What Is the UK Solar Roadmap?
Published on 1 June 2025 by the Department for Energy Security and Net Zero (DESNZ), the UK Solar Roadmap is a strategy document setting out how the Government plans to reach 70 gigawatts (GW) of solar capacity by 2035. That represents a roughly fivefold increase from the approximately 17GW installed at the time of publication — an enormous ambition requiring significant policy action across utility-scale solar farms, commercial rooftop, and residential solar alike.
The document runs to over 80 pages and covers planning reform, grid connection, skills and supply chain, finance, and — crucially for our purposes — small-scale and residential solar, including a specific section on plug-in solar devices.
The Big Numbers: 70GW by 2035
The 70GW target breaks down roughly as follows in the Roadmap's modelling:
- ~45–50GW from large-scale ground-mounted solar farms (utility-scale)
- ~12–15GW from commercial and industrial rooftop (warehouses, offices, factories)
- ~6–8GW from residential rooftop (homes with roof-mounted systems)
- ~1–2GW from small-scale and emerging formats, explicitly including plug-in solar
The 1–2GW plug-in solar contribution may sound modest in the context of a 70GW target, but it represents an enormous number of individual installations — at 600W per system, 2GW would mean over 3 million installed units. For context, Germany reached 1.2 million after legalising in 2024 within twelve months.
What the Roadmap Says About Plug-In Solar
Section 4.3 of the Solar Roadmap, titled "Democratising Access to Solar," includes the most direct treatment of plug-in solar to appear in any UK government document to that point. Key passages include:
"Plug-in solar devices — sometimes referred to as balcony solar — represent a significant opportunity to extend the benefits of solar energy to the millions of households that currently cannot access it due to tenure, building type, or upfront cost. The Government will explore the regulatory and standards changes required to establish a simplified pathway for these devices, drawing on the experience of Germany and other European neighbours."
The Roadmap goes on to commit to a consultation on plug-in solar regulation, to be launched before the end of 2025. That consultation subsequently informed the March 2026 ministerial statement announcing the formal commitment to a regulatory framework.
The Roadmap as a starting gun
What the Roadmap Says About Residential Rooftop Solar
Beyond plug-in solar, the Roadmap contains several provisions relevant to residential solar more broadly:
- Permitted Development reform. The Roadmap commits to reviewing Permitted Development Rights to remove "unnecessary barriers" to rooftop solar on homes, including in conservation areas and on listed buildings where appropriate.
- Smart Export Guarantee (SEG) review. The Government committed to reviewing the minimum export tariff (currently 0p — i.e., suppliers must offer something but it can be negligibly low) to ensure householders receive "a fair price" for exported electricity.
- Social housing solar. A specific workstream on accelerating solar on social housing is established, with a target of 1GW from social housing by 2030.
The Role of the Energy Saving Trust
The Solar Roadmap designates the Energy Saving Trust (EST) as a key delivery partner for small-scale and residential solar communications. The EST has been tasked with developing consumer-facing guidance on plug-in solar, including awareness campaigns aimed at renters and those in multi-occupancy buildings.
This is significant because the EST's involvement brings credibility and reach. Their existing home energy advice services — used by millions of UK households — will incorporate plug-in solar information as the regulatory picture clarifies. This should accelerate mainstream awareness of the technology well beyond the current enthusiast and early-adopter market.
Germany as the Model
The Roadmap explicitly cites Germany as the leading example of successful plug-in solar policy. Germany's journey is worth understanding in detail because it is, in effect, the template the UK is following.
Germany introduced its first simplified rules for Balkonkraftwerke (balcony power plants) in 2023, relaxing notification requirements and increasing the single-unit wattage limit from 600W to 800W. In May 2024, the Bundestag passed the "Solarpaket I" — a broader solar package that included further simplification: owners can connect plug-in solar devices to a standard household socket without a registered electrician, feed-in to the grid is permitted without a separate metering installation, and landlords are obliged to permit tenants to install them unless there is a material objection.
The results were rapid. Within twelve months of Solarpaket I taking effect, Germany registered its 1.2 millionth plug-in solar installation — a figure that continues to grow rapidly. Prices fell as demand scaled, and the market diversified with integrated battery storage systems becoming increasingly common.
The UK Solar Roadmap authors were clearly aware of this trajectory, noting that "regulatory clarity and simplification can unlock latent consumer demand that pre-existing uncertainty has suppressed." That is precisely what happened in Germany, and what the UK Government now intends to replicate.
Next Steps From the Roadmap
The Roadmap set out a series of action points relevant to plug-in solar, with indicative timelines:
- H2 2025: DESNZ to launch consultation on plug-in solar regulation, covering grid connection, building regulations, and consumer protection standards.
- H2 2025: Energy Saving Trust to publish consumer guidance on plug-in solar.
- H1 2026: Government response to consultation and announcement of intended regulatory approach. (This is the commitment fulfilled by the March 2026 announcement.)
- 2026–2027: BSI standard development, G98 amendment, and Part P update — aiming for a complete simplified framework by end of 2027.
Don't wait for the paperwork
What Does This Mean for You?
If you are a renter, flat-dweller, or anyone who has been waiting for the regulatory picture to clarify before investing in balcony solar, the Solar Roadmap and the March 2026 announcement that followed it provide strong grounds for confidence. The technology is proven, the government is supportive, and the regulatory direction is clear.
The Solar Roadmap is the most comprehensive signal yet that plug-in solar will eventually be as mainstream in the UK as it has become in Germany. The question is not whether it will happen, but how quickly the standards bodies and government departments can move.