Green, ethical, energy issues in the news

zeupater

QrizB said:

zeupater said:

..., on new homes the inclusion of  "High efficiency solar PV panels covering equivalent of 40% of ground floor area." would result in a development of larger homes needing to cope with ~10kW peak excess generation per home (therefore three phase supplies) and therefore having grid capability to cope with this as a potential excess (ie 1MW per 100 homes!)

10kWp of generation doesn't necessarily require three phase any more than a 10kW electric shower does (and, for clarity, a shower doesn't). I can however imagine that large properties might routinely need three phase of they're going to be equipped with heat pumps and EV chargers.

Also, 10kWp of panels can still be limited to less export if the local grid can't handle more.

Hi

If we were talking about single home retrofitting I'd tend to agree in that 15kW would seem to be the upper allowable potential export limit on a single phase .... however, we're talking about mandated high efficiency solar panel installations based on 40% of ground floor area, which would equate to ~10kW of potential export for extended periods for EVERY home on a development, so as mentioned, that's the equivalent of 1MW per 100 homes. To place that size development in context, a recent semi-rural development not far from us contains >600 new build homes the majority of which are of the large executive type, so we're talking about ~6MW, that's the equivalent of 2x11kV lines, but may be prudent to move to 33kV to allow for long term usage and system redundancy ...

Remember, we're looking at both the intermittency of large scale local solar having an affect on what really equated to a relatively small developed areas as opposed to (say) equivalent large solar farms with dedicated connectivity to a nearby substation (we also have a couple of ~5MW pv farms locally) ... the difference being infrastructure (substation) availability & access, which of course is subject to grid operator & DNO input into the planning & approval process .... and this is the issue at hand, not only is there a question as to whether this been recognised by the article & quoted government official, but also there's the associated impact on the DNO and whether their additional infrastructure requirements will further delay the planning consent process .... it strikes me that this is pretty similar to the initial announcements regarding smart-meters where ill thought through concepts resulted in absolute chaos as opposed to well-planned change.

Regarding the equivalence to electric showers .... well, that's pretty different in that showers only take a few minutes & it would be an exceptional event for every property in a development to be running showers at exactly the same time, whereas the solar will regularly be creating large amounts of excess power for hours on end. This is effectively a similar argument as raising 7kW ev charging being allowed on single phase, but again, that limit has been judged to be the maximum that domestic single phase supplies can safely handle for extended periods (a closer analogy to solar)  ... if you need faster charging (>7kW to 22kW) you're really looking at 3 phase supply.

As for clipping generation ... well, isn't that the very issue regarding the 40% area rule?. Wouldn't regular clipping in an area due to unreasonably high local voltages simply point at the rule leading to unnecessary expenditure (ie frequent clipping), potentially resulting in totally unworkable and potentially destabilising grid conditions really point towards the target being (let's say) overambitious ....

I can surely see an argument for changes to mandatory planning requirements covering at least an average property base-load and a little more, which would likely mean around 4x500Wp pv panels, which in itself would have a huge impact on many/most users and collectively generate more than the total UK grid demand on good sunshine days .... above that you're looking at serious clipping for large proportion of the year (especially summer!) ... (basis ~2kWp x ~30million homes vs ~35GW average peak demand) ....

Effectively, the missing piece in the puzzle that wasn't raised is mandated dedicated domestic battery storage, but then again a large property complying with the 40% national footprint rule, having 10kWp of pv in conditions where the grid demand is ~35GW only needs around 50 kWh of storage just to stop massive nation-wide clipping to protect the grid.... of course, unnecessarily spending an uncalculated/undisclosed sum on this kind of scale makes perfect sense to anyone, doesn't it???  (well, maybe not then! ... )

HTH - Z

silverwhistle

Well, it's a lot easier to plan when you know what is coming with a new estate, and the idea isn't a complete surprise to DNOs. Usual comments about diversity applies and the uptake of EVs/heat pumps etc is also in the equation.

Reminds me of an SE distribution engineer joking about substation upgrades for a new estate: "it would be cheaper to give them all a few CFLs". Yep, that long ago, so these issues have always been around.

