It is often asserted that Weather Dependent Renewables are now competitive, without subsidies, with traditional electricity generation technologies. The massive UK Renewables installations, (33.7 GW), might surpass conventional generation on rare moments with a combination of appropriate weather and demand conditions.
But in its announcements the Renewables industry conveniently forgets the capacity / load factor differences with traditional generation mean that overall Renewables only produce about 1/10 – 1/4 of their stated Name Plate output values.
Capacity factors calculate the actual power output of a generation technology divided by the nameplate value of the installation, thus assessing its generating efficacy.
The UK in 2017 had Renewable Energy installations:
- Solar Power nameplate 12.7 GW: capacity 9.6%: producing 1.22 GW
- Wind Power nameplate 19.0 GW: capacity 19.6%: producing 3.72 GW
- Biomass Drax nameplate 2.04 GW: capacity 82.1% dispatchable: producing 1.67 GW
- Total Renewables nameplate 33.7 GW: combined capacity 19.8%: producing 6.67 GW contribution to the grid overall in 2017.
Because of both these poor capacity factors and their unreliability, the business case for Weather Dependent Renewables is not viable without the massive subsidy support. This means that those essential additional costs are charged to electric power consumers and advantageous business environments for Renewables are imposed by Government mandates.
Overall Weather Dependent Renewable technologies in Wind and Solar PV in combination are about 8-9 times more costly in overnight capital costs and about 10 times more costly in terms of long-term running costs than using Gas-firing for generation, even when including the cost of fuel.
Certainly Onshore wind power is the least costly Renewable technology. But in spite of its higher performance capacity percentage ~30+% Offshore Wind Power is probably the most costly overall. Even when the significant reduction of the manufacturing costs of the solar panels themselves is taken into account Solar PV is still very expensive in comparison to Onshore Wind power and even Nuclear power, when compared long-term.
These analyses do not take account of the intrinsic
of output from Weather Dependent Renewables which make the power they produce much less useful and much more expensive to utilise.
Their poor cost performance is compounded by the further major disadvantage that Weather Dependent Renewables are unpredictably unrelated and unrelatable to demand. In adverse environments, particularly Offshore, Renewables often fail well before their anticipated service life.
In 2017 the UK was responsible for only 1.2% of Global CO2 emissions.
Any useful impact that that UK can have by controlling its own CO2 emissions to limit Man-made temperature rise can therefore only ever be marginal to non-existent in effect. This is especially so in the context where all other developing and developed Nations, (except the USA), are increasing their use of Coal and other fossil fuels and thus continue to increase their output of CO2 substantially, thus totally failing to respect to the Paris Climate Accord.
This post examines the performance of all types of UK electrical Generation systems over a period from 1 January 2017 to 31 August 2018. It relies on the data provided by Gridwatch templar:
The Gridwatch data is provided at 5 minute intervals for each generation type. This data (172,800 entries) for the 20 months has been condensed to some 14500 hourly values and reorganised as the following generation classes:
- interconnect: net cumulation from French, Dutch and Irish inter-connectors
- gas-fired ccgt
- pumped+hydro: the combination of hydroelectric and pumped storage generation
- biomass: primarily generation from the DRAX generators now converted to burn wood pellets shipped from the USA
- wind: onshore and offshore combined
- solar PV: on grid Solar energy
Cost data used is from the US Energy Information Administration who publish comparable costings for different electricity generation technologies:
The pie charts above give the proportional contribution of different generation technologies to the UK grid for the 20 month 2017 – 2018-8 period. The second chart shows the actual generating installation where Renewables amount to ~35 Gigawatts or ~56% of the total generation installation: were those generators fully productive 35 GW would exceed UK demand on many occasions.
The chart shows the name plate value of the Renewable installations but it does not assess the usefulness of those contributions are in terms of the timing and variability of their power output.
There is no economic, large scale mechanism so far, (save a minimal amount of UK pumped storage), for storing power when power it not useable and thus it is wasted. The fact is that solar power peaks at midday and is non-existent at night and that Wind power can be becalmed at any time on a unpredictable basis means that contributions of these Weather Dependent Renewables are much less valuable to the grid than base load power from Nuclear or Coal-fired sources and the variable power from Gas-firing is intrinsically more useful to support the consistency of the Grid.
Unlike other Western nations, the UK has made legally binding commitments to decarbonisation as a result of the 2008 Climate Change Act. This Act gives the UK much less flexibility to react to the coming failure of its electricity grid, caused by the replacement of reliable base load power from Coal-firing and Nuclear with the installation of an increasing proportion of unreliable, non-dispatchable, intermittent Weather Dependent Renewables.
