Decarbonizing UK Electricity Generation – Five Options That Will Work

At the end of my recent post on the National Grid’s energy future scenarios I mentioned that I was working on a plan for decarbonizing the UK electricity sector that works in practice and which gets the UK least some way down the road towards an increasingly elusive green energy future. The work is now complete, and here I present five future energy options that employ nuclear, gas and variable amounts of wind to achieve large reductions in CO2 emissions while at the same time meeting UK demand in a typical winter month.


The options are designed to meet hourly electricity demand in February 20XX, where XX is an unspecified year in the future. Basic assumptions are:

  • Demand in February 20XX is the same as it was in February 2013. (The February 2013 generation data are from Gridwatch.)
  • Wind conditions in February 20XX are the same as they were in February 2013, allowing hourly wind generation in February 20XX to be estimated by factoring February 2013 wind generation.
  • Hydro and “other” generation is the same as it was in February 2013.
  • 20GW of the 28GW of the nuclear capacity currently in operation, planned or being considered will be on line in 20XX. Operating at a capacity factor of 90% this delivers a constant 18GW of baseload power.
  • Gas-fired capacity remains substantially the same as it is now.
  • All existing coal-fired capacity is decommissioned.
  • In February 20XX there will be no significant amount of electricity available from imports, CCS, biomass, biogas or solar and no significant amount of energy storage capacity.

Generation mixes for the five options are quantified as follows:

  • Nuclear plus hydro/other generation is the same for all options.
  • Wind generation is progressively increased.
  • Wind generation is added to nuclear plus hydro/other generation. If the sum exceeds hourly demand the surplus wind generation is curtailed. Shortfalls are filled with load-following gas and “peaking” generation.

Installed wind capacity increases from 10GW in Option 1 to 20GW in Option 2, to 50GW in Option 3, to 100GW in Option 4 and to 200GW in Option 5 assuming a capacity factor of 20%. Increasing wind capacity does not lower the requirement for gas capacity because peak load for gas is about the same in all five options.


Generation mixes, emissions reductions and percent renewables generation for the five options are summarized in Figure 1:

Figure 1: Generation mix, emissions relative to 2013 and percent renewables generation by Option

Option 1, which replaces coal-fired generation with nuclear generation and expands gas generation, achieves a 55% reduction in CO2 emissions relative to 2013 levels without expanding wind capacity. Options 2 through 5 show emissions continuing to decrease as installed wind capacity increases. In Option 5 they are cut by over 90% relative to 2013.

Increasing wind generation, however, comes at a cost. Figure 2 shows how wind and gas capacity factors decrease as wind capacity increases, to the point where in Option 5 they are down in the 10% range, which is hugely inefficient. Accompanying the increase in wind generation is a rapid increase in the percentage of wind generation that has to be curtailed. It is in fact impossible to increase renewables penetration much above 50% by increasing wind capacity because almost all of the wind generation added above the 50% level gets curtailed.

Figure 2: Gas & wind capacity factors and wind generation curtailments by option

Another problem is the erratic and largely unpredictable shape of the gas generation curve needed to match demand in the higher-wind cases. Figure 3 shows the generation curve for Option 5. The operators of the CCGTs, OCGTs and “peakers” that have to follow it will insist on being well compensated before agreeing to subject them to this level of abuse and underutilization:

Figure 3: Gas generation needed to match demand, Option 5

Generation plots:

Figures 4 through 8 show generation by source for the five options. Option 1 (Figure 4) shows actual February 2013 generation with coal replaced by nuclear. The impact is to cut CO2 emissions to 43% of 2013 levels with renewables generation remaining at 8% of total generation:

Figure 4: Top graph: Monthly demand & generation by source for February 20XX. Bottom graph: Gas generation needed to match demand (hourly data) – Option 1

Option 2 (Figure 5) doubles wind generation over February 2013 levels. This Option cuts emissions to 38% of 2013 levels and increases the percentage of renewables generation (wind plus hydro/other) from 8% to 13%.

Figure 5: Top graph: Monthly demand & generation by source for February 20XX. Bottom graph: Gas generation needed to match demand (hourly data) – Option 2

Option 3 (Figure 6) expands wind generation by a factor of five. This Option cuts emissions to 27% of 2013 levels and increases renewables generation to 26% of total generation. At this level, however, curtailment of surplus wind generation becomes necessary. (Note that the gas generation curve assumes complete shutdown of gas-fired capacity during wind surpluses. If an operating reserve is maintained the level of wind curtailment during surplus periods increases.)

Figure 6: Top graph: Monthly demand & generation by source for February 20XX. Bottom graph: Gas generation needed to match demand (hourly data) – Option 3

Option 4 (Figure 7) expands wind generation by a factor of ten. This Option cuts emissions to 16% of 2013 levels and increases renewables generation to 39% of total generation, but 24% of total wind generation now gets curtailed:

Figure 7: Top graph: Monthly demand & generation by source for February 20XX. Bottom graph: Gas generation needed to match demand (hourly data) – Option 4

Option 5 (Figure 8) expands wind generation by a factor of twenty. This Option cuts emissions to 7% of 2013 levels and increases renewables generation to 50% of total generation. Wind curtailment, however, is now up to 50% (the light green “curtailed” areas on the Figure go way off scale).

