If I did not know better.

[pdf27]

17 minutes ago, Andehh said:

But then its a 20 year life span for a deep sea wind turbine according to Google, which are full of complex multi material composite components with no recyclablility at all, that are miles offshore. OK its not nuclear waste (quality of headache) but there are 100x more of then (quantity of headache). When these wind turbines need decommissioning I'm confident they will cause more 'environmental harm' then the equivalent nuclear waste per MW.... 

See https://cen.acs.org/environment/recycling/companies-recycle-wind-turbine-blades/100/i27 - the blades are recyclable at the moment but the economics are problematic (landfill is cheaper in some countries). It's getting better with time though, certainly by the time the current installs are decommissioned it won't be an issue.

[joe90]

Very interesting article and nice to see modern products becoming more recyclable.

[DavidFrancis]

According to the latest DUKES report from the goverment, we lose more than 50% of our electricity generation in "conversion, transmission & distribution losses". I never seem to hear anything about what's been done to reduce those losses. Anyone know?

 

 

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1094628/DUKES_2022_Chapter_5.pdf&ved=2ahUKEwjLsJ3R17f8AhWSdcAKHdMVCR0QFnoECAoQAQ&usg=AOvVaw1Lf32nQsybhTjyvh6DJ4Nd

 

[SimonD]

2 hours ago, Andehh said:

OK its not nuclear waste (quality of headache) but there are 100x more of then (quantity of headache). When these wind turbines need decommissioning I'm confident they will cause more 'environmental harm' then the equivalent nuclear waste per MW.... 

 

Until cheap energy storage becomes available, no energy source has the answer, and a mixture is required... Nuclear though has the reliability, robustness and longevity more then any other 'minimum baseload' generation sources. 

 

This is the kind of argument that comes from the nuclear gaslighting sector, with very little understanding of the reality of nuclear, especially both the current and future waste problem. Here's an amusing video looking at the US situation alone-

 

 

Otherwise perhaps this, which interestingly deals with the similar false argument that solar is somehow worse from a recycling perspective than nuclear: https://www.scientistswarning.org/2020/06/04/nuclear-power-a-risk-analysis/

[Sparrowhawk]

19 hours ago, ProDave said:

So even on a low demand period, 9% is being generated by gas.

I've been thinking about this and a few possibilities are:

• to get a power station built there may be contractual purchase amounts. So always going to be some as would be more expensive to tell that power station to "shut down"
• ability to ramp up quickly means the power station has to be already running, so must keep it generating at a low level

Be interesting to hear from someone in the know about gas power stations.

[pdf27]

28 minutes ago, DavidFrancis said:

According to the latest DUKES report from the goverment, we lose more than 50% of our electricity generation in "conversion, transmission & distribution losses". I never seem to hear anything about what's been done to reduce those losses. Anyone know?

That's overwhelmingly conversion of fuel into electricity. Fuel -> heat is pretty efficient, but heat -> electricity is not. Efficiency for the latter process varies from ~30% for nuclear stations up to ~60% for the very latest gas stations. There are transmission and distribution losses, but they're pretty small in comparison.

[pdf27]

5 minutes ago, Sparrowhawk said:

I've been thinking about this and a few possibilities are:

• to get a power station built there may be contractual purchase amounts. So always going to be some as would be more expensive to tell that power station to "shut down"
• ability to ramp up quickly means the power station has to be already running, so must keep it generating at a low level

Be interesting to hear from someone in the know about gas power stations.

It's mostly a grid stability thing, rather than costs. Wind farms are largely not built where the demand is (the London Array being a notable exception), and as inverter-driven devices they also don't provide inertia to the system. This makes it very difficult for the grid to cope with major faults, etc. without it becoming a cascading failure.

With thermal power stations, this "spinning reserve" means that in the event of a sudden load added to the system the turbines will slow down slightly, with the kinetic energy stored in the turbines and generators providing a lot of extra power for a few seconds. At present wind turbine systems can't offer this (although it's possible in theory, the way they're designed at the moment doesn't support this), so to ensure that the system can accept faults and not crash then they need to keep a certain minimum amount of thermal generation on the system.

This is rapidly changing, but we aren't there yet.

