National and Global Energy Resources

Non-renewable energy resources will eventually run out — they are formed much more slowly than we use them.

Non-renewable	Source	Carbon emissions	UK use
Coal	Buried plants over millions of years	Very high	Phased out for electricity 2024
Oil	Buried plankton	High	Mostly transport (petrol, diesel)
Natural gas	Buried plankton + coal beds	Medium-high	~33 % of UK electricity; heating in most homes
Nuclear (uranium)	Mined ore	Very low (in use)	~14 % of UK electricity

Renewable resources are replenished on human timescales:

Renewable	Source	Carbon	UK use
Wind	Pressure differences from Sun's heating	Near-zero	~28 % of UK electricity (onshore + offshore)
Solar	Direct sunlight (PV)	Near-zero	~5 %; growing fast
Hydroelectric	Falling water in dams	Near-zero	~2 %; limited UK sites
Tidal	Moon's gravity → tides	Near-zero	Trial-scale only in UK
Wave	Wind acting on sea surface	Near-zero	Trial-scale
Geothermal	Heat from Earth's core	Near-zero	Trial in Cornwall; major in Iceland/NZ
Biofuel/Biomass	Recently grown plants/wood	Near-zero IF replanted; otherwise high	~6 % (Drax wood-pellet station)

Nuclear edge case. Uranium is mined (and will run out), so technically non-renewable. But it produces very little CO₂ in use, so it's often grouped with low-carbon energy. AQA mark schemes will accept either classification if you justify it.

Exam questions ask you to compare resources using these criteria:

1. Cost — build cost vs running cost vs decommissioning cost.

• Wind & solar: high build, very low running.
• Gas: medium build, high running (fuel + carbon).
• Nuclear: very high build (£20+ billion for Hinkley Point C), very high decommissioning, medium running.

2. Reliability — does it produce power 24/7?

• Fossil & nuclear: high (can be turned on/off as needed = 'dispatchable').
• Wind: variable; depends on weather.
• Solar: variable; nighttime gives zero output.
• Hydro: reliable but reservoir capacity matters.
• Tidal: predictable (Moon-driven).

3. Environmental impact — beyond carbon.

• Coal: CO₂, sulfur dioxide (acid rain), mining damage.
• Gas: CO₂ (less than coal), methane leaks.
• Nuclear: high-level radioactive waste storage for thousands of years.
• Wind: turbine landscape impact, bird strikes (small).
• Solar: large land use for solar farms; manufacturing impact.
• Hydro: dam floods ecosystems and displaces communities.
• Biomass: CO₂ if not replanted; air-quality concerns.

4. Energy security — does the UK control the supply?

• Wind & solar: domestic resource = high security.
• Gas: imported from Norway, USA, Qatar — vulnerable to politics (e.g. post-Ukraine prices).
• Nuclear fuel: imported uranium, but stockpiles last years.
• Hydro: domestic but capacity limited.

UK trends 2010–2024:

• Coal: 30 % → 0 % (closed Ratcliffe-on-Soar Sept 2024 — last UK coal station).
• Gas: 45 % → 33 %.
• Wind: 3 % → 28 %.
• Solar: 0 % → 5 %.
• Nuclear: 15 % → 14 % (slight decline; aged fleet).

Drivers: the 2008 Climate Change Act (UK), 2050 net-zero target, falling solar/wind costs (~70 % cheaper than 2010), carbon pricing (UK ETS).

Global trends (IEA 2024):

• Coal still ~35 % of global electricity (China, India).
• Gas ~22 %.
• Hydro ~15 %.
• Wind + solar combined: ~13 % and rising rapidly.
• Nuclear: ~10 %.

Big tensions for exam essays:

• Climate: must move off fossil fuels rapidly.
• Cost: renewables now cheapest at point of generation, but storage and grid upgrades are expensive.
• Reliability: need backup for windless / cloudy days — batteries, pumped-storage hydro, gas peakers.
• Energy security: domestic renewables reduce dependence on imported fossil fuels.
• Land use & ecology: large-scale solar/wind has visual and ecological impacts.

A top-grade evaluative answer will list 3–4 points on each side and reach a clear judgement (e.g. 'renewables are preferable overall because…').