Assessing transmission network planning timelines for NESO

Over the summer of 2024, Regen worked closely with the (then) Electricity System Operator, to develop some analysis and evidence to support their wider work to reform the connection process and their management of the growing GB connection queue. This work focused on analysis of both the development status of the current transmission network connection queue and historic planning timeframes for energy projects.

After transitioning to the National Energy System Operator (NESO) in October, more work and engagement has been progressed to understand the fuel mix required for a clean power system in 2030, as well as more clarity on the process to address the connection queue. Our analysis has provided some of the background evidence and datapoints for NESO as they make some of these crucial decisions for our future energy system. This article provides a bit of a breakdown of the work we undertook, the data sources we used and the results we have shared with NESO.

NESO has now published cornerstone analysis on what will be required to achieve clean power by 2030. The accompanying report and data workbook can be downloaded here.

Background

On 9 July 2024, the Secretary of State for Energy Security and Net Zero tasked the Electricity System Operator (ESO) with providing recommendations on achieving a clean power system by 2030.

NESO has further progressed plans to reform the grid connections process, through its Target Model Option 4 or TMO4+ programme of work. In an open letter to industry on clean power 2030, NESO has stated that these ongoing connections process reforms will run in parallel to the development of a whole systems spatial view of “what is required to deliver a clean, secure and operable electricity system by 2030”.

To inform the connections reform process, NESO recognised the need for a deeper understanding of the status of projects currently in the connections queue, as well as understanding the likelihood and timescales for these projects to progress through to development and buildout. To do so, pipeline projects will be assessed against so-called ‘Gate 2’ criteria, where project developers will be required to provide evidence of spatial planning status and land rights, to demonstrate progress in the connection queue. To assess the impact of implementing these requirements, the ESO issued a Request for Information (RFI), which closed on 28 June 2024, asking developers to provide up-to-date information on the land rights and planning status for specific projects in the connection queue.

To supplement this, Regen was commissioned by NESO to assess the planning status and timeframes of the UK electricity transmission project pipeline. To do this, Regen undertook three separate assessments:

1. An analysis of the historic timescale for projects to progress from submitted in planning or planning approval to build out
2. An assessment of the current planning status of a proportion of the current pipeline projects seeking to connect to the electricity transmission network
3. A high-level review of the responses (then) ESO received to the RFI, summarising high-level response rates and cross-referencing to the results of Regen’s planning site research.

This blog takes a closer look at some of the results of the first work package on historic timescale analysis, comparing results from different technologies using planning data that is publicly available from the Renewable Energy Planning Database register.

An analysis of planning timelines – approach taken

We were asked to provide an evidence-based indication of the amount of time it takes for renewable energy and storage projects to progress through spatial planning regimes in GB. To answer this question, we needed to consider the various factors that influence planning progression:

• The key planning stage gates to focus timeframe analysis on
• The set of planning regimes that apply to different project scales and devolved countries
• The specific planning timeframe considerations for different technologies
• Any locational factors that influence planning timeframes.

Multiple planning stage gate timeframes were identified and analysed, to get a full picture for how long projects take to connect to the network and become operational, after having submitting a planning application. The key planning stage gates we focused our analysis on were:

• Planning application submitted to decision determination
• Planning granted to under construction
• Under construction to operational
• End-to-end timeframe of planning submitted to operational.

While we analysed all technologies in the REPD, (where enough data points were available), the most interesting results were found for solar PV and onshore wind projects, due to the wealth of data available for these two as established technologies. The larger statistical sample size allowed us to cut the data in several different ways. A summary of how data was categorised is in Table 1 below:

Table 1: Categorisation of planning timeframe analysis

Planning timelines – results

Figure 1 below shows the results of our analysis of planning timeframes for solar and wind projects across three capacity scales. This illustrates that capacity size does not seem to affect how quickly solar projects become operational after obtaining planning permission, while onshore wind projects progress faster on average as MW-size decreases.

Some other key points from this analysis include:

• Solar PV projects on average required 16 months (c. 1.3 years) to progress from submitting a planning application to becoming operational at the local level. Local planning authorities typically took five months to deliver a decision on solar PV applications, whereas decisions on projects under national planning regimes took on average 14-16 months. Once planning permission was granted, solar PV projects took on average 11 months to become operational. Interestingly, the capacity scale (in megawatts) of the solar farms did not significantly impact the time it took for projects to move through the planning process.
• Onshore wind projects experienced considerably longer timelines. At the local authority level, these projects required an average of 53 months (c. 4.4 years) to progress from planning submission to operational status. At the national level, this timeframe extended to 84 months (c. 7 years). Onshore wind projects typically took 15 months to receive a decision from local planning authorities, while projects under national planning regimes took an average of 35 months for a decision to be issued. Once granted planning permission, it took on average 34 months for onshore wind projects to become operational.

Some regional variation in planning timelines could also be seen, from comparing solar and wind project planning timeframes for different regional planning authorities. Figure 2 provides an overview of these regional variations. Key findings were:

• Projects in the Yorkshire and the Humber region experiencing the longest lead times overall
• Solar PV projects generally progressing more quickly in the North East, North West, East Midlands and South East regions.
• Onshore wind farms progressing fastest in the North West, East Midlands and East of England regions.

Note – regions where insufficient project data was available were removed from the analysis

Figure 3 breaks this analysis down further to individual local planning authorities, as well as focusing on solar and wind projects that were progressed from 2015 onwards. Key findings from this analysis were:

• Solar PV sites submitted at any point (3,997 sites) took on average 3.6 months to receive a decision. Whereas those that were submitted on or after 2015 (2,916 sites) were slightly faster at 3.4 months. Those submitted on or after 2020 (2,289 sites) were faster again at 3.1 months.
• For onshore wind, across all capacity sizes, the average number of months from planning submitted to operational for sites submitted from 2015 onwards (15 sites) is 39 months. This is notably quicker compared to the average for all sites submitted in planning (596 sites), at 53 months. While at first glance this indicates that recent windfarms are being build out more quickly, the low sample size of 15 projects affects the certainty of these results. To confirm these results, we extended the sample size by including sites submitted on or after 2010 (210 sites). This show an average of 48 months, which confirms a trend of decreasing project buildout timeframes over time.
• The trend for onshore wind is also true when we isolate timeframes around progressing from planning submitted to decision determination. Sites submitted at any point in time (1,414 sites) took on average 16.1 months to receive a decision. Those that were submitted on or after 2015 (208 sites) were faster at 11.8 months. Finally, those submitted on or after 2020 (74 sites) were faster again at 9.4 months.
• This indicates a more significant decrease in planning application timeframes of onshore wind projects than solar PV.

Conclusion and considerations for this analysis

The analysis of historic planning timeframes is a useful indicator and evidence base for NESO to include in their internal analysis on the timescales of key milestones and the impact and viability of implementing TMO4+ and other connection policy reforms.

However, with significant reforms being consulted upon around the National Planning Policy Framework for energy projects (see Regen’s response from September), there is also the potential that planning timeframes for future renewable energy and storage projects could change or be fast-tracked to meet Clean Power 2030 targets. However, we remain closely engaged with NESO as connection reform is put into place and we will be closely monitoring the outcomes of the NPPF and how this will impact the development of clean power projects in GB.

For more information on this assessment or our wider work on grid connections and planning, please contact: Tamsyn Lonsdale-Smith – senior energy analyst (tlonsdalesmith@regen.co.uk)