QrizB

Rather than mandating domestic batteries, it would make more sense to put something like a Tesla Megapack at the substation. You could time-shift demand at the neighborhood level, as well as capturing excess solar.

This would need joined up thinking and is thus unlikely 😄

zeupater

QrizB said:

Rather than mandating domestic batteries, it would make more sense to put something like a Tesla Megapack at the substation. You could time-shift demand at the neighborhood level, as well as capturing excess solar.

This would need joined up thinking and is thus unlikely 😄

Hi

Totally agree, and that's been the point all along ... instead of simply pushing what initially looks like a good idea on a standalone basis without considering the potential for associated issues, it'd be preferable to use a logical, joined up thinking approach.

As I read the recommendations it struck me that there seemed to be a strong bias towards what the supply industry would want, with little regard to what the consumer would need, let alone what the potential issues would eventually cost the public purse ... as such it looks to be driven more by economic activity than actual need - after all, who in their right mind would really need the ~10kWp of pv that the 40% footprint rule would mandate, especially without a battery to mitigate the issues that this would invariably introduce? ....

Anyway, my guess is that having had this discussion, the reason, need & particularly timing for the media raising it has passed so I wouldn't expect to hear much more until media & politics deem that it's recycled at some time ... work will continue on the underlying problems to the extent that either someone finally applies a little logic or some complete lunatic with little appreciation of the subject messes everything up and needs to be promoted to indulge in something less costly/dangerous (as normal?) ...

HTH - Z

Martyn1981

QrizB said:

Rather than mandating domestic batteries, it would make more sense to put something like a Tesla Megapack at the substation. You could time-shift demand at the neighborhood level, as well as capturing excess solar.

This would need joined up thinking and is thus unlikely 😄

Yeah, I was going to say that, but poor Z is probably bored to tears of me by now. [Edit - waffling on about localised DNO energy storage.]

Every party gains, transmission network shifting energy earlier if needed, distribution network being able to work more to averages than peaks, leccy supply companies maybe buying less peak price leccy, and through it all ..... hopefully, consumers.

But my big win, or at least I think it is, is that PV export limits could be loosened if there's a big buffer on the local network to cope. So more installs, and more larger installs may be possible.

Is it likely, well a friend sent me some video clips of one being installed, looked to me like something around 1MWh, as it was a large containerised battery being hoisted in by crane. Unfortunately he/his company that were doing the filming work for the DNO, suggested that H&S was a tad off, so recommended it wasn't used for publication. This was about 2yrs ago I think.

zeupater

silverwhistle said:

Well, it's a lot easier to plan when you know what is coming with a new estate, and the idea isn't a complete surprise to DNOs. Usual comments about diversity applies and the uptake of EVs/heat pumps etc is also in the equation.

Reminds me of an SE distribution engineer joking about substation upgrades for a new estate: "it would be cheaper to give them all a few CFLs". Yep, that long ago, so these issues have always been around.

Hi

Maybe mandating pv wouldn't be a complete surprise, but I'd reckon that the 40% of property footprint rule would be and that this level of domestic pv capacity wouldn't fall with their view of what decentralised generation would look like ... 

It's not really (/just) the impact on DNOs that I'm considering, rather it's the knock-on effect that necessary DNO decisions will have on the planning departments, the upstream issue that will manifest in delivering central government housing targets and policy making resulting in the need to commit serious amounts of public funding to avoid seriously red faces as political targets are inevitably missed (if the currently described proposal isn't re-evaluated .. ) ...

HTH - Z

zeupater

Martyn1981 said:

QrizB said:

Rather than mandating domestic batteries, it would make more sense to put something like a Tesla Megapack at the substation. You could time-shift demand at the neighborhood level, as well as capturing excess solar.

This would need joined up thinking and is thus unlikely 😄

Yeah, I was going to say that, but poor Z is probably bored to tears of me by now. [Edit - waffling on about localised DNO energy storage.]

Every party gains, transmission network shifting energy earlier if needed, distribution network being able to work more to averages than peaks, leccy supply companies maybe buying less peak price leccy, and through it all ..... hopefully, consumers.