Figure 8: Top graph: Monthly demand & generation by source for February 20XX. Bottom graph: Gas generation needed to match demand (hourly data) – Option 5

Solar power:

Some future energy scenarios make copious use of solar. I do not. As well as being inefficient at high latitudes – particularly in the winter when the power is most needed – solar roughly doubles the number of hoops the gas plants have to jump through to balance generation against load. This is illustrated in Figure 9, which shows Option 3 with approximately 20GW of solar added. Compare the gas generation curve with Figure 6, which shows Option 3 without the solar:

Figure 9: Option 3 with solar generation added


UK Energy Policy:

Any future UK energy scenario should conform with established UK energy policy, and with the current fixation on wind and solar it’s easy to forget that UK energy policy statements heavily emphasize nuclear and gas. The July 2011 National Policy Statement for Nuclear Power Generation, for example, considers nuclear to be “vitally important”:

Any new nuclear power stations consented under the Planning Act 2008 will play a vitally important role in providing reliable electricity supplies and a secure and diverse energy mix as the UK makes the transition to a low carbon economy.

And in his introduction to DECC’s 2012 “Gas Generation Strategy” paper Ed Davey acknowledges that gas is “crucial” to keeping the lights on and the economy working:

Gas – as a flexible source of generation which emits half the CO2 of coal – will be needed to help balance the relatively inflexible and intermittent low-carbon generation our policies will bring forward. It will provide crucial capacity to keep the lights on and the economy working.

So nuclear and gas are acceptable future energy options.


All options depend on having 20GW of operating nuclear capacity in place by 20XX. Can this be done? Without specifying what year XX refers to the answer is of course yes. But according to the 2014 DECC report New Nuclear in the UK five proposed nuclear plants with a combined installed capacity of 15.4GW have firm development plans and scheduled completion dates, and adding them to presently-existing nuclear plants still in operation would give ~19GW of installed nuclear capacity by 2027. Three other designated nuclear sites could add ~9GW more, giving a total of ~28GW of installed nuclear capacity by, say, 2030. Adding 20GW of nuclear capacity over the next fifteen years is therefore not only feasible but also in accordance with existing plans. And all it will take to add it is a firm commitment on the part of the government and maybe a little less messing around with experimental reactor designs.

The gas generation curves peak out around 30GW in all cases, meaning that roughly 35GW of installed gas capacity would be needed. The UK presently has about 30GW of installed CCGT capacity, so this should not be a problem either. There would even be time to modernize or replace some of the more inefficient older plants.

Energy Security:

Replacing coal with nuclear will eliminate the UK’s dependency on imported coal, much of which has been coming from Russia in recent years. Gas imports will either increase or decrease depending on the level of wind generation, with the gas plants burning 80% more gas than they did in 2013 under Option 1 but 70% less under Option 5. I haven’t looked into the situation regarding security of uranium imports but assume that it will not be a problem.


I haven’t looked into this in any detail either, but 20GW of nuclear at £5,000/installed kW will cost £100 billion, and to this we can add maybe £5 billion for additions and upgrades to gas plants. Spreading this £105 billion over 15 years gives £7 billion/year, less than the £9 billion/year the UK is projected to be spending on renewable energy subsidies by 2020. Moreover, roughly 50GW of offshore wind capacity would be needed to match the 18,000GW average output of the nuclear plants (although delivery would of course be intermittent), and at £3000/installed kW this would cost about £150 billion, 50% more than the nuclear plants.

Concluding comments:

The five energy options described above actually define a continuum of possibilities where nuclear generation is held constant, wind generation is progressively increased and decreasing amounts of gas generation are used to match wind generation to demand. The best choice of options occurs at the point where the advantages and disadvantages balance out, but exactly where one picks this point depends on what one considers most important. Being more concerned with system reliability and efficiency I would be inclined to pick Option 2, which cuts emissions by over 60% below current levels but includes only 13% renewables generation. Those more concerned with emissions and sustainability might prefer Option 4, which cuts emissions by over 80% below current levels and includes 39% renewables generation, but at the cost of a significant decrease in system efficiency and reliability. I doubt that anyone would go for Option 5.

Finally, all the options presuppose a continuing supply of fossil fuels. A fully-sustainable, zero-emissions energy system powered dominantly by intermittent wind and solar will not be achievable until energy storage can be commercialized on a large enough scale.

Footnote: Comparisons are invited with Euan Mearns’ July 2013 post Energy Matters 2050 pathway for the UK, which I note with interest includes over four times as much nuclear as I do.

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72 Responses to Decarbonizing UK Electricity Generation – Five Options That Will Work

  1. Leo Smith says:

    what we ought to be doing is covering all the baseload with nuclear. Probably about 30GW of it, in the certain knowledge that lots of it will be down for scheduled maintenance when we need it least – high summer.

    Add in some hydro and pumped to cover daytime peaks, and use gas for everything else.

    Renewables of the intermittent kind should be consigned to the dustbin of history.

