Dr Alona Armstrong                            OSE0070

Written evidence submitted by Dr Alona Armstrong

Environmental Audit Committee: Technological innovations and climate change: onshore solar energy inquiry

The below evidence is provided by Dr Alona Armstrong, Director of Energy Lancaster and Senior Lecturer in Energy & Environmental Sciences at Lancaster University, with contributions from Fabio Carvalho. It is underpinned by research undertaken by Fabio Carvalho, Hollie Blaydes, Lucy Treasure, and Ryan Holland. Information relating to Q1 and Q3 are from awareness of the broader literature and are not our research expertise. Information related to Q2 is directly underpinned by our research and innovation activities.

Our research is funded by UKRI, InnovateUK KTN, Low Carbon, Eden Renewables, Clarkson and Woods Ecological Consultants, Wychwood Biodiversity, and Solar Energy UK with support in kind from numerous farming, solar and nature focussed stakeholders. The research is in collaboration with Prof Piran White (University of York), Prof Simon Potts (University of Reading), Dr Simon Smart (UKCEH), Dr Emma Gardner (UKCEH), Dr Stuart Sharp (Lancaster University), Prof Duncan Whyatt (Lancaster University), with valuable contributions from Hannah Montage (Clarkson and Woods), Tom Clarkson (Clarkson and Woods) and Guy Parker (Wychwood Biodiversity).

1.     What are the current barriers (regulatory, technological or otherwise) to expanding the number of small and large-scale solar installations in the UK?

Community acceptance is a significant factor in the approval of ground-mounted solar parks in the UK. Several studies detail case studies that provide insights into the reasons for opposition to renewables. In addition, Roddis et al 2018[1] undertook an analysis of all planning applications between 1990 and 2017 for solar parks, analysing a range of potential factors that influenced the planning decision. They found (italics denote direct quotes):

• ‘the less that the project represented a ‘new’ visual addition to the landscape, the more likely it was to be approved’
• landscape remoteness/ruggedness was associated with a lower likelihood of approval, although attributed to terrain suitability and accessibility
• ‘proximity to Special Areas of Conservation or ‘SACs’ (protected areas designated under the EU Habitats Directive) had a positive effect on the likelihood of planning consent for solar farms.’ Whilst counterintuitive this may be explained ‘may be explained by the suitability of solar farms to rural and semi-rural areas, which are more likely to host protected habitats.’
• ‘the grade of agricultural land had a significant effect on solar farm applications: when compared to the highest grade, proposals made on lower grades of land are between 2.1 and 2.8 times more likely to gain planning consent, and proposals made on non-agricultural land are 4.5 times more likely’
• ‘Increased numbers of tourists staying in the county for one or more night was associated with decreased likelihood of a positive planning outcome for solar farms. This is potentially explained by the concerns around their negative impact on tourism and scenic re-creation, or perhaps simply because sunny places attract more tourists and are also more suitable for solar farm development.’
• ‘the more deprived the local area … the more likely it was for solar farm applications to be approved’
• ‘A unit increase in installed capacity, measured in megawatts (MW), had a negative effect on the likelihood of achieving planning consent’
• ‘In terms of the time at which the planning application is made, each

successive year decreased the likelihood of planning success by…21.5% for solar farms. This indicates that rather than becoming more acceptable over time, perhaps a ‘saturation effect’ is approached’

Roddis et al 2020 studied what shapes community acceptance of a large-scale (nationally significant infrastructure projects) solar park[2]. Given the increasing number of very large sites, this understanding is highly relevant. They found that the impacts on wildlife and habitats was the most common rationale for opposition (Fig 1). However, it was also a rationale for support, although much less frequently, given the implications of climate change.

Fig. 1. Factors which impact opposition and support of Cleve Hill Solar Park. Source: Roddis et al 2020.

2.     Does Government policy and current planning guidance adequately address the issues raised by proposals to install solar farms on land with high agricultural or ecological value?

2.1             Land take by solar parks

Solar parks currently occupy ~144 km2, covering:

•          0.06% of the UK land surface

•          0.17% arable land

•          0.06% improved grassland

•          0.02% semi-natural grassland

These calculations are based on a digitised solar park boundary dataset[3], UK Centre for Ecology and Hydrology land cover dataset[4].

If the capacity of solar PV grew in line with the Climate Change Committee’s projections in their 2019 Net Zero Technical report[5] and the proportion of ground-mounted PV remained the same across land covers, this could change to:

•          0.62-2.64% of the UK land surface

•          1.18-7.66% arable land

•          0.59-2.52% improved grassland

•          0.26-1.10% semi-natural grassland

2.2             Scientific uncertainty of the impacts of solar parks

The suitability of Government policy and planning guidance is uncertain given limited scientific evidence of the impacts, both positive and negative, of solar parks on agriculture and ecology. At Lancaster University, in partnership with those mentioned above, we have been developing understanding in this area. This comprises insights based on existing scientific understanding, modelling with established models and data sets, and collection of field data.

2.2.1        Insight based on existing scientific literature

Solar Park Impacts on Ecosystem Service (SPIES) decision support tool: The SPIES tool informs solar park management for ecosystem services, demonstrating the range of positive and negative ecosystem service impacts of a selected suite of management actions (e.g., cutting hedges every other year, planting wildflower seeds, installing bat boxes). It is based on a peer-reviewed scientific evidence base, with evidence drawn from articles examining the effect of land management on ecosystem services given the very limited understanding developed specifically for solar parks. The SPIES tool summarises the number of pieces of scientific evidence that suggest significant degradation, degradation, neutral, enhancement and significant enhancement of each of the UK National Ecosystem Service Assessment ecosystem service classifications. Consequently, it provides insight into the likelihood of outcomes, as well as ecosystem services for which there is very limited evidence. The SPIES tool is actively used by some in industry, but specifying the use of this, or a similar tool, as part of planning (in a similar way the wind farm carbon payback calculator needs to be used for any wind farm application on peatland in Scotland[6]) would boost engagement and thus positive ecological outcomes at solar parks. More information, including a policy briefing can be found here: www.lancaster.ac.uk/spies

Managing solar parks for pollinators: we have developed solar park management guidance, based on a systematic review (using the DEFRA methodology), of the environmental and land management changes that affect pollinators[7] (Fig. 2). Similar to SPIES, the underpinning scientific evidence is from the broader literature rather than specific to solar parks. Encouraging or legislating the use of this guidance would help promote pollinator communities, with potentially positive implications for food production in arable land.

