The Arithmetic of Sustainability - Part 8: The Gigawatt Gambit

Throughout this series, we have performed the arithmetic of energy: quantifying Britain’s current consumption, projecting the demand of an electrified future, assessing the realistic contributions of indigenous renewables, evaluating imports, and examining storage. The numbers are clear, if sobering.

The challenge is defined: deliver 48 kWh/d per person of clean electricity (120 GW nationally) to power an efficient, electrified lifestyle, replacing the current ~125 kWh/d/p of primary energy consumption.

This concluding post presents five illustrative energy plans for Britain. Each plan takes a different philosophical approach to the energy mix but is rigorously constrained by the arithmetic: the numbers must add up.

I. The Universal Constraints

Before presenting the plans, we must establish the constraints that bind all of them:

1. Demand target: 48 kWh/d per person of delivered electricity (after aggressive efficiency measures).
2. Social ceiling: Indigenous renewables are limited by public acceptance of industrialized landscapes to approximately 18 kWh/d/p.
3. Technology readiness: Only technologies that are currently deployable or reasonably expected within the next two decades can be counted.
4. Sustainability: The plan must be low-carbon and not rely on unsustainable extraction rates of fossil fuels.

All plans must hit 48 kWh/d/p with proven or near-term technologies

With these constraints in mind, the following five plans represent different points on the spectrum of energy strategy.

II. Plan 1: The Nuclear Maximum

This plan maximizes the contribution of nuclear power, leveraging its high power density, reliability, and zero carbon emissions.

Energy Mix

Requirements

• New nuclear capacity: Approximately 75 GW of new nuclear capacity (60–70 new reactors of Sizewell B scale) would be required.
• Land use: Even at this scale, total nuclear site area would be under 100 km².
• Public acceptance: Requires overcoming significant anti-nuclear sentiment.
• Waste management: Necessitates a robust long-term strategy for spent fuel (geological disposal).

Assessment: This plan minimizes land-use impact and reliance on variable renewables but depends heavily on a single technology and faces political challenges.

II. Plan 2: The Renewable Maximum

This plan pushes indigenous renewables to their social ceiling and fills the gap with massive solar imports.

Energy Mix

Requirements

• Desert solar infrastructure: The plan requires sourcing 20 kWh/d/p (50 GW) from North African or Middle Eastern CSP facilities.
• HVDC interconnectors: A 25-fold increase in interconnector capacity from the continent.
• Geopolitical risk: Heavy reliance on foreign energy sources introduces supply security concerns.
• Backup nuclear: Even this plan requires 7 kWh/d/p of nuclear to provide reliable baseload.

Assessment: This plan minimizes nuclear dependence but creates major geopolitical vulnerabilities and requires unprecedented infrastructure investment.

III. Plan 3: The Balanced Approach

This plan seeks a pragmatic balance, diversifying across multiple sources to reduce risk.

Energy Mix

Requirements

• New nuclear: Approximately 40 GW of new nuclear capacity.
• Renewable expansion: Significant but achievable expansion of offshore wind and tidal.
• Solar imports: A substantial but manageable 35 GW of HVDC solar imports.
• Grid investment: Major investment in smart grid and storage infrastructure.

Assessment: This plan distributes risk across technologies and sources. It requires commitment on all fronts but avoids excessive dependence on any single solution.

IV. Plan 4: The NIMBY Extreme (No Industrialization)

This plan represents the extreme position of those who oppose any large-scale industrialization of the British landscape—no new wind turbines, no new nuclear plants, no tidal lagoons on UK territory.

Energy Mix

Requirements

• Extreme import dependence: This plan requires importing 38 kWh/d/p (95 GW) from foreign solar sources—nearly the entire demand.
• HVDC infrastructure: A 50-fold increase in interconnector capacity.
• Cost: The infrastructure and energy costs would be astronomical.
• Energy security: Britain would be entirely dependent on foreign goodwill and the security of transcontinental power lines.

NIMBY plan: 95 GW import—complete dependence on foreign energy

Assessment: This plan is politically naive and strategically dangerous. It exports the environmental impact rather than eliminating it and creates unacceptable vulnerabilities.

V. Plan 5: The Transition Plan (Near-Term Realism)

This plan acknowledges current political and economic constraints and focuses on what can realistically be achieved in the next 15–20 years as a transition towards a fully sustainable system.

Energy Mix (2040 Target)

Requirements

• Gas bridge: This plan includes 10 kWh/d/p from natural gas with carbon capture and storage as a transitional measure while nuclear and renewable capacity is built.
• CCS deployment: Requires successful large-scale deployment of CCS technology within the next decade.
• Phase-out timeline: The gas-with-CCS component must be phased out by 2050–2060 as clean capacity increases.

Assessment: This plan is the most pragmatic for near-term implementation. It acknowledges that the perfect should not be the enemy of the good. However, it requires vigilance to ensure the “bridge” does not become a permanent fixture.

VI. Comparing the Plans

(All figures in kWh/d/p)

VII. The Verdict: Any Plan Requires Commitment

The arithmetic is unyielding. There is no free lunch in energy. Every plan requires difficult trade-offs:

• Land use: Wind and solar industrialize the landscape.
• Public acceptance: Nuclear faces historical opposition.
• Energy security: Imports create dependencies.
• Technology risk: CCS and fusion remain uncertain.

The only approach that is guaranteed to fail is to do nothing, or to pursue policies based on wishful thinking rather than arithmetic.

The arithmetic is unyielding. Any credible plan requires massive, sustained commitment.

The path forward demands that citizens, policymakers, and industry leaders confront these numbers honestly. The debate must move beyond slogans to engage with the actual scale of the energy system and the real constraints imposed by physics, economics, and society.

The arithmetic of sustainability is not a problem to be solved once and forgotten. It is a challenge that will define the coming decades. The question is not whether we will make difficult choices, but which difficult choices we will make.

The numbers must add up. The choice is ours.

Series Summary

This nine-part series has walked through the arithmetic of sustainable energy for Britain:

1. Part 1: The power of proof—why numbers matter
2. Part 2: The red stack—Britain’s current 125 kWh/d/p consumption
3. Part 3: The electric drive—efficiency gains from electrification
4. Part 4: Winning the heat war—heat pumps and insulation
5. Part 5: The physical ceiling—Britain’s renewable limits
6. Part 6: Sunshine squared—solar from rooftops to deserts
7. Part 7: Beyond fossil fuels—nuclear and “clean” coal
8. Part 8: The gigawatt gambit—storage and demand management
9. Part 9: A plan that adds up—five energy scenarios

The arithmetic is complete. The decision is political.