Energy Mix (AQA A-Level Geography): Revision Notes

Energy mix

Understanding energy mix

The global energy supply varies significantly between countries, creating what we call an energy mix. Understanding these differences helps us recognise why nations make particular energy choices and how they meet their energy security needs.

When examining energy statistics, it's crucial to recognise what the data actually represents. Some figures focus exclusively on electricity generation, which provides an incomplete picture. The full primary energy mix of a nation includes all energy forms used across different sectors - not just electricity, but also transport fuels (petrol, diesel), heating sources (natural gas, oil for boilers), and cooking fuels (biomass, LPG). Looking only at electricity generation misses these other vital energy uses.

Factors that shape a country's energy mix

Multiple interconnected factors determine which energy sources a country relies upon. These factors work together to create each nation's unique energy profile.

Availability of energy sources within the country

Nations naturally prioritise using energy resources they possess domestically. This reduces import dependency and leverages existing resources. Countries with abundant coal reserves, for instance, historically developed coal-based energy systems, whilst those with strong river systems could develop hydroelectric power.

Inertia

Once an energy system becomes established, changing it proves challenging. Economic factors and technical difficulties create resistance to transformation, even when better alternatives exist or original reasons for the energy mix no longer apply. Existing infrastructure, trained workforce, and established supply chains create momentum that maintains current systems.

Government energy policy

Policy decisions fundamentally shape national energy direction. Governments might pursue energy security by reducing reliance on imports, or commit to international environmental agreements like the 2015 Paris Climate Agreement. These political choices drive investment, regulate markets, and set targets that determine which energy sources receive support and development.

Geopolitics

International relationships significantly influence energy choices. Nations prefer trading with friendly, reliable partners. Conversely, suppliers that prove unreliable or represent potential conflict risks become less attractive, regardless of their resources. Political tensions can eliminate certain energy import options entirely.

Level of development (economic and technological)

Development level determines what energy sources prove 'appropriate' for a nation. Less economically developed countries often cannot afford nuclear power development or risk over-dependence on expensive fossil fuel imports. They may rely more heavily on traditional biomass for cooking and heating, lacking the infrastructure for grid electricity distribution that developed nations take for granted.

Physical and locational conditions

Geography determines which renewable energy sources become viable. Certain locations suit specific renewable technologies - the UK benefits from strong, consistent winds; Iceland and Norway possess excellent hydroelectric potential from mountainous terrain and high rainfall; Spain enjoys abundant sunshine for solar generation. Without appropriate physical conditions, these renewable options remain impractical regardless of desire to use them.

Diversity

Governments may deliberately choose to diversify their energy sources, ensuring countries don't become overly dependent on just one or two options. This diversification strategy provides resilience against supply disruptions and price volatility in any single energy market.

Geothermal energy

Renewable energy sources possess the overarching advantage of sustainability - they reduce long-term dependency on finite fossil fuels. However, different renewables create varying environmental impacts during manufacture, construction, or operation. Critically, apart from biomass, renewable sources require specific physical conditions to function effectively, making them geographically specific - a potential limitation for widespread deployment.

Geothermal energy harnesses heat from within the Earth's crust. The process involves pumping cold water deep underground through a network of pipes. As this water descends, it contacts hot rocks heated by geothermal energy from the Earth's interior. The intense underground heat transforms the cold water into steam and extremely hot water.

This superheated steam and water then rises back to the surface through separate pipes. At the surface, the steam drives turbines connected to electricity generators at the generating station, producing electrical power. The system creates a continuous cycle - cold water goes down, hot steam comes up, drives turbines, generates electricity.

Comparing renewable energy sources

Each renewable energy source presents distinct advantages and disadvantages. Understanding these trade-offs helps explain why different countries favour particular renewables based on their circumstances.

Solar energy

Solar power offers pollution-free operation (except during manufacturing and disposal of panels) and works particularly well in less developed countries where decentralised generation proves beneficial. The technology contains no moving parts, providing high reliability, whilst silicon resources for panel manufacture remain plentiful.