Managing solar parks for carbon: we have developed solar park carbon management guidance[8] and have a beta solar park carbon calculator that considers both technical and ecological carbon costs (anticipated release summer 2023). Similar to the SPIES tool and pollinator management guidance, encouraging or legislating the use of the guidance and carbon calculator once released could lead to increased soil carbon stocks. Given the soil carbon losses associated with agriculture and implications for food production, this could have positive impacts on agriculture if solar parks were reverted to farmland after decommissioning.

2.2.2        Insight based on modelling

Solar park pollinator modelling: a modelling study[9], using an established pollinator model has shown that solar park shape and size did not impact the number of bumble bees (normalised for area) inside solar parks. However, solar parks managed as meadows or with meadow margins (more practical for the industry) enhanced pollinator populations. The characteristics of the surrounding landscape also impacted pollinator populations, suggesting that outcomes are not wholly dependent on solar park management. Managing solar parks for pollinators would likely prompt other ecological benefits given the associated benefits of habitats, as well as increasing yields of pollinator dependent crops in areas of pollination deficit.

Pollination service benefit of honeybee hives in solar parks: we undertook a study using existing data solar park location, pollination-dependent crop (field and fruit) location, yields and value, and honeybee pollination dependencies to simulate the economic benefit of installing honeybee hives in all solar parks in England[10]. Depending on the crops grown within the foraging zone around the solar park, economic pollination service benefit varied from £4.5 to £80M, with higher values associated with scenarios where fruit was grown within the honeybee foraging zone. However, these high values are unlikely to be realised given other critical considerations, including factors that influence crop location, the potential trade-offs with wild pollinators and the level of pollinator deficit across England. Moreover, managing solar parks for wild pollinators would bring additional valuable ecosystem service benefits.

Fig. 2. Ten techniques to enhance pollinator biodiversity at solar parks.

2.2.3        Field assessment of solar park impacts on ecology

Natural capital and ecosystem service assessment: we are developing a rapid natural capital and ecosystem service assessment for solar parks. Within this project, we have assessed ~35 solar parks for a suite of vegetation and soil properties that are linked to natural capital stocks and the delivery of ecosystem services (e.g., nutrient cycling, soil carbon storage). This work is on-going and we hope to analyse the complete data set and deliver insights into the impact of solar park management and characteristics in 2023. The assessment methodology (currently under review in Ecological Solutions and Evidence[11]), underpins Solar Energy UK’s Standardised Approach to Monitoring Biodiversity[12].

The aim of Solar Energy UK’s Standardised Approach to Monitoring Biodiversity is to encourage industry to routinely assess biodiversity and environmental indicators (e.g., soil health) at their sites with the objective of collectively analysing the data generated to identify impacts of site characteristics and management on ecosystems, ultimately leading to improved management and location decisions. We are currently analysing the first year of submitted data. Legislating that the industry undertakes routine monitoring and submits the data would be beneficial to promoting evidence-based solar park management for ecological benefit. In addition, SEUK have also developed Natural Capital Best Practice guidance, aimed to promote biodiversity benefits at all stages of a solar farms life cycle[13] and has a dedicated natural capital working group.

Soil health: we have undertaken a study that assesses the soil health (including physical, chemical and biological properties) of 12 solar parks that were previously arable land or pastureland. The dataset will be completed and analysed in 2023.

Pollinator populations: we have assessed pollinator abundance and diversity at 15 solar parks with different levels of on-site floral resources and landscape characteristics. The paper is under review with the main finding that ‘local and landscape scale factors affect pollinator biodiversity within solar parks. Maximising floral resources through appropriate management actions may be the most effective way to support pollinators, especially within solar parks located in resource-poor, disconnected landscapes.’

Soil carbon: we have an eddy covariance tower, which measures carbon uptake and release from the land, installed at a solar park and we are awaiting the outcomes. There is also carbon analysis embedded within the natural capital and ecosystem service and soil health assessments.

2.3             Definition of high-quality agricultural and ecological land

There has been much focus on the use of best and most versatile (BMV) land, which comprise farmland categorised as grade 1, 2, and 3a in the agricultural land classification[14]. Whilst a UK wide map of agricultural land classes exists, Government advice is to undertake a site-by-site assessment. Consequently, there is no reliable estimate of what area of BMV has been converted to solar. Moreover, the agricultural land classification does not reflect the economic value of the land given a lack of field output data available when the classification was developed in 1988 and the influences of weather (& a changing climate) and management on yields. Consequently, when assessing if policies are sufficient, consideration of the value of land for ecology and agriculture under a changing climate and crop demand should be considered.

3.     Does the concentrated global distribution of solar panel supply chains (80% manufacture in China) pose a risk to solar technology expansion in the UK? If so, how could this be mitigated?

As well as the supply chain risks, the embedded carbon intensity of components needs to be considered. PV panels produced in countries with a greater reliance on coal (e.g., China) will have a much higher carbon intensity (potentially four times) than that of those produced in nations with a less carbon intense energy mix.[15]

January 2023