    • Mark Pawelek says:

      UK energy policy is a mess because it’s run by politicians and economists who give lip service to the market. At the same time, they legislate in favour a raft of rules to deform the market beyond recognition. We have renewable obligations, contracts for difference, carbon levy, biofuel mandates and carbon trading. All of it married with clear central planning (or unplanning – call it what you will). There’s actually no market at all in operation for nuclear power in the UK; we pretend there’s one. If we really wanted to use the market to incentivize economic non-carbon electricity generation we’d have plumped for a single regulation: fee and dividend. Within the electricity sector, a fee would be levied on CO2 output (say £50/tonne CO2). This makes existing coal non competitive with new nuclear build (provided we avoid ultra-expensive designs such as the AREVA EPR). Unlike a carbon levy, this £50 fee doesn’t raise electricity bills so much because all the fees raised are refunded to customers as a “dividend”. It makes a non-CO2 electricity transition far more palatable to the public.

      PS: I’m happy to see that 3 proposed AP1000 reactors at Moorside are estimated to cost £10 billion in total. Yet we can’t start this until the AP1000 passes its GDA (estimated to be some time in 2017).

      PS 2: Why there’s no UK “market” in nuclear power:

      • Peter Lang says:


        If we really wanted to use the market to incentivize economic non-carbon electricity generation we’d have plumped for a single regulation: fee and dividend. Within the electricity sector, a fee would be levied on CO2 output (say £50/tonne CO2).

        Carbon pricing of any type almost certainly cannot succeed. These two posts explain why:

        Having read these it should be clear that fee and dividend cannot succeed either, especially if applied to just electricity sector or to a few selected sectors of the economy or selected sources of GHG emissions. For any carbon pricing to succeed it would have to be applied uniformly to around 80% of all GHG emissions from all economies throughout the world. Clearly, that will not happen.

        Carbon pricing is the wrong approach. It is government intervention that causes market distortions. There is a better approach. It’s the economically rational approach. It’s to remove the unjustified impediments that have been imposed on selected types of energy. The rational approach is to remove the irrational market distortions and allow the markets to operate. By far the greatest market distortions are the impediments to nuclear power.

    • A C Osborn says:

      Mark, it would appear that there is some common sense breaking out.
      see this post.

  2. Willem Post says:


    A great piece of analysis. It should be a power point presentation to the UK Parliament, for starters.

    In Option 5, both the wind and gas turbine population would be grossly underutilized. True to RE aficionado habits, they likely will be punished for it with higher taxes.

    All this to lower the CO2 emissions of energy generation, i.e., treating about 40% of the problem. What paths would be required regarding transportation, buildings, etc?

    The required investments, over several decades, will only occur with significant incentives, i.e., taxes, fees, surcharges, etc., added to electric bills, low-cost loans, capital grants, fast depreciation schedules, tax credits, capacity payments to wind and gas turbine owners, etc.

    Such an effort will grossly distort and make less efficient the UK economy, as it will other economies, making it that much harder to make subsequent investments, plus to maintain and dismantle the old electrical system setup as it is being phased out, plus to build and maintain the new set up.

    Interesting times ahead!

    • soarergtl says:

      And all that spending, just to ensure that, even if CO2 really is, as claimed, the climate control knob, there is a reduction in global temperature which is impossible to feel, or to measure, or to show any evidence for.

      That’s an awful lot of resource to waste on a rounding error.

    • Willem: Thank you. I’d be interested in your opinion as to whether the Option 5 gas generation curve is physically achievable. Ramp rates are up to 140MW/minute and probably higher over shorter periods.

      • Willem Post says:


        You had not mentioned ramp rates in your analysi, but 140 MW/minute would require a number of large units in parallel each ramping, say 15-20 MW/minute.

        How long would such ramping last? If too long, the units may run out of range.

        Most units have a range of 50 to 100% of rated output. To ramp up and down, they typically would operate at around 75% of rated output.

        Some hydro storage may need to be part of the mix to cover unusual conditions.

      • Geoff M says:

        Recently I looked for the biggest Wind ramp rates (up or down) during one of the recorded Elexon past years, and factored it up to 39 GW of Wind (one of the old Nat Grid FESs- future energy scenarios). The biggest I found was the equivalent of 4 UK nuclear stations in 5 minutes, can’t remember the exact figure. The problem is, some of the Elexon figures are showing what was obviously a failure in some of the reporting equipment, but some of the big rises/falls looked realistic, but I can’t be sure. We’ll find out in the future. Equivalent of 4 nucs coming offline in 5 minutes: that’ll be interesting!

      • According to Gridwatch data the highest ramp rate achieved by CCGTs in February 2013 was 865MW in five minutes, or 173MW/minute.

        • Willem Post says:


          Achieving is one thing, without damage is another.

          How much capacity, MW, of CCGTs was actively ramping to do 173 MW/minute?

          What if 2 times or 3 times wind energy?

          • “How much capacity, MW, of CCGTs was actively ramping to do 173 MW/minute?” Dunno.

            Here are maximum ramp rates measured over one hour periods for the five options. Option 5 is slightly lower than Option 4 because the spikier spikes get curtailed at this level of wind penetration. Actual=85 MW/min, Option 1=108, Option 2=113, Option 3=128, Option 4=140, Option 5=138.

