Energy

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

compressed remains of dead plants and animals

Coal