Energy: global supply, insecurity and sustainable energy use

Global energy demand has roughly doubled since 1990 and will rise another ~40 % by 2050 (IEA). The challenge is meeting that demand while cutting CO₂ emissions to net zero — a global energy transition is underway.

Global energy mix (2024)

• Fossil fuels ~78 %: oil ~30 %, coal ~26 %, gas ~22 %.
• Renewables ~14 %: hydro 7 %, wind/solar 5 %, biomass 2 %.
• Nuclear ~4 %.

Fossil fuel share has fallen from 87 % in 1990 — slow progress, but accelerating.

Inequalities in energy consumption

• US household uses ~11 000 kWh/year electricity; rural Bangladesh under 200 kWh.
• 760 million people lack electricity entirely (IEA 2023).
• HIC consumption is plateauing; NEE consumption growing fast (China is now the world's biggest energy consumer, ~26 % of global use).

Factors affecting energy supply

• Physical — fossil fuel reserves (Middle East oil; Australian coal); rivers for HEP (Brazil, China); wind regimes (UK); solar zones (Sahara, US southwest).
• Cost — extraction expense (deep sea oil); high upfront cost of nuclear and renewables.
• Technology — fracking unlocked US shale gas (US now #1 oil and gas producer); offshore wind costs fell 60 % since 2010.
• Politics — Russia-Ukraine war (2022) disrupted European gas supply; OPEC controls oil prices via output quotas.
• Climate change policy — Paris Agreement (2015), national net-zero targets driving the transition.

Energy insecurity — impacts

• Price shocks — UK gas/electricity prices rose 200 %+ in 2022 after Russia's invasion; cost-of-living crisis.
• Industrial costs — energy-intensive manufacturing closes (UK steel, glass).
• Geopolitical conflict — Middle East wars often energy-related; Strait of Hormuz a chokepoint for 20 % of global oil.
• Reduced services — when supply is short, hospitals, schools and businesses suffer (winter blackouts in Pakistan).
• Environmental damage — desperate countries burn more coal/wood, accelerating climate damage.

Sources of energy

Non-renewable

• Coal — most polluting; Indonesia, Australia, China lead production.
• Oil — transport fuel; Saudi Arabia, US, Russia.
• Gas — heating, power; Russia, US, Qatar (LNG).
• Nuclear — low-carbon but waste/safety concerns. France 65 % nuclear; Germany phased out 2023.

Renewable

• Hydro — biggest renewable globally. Three Gorges Dam (22 GW). Issues: displaced 1.3 m people; methane from flooded vegetation.
• Wind — onshore and offshore. UK leads offshore (Hornsea Two, 1.4 GW).
• Solar — PV and concentrated. China dominates manufacturing (80 % of panels).
• Biomass — wood, crops; Drax (UK) converted from coal.
• Geothermal — Iceland gets ~30 % of electricity from geothermal.
• Tidal/wave — small scale; MeyGen Pentland Firth (Scotland).

Energy resource extraction case study — fracking in the USA

Hydraulic fracturing of shale rock (Bakken, Permian, Marcellus formations).

• Successes — US went from net importer to #1 oil and gas producer; cut electricity prices; coal displaced from US power generation; created ~2 m jobs.
• Failures — water consumption (5–20 m L/well); methane leaks (more potent GHG than CO₂); seismicity (Oklahoma earthquakes); contaminated groundwater; hundreds of communities affected.

Sustainable energy use

• Efficiency — insulation, LED lighting, heat pumps. UK heat pumps growing slowly (60 000 in 2022, target 600 000/year by 2028).
• Smart grids — match supply with demand; integrate intermittent renewables.
• Demand management — time-of-use tariffs, smart meters.
• Behavioural — turning down thermostats, using public transport.
• Innovation — green hydrogen (electrolysis from renewable electricity), small modular nuclear reactors.
• Renewables expansion — record 510 GW of renewables added globally in 2023.

Examiner tips

• For 6/9-mark questions, name specific examples — Hornsea (wind), Drax (biomass), Ratcliffe-on-Soar (last UK coal closure 2024), Three Gorges (HEP).
• Always pair advantage with limitation — wind has zero fuel cost but is intermittent; nuclear is low-carbon but produces waste.
• The energy transition is the big-picture story — show awareness of how the mix is changing.