Posted by: @ianmk13

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I am in Milton Keynes - a new city, so you might think the local infrastructure would have plenty of capacity. However, many of the sub-stations already have limited availability for prospective solar generation, batteries and EV chargers.

Unfortunately MK was designed when the national grid was still viewed as a system to deliver electricity.
Little thought would've been given to 'reverse power' from local generation.

The local situation is a 'mixed bag'.

The following map shows the Bulk Supply Point (BSP) and Primary Substation available capacity to receive local generation.

Green pins have available headroom for more local generation, red is 'at or over capacity' and blue is 'not enough data to define'.

If I zoom in to a lower level and pick out a typical 500kW local substation (11kV input) in the Titchmarsh area, then I can see

• 400kW Daytime peak demand
• 512kW Night peak demand (marginally outside spec)
• 191kW Total connected generation
• and there are 5 properties with EV charge points

That's fairly typical for SE England.
Consumption per household is particularly high, and the region is dependent on substantial energy supplies from elsewhere in Britain and the overseas Interconnectors.
That can be seen from the orange arrows on the grid-flow maps from National Grid ESO.

I've picked up this area, not just because it's of interest to Ian, but that it shows deficiencies in the DUKES statistical approach.

The more GB uses electricity generated from distributed renewable sources, the less useful it is to create policy based on national traits.

We need to think much more strategically about how we use the generation sources that are local to us.

The Titchmarsh area was one of the first areas to be built in the new town, including housing for people who built the new town. Fishermead in that area is particularly poor quality housing so I am not surprised that area is an issue. I wonder if the in fill of flats around the center and the expansion of retail, snowdome and business sites also exacerbated the challenge in that area. It is very different to the wider new town estates.

I wonder if some of the other red areas are historical and pre date the new town. They look like Wolverton and Newport Pagnell rather than Milton Keynes.

I use to live in next to the old Milton Keynes Village.

Posted by: @jeff

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The Titchmarsh area was one of the first areas to be built in the new town, including housing for people who built the new town.

Amazing.  I've lived a couple of miles north of Fishermead for over 40 years and never heard of any 'Titchmarsh' area.  I thought he was a gardener on the telly.

@Transparent. I'm on the local substation by Broughton and if I remember correctly (which I may not), this has available capacity for local generation but its my local neighborhood substation that's creaking at the seams.

@ianmk13 - There are two Primary Substations (33kV/11kV) at Broughton:

Kingston 940070; 23MW transformer; 9MW demand headroom, 10MW reverse-power (generation) headroom

Fox Milne 940043; 23MW; 1.5MW demand headroom, 6MW reverse-power headroom

In both cases, the National Grid data suggests that these transformers could be opened up to far more generation assets than the reverse-power headroom figure suggests. There will be technical reasons for this which are not explained by the raw figures.

Just because the local substations (11kV/440v) have generation constraints on them doesn't prevent you from making better use of the available reverse-power headroom.

Instead of thinking at the level of each individual house, consider the issue in a wider context.

A local Community Energy Group should be opening discussions with NGED about adding community-operated solar/wind/anaerobic-digester types of generation. You could connect at the 11kV level within the area already served by those two Primaries.

Alternatively, NGED may be even more attracted by the possibility of community-run battery storage, especially in areas of higher-density social housing.

The available Demand Headroom at these two Primaries is defined by the Peak Demand in the early evening.

If a community operated storage network could deploy batteries which remove 10% of the housing from any demand at peak time, then that would alleviate thermal stresses on underground cables and prevent outages. That's highly desirable from NGED's viewpoint.

The problem you're up against is a low level of social enterprise, partly due to the way in which Milton Keynes was designed.

@transparent

While I agree with your suggestions, and have made similar ones myself on a number of occasions, the point at which I feel it falls down is when you state 'community-run battery storage'.

For such systems to operate in the most efficient and cost effective manner, the battery storage would need to be under the control of NG and/or the DNO's. Afterall, they are the ones controlling the supply of electrical energy to the various consumers, so are in a much better place to know how best to fully utilise such a system.

I realise that at present NG and the DNO's are prohibited from doing so, because it is deemed to be generation, and therefore violates their license to operate. This limitation needs to be changed, such that energy storage is not classified as generation.

@transparent Are you advocating communities collaborating on storage at the 11kV level only, or an alternative of a cluster of homes somehow collaborating at the 440V level (potentially complicated by the 3-phase element) ? As far as I am aware, no suppliers are (yet) offering a ToU Export tariff, but you seem to be suggesting that NGED may welcome the idea.

Incidentally, an error/fault/anomaly occurred on my newly-installed home battery system a week or so ago and neither battery inverter nor solar inverter's G100 system activated. I am restricted to 5kW but I actually exported at 6-8kW for a while with my grid voltage knocking on 253V. Presumably this will have increased the grid voltage of others on the same phase, but I didn't hear any neighbours shouting 😉 .