            Wartsila advertises turbines that can do nought to sixty in less than five seconds. 😉


          • Willem Post says:


            Your reference regarding Wartsila RECIPROCATING gas-fired engine-generators and GE and Siemens combined cycle, gas turbine-generators illustrates the changes required in generator population, and trained personnel capabilities, and front end and back end infrastructures for ramping large quantities of wind energy.

            If these Warsila engines had heat recovery systems, their ramp rates would be constrained as well, although not as much as with CCGTs.

            The article compares ramping rates, but does not compare efficiencies at these ramping rates and at steady conditions.

            Hydro plants with multiple generators, with storage reservoirs, already have high ramping capability over a large output range (about 10% to 100%), AND do it at high efficiency, but there are not enough of them for ramping large quantities of wind energy.

            The world is running out of ramping capability, if wind energy increases as envisioned, the reason Germany, Denmark, etc., like/need to be connected to nearby grids to use their spare ramping capabilities.

            But if everyone has much wind energy, then interconnection within a weather system is of little use.

            Wind energy curtailment would be required to maintain a less variable wind energy output well within ramping capabilities.

            Such curtailment already is practiced in Ireland and curtailed energy quantities (along with compensation payments) have been increasing as wind turbines were added.

  3. soarergtl says:

    “The required investments, over several decades, will only occur with significant incentives, i.e., taxes, fees, surcharges, etc., added to electric bills, low-cost loans, capital grants, fast depreciation schedules, tax credits, capacity payments to wind and gas turbine owners, etc.”

    And, at the end of the century, even if CO2 is the climate control knob as claimed, will have reduced global temperatures by an amount too small to measure, or to feel, or see any evidence of.

    That’s an awful lot of resource wasted on a rounding error.

  4. Andrew says:

    Installed capacity usually means the maximum capacity if the wind were blowing. When you say installed capacity, have you already taken into account the capacity factor?. You state, under Assumptions: “Installed wind capacity increases from 10GW in Option 1 [and so on]……… assuming a capacity factor of 20%.” That implies 2GW will be generated from wind under Option 1 [and so on]. And Figure 1 describes “Percent of total generation”, so I assume the 2GW is there under Option 1. Or is the 10GW under Option 1 actual output, implying an installed capacity of 50GW?

    Note that, according to REF, in May 2015, in the UK already “there is now 49 GW of consented capacity (21.2 GW built, 28.1 GW under or awaiting construction)”

    • The numbers at the bottom of Fig 1 are installed capacity. When you apply a ~20% capacity factor (the average for wind in February 2013) to these installed capacities you get the right percentage of wind power in the generation mix. 49GW of wind would be Option 3.

  5. clivebest says:

    The curtailed wind should be used to make synthetic methane even though the efficiency is low. The rest of us should not have to pay wind farm operators for unused energy! Fraunhofer have been working on this for years. First you use electrolysis to split hydrogen and oxygen from water. Then you combine the hydrogen with CO2 to make methane. This could then be fed back into the gas system or burned in gas power stations.

    The conversion of electricity into methane gas has a maximum theoretical efficiency of 60 %. However, the best that has been achieved so far is just 40 %. If the methane is then used in a natural gas power plant to produce electricity, the efficiency falls again by at least a factor 0.64.

    Therefore using methane to store excess wind energy for later use in electricity generation has a maximum theoretical efficiency of about 38%. But even that is better than throwing it away!

    Abolishing constraint payments by the National Grid to wind operators for excess energy would force them to invest in such technology.

    One other point. If the UK seriously wanted to decarbonise the ‘economy’, then electrical power generation would have to increase by a factor 3 to something like 180GW. That is because nearly all transport and heating depends on fossil fuels and would also have also to be electrified !

    • Willem Post says:


      “Maximum theoretical efficiency of 38%” In real life that would likely be 50% of that. The life cycle cost of producing the methane with on and off surplus wind energy?

      With very serious increases in transportation sector efficiencies, such as plug-in all-electric vehicles and plug-in biofuel-hybrid vehicles, and battery-powered bicycles/tricycles, etc., and thermal sector efficiencies, such as near-zero energy, or energy surplus buildings, etc., the energy for these sectors would be reduced by a factor of 3 to 4.

      Their smaller energy needs would also reduce the electrical sector demand.

      There is a way out and, at the same time, provide a chance for the other fauna and flora to survive and thrive, but it would require drastic changes:

      – Population reduction from 10 billion in 2050 to 1 billion in 100 years
      – Energy consumption per capita to be reduced by a factor of 4 in less than 50 years
      – Consumption of other resources per capita by a factor of at least 10 in less than 50 years

      Those conditions existed in 1800, until fossil fuel, etc., “rescued us”.

      But today we are so much smarter, can do so much more with less, so lifestyles would still be significantly better than in 1800.

      • A C Osborn says:

        Wilklem, without murdering 6 billion people this is not going to happen.
        All of those people have aspiration, firstly of their own and then for their children and grand children.
        You will never persuade them to do what you have outlined previously in that short a time period and nor should they.
        The world is not having any real problems supporting 7 Billion people now and as people gain education and wealth so their populations will decline.
        With Scientific advances (and no Ice Age) the world will continue to support them.

        • Willem Post says:

          AC, more boat people is ok.

        • Willem Post says:


          No one is being “murdered”. They are not born, because of incentives not to have children.