The following sections and graphics dissect the output of various technologies based on hourly information for 2017 and 8 months of 2018. These results apply to the whole of the UK and include the output from Offshore wind farms. Even so on occasions the universal absence of wind production for considerable periods, (26 consecutive days in the summer of 2018), gives the lie to the idea that the wind is always blowing somewhere.
Technologies Generating CO2 emissions
The use of Weather Dependent Renewables is predicated on the assumption that extra Man-made CO2 is the sole control knob on global temperature and climate, and that trying to reduce man-made CO2 emissions is worthwhile.
But from a current value of ~400 ppmv only 13% of the effectiveness of CO2 as a Greenhouse gas remains.
The current value of 400 ppmv is only twice the value at which photosynthesis stops and the world as a whole dies. Any extra atmospheric CO2 can only be a benefit to the biosphere and thus man-kind. About 1200 ppmv is value used by horticulturalists to artificially enhance greenhouse plant productivity, any value below that is in effect limiting plant life and diminishing plant productivity. Any marginal amount of warming that may result from the extra atmospheric CO2 can only be beneficial to the planet by providing more access to viable farmland. To quote Will Happer:
CO2 is not a pollutant, but a benefit to the world and will remain so until current low CO2 levels are restored to something closer to the norms of geological history, the optimum levels for most plants. That is three or four times more the current levels. It will take many centuries to reach such levels, even if enough resources of fossil fuels can be found.
However it seems more likely that the long-term climate context is now one of global cooling as we move towards the end of our current benign Holocene interglacial period. For the last three millennia each one has been progressively colder since 1000BC.
So regarding any extra CO2 as a control knob on temperature and as a pollutant is particularly fatuous.
It should also be noted here that the promotion of Biomass as being beneficial, which when burnt produces about 4 times the amount of CO2 than Fracked Gas simultaneously negates all the potential CO2 emissions savings possibly achievable by the use of Weather Dependent Renewables.
The largest contribution to electricity generation in the UK is from Gas-firing, about 42% over the 20 month period. This Gas is largely imported and thus costly to the balance of payments. As and when Fracking is permitted and productive in the UK that Gas should be fully supplied from indigenous sources. Fracking has been opposed by the UK Green movement and they delayed its beneficial introduction on a wide scale. The use of dispatchable Gas-fired electricity is essential to provide consistent end user supply in the context the preferred use, (by Government policy), of intermittent and variable Weather Dependent Renewables.
The fact that the use of Gas-firing produces a minimum amount of CO2 emissions has been well proven in the USA, where the use of Fracked gas for electricity generation has substantially reduced the total CO2 output by replacing coal for generation. More CO2 emissions reduction has been achieved in the USA than by all the other Green induced policies elsewhere world-wide. This has amounted to about 1.4 billion tonnes of CO2 reduction over the past 10 years or a reduction of about 4.5 tonnes/head Nation wide. Whereas by 2017, CO2 emissions were increasing worldwide.
The electrical generation from “biomass” in the UK about 5% of total electrical supply is primarily the output of the Drax power site. With very substantial subsidies and because the EU / UK Governments erroneously regards Biomass burning as “Renewable”, this major UK power generation site has been converted and is subsidised to burn wood pellets. These are imported, at a cost to the UK balance of payments, from the East coast of the USA, where clear felling of virgin forest, with resulting natural habitat loss, is continuing apace to meet this demand. The combined processes of felling, pelletisation, sea transport, and wood burning immediately releases substantially more CO2 per unit of power generated than even the burning of Coal at Drax. On the other hand the recovery of the American forests will take at least a century.
As Drax itself is by design located on very large existing Coal reserves, the burning of wood pellets, transported from across the Atlantic, would seem to be a fatuous mechanism to control climate change, as it produces substantially more CO2.
Using Biomass is less efficient than coal and releases about 4 times as much CO2 as burning Fracked gas. This adverse ratio does not include the additional CO2 costs of sea transport from the USA to Drax.
The following graphic gives an idea of the comparative costs in terms of CO2 emissions of using Biomass as fuel at Drax as opposed to Gas-firing or locally sourced Coal.
Coal – firing
In spite of Government policy for their closure, some Coal-fired power stations are still open in the UK and provided more than 6% of UK power over this 20 month period. This power is dispatchable and its base load can compensate for the intermittency and unreliability of Weather Dependent Renewables, even though its control is less agile than Gas-firing. Coal firing over this period has been mostly used to supplement generation in winter periods.
