"Derril Water Solar Park is a 42 MWp solar farm containing over 68,000 solar modules capable of generating renewable energy sufficient to power around 14,000 homes annually."

Being a N.Devon resident, with a combined 12kWp PV roofspace. (E&S), I think it might be a while before we get a knock on our door .... 🤔 

@colinc Knock-Knock…. err, excuse me Colin C but I believe you are generating elicit solar power and causing our cables to heat up an additional 0.00000001 degree C and this is upsetting our sensibilities…

@toodles ... I am humbled to know that one might even measure my meagre contribution to global warming, given that it is in the realms of nano ⁰C; and no doubt there's an App too.

That said, most of the energy is for  self-consumption ... 😎 

Posted by: @toodles

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Any readers with an interest in Solar Farm generation in North Devon may be interested in this announcement I have received from The Derril Water team.

 

”

We are writing to inform you of an unexpected electricity grid issue that requires Derril Water Solar Park and other renewable generators in North Devon to shut down.

 

We have been notified by the electricity Distribution Network Operator that they are constraining Derril Water Solar Park and other generators in North Devon to prevent potential network overloads. The problem has been triggered by works being carried out at the Transmission Network sub-station at Alverdiscott near Barnstaple. The constraint is unexpected and has been enforced on our solar park and other generators in North Devon with no warning.

 

The information we have so far from the Network Operators is the curtailment may remain in place through the summer until early September.” Regrets, Toodles.

Do the generators still get paid via the curtailment mechanism with the costs loaded onto customer bills in the DNO region or nationally? 

@colinc Mmmmm, that’s what they all say!

At least the DNO is being proactive! Our local pylon and cables went on fire the other day, causing a loss of power to part of the village for 4 hours! 😀  Possible heat and overload maybe?

Posted by: @toodles

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We have been notified by the electricity Distribution Network Operator that they are constraining Derril Water Solar Park and other generators in North Devon to prevent potential network overloads. The problem has been triggered by works being carried out at the Transmission Network sub-station at Alverdiscott near Barnstaple. The constraint is unexpected and has been enforced on our solar park and other generators in North Devon with no warning.

Well, not entirely with no warning.

The over-supply of electricity in the area was known well before Derrill Water applied for planning permission from Torridge District Council.

Here's a section of NGED's EHV Constraints Map; they are the DNO for SW England.

It shows only the two higher-voltage levels of the Distribution Grid, and those generation sites which connect directly to them.

I've placed orange circles around the Bulk Supply Points, where the transformers interface between 132kV and 33kV, and I've labelled both Alverdiscott and Pyworthy BSPs

The Alverdiscott site is also a Grid Supply Point (GSP) which connects to the 400kV Transmission Grid.

Derril Water connects to the grid at 33kV. It's very close to Pyworthy BSP, which takes its output.

Route K is probably the most seriously affected by excess generation in the region.

Potential shareholders in Derril Water Solar Farm should've been made aware of the constraints in the area when they invested.

All solar and wind generation in Devon and Cornwall is curtailed by NGED to prevent damage to cables and transformers from over-voltage and breakdown of insulation. Thus Derril Water isn't permitted to export the theoretical maximum power which it could generate.

In this case it seems that an unexpected fault has affected the GSP side of the Alverdiscott site.
I'm unsurprised.

I've heard from others living in the vicinity of Derrill Water solar farm, near Holsworthy in NW Devon..

The indications are that there is a delay in ongoing work to increase capacity at Alverdiscott.
This is both a Bulk Supply Point and Grid Supply Point.

Derrill Water was meant to commence generating this month (June'26), and that has been postponed until September.

I have no evidence of any fault, nor any other generation site in the area being affected.

Posted by: @technogeek

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Our local pylon and cables went on fire the other day, causing a loss of power to part of the village for 4 hours! 😀  Possible heat and overload maybe?

Have you emailed UKPN to ask the reason for this damage occurring?

