Energy Matters Global and Domestic

[PaulC5]

All the 'green or not green' arguments mean nowt to me, all I know is that by using solar panels, battery storage and an electric car my expenditure is less.

Is this saving you money if you include the cost of the installation or over how many years does it take to pay back ?

A neighbour of a brother has battery storage and has said in a power cut the batteries could just power the lights. Not sure how accurate that is though.

[bobins]

I can well imagine that they will easily function as UPSs - though I did wonder if they need a mains supply to sync to. I could also see the Musk-o-power ones needing an extra subscription to enable full UPS functionality !

[Gibbo2286]

All the 'green or not green' arguments mean nowt to me, all I know is that by using solar panels, battery storage and an electric car my expenditure is less.

Is this saving you money if you include the cost of the installation or over how many years does it take to pay back ?

A neighbour of a brother has battery storage and has said in a power cut the batteries could just power the lights. Not sure how accurate that is though.

My solar panels paid for themselves with savings on the electric bill and with the feed in tariff payment in just over four years, the battery I added when I was satisfied the panels had done so, battery will take less time to pay back its cost.
Since I bought mine the price of panels has come down so should take less time to pay off.
I suppose if you do things by using hire purchase borrowing the numbers will be less favourable but I always pay up front.

[PaulC5]

4 year pay back looks good. We pay 21p / kWh and estimated 2000 kWh a year so about £420 plus standing charge a year. For us we would need the solar panel installation to be about £1700 to pay back so soon, are they really that cheap now or do you need to be a high user to get a financial benefit ?

[MattBLancs]

Any ideas if your battery storage will function to power your home in the event of a major power cut ? i.e. does it need mains voltage to function, or can it work on a wholly standalone basis ?
It's a genuine question on my part as I don't know the answer

My understanding is most domestic solar installations are a "grid tied" inverter - where the inverter generates it's AC to be in phase with (and hence able to feed into) the grid - as such loosing the grid would remove it's timing signal so I believe they shut down.

Don't think we've had a power cut in the past 13 months we've had solar so can't confirm or deny if the above proves true !

[myglaren]

The only power cut we have had was very brief and in the middle of the night so the solar was useless at the time. No batterbies.
It was installed by the housing association before we bought the house. They forgot to include the panels in the cost of the house and when they did later I declined as I get the electric free and they get any excess.
And they remain responsible for the upkeep

[bobins]

Any ideas if your battery storage will function to power your home in the event of a major power cut ? i.e. does it need mains voltage to function, or can it work on a wholly standalone basis ?
It's a genuine question on my part as I don't know the answer

My understanding is most domestic solar installations are a "grid tied" inverter - where the inverter generates it's AC to be in phase with (and hence able to feed into) the grid - as such loosing the grid would remove it's timing signal so I believe they shut down.

Don't think we've had a power cut in the past 13 months we've had solar so can't confirm or deny if the above proves true !

It's interesting how the Iberian peninsula countrywide power cut story is developing at the moment. Fingers are being pointed at the various industrial scale solar inverters that may have started the voltage to wobble across the whole network which eventually (i.e. quite quickly !) caused the whole network to catastrophically fall over. Apparently inverters aren't quite as good at supplying large scale power as traditional generators ...and also not as good as they thought they were.

More research and development needed, methinks

[thorter]

As someone with some experience but no expertise in control systems, the recent Spanish grid collapse looks suspiciously like running out of capacity. Think car alternator, and at some point of increasing load it will reach the limit that the excitation can provide for. The voltage then droops. The grid is much more complex with distributed generators, with the control effected using both the voltage and the frequency. If the specified narrow limits are not achieved, disconnections or tripping are the safeguards.

In the case of a traditional thermal power station, this will always be operated with a margin for unexpected extra loading to buy time for the grid operator to add more generation. However, both wind power and solar are designed to run flat out, unable to supply any extra. All right if there is enough residual thermal generation to keep things stable. Trying to operate with insufficient flexible capacity is likely exactly the recipe for this sort of failure. The frequency fluctuations were a symptom of the mal-operation, not the cause!

[bobins]

There's an insight to what might have gone on with the Iberian FUBAR part way down the article here -----> https://watt-logic.com/2025/06/18/shoul ... quirement/
(it's a long read !). Whilst I read it with plenty of caveats to hand, it also sheds a light on the complexities of the power distro issue and also on possible 'green at any cost' pressures from those with an agenda to sell
I'm sceptical as to whether the truth will ever properly come out regarding the Iberian issue if the reasons don't sit well with the current 'green' narrative.

[PaulC5]

If half the UK ends up covered in solar panels all with planning approval for a 40 year life when the land will revert back to its previous use, does that mean in 40 years time the other half of the country will then need to be covered in solar panels ? More likely the 40 years will be extended or the lights go out.

