Powering the Future

No best source, only a best mix

Ask which energy source a country should use and you have asked the wrong question. Every strategy trades four things against each other, and nothing wins on all four. How much it produces: Hinkley Point C will generate 3.2 GW, roughly 7 per cent of UK electricity, where a village gasifier in Bihar produces a few tens of kilowatts. When it produces it: a gas station can be switched on within minutes, a wind farm produces when the wind blows, and a nuclear station runs steadily and cannot easily be turned down. What it costs: renewables are expensive to build and nearly free to run, while gas is cheaper to build and its fuel bill never ends, and the Hinkley estimate rose from around 18 billion pounds in 2016 to over 30 billion. Who carries the side effects: emissions fall on everybody and eventually, while noise, traffic, land take and tremors fall on the people living nearest and immediately. Those four pull against each other, which is why every country runs a mix rather than picking a winner. The UK is a clear case: coal supplied about 40 per cent of electricity in 2012 and under 2 per cent by 2020, the last coal-fired station closed on 30 September 2024, and renewables reached about 43 per cent of electricity in 2020. No single decision did that. A mix shifted. So an answer that argues for one favourite source has misunderstood the question. The marks are in the weighing.

Six terms, and the last two are the cheapest energy there is

The third is the one candidates most often miss, and it explains why a country cannot simply build more wind farms and stop.

One site, eight years

These six stages trace the Lancashire fracking story from proposal to moratorium. Put them in order.

• A national survey in 2013 estimates 1,300 trillion cubic feet of gas in place in the shale beneath the region
• The county council refuses planning permission in June 2015 on grounds of noise and traffic
• The refusal is overturned on appeal by the Secretary of State in October 2016
• Fracking begins at the site in October 2018, with operations to halt if any tremor reaches magnitude 0.5
• A tremor of magnitude 2.9 is recorded on 26 August 2019, far above the pause threshold
• A moratorium on fracking across England follows on 2 November 2019

Why does a country run a mix?

Wind is cheap to run and produces no emissions. Which reasoning best explains why a country does not simply build wind farms and stop there?

• Because output is only one of four things a source is judged on, and the others pull the other way. Wind generates when the wind blows rather than when demand peaks, so it has to be paired with storage, interconnectors or something switchable; a grid also needs a steady minimum supply and a way of meeting sudden peaks. The mix exists because no single source covers all four requirements at once.
• Because there is not enough wind in most countries to meet demand.
• Because wind turbines are too expensive to build in large numbers.
• Because wind power is unreliable and often fails without warning.

Three routes, each with a price

The specification asks for advantages and disadvantages, so learn them in pairs rather than as two separate lists. Every entry below carries its own cost in the same breath.

Match each fact to what it shows

Weigh the example, do not judge the fuel

The content map singles this out, and it is the difference between a middling answer and a strong one. A question about extracting a fossil fuel is not an invitation to write that fossil fuels are bad. It asks you to weigh one named example on both sides, and the marks are in the specifics. Take Lancashire. The case in favour was real: a national survey in 2013 put 1,300 trillion cubic feet of gas in place in the shale beneath the region, and gas produced at home is gas not imported, with jobs and tax revenue attached. The case against was also specific, and this is the part candidates rarely reach. Operations stopped because of a measurement, not a mood: work had to pause at any tremor of magnitude 0.5, a tremor of 2.9 was recorded on 26 August 2019, and a moratorium across England followed on 2 November 2019, lifted briefly in September 2022 and reimposed the following month. Notice also what the 2013 figure does not say, since gas in place is not gas that can be got out, and no recoverable estimate accompanied it. Write it that way and you are evaluating. Write "fracking causes earthquakes and pollution" and you have given an opinion that would fit any site in any country, which earns what any unanchored claim earns. One more habit. Do not rank schemes by size. A 1.3 GW wind farm and a village gasifier are both good answers to different questions, and the right test is what problem each was built to solve.

Complete the energy strategy figures

Coal produced about 40 per cent of the electricity in the UK in 2012 and under _____ per cent by 2020, while renewables reached roughly _____ per cent in that year. The nuclear station under construction at Hinkley Point is designed for _____ GW, around 7 per cent of national supply, at an estimate that climbed past 30 billion pounds. In Lancashire the operator had to stop work if tremors reached magnitude _____, and the England-wide moratorium followed one far bigger than that in _____. Carbon dioxide has meanwhile been stored under the Norwegian North Sea at about a million tonnes a year since 1996.

