As appeared in the RTPI Politicians in Planning Network (PIPN) newsletter January 2025.
Amid growing climate challenges, solar photovoltaic (PV) energy has gained global attention. In the UK, this was underscored by the formation of the UK Solar Taskforce in 2023 and their upcoming Solar Roadmap Plan in 2024; a strategic move designed by the UK Government to help achieve the statutory commitments of net-zero enshrined in the 2050 Target Amendment Order (2019) related to the UK’s Climate Change Act (2008). This means that the total greenhouse gas emissions should be equal to the emissions removed from the atmosphere by 2050, with the aim of limiting global warming and resultant climate change.
All of the UK’s nations and regions must meet net zero by 2050. However, the four parts of the UK (England, Scotland, Wales and Northern Ireland) have different emissions profiles and different approaches to achieving net zero. Therefore, each have taken various steps in line with their differing devolved powers related to energy, planning and other matters in delivering on their statutory commitments.
On this, lessons can be learnt across the UK’s regions based on how Northern Ireland have recently taken a novel step in using highly accurate 3D modelling, climate modelling, energy modelling and financial modelling at city scale to create energy simulation systems that can comprehensively support their collective net zero journeys.
Northern Ireland’s Pioneering Approach to Solar Energy and Net Zero Planning
Northern Ireland’s Energy Strategy, The Path to Net Zero (2021), initially set a target for 70% renewable electricity by 2030, later increased to 80% through the Climate Change Act (2022); first-of-a-kind legislation for Northern Ireland and aligned to the UK 2008 Climate Act. In line with these goals, Belfast City Council and the Department for the Economy NI commissioned GIA to assess solar PV potential across Belfast using advanced 3D modelling, along with expertise in daylight, energy and financial modelling, setting a new benchmark for solar energy analysis.
After a small-scale pilot assessing 60 government properties, the project expanded to cover a 3km² urban area, encompassing over 5,200 properties with diverse land uses and a mix of existing and planned developments. These factors play a key role in determining the effectiveness, suitability, and financial viability of PV installations.
The rationale for the project was to create a vital evidence base as to the potential contribution of brownfield assets towards the renewable technology mix necessary to achieve net zero in Belfast; the NI local authority with the highest annual consumption of electricity per year and an ideal pilot to understand potential scaling up nationally. In Belfast, this evidence was then used to support renewable action planning, property retrofit programmes, including those aimed at addressing fuel poverty, asset decarbonisation programmes, local area energy planning, incentivisation scheme modelling and network upgrade planning.
The innovation of this project lies in the precision and scalability of its results. GIA achieved up to 97.5% accuracy in PV performance estimates compared to real-world installations. This success is due to GIA’s rigorous analysis, which calculates the net usable roof or open space for each property, the performance potential of every panel, and accounts for contextual factors like shading, local climate data, and surrounding developments.
GIA’s output solutions also provide interactive tools to manage and model various scenarios at any scale i.e., individual panel, property, portfolio, electoral ward, etc. This ensures that the user/decision maker has an energy simulation tool, in this instance related to solar PV, that they can use as part of interactive asset management, policy development, and progress monitoring.
Lessons for the UK’s Devolved Regions
GIA’s work highlights key learnings for all of the UK’s regions to advance toward net-zero:
- Urban solar PV can make a significant contribution to localised and national targets. The Belfast project evidenced that the existing building stock of circa 5,200 properties could provide:
- 68,743kW of solar PV systems.
- 196,409 solar panels.
- 39,270,180kWh/year of renewable energy production.
- a payback period for the combined systems around 9.5 years with many as quick as 6 years.
- 14,565 tonnes co2e savings per year.
- 10% of the city centre’s total energy demand and 3% of Belfast’s entire electricity demand using a renewable source.
This demonstrates that urban scale PV can and should play a significant role in the composition of renewable technology strategies addressing climate change targets and wider fuel poverty goals.
- Collaborative working between central and local government, distribution network operators, the private sector and communities is crucial to move projects from technical feasibility to implementation.
- The development of large scale, interactive, urban technical assessments represents a fundamental starting point for any city, country, asset manager or elected representative to understand how they can maximise decarbonisation gains through PV while optimising financial investment.
Comparatively, Scotland’s Draft Energy Strategy and Vision for Solar includes a commitment to deploy between 4-6GW of PV by 2030; a commitment that requires strategic and localised plans for commercial, domestic and utility-scale roof and ground-mounted solar. Similarly, the Welsh government’s recent consultation reviewing the country’s renewable energy targets recognised the need for a “fivefold increase in generation of electricity in Wales between now and 2050” while cumulatively across the devolved nations and England, the UK Government aims to achieve 70GW of solar PV by 2035. As of March 2024, the UK’s cumulative installed capacity is just 15.8GW.
As such, strategic planning based on sound evidence bases to inform central and local government decision makers, such as local planners, politicians and elected officials is crucial to rapidly deliver on these targets.
Herein, GIA’s approach in Belfast provides a lighthouse project, demonstrating exactly how urban environments can help achieve these targets and best inform strategic planning and decision making to drive change forward. If Belfast’s urban environment could produce approximately 10% of the city centre’s entire electricity demand annually, imagine the contribution possible to decarbonisation targets across all of the UK’s towns and cities should England, Scotland and Wales follow suit across their existing building stocks where, for example, London alone consumes 34,454.9GWh/year as the combined local authority with the highest electricity use in England, Glasgow consumes 2,402.4GWh of electricity per year as the largest electricity user in Scotland, and Cardiff consumes 1,402.2GWh/year as the largest electricity user in Wales. Accurate, interactive, evidence bases are crucial to planning the renewable transition and mix of technologies required.
To discuss how we can help support your net zero journey reach out to Justin McHenry or Simone Pagani.