Department for Energy Security and Net Zero: Policy Powers

1. Introduction

The Department for Energy Security and Net Zero (DESNZ) is a UK government department established in February 2023. It is responsible for major areas of energy policy, including energy security, protecting billpayers, clean energy, economic growth and reducing greenhouse-gas emissions. (GOV.UK)

Its role is mainly policy-making and strategic direction. It is different from Ofgem, which performs independent economic regulation. DESNZ works with Ofgem, NESO and other public bodies through formal framework arrangements defining their respective roles and accountability. (GOV.UK)

2. Meaning of Policy Powers

Policy powers are the powers used by DESNZ and the Secretary of State to decide the government's overall direction in the energy sector.

These powers include:

preparing energy policies;

developing energy-security strategies;

supporting renewable energy;

promoting clean electricity;

developing net-zero policies;

supporting nuclear energy;

planning energy infrastructure;

developing energy-market reforms; and

supporting consumers and billpayers.

DESNZ's official framework states that its responsibilities include securing long-term energy supply, ensuring properly functioning energy markets, improving energy efficiency and leading the transition to net zero. (GOV.UK)

3. Energy Security Policy

One of the most important policy powers of DESNZ is energy security.

Energy security means ensuring that the UK has a reliable supply of energy at reasonable cost and can manage risks such as:

international conflicts;

supply interruptions;

dependence on imported fuels;

electricity-system failures; and

sudden changes in energy prices.

Therefore, DESNZ can develop policies supporting domestic generation, energy storage, nuclear power, renewable energy and stronger energy infrastructure.

This policy role has become particularly important because the UK must address energy security while also reducing carbon emissions.

4. Net-Zero Policy Powers

DESNZ has a major role in implementing the UK's legally established net-zero framework.

The department develops policies and proposals intended to reduce emissions from electricity, buildings, transport and industry.

The Climate Change Act 2008 provides the important statutory framework for carbon budgets and the UK's long-term emissions target.

Case: Friends of the Earth v Secretary of State for Energy Security and Net Zero [2024] EWHC 995 (Admin)

This case is especially important for understanding DESNZ's policy powers. The High Court held that the government's earlier Net Zero Strategy did not comply with the statutory requirements of sections 13 and 14 of the Climate Change Act because it did not provide sufficient information about the quantitative contribution of individual policies and how the required carbon-budget reductions would be achieved. (Courts and Tribunals Judiciary)

Relevance: Government has considerable freedom to choose energy policies, but it must exercise that policy power according to the requirements of the Climate Change Act.

5. Clean-Energy Policy

DESNZ also develops policies for renewable and low-carbon electricity.

These may include:

offshore wind;

solar power;

nuclear power;

hydrogen;

carbon capture and storage;

electricity networks;

energy storage; and

clean-energy investment.

The current Energy National Policy Statement EN-1 (2025) provides government policy for nationally significant energy infrastructure projects and explains how such projects should be assessed. It came into force on 6 January 2026. (GOV.UK)

This demonstrates how DESNZ policy can influence major infrastructure decisions without replacing the legal decision-making role of the relevant authorities.

6. Policy Powers and Energy Infrastructure

The Secretary of State has important functions under the Planning Act 2008 concerning nationally significant energy infrastructure.

These can include major:

electricity-generating stations;

electricity transmission infrastructure;

offshore energy projects; and

carbon-capture infrastructure.

Case: Boswell v Secretary of State for Energy Security and Net Zero [2025] EWCA Civ 669

The case concerned a proposed gas-fired electricity generating station with carbon capture at Teesside. The Court of Appeal considered challenges to the Secretary of State's development-consent decision. (Courts and Tribunals Judiciary)

The Court recognised the Secretary of State's decision-making role under the planning framework and rejected arguments that would improperly substitute the court's assessment for the statutory decision-maker's judgment. (Courts and Tribunals Judiciary)

Relevance: DESNZ policy powers can involve significant discretion, but that discretion must operate within the statutory planning framework.

7. Policy-Making and Ofgem

A very important point is that DESNZ is not the same as Ofgem.

DESNZ generally develops government policy and exercises ministerial/statutory functions, while Ofgem performs independent regulation of gas and electricity markets.

This separation is important because:

Government policy → DESNZ

Independent economic regulation → Ofgem

The formal DESNZ framework documents expressly set out the roles, responsibilities and accountabilities between the department and its public bodies. (GOV.UK)

Thus, DESNZ can establish policy direction without simply taking over the regulator's independent functions.

8. Policy Powers and Consumer Protection

DESNZ also has policy responsibilities concerning energy consumers and billpayers.

Its official responsibilities specifically include protecting billpayers. (GOV.UK)

This can involve policies concerning:

energy affordability;

market stability;

consumer support;

energy efficiency;

supplier resilience; and

protection during energy-market crises.

Case: British Gas Trading Ltd v Secretary of State for Energy Security and Net Zero [2025] EWCA Civ 209

This litigation concerned government decisions connected with the acquisition of Bulb's assets following the supplier's failure. The Court of Appeal considered challenges involving government intervention in the energy market. (Courts and Tribunals Judiciary)

Relevance: The case demonstrates that government energy policy can involve intervention during market failures, but such intervention remains subject to legal scrutiny.

9. Policy Powers and Democratic Accountability

Because DESNZ is a ministerial department, its policy powers have a democratic dimension.

Ministers are politically accountable to Parliament for departmental policies and expenditure. At the same time, internal departmental governance provides additional scrutiny. The DESNZ Departmental Board advises ministers and senior officials and scrutinises departmental programmes, policies and performance. (GOV.UK)

Therefore, DESNZ policy power is not unlimited administrative power. It operates through:

Parliament → legislation → ministerial policy → public bodies/regulators → implementation → judicial and parliamentary accountability

10. Judicial Review of Policy Powers

Courts generally do not decide which energy policy is economically or politically preferable. Their role is mainly to examine legality.

They can ask whether:

the minister had legal authority;

the correct statutory test was applied;

relevant considerations were taken into account;

irrelevant considerations were avoided;

the procedure was lawful; and

the decision was rational and properly explained where required.

The Friends of the Earth case illustrates that even high-level government climate policy can be reviewed where statutory duties are not properly followed. (Courts and Tribunals Judiciary)

11. Conclusion

The policy powers of DESNZ are central to modern UK energy governance. The department develops the government's strategic approach to energy security, clean electricity, renewable energy, net zero, infrastructure, markets and consumer protection.

However, DESNZ does not possess unlimited power. Its policies must operate within Acts of Parliament such as the Climate Change Act 2008 and Planning Act 2008, while independent bodies such as Ofgem and NESO perform their own statutory functions.

Cases such as Friends of the Earth, Boswell, and British Gas/E.ON demonstrate an important principle: the government has substantial policy-making discretion in energy matters, but that discretion must remain within the law and can be reviewed by the courts when statutory duties or legal requirements are challenged.