Do you know what voltage that line was carrying?

A supply to a village would usually be 11kV, but you'd expect to see that carried by wooden poles rather than a Transmission Tower (aka pylon).

It is extremely rare for overhead cables to catch fire. That's a serious thermal overload, which should've been picked up in advance by monitors at the Primary substation. 

@transparent The latest ‘news’ from Derril Water Co-Operative:

“Following our last communication on May 26, we’re writing to update you on the Derril Water export curtailment.

Around three weeks ago, we were informed, without any notice, that our solar park has been required to stop exporting electricity to the grid until September 2026.

This instruction has come from the electricity network operators due to technical issues at a piece of infrastructure known as the Alverdiscott Supergrid Transformer, located around 20 miles from our solar park. Work being carried out there has led to wider grid stability concerns, meaning several generators in North Devon, including Derril Water, have been curtailed for the summer. The shut down is due to issues with the transmission network not our solar farm and is outside of our control, and the shut down is within the network operators’ rights to ensure a safe and reliable system. 

What does this mean for Derril Water?
The timing of this outage is particularly challenging, as it affects the peak summer generation period in our first year of generation, on top of the construction delay. Based on current expectations, this could result in a loss of approximately £2 million in revenue.

As members will know, the co-operative was financed through a combination of £22 million of member investment and a £20 million long-term bank loan. The interruption creates unexpected financial pressure and will impact our ability to pay members at least in the near-term.

What are we doing about it?
Your Board of volunteer Directors is doing what it can to protect the co-operative’s interests. We are:

• Engaging directly with the relevant network operators (National Grid Transmission and Distribution) to seek clarity on the cause of the shut down and ensure they are doing what they can to mitigate the impact
• Exploring all available options to mitigate the financial impact
• Raising the issue with Government, including writing to the Minister for Energy Security and Net Zero, the Constituency MP and other stakeholders

While we fully recognise the importance of maintaining a safe and stable electricity system, we are pressing all parties to ensure that the burden of this situation is handled fairly, transparently, and with the urgency it deserves.

What happens next?
At present, we have been advised that the outage is expected to last until 6 September 2026. We will continue to push for updates and will inform members promptly if anything changes.

We understand this news is concerning, particularly so soon after the completion of the solar park. However, it’s important to emphasise that this is an external issue affecting the grid, not a problem with the solar farm itself.

We remain committed to the long-term success of Derril Water Solar Co-op and to delivering the energy savings, environmental and community benefits that members invested in. We will continue to act in the best interests of the co-operative and keep you fully informed with regular updates. If you have been in touch with us by email, please bear with us as we navigate the current situation.

We are in dialogue with the network operators and will write to you again in the coming weeks with further updates.

Thank you for your continued support and patience.

Yours sincerely,

The Board of Directors
Derril Water Solar Co-operative”

By the way, solar production was supposed to have commenced some months back so it appears the ‘facts’ are somewhat ‘flexible’!

Regrets, Toodles.

Thanks @toodles for delivering the full text.

I'm getting most of the Derril Water story from elsewhere, but I'm missing the crucial source references.
For example I'm told that the curtailment of export to the grid extends to other renewable sites in the same area...
... so I asked to be told who those were or how that was known, and heard nothing!

The next step is for the Derril Water Board to ensure that they're present at NGED's next South West Workshop at Exeter on Weds 1st July.
They should've had an invitation already, via EQ (the company managing the event).

This is a follow-on event from those held by NGED in April in their four DNO Licence areas.
The South West one was on 14th April.

The 'report' from those first NGED workshops can be read here.

Although NGED are setting the agenda, The email address for these events can be used to pre-notify NGED that we'd like certain issues raised.

I will be at that Exeter workshop, but the Derril Water directors are unlikely to see me because I'll be transparent of course.

But I'm sending you a PM to tell you how they make contact with me beforehand.

@transparent Thank you very much! Toodles.