[bobins]

As someone with some experience but no expertise in control systems, the recent Spanish grid collapse looks suspiciously like running out of capacity. Think car alternator, and at some point of increasing load it will reach the limit that the excitation can provide for. The voltage then droops. The grid is much more complex with distributed generators, with the control effected using both the voltage and the frequency. If the specified narrow limits are not achieved, disconnections or tripping are the safeguards.

As a taster, and to tempt in the mildly interested..... here's a snippet from the web article I linked to:

"On 28 April, at around 12:30 pm local time in Spain, just before the grid collapsed, renewable sources accounted for 78% of electricity generation on the Iberian system, with solar accounting for almost 60%. By contrast, conventional generation, such as gas and nuclear power plants, comprised only around 15% of the total generation mix.

According to Raúl Bajo Buenestado of the Baker Institute, two consecutive generation loss events occurred in southwestern Spain, likely involving large solar installations. “In just five seconds, Spain lost approximately 15 GW of capacity, equivalent to 60% of its national electricity demand. The remaining generation was insufficient to meet demand, thus triggering a cascading failure across the entire grid. Various generating units were automatically disconnected to protect infrastructure, and nuclear plants were shut down in accordance with safety protocols.”

Now, according to reporting by Reuters, the first official report by the Spanish authorities has blamed REE for miscalculating its power capacity needs on 28 April, meaning that a surge in voltage led to a massive blackout. REE did not have enough thermal power stations switched on during peak hours according to Spain’s Energy Minister Sara Aagesen in a news briefing in Madrid.

The report describes the blackout as being “caused by an overvoltage problem with a multifactorial origin: the system had insufficient voltage control capacity, there were oscillations that conditioned the operation of the system and disconnected generation facilities, in some cases in a seemingly undue way”.

And.....

"Phase1: Oscillations in the system (12:00 – 12:30)
At 12.03 pm an atypical oscillation of 0.6 Hz was recorded, which caused large voltage fluctuations for 4.42 minutes. This oscillation forced the System Operator to apply measures to cushion it, such as increasing the grid meshing – restricted by low demand – or reducing the flow of interconnection with France. All these actions dampened the oscillation, but had the side effect of increasing voltage. At 12.16 pm the same oscillation was recorded again, this time smaller, and 3 minutes later there was a further oscillation of 0.2 Hz. The System Operator applied the same measures to cushion it, which also contributed to increasing the voltage.

PHASE 2: Generation losses (12:32:57– 12:33:18)

Voltage began to rise rapidly and steadily, and numerous and progressive disconnections of generation facilities were recorded in Granada, Badajoz, Segovia, Huelva, Seville, Cáceres and other provinces.

PHASE 3: Collapse (12:33:18 – 12:33:30)

The progressive increase in voltage caused a chain reaction of overvoltage disconnections that could not be contained, as each disconnection contributed to further increases in voltages. There was also a drop in frequency that led to the loss of synchronisation with France. The interconnectors with France tripped, and the Iberian peninsular saw its power grid fall to zero."

......."But what is striking from this initial report into the Iberian blackout is that there is still no explanation for the initial cause. Three generators didn’t just trip off at the same time for no reason – the frequency oscillations described triggered their trips. But the report is silent on the origin of those oscillations. I suspect that if there had been some mundane grid fault, this would have been made public, which leads me to suspect we’re dealing with inverter-induced oscillations, something they would be reluctant to admit. We shall have to see if more comprehensive subsequent reports uncover more detail."

https://watt-logic.com/2025/06/18/shoul ... quirement/

[thorter]

I think that confirms what, in an over simplified way, I said. What it amounts to is that Spain already has too much renewable generation. That may end up being corrected by battery storage, unfortunately at monumental cost due to the amount that would be necessary. Think electricity at more than ten times lowest USA prices, rather than our UK five times currently. Why have so many of our basic industries disappeared?

[bobins]

Yes, they didn't have enough reserves to pull them out of the nosedive..... or at least they might have thought they did but they were let down by the commercial generators, but the issue still remains that the root cause was power oscillations caused by - at present either unknown or unacknowledged - issues. Without sorting the root cause they're still vulnerable to this happening again, although they'll probably be wise to it and have more reserves on standby...... which will cost more money. The oscillations might be (ultimately) as a result of no or little inertia in the system, and battery backup doesn't quite cut it as 'good' inertia - yes, technology might improve battery (and 'green') solutions to give better reliability, but we're not there yet.
I'm sure the population won't mind doing the Beta testing for the industry, I mean - only a few people died bacause of the Iberian blackout

[thorter]

None of this should be a surprise. More than 25 years ago, some very proficient people running the grid at that time predicted a limit for renewables of about 60% penetration, beyond which instability was likely. This message did not fit well with the “net zero” mindset, so was the facts were suitably redesigned.

[Gibbo2286]

None of this should be a surprise. More than 25 years ago, some very proficient people running the grid at that time predicted a limit for renewables of about 60% penetration, beyond which instability was likely. This message did not fit well with the “net zero” mindset, so was the facts were suitably redesigned.

That would be before widespread battery storage was brought into the equation.