Green, ethical, energy issues in the news

edited 12 July 2021 at 11:38AM in Green & Ethical MoneySaving
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  • Piddles wrote: »
    That's not what I remember when I crossed it (twice), unless things have changed since.... Plus I can tell you that that place is very, very, very empty. You could put PVs in there to satisfy the world's entire energy demand and no one would notice! :rotfl:

    Sunshine hours in January: Sahara 290, London 60.

    You guys will probably tell me otherwise, but wouldn't that be cheap enough to displace the single most carbon intensive element of UK's emissions: natural gas for home heating?

    Anywhere on the Northern hemisphere is more during our summer and less during our winter

    It's not at all likely because the cost to move the power will be too much but more importantly no nation would want to rely on another for its electricity imports

    The UK isn't going to invest a trillion dollars (or whatever) in an African country when all it takes is one 'democratic vote' to vote that investment as no longer yours. Or do it in one of hundreds of other ways. Introduce an electricity export tax. Same thing basically extortion. It's not like we will nuke them for them. We will just look back at the idiots today who made this crippling decision as we sit in our cold homes and try to figure out a way to heat homes domestically

    It's somewhat different with fossil fuels because there are many suppliers
    With the mass PV in country X you can't take your trillion dolla investment and put it in another country
  • Piddles wrote: »
    It can damn windy to. On-shore wind with zero NIMBY factor!


    We won't and probably can't afford to send that much capital overseas especially due to the risk

    It will have to be domestic even if it costs more to do it domestically

    Electricity is an economic enabler we can't give control of it to any other countries even our besties
  • http://www.world-nuclear-news.org/Articles/CNNC-completes-design-of-district-heating-reactor

    This is fascinating and solves hearting in perhaps the cheapest way possible

    It also solves the problem of loss of coolant accidents (which is what got Fukushima) by simply immersing the reactor in a large enough pool of water such that decay heat problem is irrelevant the thermal mass of the pool is sufficient to absorb the decay heat.

    Run it for the colder 6 months and have it off (or at lower power) for the remaining 6 months.

    The chance of it being deployed in the UK.... pretty much zero

    But it is a technically brilliant solution and could work so well in China (where 98% of homes are apartments so you can build District heating when building their homes)
  • edited 11 July 2019 at 6:13PM
    Martyn1981Martyn1981 Forumite
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    edited 11 July 2019 at 6:13PM
    Piddles wrote: »
    CF?

    Presumably the Sahara sun is more reliable than the North Sea wind?

    CF is capacity factor. For UK PV we can expect about 1,000kWh's pa from 1kWp of PV. To work out the capacity factor we divide that by 8,760 (24hrs x 365 days) and get approx 11.5%cf.

    For North Africa, a quick play with PVGIS suggests between 1,500-1,700kWhs pa, so upto 19.5%cf.

    [Edit - Spain is around 1,400-1,600kWh/kWp so approx cf of 18%. So an expansion of interconnectors across Europe to exchange leccy would do the job without N. Africa. But including N. Africa via southern Spain or Italy is clearly excellent. M.]

    The latest off-shore wind farms are around 45%cf now, and should hit/exceed 50%cf* soon.

    But, I don't think you are particularly concerned about cf, since that's reflected in the cost of the leccy, and PV comes out cheaper anyway. So, as you point too, reliability/predictability over cf.

    This is something that makes Spanish PV so much better than the UK, not only does it generate approx 50% more pa, but crucially it's more predictable and varies less across the year. June v's Dec in the UK is about 4:1, or 3:1 for steep pitched panels, whilst steep pitched Spanish panels only vary by about 1.5:1. So 5kWp would generate approx 500kWh's in December, making PV highly suitable for the demand side and year round dependence (with storage).

    *Word of warning, cf's for wind are not as simple as PV, since they can be manipulated to suit the needs and location. For instance, installing a slightly smaller generator on the same size WT will increase the cf, but reduce annual generation slightly, and vice versa. If low speed generation is crucial (you need generation all year round), and maximising annual generation isn't, then cf's can be lifted to help.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
  • Martyn1981 wrote: »
    *Word of warning, cf's for wind are not as simple as PV, since they can be manipulated to suit the needs and location. For instance, installing a slightly smaller generator on the same size WT will increase the cf, but reduce annual generation slightly, and vice versa. If low speed generation is crucial (you need generation all year round), and maximising annual generation isn't, then cf's can be lifted to help.


    Better to oversize blades and keep everything else the same and aim for 55%+ CF wind farms

    Much less of a need to do storage the higher the CF goes
  • Martyn1981Martyn1981 Forumite
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    Piddles wrote: »
    Well, that went over my head somewhat....