In total Renewable installations amount to a name plate generating capacity of close to the average UK demand of ~35,000 Megawatts, but in fact because of their limited capacity its combined output is only equivalent to 6,670 Megawatts.
The combined production of “Renewables” is shown above. Although the installed Renewables may in rare unique weather conditions almost meet UK demand, (which is much celebrated by the Renewables industry), the combined picture over these past 20 months is shown below.
The UK in 2017 had Renewable Energy installations:
- Solar Power nameplate 12.7 GW: capacity 9.6%
- Wind Power nameplate 19.0 GW: capacity 19.6%
- Biomass Drax nameplate 2.04 GW: capacity 82.1% dispatchable: output 1.67GW
- Total Renewables nameplate 33.7 GW: combined capacity 19.8%: output 6.67GW
Unsurprisingly Solar shows substantially greater performance in summertime and particularly in the output during the recent summer of 2018. Summertime is the period with the lowest demand for power.
However overall Solar energy has a capacity factor for the period of 9.96%: that means an actual output equivalent to 1,270 Megawatts as opposed to the Solar installed name plate value of 12,760 Megawatts. Unfortunately Solar energy is not produced when it is needed: it is virtually absent in winter months and it always peaks at whatever level at midday, but demand is highest in the evenings, especially winter evenings.
The contrast between winter and summer output from Weather Dependent Renewables is shown below. There are periods of low Wind power output in both Winter and Summer.
The chart below shows the profile of supply from Weather Dependent Renewables in July 2018. The variability of Wind power is clear and there is a period that July of some 25 days when Wind Power was meeting demand in the range from 10% to 0% from its total installed configuration of 19,000 Megawatts.
The extended fine weather of last summer 2018 showed a very substantial periods of wind drought in the June and July.
There was rather more wind output in the summer of 2017 but even so it was quite variable for that period as well.
Wind power, even including the more productive Offshore wind farms, is inevitably variable according to the weather. Wind power is certainly it is more productive in the winter months but anti-cyclonic conditions can arise with low wind output widely across the whole UK in Winter as well.
The problem for the grid posed by Solar PV power is also well illustrated above. There are massive load changes throughout the day from 25% of demand to nil at night. At the end of the month the diagram also shows how susceptible Solar Energy is to adverse weather, its peak output dropping by 2/3 on a cloudy day.
The combined UK Wind energy, (Onshore and Offshore), had a capacity factor for this 20 month period of 19.57%: that means an actual output equivalent to 3,718 Megawatts overall as opposed to the Wind power from an installed name plate value of 19,000 Megawatts. Unfortunately Wind energy is randomly intermittent and it is not necessarily produced when it is needed. Therefore the wind energy output cannot be dispatched to meet demand: as it is uncontrollable it is intrinsically less useful and thus less valuable: on occasions the production stands a high likelihood of being wasted. In the 2 month period shown above wind power capacity was less than half the overall average
Also included under Renewables are combined Hydro and Pumped storage and Biomass, (see earlier).
Hydro electricity and pumped storage
The topography off the UK means that very little Hydro electricity generation is possible except in restricted parts of Scotland and Wales. The few pumped storage schemes can make a very limited contribution to balancing out the variable output of the installed base of “Renewable” installations. Hydro electricity is dispatchable but overall only accounted for ~2% of production. Production is also inevitably limited in drier summer months.
Nuclear Energy and Interconnections
Indigenous Nuclear energy (~10,000 Megawatts) still supplies almost a quarter of all the power in the UK. As these plants are reaching the end of their service lives, their replacement for base load provision is progressively becoming more essential to avoid grid failure. But the idea that they could be replaced with unreliable Renewables is illogical.
The French interconnector has a capacity of 2,000 Megawatts and the Dutch interconnector has a capacity of 1,000 Megawatts. On many occasions throughout this 20 month period these have both been fully employed.
Interconnectors from France and the Netherlands even in the low demand summer season are still providing a very substantial proportion of UK base load power, (~6% in the 20 month period considered). This power contribution is mainly from French Nuclear generation.
This implies that about 1/3 of total UK power is presently provided by Nuclear energy, either locally or from the continent.
It should not be assumed that power imports are inevitably available, they are not necessarily guaranteed. French government policy has been to reduce its Nuclear generation by about 1/3 to 50% of French generation, however the Green oriented minister in the Macron government has recently resigned, because he has failed to get the idea of reducing Nuclear power accepted. Nonetheless if France requires that remaining power to service its domestic needs, its power will not be available for export. As it seems to be Government policy to impede further development this crucial Nuclear base load power source, the UK is facing a substantial future supply crisis in power generation.