          The world is having a huge problem supporting 7 billion, or 10 billion, and does it at the expense of the environment and the other fauna and flora, both of which, as even the most obtuse people will admit, have largely falling by the wayside as collateral damage, i.e., modernity road kill.

          The boat people situation will get worse as word gets out a safe haven exists in Europe.

          Europe will have an influx of desperate Middle East and African people, similar to or greater than, the on-going hispanic influx to the US, which, thus far, has resulted in about 42 million largely poorly skilled/educated hispanics exceeding the about 42 million largely poorly skilled/educated negroes, both groups existing in parallel with at least 40 – 50 million poorly skilled/educated whites.

    • Clive:

      In my power-to-methane post I concluded that power-to-methane was probably impracticable regardless of the efficiency or cost of the process. To make it work you need lots of cow manure, which because of its mode of occurrence is a resource that’s going to be extremely difficult if not impossible to commercialize at any kind of meaningful scale.

      If the UK seriously wanted to decarbonise the ‘economy’, then electrical power generation would have to increase by a factor 3 to something like 180GW. That is because nearly all transport and heating depends on fossil fuels and would also have also to be electrified

      I’m not sure this has occurred to the energy czars yet.

  6. Graeme No.3 says:

    I note Ed Davy’s claim that gas produces half the CO2 emissions of coal; he seems to have confused CCGT with OCGT, with the latter being useful for fast response to changes in wind supply. If he thinks that CCGT plants can be turned on and off he is {snip}.
    In any case the current situation involves large numbers of contracted diesel generators, with even higher emissions. When do those lucrative contracts run out?

    IN the Falklands they use wind and diesel, but the wind is subordinate to the diesel. The power station uses the blade angle control to give close to a steady supply from the turbines. This results in less than optimal output ( CF) from a turbine but flattens the output over a wide range of wind speeds. Mind you there is reputed to be a pretty steady supply of wind in the Falklands.

    • Euan Mearns says:

      The 50% CO2 argument is normally derived from the chemistry. In coal C-C bonds are broken to produce 2CO2. In gas, C-H bonds are broken to produce CO2+H2O.

      But the reduced efficiency of using OCGT and ramping up and down still stands. Renewables enthusiasts are not really that bothered about efficiency and cost.

      • Willem Post says:

        “Renewables enthusiasts are not really that bothered about efficiency and cost.”

        They LOVE to drive up the cost of “Other”, so RE can shine in comparison

  7. Leo Smith says:

    The curtailed wind should be used to make synthetic methane even though the efficiency is low.

    Substitute ‘nuclear’ for ‘wind’, and the above makes even more sense.

    Dealing with demand fluctuation is an issue with any technology: adding intermittent renewables simply exacerbates it.

  8. Euan Mearns says:

    Note that my DECC 2050 pathway provides an energy mix for decarbonising the whole energy system including space heating and transport that are to large extent electrified. Hence the greater need for electricity.

    One of the key things I learned from MacKay’s book is that electrification makes things more efficient – especially heat pumps that have +ve efficiency and cars.

    I agree with Leo’s opening comment. Nuclear should be built out to cover all base load. We could perhaps expand pumped hydro a bit – Coire Glas makes a lot more sense run on a diurnal nuclear cycle. The remainder of the peaks covered by gas, some of this could be syn-gas made using summer time surplus nuclear and stored in old gas reservoirs like Rough.

    • Euan: The reason you need four times as much nuclear as I do is of course that I’m only looking at the electricity sector while you are looking at the entire economy. But if you want a case that decarbonizes the transportation sector as well as the electricity sector you can just take my electricity numbers and multiply them by whatever factor you need to add 100%-electric trains, trucks, buses, cars etc. This would increase emissions from electricity generation but these would be more than offset by decreased emissions from transportation. No guarantees given that the plan will work in this case, however.

    • Hugh
      To achieve ‘decarbonisation’ by 2050, it has always been expected that space heating would be electric instead of gas and personal transport would be electric, instead of petrol/diesel. It may well turn out that way, but, the process would challenge a well-rooted dictatorship, let alone a system which is meant to be market-driven (but, is so interfered with that it cannot work). The social and economic implications of switching to electric cars, for example, go way beyond small matters like improving battery life or building electricity systems – they are affect individuals, families and companies who would not tolerate a messy transition. But, it promises to be messy. Without huge (unaffordable) government hand-outs to scrap old cars and buy new ones, how would it work? And, as electric vehicles began to take up more of the market, we would see the same effect on petrol stations as the forced growth of ‘must take’ renewables has made on perfectly good gas-fired power stations.
      Don’t get me started on how we persuade millions of home-owners to scrap their ‘GFCH’ and go electric.
      See Porter’s book, page 320-321!

      • Euan Mearns says:

        David, i’m sorry I never got around to reading and reviewing your book – I’m on a post writing treadmill:-((

        Guest posts are welcome if you felt like summarising parts of it for us. I’m particularly interested in the role the state played in building our legacy infrastructure.

        • Euan

          Many thanks. I should like to do that and I shall be in touch.

          Not sure that I can say much about the state-built infrastructure, though – except that the existence of pretty good networks and ample generating capacity made the privatisation easier than it might have been. My involvement began in 1987, so the book does not have much to say about the state industry, other than the fact that it made life difficult for the independent producers that I represented at that time – state- owned monopolies don’t like interlopers.

