The Alternative Green Energy Thread

JKenH

michaels said:

JKenH said:

For 12 hours overnight, approx 7am to 7pm, on 28th/29th September renewables contributed 2GW or less of generation, the low point being just 0.51 GW.

https://electricinsights.co.uk/#/dashboard?start=2025-09-28&&_k=jaa8b8

You do understand that 'net' in net zero does a lot of the heavy lifting don't you?  The plan is to offset fossil fuel usage during RE lows with renewable exports during RE over production periods.  It is amazing how many intelligent people fail to understand this when discussing the issue.

By the conventional understanding of the term, heavy lifting (the most strenuous or demanding part of a project or task), is in fact done by gas. Gas is reliable and works when renewables just aren’t up to the task of meeting demand. Meeting our generation needs from renewables is like trying to run a successful retail business relying on a volunteer workforce committing to work 20 hours a week with no rota. 

JKenH

QrizB said:

JKenH said:

For 12 hours overnight, approx 7am to 7pm, on 28th/29th September renewables contributed 2GW or less of generation, the low point being just 0.51 GW.

https://electricinsights.co.uk/#/dashboard?start=2025-09-28&&_k=jaa8b8

I guess that depends on whether you count hydro (0.61GW) and biomass (3.60GW) as being renewables?

An alternative reading of that same graph would be "even in a windless night, we could meet almost half our electricity demand without burning gas".

In contrast I offer the 15th of September, when barely 10% of our electricity (~75GWh) came from gas ...

https://electricinsights.co.uk/#/dashboard?start=2025-09-15&&_k=cf9onf

... and we could have got at least half of that from Scotland if we'd built the interconnectors already:

https://wastedwind.energy/2025-09-15

Ah, yes, Biomass. How wonderfully renewable. Yes it could be if it was fuelled by rotational cropping but the reality is something different. 

I note your point about 15th September but the reality is wind isn’t reliable so we have to have sufficient back up capacity to cover when wind produces virtually nothing at all. I totally agree with the use of (weather dependent) renewables energy but unlike many other countries which can make it work extremely well (e.g. Norway, Iceland, Uruguay where alternative sustainable generation sources are abundant) )it is hard to make a viable business model for it in the UK. Thirty years in and the vast majority of wind generation still needs some form of state support and the suggestion is that the next auction round will offer a further 20years of support. Small scale projects can work with PPAs but that wouldn’t work for the country as a whole. Texas seems to be able to incorporate significant renewables generation without it being a drag on the economy (PPAs are big business there) and what is also interesting is that, there, fossil fuel companies are heavily invested in renewables. 

The UK renewables business model just doesn’t work. In fact it is symptomatic of the mentality of much of the UK. We demand to be paid even if we are not working and contributing. Once you offer businesses an open cheque book to achieve political aspirations it is never going to end well economically. 

JKenH

Winter fuel - good or bad? What do you think?

All from trees I planted. Some clear felled but most thinned out trees. Most of it is birch which grows out again from stools provided the trees are not too old when felled. Trees are continually seeding themselves. White Poplar (my least favourite tree) has an annoying habit of suckering particularly when felled such that I have taken to mowing the suckers with my ride on but a few will be left to regrow. No transportation costs but I probably used 10l of fuel chopping it up. Brash has been used for dead hedges rather than burning. I would chip it but it needs an industrial chipper for the amount I generate. A lot of small stuff gets bagged up for kindling but there is a limit. Bark and shavings generated are used for mulch.

NedS

JKenH said:

Gas generation has actually increased in the last 12 months and is 12% higher than the combined gas and coal figure of the previous year. Total generation has increased by 1.7%. Gas generation accounted for 28.44% of total generation in the last 12 months compared to 25.86% (gas and coal) in the previous 12 months. Whatever the plan is, it isn’t working too well. 

https://electricinsights.co.uk/#/dashboard?period=1-year&start=2024-10-01&&_k=2vkpvv

Is there a correlation with wind farm curtailment? Are gas fired power stations becoming more aggressive with undercutting prices to prevent shutting down?

Also, I think wind levels / generation has been below long term averages in the last year, which has maybe been a factor?

JKenH

Installed wind farm capacity increased from 30GW in 2023 to 32 GW in 2024 so we might have expected an increase in output. However, as you say, wind speeds were lower. Since around 2015 there appears to have been a downward trend in wind speeds.

This article is quite informative in relation to wind speeds and capacity factors. It does suggest the DESNZ are being very bullish in their estimates for future wind farm cfs (with the caveat that DESNZ figures relate to new projects)  given we have not seen the significant increases anticipated in cfs as bigger turbines are deployed. 





https://wattdirection.substack.com/p/uk-offshore-wind-capacity-factors

QrizB

@JKenH that's a good-looking log store!

michaels

JKenH said:

Winter fuel - good or bad? What do you think?

All from trees I planted. Some clear felled but most thinned out trees. Most of it is birch which grows out again from stools provided the trees are not too old when felled. Trees are continually seeding themselves. White Poplar (my least favourite tree) has an annoying habit of suckering particularly when felled such that I have taken to mowing the suckers with my ride on but a few will be left to regrow. No transportation costs but I probably used 10l of fuel chopping it up. Brash has been used for dead hedges rather than burning. I would chip it but it needs an industrial chipper for the amount I generate. A lot of small stuff gets bagged up for kindling but there is a limit. Bark and shavings generated are used for mulch.

You probably want to avoid seeing the BBC report today on the health impact of particulates from wood burning....

silverwhistle

QrizB said:

@JKenH that's a good-looking log store!

A lot tidier than mine, that's for sure, which is populated with a variety of scrounged woods depending what has come down in gales or whatever the local arb guys have going spare!  

The problem with going on about the guaranteed prices for wind is that they are now much lower than they were, they are guaranteed for a lower period than new nuclear which is in any case at a much higher price (whener it finally comes on stream..). The earlier turbines are now coming off subsidy too.

Perhaps you should be talking about intermittency not reliability. If you want to talk about the latter perhaps in relation to nuclear which not only has planned down-time for refuelling and maintenance but also quite a lot of unplanned.. I seem to recall one of the Heysham sets is particularly unreliable, though I concede their age doesn't help. Lets hope the new designs are better although the Finnish and French experience doesn't engender much confidence. The French also had problems with their plant a couple of years ago which led to an awful lot of gas burned here to fuel our exports over the connectors.

As I'm on Agile an awareness of the weather is a prerequisite, and there's a decent pile of laundry and a car to charge awaiting the weekend cheap prices. As a final customer one doesn't have full knowledge of the workings of that market, but my experience shows that a bit of flexibility is one of the solutions to an increase in renewables.  

There's going to be a fair bit of cheap LPG coming on stream in the next few years in various parts of the world but from both strategic and environmental reasons getting to rely on it doesn't appear a good idea. 

NedS

QrizB said:

@JKenH that's a good-looking log store!

I have log envy