Interconnectors are vulnerable. In late 2016 the French interconnector was damaged by a dragged anchor in a storm. This reduced its capacity by half to 1,000 Megawatts and lead to a drop of UK electricity operating margin to as low as 1%. Full service was not resumed for about 4 months. In winter the low operating margin that resulted amounted to an existential emergency for the UK power grid for that period.
The UK also exports some power, this is mainly to support the Irish grid which has a heavy commitment to Weather Dependent Renewables.
The US Energy Information Administration publish comparable costings for different electricity generation technologies:
The EIA values have been translated and condensed into the following table giving consistent comparative values in terms of $:€billion/Gigawatt.
This table uses the following assumptions:
- capital costs are assessed as the EIA overnight capital cost standard for newly installed generation technologies
- the long-term costs are assessed over 60 years, the approximate service life of a nuclear generator
- the Euro and US$ have approximately the same purchasing power
- the long-term costs are dependent on the the achievable service-life of different generator types and therefore full cost of replacement over the 60 years
- published EIA costs are assumed for variable costs including fuel and ongoing fixed maintenance costs
- the actual cost per Gigawatt generated and supplied to the grid is dependent on the capacity factors achieved, with non dispatchable technologies ie Weather Dependent Renewables these are low compared to conventional generation technologies. The outcome is that the true costs / Gigawatt supplied to the grid by Renewables can be extraordinarily high
- these values do not reflect any of the difficulties arising from using Weather Dependent Renewables to provide a consistent power supply of their:
The following diagram gives an indication in percentage terms of the effects of capacity and capital and long-term costings.
- Weather Dependent Renewables produce about 25% contribution to the grid but even at current, 2017, installation levels involve 55% of the installation and capital costs and require more like 65% of the long-term costs
- for Solar energy to produce 3.9% of the power mix requires some 20% + of the installation and would be responsible for 20% of the long-term costs
- for Offshore wind to produce 6.0% of the power generation mix requires some 10%+ of the installation and would be responsible for 25%+ of the capital and long-term costs
- for Onshore wind to produce 9.6% of the power generation mix requires some 20%+ of the installation and would be responsible for 14.5% of the long-term costs
- Gas-fired CCGT to produce 40%+ of the power generation mix requires some 24% + of the installation and would only be responsible for 10% of the long-term costs
- UK Nuclear to produce 21%+ of the power generation mix requires some 13% + of the installation costs and would be responsible for 18% of the long-term costs
The following diagram puts actual values to the same chart:
- installed Renewables in total amount to a Name plate value of ~35 Gigawatts or ~56% of UK generation. 35 gigawatts exceeds total UK demand on many occasions.
- the UK electrical grid would be more stable and cheaper too run without the “Renewables Obligation” that, by policy, ensures that Renewable energy has to be used whenever it may be available.
- using Gas-fried power at full capacity is more cost effective and produces less CO2 emissions than insisting that it works intermittently load following Renewables and in spinning reserve to be instantly available whenever needed.
- Wind power and Solar PV power are not carbon neutral, (they require more CO2 emitted for their manufacture and installation than they can ever save during their service life)
- likewise the EROI, (Energy Return on Energy invested), of Wind power and Solar PV power is less than neutral. They are thus entirely dependent on fossil fuels based energy for their very existence.
- the UK use of Biomass is costly for the balance of payments and in subsidies. It produces substantially more CO2 that either Coal-firing with locally sourced coal or Gas-firing, which with the success of Fracking will be eventually be supplied indigenously in the UK.
- because of the dilute nature of the energy captured, the use of biofuels, unless exclusively derived from real waste materials, is both costly and damaging to the environment, for other examples beyond clear felling native forest in the USA:
- the use of 40% of the USA corn crop to create bioethanol
- the clearance of tropical forests to grow palm oil.
- the UK dependence on European interconnectors can pose an existential risk to the UK power grid as well as a burden on the balance of payments.
- because of their low capacity factors and unreliability, the use of Weather Dependent Renewables are a substantially more costly forms of electrical generation than using conventional fossil fuels particularly Gas or even Nuclear energy in the long run.
- overall the late Professor David Mackay said it all: ie that by ignoring simple arithmetic, the use of Renewable energy to try to power a developed country is an
“there is no point in having wind power or solar power in the UK”