However, solar generation depends on sunlight availability, creating intermittency challenges. Energy storage remains problematic, some panel production uses toxic materials, and connecting solar installations to existing grids presents technical challenges.

Wind energy

Wind turbines install and dismantle relatively easily, particularly offshore installations. The technology remains straightforward, produces no atmospheric pollution during operation, and land use often permits other activities like farming to continue around turbines. Offshore sites can combine with tidal energy generation.

Unfortunately, wind energy creates some land use conflicts, visual impacts, and affects wildlife, particularly birds. Local communities sometimes object to installations, citing visual intrusion and noise. Wind's intermittent nature makes it relatively inefficient and unreliable, whilst offshore technology creates sea navigation concerns.

Biomass

Biomass provides proven combustion technology and offers an oil alternative for transport when converted to biofuels. Energy crops efficiently use 'marginal' land unsuitable for food production and approach carbon neutrality. The fuel offers high energy density and format flexibility (solid, liquid, gas).

However, questions remain about true carbon neutrality, as carbon dioxide sinks may be lost in the process.

Hydroelectric power (HEP)

HEP features low operating costs, produces no waste or carbon dioxide emissions, and employs proven, reliable technology. Systems can increase supply during peak demand periods by releasing more water through turbines.

Nevertheless, dam construction costs prove substantial, requiring large land areas that cause conflicts, particularly affecting communities requiring relocation. Environmental impacts include drainage basin alterations and micro-climate changes.

Tidal energy

Tidal generation benefits from predictable generation periods following tidal cycles, with large potential power output from major installations. However, power generation occurs intermittently, limited to tidal flow periods, and ecological impacts on marine ecosystems require careful consideration.

Wave energy

Wave power produces electricity consistently, creates less environmental impact than tidal barrages, operates pollution-free, and coastal installation sites prove relatively affordable. Challenges include transmitting power from offshore locations, large sea areas required for wave 'farms', relatively inefficient onshore technology, and environmental impacts from offshore installations that reduce turbulence and increase sedimentation.

Geothermal energy

Geothermal systems provide clean, sustainable energy with relatively low costs in geologically suitable areas. However, viability depends entirely on specific geological conditions, restricting potential locations significantly.

Case study: Niger's energy mix

Niger demonstrates how development level, resource availability, and economic constraints create a particular energy profile. Understanding this West African nation's energy situation illustrates the challenges facing less developed countries.

Energy mix composition

In 2018, biomass sources provided the overwhelming majority (77%) of Niger's primary energy supply totalling 3,100 million tonnes of oil equivalent. This biomass primarily comprises fuelwood, charcoal, and animal waste. Approximately 84% of Niger's population lives in rural areas, where communities depend almost entirely on these traditional fuels for cooking and heating needs. Only 20% of the population accesses electricity from the grid.

Why this energy mix exists

Despite being one of the world's ten largest uranium producers, with half a million tonnes of proven reserves, Niger lacks the wealth and technical expertise required to develop nuclear energy domestically. The country possesses significant underdeveloped oil reserves, which it uses to supplement energy supply for transport and power generation sectors, rather than developing them fully.

Households consume 82% of Niger's energy. Road transport accounts for 14%, whilst industry (predominantly mining) and commercial/public services divide the remainder. The dominance of household consumption reflects the rural population's reliance on firewood as the cheapest and most readily available energy source. Limited coal and oil reserves exist but remain largely unexploited.

Future energy potential

Niger possesses considerable potential for diversifying its energy mix. Construction of the Kandaji HEP station commenced in 2019 on the Niger River, with expected completion in 2025. This hydroelectric facility should provide renewable electricity generation capacity.

The country also shows promise for expanding solar and wind energy generation, supported by a United States government organisation called Power Africa. This initiative specifically encourages electricity development in rural areas, potentially reducing reliance on traditional biomass and extending grid access to more communities.