    Quick lesson if you're interested, as this is a major step, and it's hard to over-stress the significance.

    The main subsidy mechanism for renewables and nuclear is the CfD (contracts for difference). Typically the government announces a pot of subsidy money and desired capacity and invites bids for a technology type. For nuclear they negotiate directly.

    Example - So for off-shore wind they may ask for bids on 1GW of capacity, and the auction (a reverse auction) looks for the cheapest bids. The CfD mechanism also has max prices for bids to be considered.

    Let's say they get 6 bids, each for 250MW

    A. £50/MWh
    B. £51/MWh
    C. £52/MWh
    D. £53/MWh
    E. £54/MWh
    F. £55/MWh

    Next they add up the cheapest bids to reach the 1GW target, so that's A to D.

    They then issue a CfD contract to companies A, B, C & D for £53/MWh (the highest successful price, so as not to 'punish' the lower bidders). That £53 figure is known as the 'strike price'.

    Once commissioned the wind farms will start selling their leccy onto the open market, and the market will have 'spot prices' (I think they are half hourly). The sell price and the spot price are compared for subsidy purposes.

    Let's say they sell at £40/MWh (and that's the spot price too, this eliminates fraud by selling cheap to your mates) then the company will get a subsidy top up of £13/MWh.

    If they sell at £53 they get no top up, if they sell at say £60, then they have to pay £7/MWh back into the subsidy pot.

    Effectively the wind farm gets a guaranteed £53/MWh for everything it produces.

    So, onto the fun bit. With average wholesale prices around £40-£50/MWh, the closer the strike price gets to the average, the smaller the total subsidy payments will be.

    So, if we compare the £65/MWh off-shore wind strike price to the £102/MWh HPC nuclear price, then whilst there is a significant difference between prices, the subsidy difference is far greater. As prices head for an expected £50/MWh average, then the subsidy payments are £15 v's £50.

    Looking at off-shore wind CfD's we see strike prices falling from £170 to £65. That's mighty impressive, but even more significant if we compare the subsidy (on a £50/MWh average price) and it's dropped from £120 to £15/MWh.

    To confuse matters most prices are stated in 2012 base prices, so the cheapest deal of £65 might get referred to as £57.50, and HPC referred to as £89.50.

    Also worth remembering that prices should really be considered in context of when commissioning will take place, as bids today, will take into account falling costs, so whilst the £65 price exists today, it's really a reflection of costs from the date works start to 2023 when commissioning will take place.


    Now, for a quick history lesson we have the government's estimate of future costs. A figure I love as it was spread all over the Guardian's comment section for most of 2016 and 2017 despite mine (and others) comments saying they were out of date. The anti-RE poster even repeated it the night before the last results came out:

    Th̲i̲s̲ i̲s̲ t̲h̲e̲ ̲G̲o̲v̲'̲t pr̲e̲d̲i̲c̲t̲i̲o̲n̲ f̲o̲r̲ 2̲0̲3̲0̲.̲ ̲(2012 pricing)
    Onshore wind to be in the range £45-72/MWh
    Offshore wind will be in the range £85-109/MWh
    Nuclear, at £69-99/MWh.
    For solar they predict £59-73/MW

    So the government (tbf the House of Lord's was very critical of these figures saying they did not reflect rapidly falling costs) claimed that off-shore wind would cost £85-£109/MWh in 2030, when reality delivered contracts of £57.50 for 2023.

    The difference here is staggering, and again greater still when you consider subsidies not prices, since £7.50 v's £35-£59 is immense.


    Back to the article, even cheaper bids are now expected from this latest auction. In fact the bid caps were set at £56 and £53 for 2024 and 2025 delivery respectively (again, 2012 baseline pricing).

    Hopefully now its clear why this is so important and significant, off-shore wind prices (which are higher than on-shore wind and PV*) are getting close to subsidy free (net subsidy free**) meaning that the subsidy pot stretches further and further.

    *Both have been excluded from CfD auctions by the government since 2015 when they launched an absolute raft of policies against both technologies.

    **Net subsidy free, since even a £50 strike price on a varying market that averages £50 will mean subsidies paid out at times, and paid back at times.)
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
  • Martyn1981Martyn1981 Forumite
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    Martyn1981 wrote: »
    Example - So for off-shore wind they may ask for bids on 1GW of capacity, and the auction (a reverse auction) looks for the cheapest bids. The CfD mechanism also has max prices for bids to be considered.

    For anyone still hanging in, and interested.

    This CfD auction is for upto 6GW of capacity and upto £65m in subsidies.

