Can We Get the Energy We Need?

Show Notes

Episode summary

Building directly on Core Episodes 3 and 4, this episode asks whether we can obtain the energy we need without burning fossil fuels. Can we power our lives without burning coal, oil or gas? It distinguishes electricity generation from the direct burning of fuels, explains how electrification can replace many fossil-fuelled machines, and introduces a varied clean- electricity system, the sources that can supply cleaner electricity, from sunlight and wind to moving water, underground heat and nuclear energy.

Belle asks the crucial question: what happens when the Sun isn’t shining and the wind isn’t blowing? The answer brings together four approaches: storing energy, connecting places, choosing when to use electricity, and including sources that can keep working day and night.

One Bright Thing visits United Downs in Cornwall, where heat from deep granite is generating electricity. The story then travels further afield—from geothermal possibilities in Scotland and northeast England to Iceland, where around nine out of ten homes use geothermal heating, and countries already generating electricity from Earth’s heat.

Key ideas

• We burn fossil fuels both to generate electricity and directly for heating, transport and industry.
• Reducing fossil-fuel use means making low-carbon electricity and using it for more of the jobs currently done by burning fuels.
• Solar, wind, hydroelectric, tidal, geothermal and nuclear power can contribute to electricity supplies. Different places will use different combinations.
• Keeping electricity dependable requires four approaches working together: storage, connections, flexible timing of electricity use, and sources available through calm nights.
• Batteries and pumped storage save energy for later. Grids allow places to share electricity.
• Geothermal energy can provide heat directly and, where conditions allow, generate electricity.
• The transition is already happening. Expanding it takes investment, skilled people and planning.

Teacher Notes

Learning objective

Explain how different energy sources and four complementary approaches can provide dependable electricity while reducing the need to burn fossil fuels. Distinguish geothermal heating from geothermal electricity generation.

Links to the Core Series

• Core Episode 3: ancient carbon stored in coal, oil and gas.
• Core Episode 4: methane and its contribution to warming.

Keywords

Fossil fuel; greenhouse gas; electricity; electrification; renewable energy; low-carbon energy; solar; wind; hydroelectricity; tidal energy; nuclear energy; geothermal energy; electricity grid; battery; pumped storage; reservoir.

Discussion prompts

1. Where do we burn fossil fuels to make electricity, and where do we burn them directly?
2. Why might different countries choose different combinations of energy sources?
3. What are the four approaches that help keep electricity dependable?
4. How does pumped storage act like a giant water battery?
5. How can geothermal energy heat a building without first being turned into electricity?
6. What can countries exploring geothermal energy learn from Iceland and other countries already using it?

Short classroom activity

Draw an imaginary town on a calm evening after sunset. Ask pupils to show how it could still receive electricity, using stored energy, connections to other places and sources that can operate through the night. Add one activity that could safely wait until electricity is more plentiful.

Additional notes for teachers

“Clean” and “low-carbon”: “Clean electricity” is accessible shorthand for electricity with low greenhouse-gas emissions. No technology is free of environmental impacts across construction, operation and disposal.

Nuclear energy: Nuclear power is low-carbon but generally classed as non-renewable because conventional nuclear fuels are finite and are not replenished on human timescales. Mining alone is not the defining distinction: renewable technologies also require mined materials.

Storage and reliability: Batteries and pumped storage hold energy supplied earlier; they are not additional primary energy sources. Storage has limited capacity and loses some energy. Reservoir output depends on water availability, and all power stations need maintenance.

Choosing when to use electricity: The cleanest time varies with the local electricity supply and weather. Overnight electricity is not automatically cleaner; a solar-rich system may have abundant low-carbon electricity during the day.

Geothermal geography: Underground temperature varies with location and depth. Around 200°C at five kilometres is possible in favourable locations, not a worldwide rule. Scotland and northeast England have promising resources, including heat-producing granites, but potential resources should not be confused with operating electricity plants.

Interpreting the examples: Iceland’s approximately 90% figure concerns home heating. National Grid describes United Downs as capable of generating up to 3 MW, sufficient for up to 10,000 homes; this is a project estimate, rather than a count of homes with dedicated connections.

Sources

• IPCC AR6 Working Group III — Chapter 6: Energy Systems; low-carbon electricity mixes, electrification, storage, transmission and flexible demand.
• International Energy Agency — Managing Seasonal and Interannual Variability of Renewables.
• International Energy Agency — Electricity Grids and Secure Energy Transitions.
• International Energy Agency — Energy Efficiency 2024; the efficiency benefits of electric vehicles and heat pumps.
• UK Department for Energy Security and Net Zero — UK geothermal energy review and cost estimations.
• National Grid — Engineers connect the UK’s first geothermal power plant to the grid.
• GEL Energy — United Downs Geothermal Powerplant; the February 2026 launch and the production and injection wells used to circulate geothermal water.
• British Geological Survey — Geothermal Technologies; geothermal heating and electricity generation, including the potential of granites in Cornwall, northern England and Scotland.
• British Geological Survey — Exploring Scotland’s Hidden Energy Potential with Geology and Geophysics: Fieldwork in the Cairngorms; research into Scotland’s heat-producing granites and their potential to supply geothermal heat.
• Government of Iceland — The Icelandic National Renewable Energy Action Plan; approximately 90% of Icelandic homes are heated directly using geothermal energy. See the section on renewable heating and cooling in individual homes.
• International Energy Agency — The Future of Geothermal Energy; established geothermal electricity generation worldwide and the transfer of expertise from the oil and gas industry.
• US Energy Information Administration — Where Geothermal Energy Is Found; The Geysers in Northern California has generated electricity since 1960.