• Batteries are already providing longer term (up to ~30 minute) response to peak demand much more cheaply than old-style peaking plant, and we're likely to see them providing synthetic inertia in the future as the technology improves. It's feasible at smaller scales at the moment, but doing it at Gigawatt scale is harder!
• We're also seeing flywheels being installed onto the grid to provide real inertia. These are just a giant spinning wheel attached to a motor/generator which is synchronous to the grid. If the grid speeds up or slows down, the motor/generator has to drive the flywheel and this provides better frequency stability to the grid. The annual running costs of these are much lower than those of a power station, so if you're only providing frequency stability services they're the way to go.

[jack]

1 hour ago, pdf27 said:

At present wind turbine systems can't offer this (although it's possible in theory, the way they're designed at the moment doesn't support this)

 

I've worked with a turbine manufacturer on and off for a few years and am pretty sure wind turbines are already providing spinning reserve in some Scandinavian countries.

[ToughButterCup]

Quote

 ... synthetic inertia ...   @pdf27 above

 

'S wot many teenagers suffer from for a few years innit...... 

Have I got this right? If we link a few hundred teenagers together (get them all to hold hands) we could manage the UK's synthetic inertia? 

 

Lets go for it I say.

[pdf27]

1 hour ago, jack said:

I've worked with a turbine manufacturer on and off for a few years and am pretty sure wind turbines are already providing spinning reserve in some Scandinavian countries.

I know it's possible - I'm doing something fundamentally very similar in Aerospace at the moment - but I'm not close enough to the problem to know if anybody else is doing it yet. Denmark would be the obvious candidate - Norway and Sweden have lots of hydro, and Finland & Sweden have quite a bit of nuclear too. It's pretty easy with a doubly-fed induction generator, for instance, but somewhat harder with a permanent magnet type as that then drives you to adopt a particular rectifier/inverter architecture.

[Mr Blobby]

23 hours ago, ProDave said:

This is why I say if you buy an EV and plug it in, then you WILL increase the amount of gas being burned.  That is FACT.

 

 

 

Not fact at all.

 

Here in Ireland wind is curtailed overnight because total generation exceeds demand. 

(as @pdf27 rightly points out you need about 25% total capacity thermal generation for reserve and inertia to stabilise system frequency)

 

So when I charge my car on economy 7 the extra demand is taken from otherwise curtailed wind turbines and not from fossil fuel generation.

 

Now of course there are exceptional times when the wind is not blowing but that is pretty unusual here.

 

[SteamyTea]

6 hours ago, Andehh said:

When these wind turbines need decommissioning I'm confident they will cause more 'environmental harm' then the equivalent nuclear waste per MW.... 

I don't think so. Wind turbine blades are made from the same plastic as swimming pool slides.

We could just pile them up as the degradation is fairly benign.

There are also ways to recycle composite plastics, just not done that much as we don't have a huge market for it.

[Kelvin]

Plus of course wind turbines don’t melt-down and cause a major disaster nor are they much threat in a war zone. 

[TerryE]

 

6 hours ago, Andehh said:

But then it's a 20 year life span for a deep sea wind turbines according to Google, which are full of complex multi material composite components with no recyclability at all, that are miles offshore.

You need two things to create a viable recycling industry: (i) volume, and (ii) time to develop it.  An analog here: the Li battery sector; exactly the same claims were made, but this industry is slowly developing  The main delay here is that the life of battery packs (with second use as grid scale and smaller fixed electricity storage) is proving to be ~ 5× longer than initial estimates, the actual volume is too small for anything other than pilot scale plants but some of these already have demonstrated ~95% recovery.

 

So I do think that it is too soon to judge on this one.  Even so let's balance this again the fossil fuel consumption over this ~20 year period, and of course all of the resources needs for its extraction, refining, and delivery to point of use.

 

And the fossil fuel industry has its own challenges, e.g. Biden Administration Announces $1.15 Billion for States to Create Jobs Cleaning Up Orphaned Oil and Gas Wells.

 

[SteamyTea]

13 minutes ago, TerryE said:

And the fossil fuel industry has its own challenges

Does it mention lowering atmospheric CO₂ by 150+ppm.

[MikeSharp01]

35 minutes ago, Kelvin said:

nor are they much threat in a war zone. 

but are tidy targets like anything else fixed down the location of which is known!

[Kelvin]

3 minutes ago, MikeSharp01 said:

but are tidy targets like anything else fixed down the location of which is known!

But it’s contained like any other part of the infrastructure of a country. Unlike a nuclear power station which would be a disaster for a much larger part of the World beyond the immediate warzone. 

