National and global energy resources

The UK and the world use a mix of energy resources to generate electricity and provide heat and transport. Each has advantages and drawbacks: cost, reliability, carbon emissions, geographical limits.

Renewable vs non-renewable

• Non-renewable — finite supply, will run out: coal, oil, natural gas, nuclear (uranium is mined and finite).
• Renewable — replenished naturally faster than humans use it: wind, hydroelectric, geothermal, tidal, solar, water waves, biofuels.

Renewable resources — pros and cons

Resource	How it works	Pros	Cons
Wind	Wind turns turbine blades; generator → electricity	No CO₂, free fuel	Intermittent; visual / noise impact
Hydroelectric	Falling water drives turbine	Predictable, large scale	Floods valleys, methane from reservoirs
Geothermal	Hot rocks heat water → steam → turbine	Constant output	Limited to volcanic areas
Tidal	Tides drive turbines in estuary barrage	Highly predictable	Disrupts ecosystems; few sites
Solar	PV cells turn light → electricity directly	No moving parts; falling cost	Intermittent (no night/cloudy)
Wave	Bobbing floats drive generators	Renewable, especially round UK	Difficult engineering, immature
Biofuel	Crops/wood burned for heat	Carbon-neutral over crop cycle	Land use vs food crops

Non-renewable resources — pros and cons

Resource	How it works	Pros	Cons
Coal	Burned to heat water → steam → turbine	High energy density, available globally	High CO₂ + SO₂ + soot; finite
Oil	Refined into petrol/diesel for transport; some power	Highly energy-dense, transportable	High CO₂; political dependence; finite
Natural gas	Cleanest fossil fuel; burns to drive turbine	Lower CO₂ than coal; flexible	Methane leaks (potent GHG); finite
Nuclear	Uranium fission heats water → steam	Low CO₂, very reliable	Radioactive waste; high build cost; risk of accident

Reliability

Reliable means available on demand. Coal, gas, nuclear and biomass are reliable; wind, solar, wave depend on weather. Hydro is reliable while reservoirs are full; tidal is reliable but cyclical (predictable but not constant).

This affects how the National Grid is planned: a "base load" of constantly running plants (nuclear, biomass) plus flexible plants (gas, hydro) that ramp up and down to meet demand.

Environmental impact

• Climate change — fossil fuels release CO₂ that traps heat; the main driver of global warming.
• Air pollution — coal also releases SO₂ (acid rain), particulates (lung disease).
• Habitat loss — hydroelectric reservoirs flood valleys; wind farms can affect bird/bat populations.
• Radioactive waste — nuclear waste needs storage for thousands of years.

Trends

The UK has rapidly shifted from coal to gas + renewables since 2000. By 2024 over 40% of UK electricity came from renewables (wind being dominant). Globally coal still leads in many regions. Solar and wind costs have fallen so quickly that they're now often cheaper per kWh than fossil fuels.

Energy in transport

Most transport still uses oil-based petrol/diesel. Electric vehicles transfer energy from the National Grid; how green they are depends on the grid mix at the time of charging. Hydrogen fuel cells are an alternative being developed.

Why politicians argue about energy

Decisions involve trade-offs between:

• Cost — capital vs running costs.
• Reliability — base load vs intermittent.
• Climate — CO₂ emissions per kWh.
• Local impact — visual, noise, habitat.
• Energy security — domestic vs imported fuels.

Examiners reward students who can compare two resources by referring to several of these trade-offs, not just "wind is good because no CO₂".