But my big win, or at least I think it is, is that PV export limits could be loosened if there's a big buffer on the local network to cope. So more installs, and more larger installs may be possible.

Is it likely, well a friend sent me some video clips of one being installed, looked to me like something around 1MWh, as it was a large containerised battery being hoisted in by crane. Unfortunately he/his company that were doing the filming work for the DNO, suggested that H&S was a tad off, so recommended it wasn't used for publication. This was about 2yrs ago I think.

Hi

I'm all for containerised localised storage, we have some just down the road (if you look hard for them!), however, the issue here revolves around how many of those ~1MWh units you mention would be required to absorb ~6MW of generation on a 600 home 40% footprint rule semi-rural development in order to avoid easily avoidable & unnecessary clipping ... furthermore, who will eventually be paying for installation and running costs ... even more, when all this unnecessary storage capacity is filled to the brim with unused electrons by some time in the early afternoon on a daily (summer) basis the only remedy is to still clip the inverters, which raises questions as to the very logic being applied ....

Surely there's a better storage solution for such huge amounts of excess generation to smooth & match supply to demand, but that would involve really serious decision-making by really serious politicians ... looking around, I can't really see many of those that are willing to stand-up against the 'little birdies & fishes' lobbyists (/political activists) ...

HTH - Z

ed110220

Coalition power plan “nuked” at poll: climate groups

The Liberal-National coalition (popularly known as the COALition for its fondness for the fossil fuel) in Australia thought it could kill several birds with one stone with its energy policy: bash the hippies and greenies by talking up nuclear power, avoid outright climate denialism which is no longer tenable, and help out FF by halting large scale renewables deployment to reserve space on the grid for nuclear sometime way in the future (the cynic would suspect that the nuclear was just a distraction and would fall away in favour of continued coal burning). It's all moot now given their landslide defeat that cost their leader his seat and by the next election it will be far too late to try again.

Coalition power plan "nuked" at poll: climate groups | RenewEconomy

michaels

ed110220 said:

Coalition power plan “nuked” at poll: climate groups

The Liberal-National coalition (popularly known as the COALition for its fondness for the fossil fuel) in Australia thought it could kill several birds with one stone with its energy policy: bash the hippies and greenies by talking up nuclear power, avoid outright climate denialism which is no longer tenable, and help out FF by halting large scale renewables deployment to reserve space on the grid for nuclear sometime way in the future (the cynic would suspect that the nuclear was just a distraction and would fall away in favour of continued coal burning). It's all moot now given their landslide defeat that cost their leader his seat and by the next election it will be far too late to try again.

Coalition power plan "nuked" at poll: climate groups | RenewEconomy

And the weird thing is that we need to thank Donald Trump for the result!

Coastalwatch

While we are all mostly aware of this the two year study below demonstrates a clear conclusion from the many sites taking part. So bucking the trend with some useful renewable research conducted amongst the myriad of FUD emanating from the US in these otherwise despressing times.

Solar grazing supports healthier soil, food for sheep, says American Solar Grazing Association

From pv magazine USA

Solar grazing makes healthier soil on Northeastern solar projects, research from the American Solar Grazing Association (ASGA) found.

The two-year study began in 2022 and aimed to examine the impacts of solar sheep grazing in soil health, forage and pasture conditions. The research included 28 grazed and three non-grazed commercial solar projects in the Northeastern United States, the majority of which were previously cropland.

Three key findings:

• Solar grazing supports healthier soil.
• Solar makes healthier food for sheep.
• Solar grazing may improve pasture quality over time.

According to Lightsource bp, one of the solar project owners that participated, the study was the first to use the U.S. Department of Agriculture pasture condition scorecard, which assigns a high “pasture condition score” to fields that are quality places to raise livestock.

https://www.pv-magazine.com/2025/05/06/solar-grazing-supports-healthier-soil-food-for-sheep-says-american-solar-grazing-association/?utm_source=Global+|+Newsletter&utm_campaign=aa137cab86-dailynl_gl&utm_medium=email&utm_term=0_6916ce32b6-aa137cab86-159300013