Energy Management: Supply and Demand
Global Energy Supply and Demand
Energy is essential for economic development and quality of life. Global energy consumption has increased by over 50% since 2000, and demand continues to rise.
Energy Surplus and Deficit
- Energy surplus — countries that produce more energy than they consume (e.g. Saudi Arabia, Russia, Norway, Canada, Qatar)
- Energy deficit — countries that consume more than they produce and must import (e.g. Japan, South Korea, India, many European countries)
Why Energy Demand is Increasing
- Population growth — more people need more energy for cooking, heating, lighting, transport
- Economic development — industrialisation requires enormous energy inputs; China's energy use increased ~5 times between 1990 and 2020
- Rising living standards — more appliances, cars, air conditioning, electronic devices
- Technology — data centres, the internet, AI, and cryptocurrency mining consume growing amounts of electricity
Uneven Access
- The richest 20% of the world's population consumes roughly 60% of global energy
- In sub-Saharan Africa, over 600 million people lack access to electricity
- A person in the USA consumes approximately 12 times more energy than a person in sub-Saharan Africa
Impacts of Energy Insecurity
| Impact | Details |
|---|---|
| Economic | Countries reliant on energy imports are vulnerable to price spikes; energy poverty limits industrial development |
| Environmental | Exploitation of fossil fuels causes pollution, habitat destruction, and climate change; pressure to develop any available resource (e.g. Arctic drilling, fracking, tar sands) |
| Food production | Modern agriculture depends on energy for irrigation, machinery, fertilisers, and food transport |
| Conflict | Competition for energy resources causes geopolitical tension (e.g. disputes in the South China Sea; Russia-Ukraine gas conflicts; Middle East instability) |
| Health | ~3.2 million people die annually from indoor air pollution caused by burning biomass (wood, dung, charcoal) for cooking — mainly in LICs |
Non-Renewable Energy Sources
Fossil Fuels
| Source | Advantages | Disadvantages |
|---|---|---|
| Coal | Abundant reserves; cheap to extract; reliable baseload power | Highest CO₂ emissions per unit of energy; air pollution (SO₂, particulates); mining damages landscapes |
| Oil | Versatile (transport, heating, plastics, chemicals); high energy density; established infrastructure | CO₂ emissions; oil spills (e.g. Deepwater Horizon 2010 — 4.9 million barrels leaked); finite resource; price volatile |
| Natural gas | Cleanest fossil fuel (~50% less CO₂ than coal); efficient; can balance intermittent renewables | Still produces CO₂; methane leaks from extraction/pipelines; finite; supply dependent on pipelines/imports |
Nuclear
- Advantages: Very low CO₂ emissions during operation; high energy output; reliable baseload power; small land footprint
- Disadvantages: Radioactive waste remains dangerous for thousands of years; risk of catastrophic accident (Chernobyl 1986, Fukushima 2011); very expensive to build and decommission; uranium is finite
Renewable Energy Sources
| Source | How it works | Advantages | Disadvantages |
|---|---|---|---|
| Wind | Turbines convert wind energy to electricity | No emissions; low running costs; can be offshore (UK is world leader) | Intermittent; visual impact; noise; threat to birds |
| Solar | Photovoltaic panels convert sunlight to electricity | No emissions; low maintenance; costs falling rapidly (~90% drop since 2010) | Intermittent; large land area needed; manufacturing has environmental cost |
| Hydroelectric (HEP) | Flowing water drives turbines in dams | Reliable; no emissions; flood control; long lifespan | Dams flood valleys; displace communities; disrupt river ecosystems |
| Tidal | Tidal movement drives turbines or fills barrages | Predictable (tides are reliable); no emissions | Very expensive to build; environmental impact on estuaries; few suitable sites |
| Geothermal | Heat from underground rocks creates steam to drive turbines | Reliable; low emissions; small footprint | Limited to tectonically active areas (e.g. Iceland); drilling expensive |
| Biomass | Burning organic material (wood, crops, waste) | Carbon-neutral if replanted; uses waste; reliable | Requires land; air pollution if poorly managed; deforestation risk |
Sustainable Energy Strategies
Moving Towards a Sustainable Energy Mix
Countries need to balance energy security (reliable supply), affordability, and environmental sustainability — the "energy trilemma."
Strategies:
- Energy conservation — insulation, efficient appliances, smart grids, reducing demand
- Carbon capture and storage (CCS) — capturing CO₂ from power stations and storing it underground (technology still developing; expensive)
- Investment in renewables — government subsidies, feed-in tariffs, renewable energy targets
- International agreements — Paris Agreement (2015) commits countries to limiting warming to 1.5°C; Net Zero targets (UK aims for Net Zero by 2050)
- Hydrogen fuel — produced from water using renewable electricity; potential for transport and heating
- Battery and storage technology — essential for managing intermittent renewables (e.g. lithium-ion battery farms, pumped hydro storage)
- Micro-generation — individuals producing their own energy (rooftop solar, domestic wind turbines, ground source heat pumps)
Case Study: Wind Energy in the UK
The UK is the world leader in offshore wind power:
- Over 14 GW of installed offshore wind capacity (enough for ~13 million homes)
- Major wind farms: Hornsea (North Sea, one of the world's largest — 1.2 GW), Dogger Bank (under construction — will be world's largest at 3.6 GW)
- Onshore wind farms across Scotland, Wales, and northern England
Advantages for the UK: strong and consistent winds (island nation); reduces dependence on imported gas; creates jobs (manufacturing, installation, maintenance); falling costs — now cheaper than new gas power stations
Disadvantages: intermittent (backup needed); visual and noise objections to onshore turbines; impact on marine ecosystems; supply chain relies on materials from abroad (rare earth metals)
Exam tip: Be ready to evaluate the advantages and disadvantages of at least two contrasting energy strategies and discuss whether any single source can solve energy insecurity alone (answer: no — a diverse mix is needed).