[TerryE]

@DavidFrancis I was just about to compose a reply to your 50% losses point, but I see that @pdf27 has already done a good response.  The only reference to actual losses in the report you cite was on page 4 which mentions a specific 8% loss.  Transmission losses are typically of the 10% ballpark because most of the transmission these days is done at 275kV and 400kV AC, with the subsea connectors using HVDC typically at 270kV.

 

In terms of generation losses you need to divide sources into two categories:

• Those with use heat as an intermediate (eg. all fossil-based generation and nuclear).  Here the physics of thermodynamics dominates efficiency constraints (see the WP article on the  Carnot cycle) and this places a upper bound on the conversion efficiency, with the hotter the working fluid then the greater the efficiency.    Those which use superheated steam as an intermediate can at best achieve 30-35% efficiency. The latest gas-based generators use superheated exhaust at ~600°C IIRC and can get over 60% efficiency.
• Those that do direct energy to electricity conversion (wind, solar, hydro).  Take wind as an example: a conventional wind turbine can extract at most ½Kρπr²V³C_P watts from a fluid stream where ρ is the density of the fluid (air), r the radius of the blades, V the wind velocity. The last C_P is a dimensionless coefficient of power; there is a empirical limit to this known as the Betz Limit (~59%) because of the macro flow characteristics of the airstream around the turbines and modern designs can get within 80% of this, say a C_P of 48%.  The actual losses from mechanical to electric energy are tiny in comparison with a generator conversion efficiency typically ~99%.

So overall conversion losses depend on your energy mix: oil/nuclear/wood pellet at ~30%; advanced gas at ~60%; wind at 99%.  So adding in the 10% or so transmission losses then your 50% is a plausible ballpark for our current mix.

 

Hope this helps.

[jack]

2 hours ago, pdf27 said:

Denmark would be the obvious candidate - Norway and Sweden have lots of hydro, and Finland & Sweden have quite a bit of nuclear too.

 

I believe there's a common forward spinning reserve market that operates across several countries in the region, but yes, Danish generators are more likely to be bidding in this market with wind turbines.

 

58 minutes ago, TerryE said:

• Those with use heat as an intermediate (eg. all fossil-based generation and nuclear).  Here the physics of thermodynamics dominates efficiency constraints (see the WP article on the  Carnot cycle) and this places a upper bound on the conversion efficiency, with the hotter the working fluid then the greater the efficiency.    Those which use superheated steam as an intermediate can at best achieve 30-35% efficiency. The latest gas-based generators use superheated exhaust at ~600°C IIRC and can get over 60% efficiency.

 

Low grade "waste" heat from power generation is used in some northern countries to heat water for district heating systems. I don't know how much that improves the overall effective conversion efficiency.

[TerryE]

10 minutes ago, jack said:

Low grade "waste" heat from power generation is used in some northern countries to heat water for district heating systems. I don't know how much that improves the overall effective conversion efficiency.

CHP requires the infrastructure in place and if used can get an effect 15% - 20% conversion efficiency in terms of avoided energy costs.  In general there is zero development here in the UK, so we are really talking about enterprise / business park level fit or retrofit.  

[jack]

46 minutes ago, TerryE said:

CHP requires the infrastructure in place and if used can get an effect 15% - 20% conversion efficiency in terms of avoided energy costs.  In general there is zero development here in the UK, so we are really talking about enterprise / business park level fit or retrofit.  

 

Just seeing how much disruption and time has been involved in refitting gas mains around my town over the last decade, I don't imagine residential installations will ever happen in the UK.

[SteamyTea]

New York City had district heating, but I think it went out of fashion when they started using natural gas.

Did we have someone called SarahSW (on the old site) who lived in a place with a shared heating system (wood pellets I think).

Broke down and there were arguments about who would fix it.

I wonder what happened to her, I think they abandoned there project as if it is the place I think it is, nothing happened for a couple of years, then there seemed to be a bit of activity, then nothing again.

[Kelvin]

Shared services work if everyone plays ball. It can become insufferable when people don’t. I lived in a group of barns that had some shared services that we ran as a collective through a mgt company. Never again. This time around we are nearly off-grid. 

[SteamyTea]

1 minute ago, Kelvin said:

Never again. This time around we are nearly off-grid. 

If you have the space, then off grid, with the occasional running of a generator is getting close to being feasible.  Still a lot of up front cost though, about what some people a nicer kitchen and bathrooms.

[Kelvin]

Yep. If our burn was bigger we could have hydro power 😂