    I believe that's the total pot for the 15yr period, so to get 6GW of capacity, we'd need bids to come in at around 16p/MWh in subsidies (I think).

    Which may sound crazy, but they are getting closer to the estimated average wholesale price, so maybe?

    From there we get a lovely comparison v's nuclear and HPC, with 6GW of off-shore wind providing approx 3GW of (average) generation and HPC's 3.2GW providing approx 2.94GW (92% cf).

    We get Ff displacing RE generation in 2024/25 (some earlier due to the modular built out) v's HPC around 2028.

    And £65m in subsidies v's £45bn.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
  • edited 11 July 2019 at 7:52PM
    GreatApeGreatApe
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    edited 11 July 2019 at 7:52PM
    The bit Marty misses probably on purpose is the fact that wind and nuclear are not comparable

    We can say the UK grid would be total carbon free if we had 55GW of nuclear... We could shut down all the gas plants and coal plants if we had that much nuclear

    Mart in his previous post was trying to suggest 1.875 units of offshore wind capacity is equal to one unit of nuclear. It isn't equal because it is quite clear 103GW of offshore wind power would not allow us to close the thermal fossil fuel plants. We would more or less need 50GW of CCGTs as backup and perhaps 30% of our generation would come from natural gas when the wind isn't blowing


    Of course we don't need the extreme of one or the other

    The UK grid is actually going to go towards 40% wind 25% import 2% hydro 3% solar 10% nuclear 20% biomass/Nat-Gas and that's a pretty good low carbon mix more than almost any other large (non hydro heavy) nation and we will get there before 2030
  • edited 11 July 2019 at 9:59PM
    GreatApeGreatApe
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    edited 11 July 2019 at 9:59PM
    GreatApe wrote: »
    The bit Marty misses probably on purpose is the fact that wind and nuclear are not comparable

    We can say the UK grid would be total carbon free if we had 55GW of nuclear... We could shut down all the gas plants and coal plants if we had that much nuclear

    Mart in his previous post was trying to suggest 1.875 units of offshore wind capacity is equal to one unit of nuclear. It isn't equal because it is quite clear 103GW of offshore wind power would not allow us to close the thermal fossil fuel plants. We would more or less need 50GW of CCGTs as backup and perhaps 30% of our generation would come from natural gas when the wind isn't blowing


    Of course we don't need the extreme of one or the other

    The UK grid is actually going to go towards 40% wind 25% import 2% hydro 3% solar 10% nuclear 20% biomass/Nat-Gas and that's a pretty good low carbon mix more than almost any other large (non hydro heavy) nation and we will get there before 2030


    Not that it matters because I'm not suggesting we burn down the current infrastructure to go nuclear but we wouldn't need 55GW of nuclear capacity something closer to 25GW would have been a deep decarb. And it wouldn't mean 25GW of new nuclear more like 15GW new nuclear plus keeping the existing nukes longer

    With 2.8GW link to Norway and 7.4GW to France 2GW to rEU (basically what we will have in a few years) the UK grid would be extremely low FF with just 25GW nuclear 20GW CCGTs (mostly idle). With a small carbon tax we'd be about 60% nuclear 20% imports 20% NG so about 80% non fossil

    Thus a direct comparison is 25GW of nuclear Vs roughly
    30GW offshore wind plus
    15GW onshore wind
    10GW PV
    45GW CCGT backup
    10GW of interconntors
    4.8GW domestic nuclear
    Which is more or less our 2030 plan

    Both get the same results roughly 80% non fossil
    Both good results and sufficient imo

    If you want to go further than 80% each additional % point is easier to do with nuclear than it is with wind and there is an obvious way to hit 100% with Nuclear (although costly) but there isn't an obvious way to get to 100% with wind power or wind and PV


    Also interesting if we didn't build any wind or PV or nuclear and instead just built the interconnectors we have built and keep our old nukes and had a modest carbon tax we would be roughly 50% fossil free still pretty good. Interconnectors have/will actually do a lot of the heavy lifting and we are lucky to be in-between France (which has about 30% of its nukes on its north coast easy to export to England) and Norway (which is in the Nord pool of cheap power so will export us a lot of cheap hydropower)
  • michaelsmichaels Forumite
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    1) I didn't realise that the CFD prices were mirrored - ie that if spot exceeds CFD then the generation is still only paid CFD price. I had always assumed it was a floor but that anything above that went to the supplier.

    2) One issue I guess is that the more wind capacity you have the more it is likely to supress spot when it is windy and thus actually increase the cost of the cfd (although obviously not the price of the leccy)
    I think....
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