Spot the three sound energy statements

Select the THREE statements that could stand as they are in an answer.

• A grid needs a steady minimum supply and a way of meeting sudden peaks as well as cheap output, so sources are combined rather than ranked, and no single one meets every requirement.
• Extraction in Lancashire ended after a tremor of magnitude 2.9 against a threshold requiring work to pause at 0.5, which is a measured limit rather than a general objection.
• A village scheme of a few tens of kilowatts and an offshore wind farm of more than a gigawatt are both effective, since the right scale is set by the problem being solved.
• Fossil fuel extraction should be opposed because fossil fuels damage the environment.
• Since wind power is cheap to run and produces no emissions, a country could meet all its needs from wind alone.
• The 2013 estimate of gas in the shale shows how much fuel the region could have supplied.

A 9-mark evaluation, marked

Using a named example, evaluate the advantages and disadvantages of extracting a fossil fuel. [9 marks] The example is shale gas extraction in Lancashire. The case for it was economic and was not trivial. A British Geological Survey estimate in 2013 put 1,300 trillion cubic feet of gas in place in the Bowland Shale beneath northern England, and gas produced domestically is gas that does not have to be imported, which matters for both the trade balance and security of supply. Extraction would have brought construction and operating jobs to an area that wanted them, together with tax revenue, and gas burns with roughly half the carbon dioxide of coal, so as a replacement for coal rather than for renewables it has a defensible role during a transition. The disadvantages proved decisive, and the reason is worth stating precisely. Operations ran under a traffic-light system requiring work to stop at any tremor of magnitude 0.5, a deliberately cautious limit well below what a person would notice. After fracking began at Preston New Road in October 2018 a tremor of magnitude 2.9 was recorded on 26 August 2019, several times that threshold, and a moratorium across England followed on 2 November 2019. It was lifted briefly in September 2022 and reimposed the next month. There were local costs throughout as well, in heavy traffic, noise and water use, and those fell on the immediate area while any benefit from cheaper gas would have been spread across the country. My judgement is that the resource is real and the extraction was not viable in this location on these terms. The 2013 figure describes gas in place rather than gas that can be recovered, and no recoverable estimate accompanied it, so the economic case was always less certain than the headline suggested. Set against a measured limit that was exceeded by a wide margin in a densely settled county, the balance fell against the scheme. That is a conclusion about this site and this rule rather than about fossil fuels in general, and a different geology in a less populated place could reasonably come out the other way. What earned the marks: a named example with dates and figures on both sides; the objection given as a measurement rather than as a feeling; the difference between gas in place and gas recoverable used as part of the argument; who gains and who bears the cost identified separately; and a judgement limited to the case in question instead of generalised to a whole fuel.

Find the two that would cost marks

Five sentences from answers about energy strategies. Two would lose credit for how they argue rather than for being factually wrong. Tap those TWO.

• This scheme should not go ahead because fossil fuels are harmful and we should be using renewables instead.
• Work had to stop at magnitude 0.5 and a tremor of 2.9 was recorded, so the scheme breached a limit it had accepted.
• The village scheme is far less impressive than the offshore wind farm because it generates only a fraction of the power.
• Wind is cheap to run but its output arrives with the weather, so it has to be paired with storage or switchable capacity.
• The benefits of cheaper gas would be spread nationally while the traffic and noise fell on one district.

Build the evaluation sentence

Assemble a sentence that judges a named scheme rather than a fuel.

Four energy decisions

Each situation is a real choice. Follow the four tests rather than an instinct about the fuel.

• Villages in a rural Indian state are off the grid, most households have no electricity, and the nearest transmission line is many kilometres away. Rice milling leaves large quantities of husk.
• An extraction site operating under a rule requiring work to pause at magnitude 0.5 records a tremor of 2.9.
• A country with a large wind fleet faces a still, cold evening when demand is at its highest.
• A government has money for one programme and wants the largest cut in emissions per pound spent.

Evaluate a strategy

Using named examples, evaluate the strategies available for increasing energy supply. [9 marks]

• Four tests: output, timing, cost and who carries the side effects
• Named examples with a figure and date each: an output, cost or threshold
• Advantages and costs together, not listed apart
• The fossil fuel objection as a threshold that was breached, not a view about the fuel
• Using less is itself a supply strategy