voltage, minimising the amount of infrastructure upgrades required to keep society functioning.

I doubt that the vast majority of homeowners will have the money, space, technical know how or even enthusiasm to have domestic battery storage installed, particularly, from recent forum posts, it would appear to be not a simple plug and play exercise.

What I therefore suggest is that larger scale battery storage, widely spread throughout the electricity supply system, could be a more efficient and cost effective method of helping to balance the system. The bulk supply systems would have larger storage capacity, with the available capacity being smaller, but more abundant, as we get closer to the end consumer. If one battery system should fail then others in the area should be able to pick up the slack without causing a cascade trip of the whole system.

@derek-m I am probably very fortunate in having the space, time, money etc. to indulge in home battery provision. I can see that in the scheme of things, regional storage on a much larger scale would be far more effective and efficient than my local system. My system (presently, at least) provides me with the bonus of TOU tariff cost reductions and of course a certain ‘smugness factor’ giving some independence should the grid be under stress; I do like the idea of helping to spread the load to lessen the need for peaker plants at moments of greatest need.

But …. This is not the most efficient way of spreading demand and providing  resilience on the National Grid. Any attempts to install home energy storage helps in a small way and may well reward the owner with some financial advantage but, this method of storage is but a drop in a bucket whereas regional storage ought to provide far more efficient, (and cheaper) dependable supplies ‘for all’. Regards, Toodles.