          Thanks for the Amazon link to the book. I am giving another one below. Your link is for the Kindle version (cheaper!), which attracted my only negative review. It came from someone that I do not know, but, somehow it felt rather personal. So, I am giving here the Amazon link for the hard copy, where someone has written a longer and – for the author – more encouraging review.

          By the way, Hugh Sharman is kindly reading it. He might have something to say. From what he has said to me, I think he likes it, but, he told me that, in the trade association story, there are too many references to ‘lunch’! He is probably right. But, I forgot to tell Hugh that, in a former life, I was a restaurateur for nearly nine years. So, that must explain it.


  9. Joe Public says:

    The object of the game is to reduce CO2 emissions.

    Call the Greenies’ bluff.

    Prohibit the use Natural Gas for generating electricity, and use it solely at point-of-use for its heat content. i.e. simply revert to what was UK national energy policy up to about the mid 1980s.

    Efficiency in use would be of the order of 80% – 90%, and at a stroke, CO2 emissions per useful kWh would be reduced by 50%.

    • Joe Public says:

      Rather – “CO2 emissions per useful kWh from that proportion of gas currently burnt in power stations would be reduced by 50%.”

  10. peter2108 says:

    Roger, a gas + wind + nuclear is present policy as I found when looking at the DECC sources ( Renewables are scheduled to double (that includes biomass I fear), nuclear to grow by 2.5 times.

    Just recenmtly DECC has approved 6GW (sic) of OCGT from Watt Power. ( – but you only get five articles free per month). These are obviously designed to follow the wind.

    As you say killing coal relies on new nuclear and this is really looking very iffy in the medium term. Areva is needing 5 billion euro bailout from French government which is presently cash-strapped, and Luxembourg is joining the suit against Hinkley ‘C’. And, of course, as Dr Flocard points out the safety requirements on new nuclear render it more or less unbuildable.

  11. Javier says:

    And why would you want to decarbonize UK energy production?

    CO2 has over 100 years of demonstrable benefits and only hypothetical downsides.

  12. Peter Lang says:

    I’ve been travelling in Scandinavia and I haven’t been able to follow all the new threads. I haven’t read this new one yet. However, this may be of interest.

    I am in Ireland. I’ve estimated the cost to power Ireland entirely with wind turbines and pumped hydro energy storage. The estimated capital is €400-€1500 billion. Their electricity consumption has been 26 TWh per year for the past 3 years.

    The €400 bn euro is based on €40/kWh energy storage cost file:///C:/Users/jeremiahjohn/Downloads/report-summarizing-the-current-status-role-and-costs-of-energy-storage-technologies.pdf and assumes 8 TWh energy storage capacity.

    The €1500 bn is based on the number of Tulloch Hill pumped storage schemes they’d need and its original cost escalated to now. Tulloch Hill is Ireland’s only pumped hydro scheme, and probably few if any others as viable as it.

  13. Confused Mike says:

    Another fascinating part of the analysis of future generation options.

    The wind curtailment factors forecast to commence at 20 GW capacity suggests to me that DECC will be reviewing the wind turbine operators ‘guarantee’ of CFD income either by putting power into the grid or as a curtailment payment will soon be on the horizon as dismantling of some of the renewable legislative architecture is undertaken. (I assume that today’s curtailment payment comes out of the Levy Control framework which is already under severe budgetary pressure?).

    I hope financiers for future wind turbine farms or any new gas turbines should be challenging the returns the operators are suggesting !

    Two questions if I may:

    1. The fact that there are interconnectors (3.5GW at present or 5-10% of Feb 20XX demand) will surely have an effect: dampening or exaggerating? – and a Norwegian 1-2GW(?) interconnector is currently being planned (with perhaps pumped hydro) and presumably will be in place by 20XX. Is there a way of representing this effect in your model albeit that neighbouring price differentials due to their present power portfolios are sometimes a surprise (to me at least!)

    2. I’m struggling to get my mind around a summer month when power demand will be lower (?) but wind availability may also be lower but proportionately less or more so as wind turbine capacity rises – is a similar August analysis worthwhile to see if the picture is less or more worse?

    • Confused Mike: Thank you. On your questions:

      Surplus wind power is already being curtailed in the UK, but only in small amounts. And as you might expect the wind power producers get paid for not producing it.

      The UK imports power through interconnectors at all times except during cold, windless winter periods, when the UK exports it even though this is when it most needs imports. See:

      The gas plant load fluctuations shown in the Figures are up to 10 times the 3.5GW of interconnector capacity the UK presently has in place, so interconnectors aren’t going to have much of an impact even if the UK could make the flows along them go in the right direction.

    • I’m struggling to get my mind around a summer month when power demand will be lower (?) but wind availability may also be lower but proportionately less or more so as wind turbine capacity rises – is a similar August analysis worthwhile to see if the picture is less or more worse?

      I’d always assumed that if you can get through a winter month then a summer month would be a breeze. But an analysis is worthwhile just to make sure, so here’s July 2013, Option 5. The only change I made was to reduce nuclear generation from 18 to 15GW to allow for a plant being down for maintenance:

      It’s not exactly a breeze but it is easier than February. We have a 90% decrease in emissions, 42% renewables generation, wind curtailment is down to 31% and the gas generation curve looks a little more tractable. Wind and gas capacity factors are still down in the 10-15% range, however.

