Quick Overview

• Global energy demand is rising because of population growth, industrial growth, transport, urbanisation, and economic development.
• Over 80% of world energy still comes from non-renewable fossil fuels: oil (33%), coal (27%), gas (24%).
• Fossil fuels are reliable and energy-dense, but they will run out and they release greenhouse gases.
• Renewable energy (hydro, wind, solar, wave/tidal, geothermal, biomass) is infinite and mostly clean, but often expensive, less reliable, and land-hungry.
• Nuclear energy is efficient and low-carbon but controversial because of waste disposal and the risk of disasters (Chernobyl, Fukushima, Three Mile Island).
• Fuelwood is still the main energy source for billions of people in LEDCs, but overuse causes deforestation and health problems.
• Energy security means having an uninterrupted, affordable, accessible energy supply — many countries (like the UK) have a widening "energy gap" and are not energy secure.
• A country's energy mix depends on its level of development — richer countries use more nuclear/renewables, poorer countries depend more on biofuels/fuelwood.
• Case study: Nepal shows how a developing country can leapfrog straight to renewable hydropower through micro-hydro schemes like Ruma Khola.

1. Why Is Global Energy Demand Rising?

Think of energy demand like a snowball rolling downhill — it keeps growing because more people are alive, and each of those people is living a more energy-hungry lifestyle than people did 100 years ago. Two forces combine here: population growth (more people needing energy) and development (each person using more energy than before).

The five drivers of rising demand

• Food production — more people need more food, which means more intensive farming (machinery, irrigation pumps, lighting, heating for greenhouses) — all of which need energy.
• Industrial growth — factories need energy to run machines, heat buildings, and light workspaces.
• Transportation — more cars, planes, ships and trains moving more people and goods means more petrol, diesel and electricity used.
• Urbanisation — as more people move into cities, more homes need domestic appliances, heating, and lighting than the rural lifestyles they left behind.
• Economic development — as people get richer, they buy more televisions, phones, fridges, air conditioners — all of which draw on the electricity grid.

2. Non-Renewable Fossil Fuels

Fossil fuels are formed from the compressed remains of dead plants and animals buried underground for millions of years. Because they take millions of years to form, they cannot be replaced at the rate we're using them up — this is exactly what "non-renewable" means. It doesn't mean they'll run out tomorrow; it means the "tank" isn't being refilled as fast as we're draining it.

Coal

Oil & Gas

Energy use around the world

MEDCs (more economically developed countries) generally use far more energy per person than LEDCs (less economically developed countries).

• Highest energy use per person: Canada, Norway, Saudi Arabia (all MEDCs)
• Lowest energy use per person: Niger, Chad, Tanzania (all LEDCs, all in Africa)
• The fastest-growing energy demand is in LEDCs and newly emerging economies like China and India, as they industrialise and urbanise.

3. Energy Security & Energy Mix

What is energy security?

Imagine your household budget: if you can always afford the food you need, get it easily, and never run short, you're "food secure." Energy security works the same way — it's about whether a country can reliably meet its own energy needs.

To be truly energy-secure, a country needs its energy supply to be:

• Uninterrupted — it doesn't randomly stop
• Affordable — people and businesses can actually pay for it
• Accessible — it physically reaches homes and industries

Energy security can also be threatened by:

• Energy sources running out
• War / conflict
• Natural hazards (e.g. earthquakes damaging power infrastructure)
• Political disputes between countries

Energy mix and development

A country's "energy mix" is simply the combination of different energy sources it uses. This mix is closely linked to how developed a country is:

• Most economically developed countries (e.g. UK) — wider use of renewables and nuclear power alongside fossil fuels.
• Newly emerging economies (e.g. China) — heavily dependent on fossil fuels, especially coal, to fuel rapid industrial growth.
• Least economically developed countries — dominated by biofuels, mostly fuelwood, used for heating and cooking, especially in rural areas.

4. Renewable Energy

Renewable energy sources are infinite — they won't run out because they come from natural processes that constantly renew themselves (the sun keeps shining, the wind keeps blowing, rivers keep flowing). Except for biomass/waste, once the equipment (turbines, panels, dams) is built, these sources produce no direct greenhouse gas emissions while running. However, some emissions do occur during the manufacturing, construction and transport of the equipment itself — so "zero carbon" isn't 100% accurate, it's "very low carbon."

Why is renewable energy use increasing?

• Fossil fuels will eventually run out, so alternatives are needed
• Fossil fuels damage the environment — burning releases greenhouse gases and sulphur dioxide (acid rain); mining/drilling destroys habitats
• Growing international pressure and awareness about climate change
• Countries want to reduce reliance on imports and improve their energy security

Hydroelectric (HEP)

Wave / Tidal

Wind

Solar

Geothermal

Biomass / Waste

5. Nuclear Energy

Nuclear power stations use uranium to generate huge amounts of energy through nuclear fission. It's especially popular in countries that don't have their own fossil fuel reserves, such as France, because it reduces their need to import oil, coal or gas.

Controversy: Major nuclear accidents

Advantages and disadvantages

6. Fuelwood

It's easy to forget wood when thinking about "energy," but for a huge chunk of the world's population, it's the only fuel they have access to.

Fuelwood is often classed as a "biofuel," but unlike proper biofuel crops, the trees cut for fuelwood are usually not replanted — which means it isn't actually sustainable in practice, even though it theoretically could be.

7. Case Study: Nepal

Use this as your named place-specific example whenever an exam question asks about energy in an LEDC/developing country.

Energy mix

• 82% of the rural population relies on fuelwood as their main energy source
• In urban areas, fuelwood use is lower, at 36%
• Nepal has no suitable coal, oil or gas reserves of its own — these must be imported
• 98% of all electricity in Nepal is generated through hydropower — this makes sense given its mountainous, river-rich landscape

Building a sustainable future

• Access to electricity has risen rapidly over the past 15 years — 88% of the population now has access
• Support from the World Bank has driven investment in hydropower
• There are now over 3,000 micro-hydro plants across Nepal

What to Memorise

Key stats worth memorising

• World energy mix: Oil 33% · Coal 27% · Gas 24% · Hydroelectric 6% · Other renewables 5% · Nuclear 4%
• Gas and oil predicted to run out by ~2080; fossil fuels still ~75% of energy by 2040
• Coal world reserves: ~120 years / Oil & gas world reserves: ~50–60 years
• Nuclear = ~4% of global primary energy supply; 439 reactors worldwide
• 2–3 billion people rely on fuelwood; ~13% of world population lacks electricity access
• Nepal: 98% of electricity from hydropower; 88% of population has electricity access; 3,000+ micro-hydro plants

Concepts Checklist

• I can explain 5 reasons why global energy demand is rising
• I can state the world energy mix percentages (oil/coal/gas/etc.)
• I can give advantages and disadvantages of coal, oil and gas
• I understand why MEDCs use more energy per person than LEDCs
• I can define "energy gap" and "energy security" and give a real example (UK)
• I can explain how energy mix links to a country's level of development
• I can give advantages/disadvantages for all 6 renewable energy types
• I understand why renewable energy use is increasing globally
• I can describe advantages/disadvantages of nuclear energy
• I can name and briefly describe Three Mile Island, Chernobyl, and Fukushima
• I know nuclear fuel is non-renewable but NOT a fossil fuel
• I can explain the importance, advantages and disadvantages of fuelwood
• I can describe the Nepal case study, including the Ruma Khola scheme, with key facts and figures

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