Energy Resources

Classification of energy sources

Non-renewable (finite — will run out)

• Fossil fuels: coal, oil, natural gas. Formed from compressed organic matter over millions of years. Combust to release energy; primary source of global GHG emissions.
• Nuclear: uranium (fissile material) produces heat via fission → steam → turbine. No direct CO₂ emissions during operation; produces radioactive waste.

Renewable (replenished naturally)

• Solar: photovoltaic (PV) panels convert sunlight → electricity; solar thermal heats water. Cost has fallen ~90% since 2010; now often cheaper than new fossil fuel plants.
• Wind: onshore and offshore wind turbines. UK has Europe's largest offshore wind capacity (Hornsea One: 1.2 GW, 174 turbines off Yorkshire).
• Hydro: dams use falling water → turbine. Oldest large-scale renewable; ~16% of global electricity. Impacts on rivers and communities.
• Biomass: burning organic matter (wood, crop waste, biogas). Carbon-neutral if sustainably managed; but air quality issues; land use competition.
• Geothermal: heat from Earth's interior drives steam turbines. Reliable 24/7 baseload. Limited to tectonically active areas (Iceland, Kenya, New Zealand).
• Tidal/Wave: emerging technology; consistent and predictable (unlike wind/solar); high capital cost. Swansea Bay Tidal Lagoon proposal (Wales).

Global energy mix trends

• In 2024, fossil fuels still supply ~80% of global primary energy.
• Renewables growing rapidly but from a low base.
• Natural gas replacing coal in many HICs (lower CO₂ per unit energy).
• China installs more solar and wind than the rest of the world combined; but also builds coal plants for energy security.

Access to energy: the energy gap

Energy security means reliable, affordable, and sufficient access to energy.

Energy poverty: ~760 million people (mostly in sub-Saharan Africa and South Asia) have no electricity access; 2.4 billion rely on traditional biomass (wood, dung, charcoal) for cooking — serious health impacts from indoor air pollution.

Factors affecting energy access

Energy security risk: countries that depend heavily on energy imports are vulnerable to price shocks and geopolitical leverage (e.g. Europe's dependence on Russian gas → 2022 energy crisis following invasion of Ukraine).

Impacts of energy production

Fossil fuel extraction

• Conventional oil/gas: platform leaks, pipeline spills (e.g. Niger Delta pollution — 40 years of Shell operations linked to chronic oil spills, impacting fishing communities; 5,000 oil spills since 1976).
• Coal mining: surface (opencast) and underground. Landscape destruction; acid mine drainage; methane release.

Unconventional fossil fuels (higher environmental impact)

• Oil sands / tar sands (Alberta, Canada): bitumen extracted from sand using hot water → very high energy and water input; tailings ponds of toxic waste; forest clearing.
• Hydraulic fracturing (fracking) for shale gas: high-pressure fluid injected to fracture shale rock → gas released. Issues: potential groundwater contamination; surface water use (millions of litres per well); seismic activity (induced earthquakes at Blackpool, 2018 → UK imposed moratorium); methane leaks during extraction.
• Deep-water oil drilling (Gulf of Mexico Deepwater Horizon, 2010 — 4.9 million barrels spilled; Macondo well blowout). Environmental damage to Gulf Coast for years; 11 workers killed.

Renewable energy impacts

Even renewables have environmental impacts:

• Wind turbines: bird and bat mortality; visual impact; noise; rare earth metals in generators (mining in China/Congo).
• Solar farms: land use; manufacturing of panels (silicon, cadmium); end-of-life disposal of panels.
• Hydro dams: flooding of valleys and ecosystems; fish migration blocked; sedimentation; community displacement (Three Gorges Dam, China: 1.2 million displaced).
• Biofuels: compete with food crops for land; can drive deforestation (palm oil biodiesel).

Towards a sustainable energy future

Efficiency and demand reduction

• Building insulation: UK homes are among Europe's least efficient; retrofitting could reduce heating energy use by 50%.
• LED lighting: 75% more efficient than incandescent bulbs.
• Smart grids: match supply and demand in real time; reduce waste.

Low-carbon technology

• Carbon capture and storage (CCS): captures CO₂ from power stations / industrial processes → stores underground in geological formations. Currently expensive (~£100/tonne CO₂). Sleipner field (Norway) is an example.
• Hydrogen (green): produced by electrolysis of water using renewable electricity → CO₂-free fuel for industry, heating, transport. Currently expensive; infrastructure lacking.
• Electric vehicles: shift transport emissions from exhaust to power plant (decarbonised if grid is clean).
• Nuclear (new generation): small modular reactors (SMRs) proposed as flexible, low-carbon baseload. Hinkley Point C (Somerset) — new large nuclear plant under construction (delayed, over budget: £35 bn+).

Meeting future demand sustainably

• Global energy demand will increase as populations grow and living standards rise.
• Decarbonisation requires: rapid scaling of solar/wind, electrification of heat and transport, demand reduction, smart grids, and some baseload (nuclear or CCS gas).
• Just Transition: must ensure LIDCs are not locked out of development by being denied fossil fuels before renewables are affordable — international climate finance (Green Climate Fund: $100 bn/year target) is key.

Edexcel B exam tip

Energy questions often use maps of global energy mix or case studies of unconventional fossil fuel extraction. "Assess the extent to which renewable energy can meet future global demand" (8 marks, L1–L3): argue for (falling costs, rapid expansion, UK's net-zero pathway) → argue against (intermittency, grid storage, energy poverty in LIDCs, scale of current fossil fuel dependency) → balanced conclusion.