  14. Jacob says:

    In your emissions calculations: did you factor in the increase in emissions per kw produced by gas because the fluctuations – i.e. because of the start-stop character of the demand?

    • No, because I didn’t have the info I needed to do it. But doubling gas consumption wouldn’t make that much difference.

    • Peter Lang says:

      Some excellent analyses are beginning to emerge that quantify the emissions avoided by wind generation. Here are some figures for CO2 abatement effectiveness* versus proportion of electricity generated by wind (penetration):

      Ireland, 2011, 53% effective at 17% penetration

      ERCOT, 2007-2009, 80% effective at 4.7% penetration

      Australia NEM, 2014, 78% effective at 4.5% penetration
      Australia NEM projected, 70% effective at 9% penetration
      Australia NEM linear projection to 15% penetration = 60% effective

      The main reason that effectiveness is less than 100% is that wind generation displaces the lower rather than the higher emissions intensity generators; e.g. wind displaces gas in preference to coal.

      Modelling by the Sustainable Energy Authority of Ireland indicates that the additional emissions caused by ramping and cycling of the back up generators is a small contributor.

      * CO2 abatement effectiveness = % emissions avoided / % of electricity supplied

      • Willem Post says:

        That was the SEAI position some time ago, but it has admitted that 53% effectiveness at 17% annual wind energy is correct. That 53% is based on the entire grid intensity, which is about 0.500 lb CO2/kWh.

        The claim had been that 17% wind would reduce that intensity by 17%, but the actual reduction is 0.53 x 17%.

        I think Brussels is aware of this, but will likely not respond, as it would upset a carefully constructed PR image of wind being the savior.

        The Irish coal and peat plants continue to be base-loaded. It is the gas plants doing the balancing.

        Ireland already has built too much wind capacity, MW, i.e., during windy periods curtailment is required. Owners receive greater payments for not being allowed to produce!!

        • Peter Lang says:

          Hi Willem Post,

          Thank you for your reply. Do you have a reference to where SEAI has acknowledged that Wheatley’s 53% effectiveness in 2011 is correct and that their analysis for 2012 overstates the effectiveness? I have not seen that acknowledgement by SEAI. However, the fact they were forced to do the modelling and acknowledge much lower CO2 abatement effectiveness than previously admitted is excellent progress – they have moved from their assumption of 100% effectiveness to the 65% effectiveness for wind power in the All-Ireland grid in 2012.

          I trust Wheatley’s analyses over the SEAI’s modelling exercise. I’ve been involved in this for some years as you know. Wheatley is a totally honest, unbiased researcher with no axe to grind other than to do rigorous analyses and let the figures speak for themselves.

          Wheatley has just completed an excellent analysis for the Australian National Energy Market. It is a fascinating study and very well written up in his submission to the Senate Select Committee on Wind turbines.

          Power mag wrote a short summary of an article I wrote on Wheatley’s analysis explaining the policy implications of it: “Is Wind’s Climate Contribution Overstated?” Note what the low effectiveness means for the estimates of CO2 abatement cost (CO2 abatement is the principal justification for renewables)

  15. Jacob says:

    Question: would it be possible to use excess wind electricity production for space-heating ? (Replacing for part of the time the gas used for heating)?

  16. Jacob says:

    The scenarios you developed actually, and mainly, replace coal generation with nuclear. That, of course, makes (technical) sense and also reduces emissions!

    Problem is: it will not happen, given the current state of affairs and attitude to nuclear power. What is happening, in the West, at this time, is that much more old nuclear plants are retired than new ones built.

    And, what about the poster child of renewables – Germany – with NO nuclear power ? Can we explain their “plans” without using the term “insane” ?

    • Willem Post says:


      The nuclear industry is alive and well, except in hysterical Europe and Japan.

      Here are some Russian data:

      Russian has sold a large number of nuclear reactors to various nations during the last half of 2014 and the first half of 2015, which indicates Russia is doing business as usual, despite sanctions. Is this how “isolating Russia” is meant to work?–Nuclear-Power/

      Country………. Qty………Capacity, MW……..Cap. Cost, $billion
      South Africa…….8………….1200……………………50
      Saudi Arabia….16………….1200………………….100
      Argentina………MOA signed
      Indonesia………MOA signed

      • Jacob says:

        These are theoretical numbers. How many are actually being built? How many enter operation?
        I repeat: in the last few years,the number reactors that were retired is greater than the number of new reactors commissioned. And none were built in the West.
        Maybe this trend will change, it’s not impossible, but the change has not yet begun.

        • Willem Post says:


          These are orders Russia has contracts for. There is nothing theoretical about them.

          The rest of the world (not Europe, not Japan, not the US) is busy placing orders, designing, building and commissioning reactors.

          It is true, more capacity, MW, was shut down than was commissioned last year, but, as Russia’s order book shows, that trend may reverse itself over the next few years.

          Russia and China are taking advantage of the self-induced nuclear coma Europe, Japan and the US.

  17. Jacob says:

    Another suggestion: for purposes of comparison – remove from you scenarios the wind, entirely, stay with nuclear+gas and see how much you reduce emissions. This would be an interesting comparison – more not the reduction vs. 2013 (which includes coal).

    • Peter Lang says:


      Here’s a quick back of an envelope analysis:
      Assume CO2-e emissions intensity of nuclear is 0 t/MWh and gas is 0.4 t/MWh
      France has demonstrated that 80% nuclear is doable in a modern industrial economy, so assume 80% nuclear plus 20% gas.
      Emissions intensity of the electricity system = 20% x 0.4 t/MWh = 0.08 t/MWh (or 80 g/kwh)

      What percentage is that of the 2013 emissions intensity of the UK electricity system?

      • Peter Lang says:

        If Australia’s electricity generation mix was 80% nuclear and 20% gas, the emissions intensity of electricity would be 8% of what it is currently.

  18. Peter Lang says:


    This is an excellent approach. Thank you. Like you. I’d opt for option 2, or perhaps option 1. Actually, I’d opt for the option that supplies electricity to consumers at least cost. In the short term that would be a slow transition from the current mix to Option 1.

    I’d make two points.

    1. I think it would be a great improvement if you add a chart, or add a curve to Figure 2, showing the cost of electricity for each option. The cost of electricity needs to include the system costs such as transmission (but much more than just transmission).

    2. I’d argue that uranium fuel supply is a low energy security risk. I argue that is about the lowest risk of all fuels that have to be imported because a country can hold many years of nuclear fuel. It requires an insignificant area for storage and is not a risk while held in storage. The storage sites can be widely distributed or stored underground.

    • I don’t have enough information to do a good job on electricity costs but I think you could assume that they would roughly double between Option 1 and Option 5.

      • Peter Lang says:

        Hi Roger,

        To do a sophisticated estimate of electricity costs requires sophisticated economic modelling and many assumptions. But a reasonable estimate can be made using authoritative published estimates of the inputs to LCOE (capacity factor, capital cost, discount rate, FOM, VOM, fuel cost, etc.). The NREL LCOE calculator is easy to use . Or you can use the simplified formulae they provide. The Australian Government, provides projected inputs for LCOE for future years and their projected rates of change for each individual technology. So these are authoritative figures for Australia. I seem to recall I’ve seen the equivalent for the UK. This OECD/NEA report provides estimates of the system costs by technology at 10% and 30% penetration: ‘System effects in low-carbon electricity systems” .

        I have done such a simple analysis for Australia, although I didn’t have access to the system costs at that time so I did a simple analysis. You can download the spreadsheet and input your own inputs for UK; the spreadsheet can be downloaded here:

        A follow up analysis with a nuclear scenario added is posted here: “Renewables or Nuclear Electricity for Australia –
        the Costs

      • Peter Lang says:


        Another option for a simple way to estimate the cost of electricity for each energy mix would be to use the Australian Energy Technology Assessment Model (AETA 2013 Model) to estimate the LCOE for each technology in the mix using the average annual capacity factor for each technology. You can change all the significant inputs. This model is in Excel and is easy to use. It was produced by the Bureau of Resources and Energy Economics and is freely available. The details and reports are here (read the 2012 report before reading the 2013 update). Email the Department at the email address provided and they’ll send you the model in Excel

        You can then use UK values as applicable.

        I’d point out that the renewable energy industry applied great pressure to get many default inputs changed in the 2013 model to agree with their beliefs about renewables versus nuclear. For example, they have used highly optimistic (unrlealistic, IMO) learning rates to 2050 for renewables and zero learning rate for nuclear.

        You can add the LCOE for the system costs for the relevant proportion of electricity generated by each technology.

        Then add that curve to your Figure 1 🙂

        I reckon that would be a great improvement, because for many (most) policy analyses and policy decisions it is the economic comparison that really is most important.

  19. John Droz points out to me that the following sentence in the post is potentially confusing:

    Option 1 shows that a 55% reduction in CO2 emissions relative to 2013 levels can be achieved simply by replacing coal with nuclear and without changing anything else.

    John is correct. The sentence now reads:

    Option 1, which replaces coal-fired generation with nuclear generation and expands gas generation, achieves a 55% reduction in CO2 emissions relative to 2013 levels without expanding wind capacity.

  20. Andrew says:

    Well, it’s an amazing conclusion that the UK is already at Option 3, provided the capacity consented gets installed; and even if it doesn’t we’re at Option 2. As you say, who on earth would want the disbenefits of going further?

  21. Rob says:

    Have you seen Jeremy Corbyn unusual solution solar power and coal with decentralised power
    and comments

    • Euan Mearns says:

      I thought for a moment Corbyn had potential, but clearly just another left wing nutter. Why would we have solar panels in a land where the Sun seldom shines and virtually never shines in winter. CCS would be economic suicide. And it sounds like he may fancy nationalising everything. But curiously, at the same time I’m not against nationalising strategic industries. He could start with National Grid – that operates strategic infrastructure. And I believe the State building new nuclear is perhaps the best way toward price discovery.

      • Rob says:

        Corbyn Anti nuclear so new build would be cancelled
        Have you done any articles on the grid busswords I keep hearing from Corbyn and Green Peace

        Smart grids
        Decentralised grids

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