Which reports a 20 ha solar farm application needs

A 20 hectare ground-mounted solar scheme is Schedule 2 development, so the first solar farm planning reports you commission are not the ones people expect. Screening comes before design. The land quality survey comes before the layout. Get those two wrong and the evidence base built on top of them has to be redone.

Schedule 2 of the Town and Country Planning (Environmental Impact Assessment) Regulations 2017 catches installations for the production of electricity where the area of the development exceeds 0.5 hectares. Twenty hectares clears that by a wide margin, which does not mean an environmental statement is required, only that the question has to be asked and answered formally.

EIA screening first

Request a screening opinion from the local planning authority under the 2017 Regulations before the design is fixed. The authority adopts an opinion on whether the development is likely to have material effects on the environment having regard to the selection criteria in Schedule 3, and it normally has three weeks to do so, extendable by agreement.

Three factors decide most solar screenings. The sensitivity of the receiving area, meaning proximity to designated landscapes, heritage assets and protected sites. The cumulative effect with other consented or proposed schemes in the same area, which is the factor most often underestimated. And the characteristics of the development itself, including the cable route and any substation.

Where the opinion is that an environmental statement is required, an Environmental Impact Assessment must be prepared by competent experts, as the 2017 Regulations require. That is a legal requirement rather than a preference, and any draft is a starting point for that team rather than a substitute for it.

Schemes above the nationally significant infrastructure threshold take the Development Consent Order route instead of the local planning authority. That threshold for solar generating stations in England has changed, so verify the current figure for your scheme rather than working from an earlier project.

Agricultural land classification

This is where solar applications are won and lost in most rural districts. National policy expects poorer quality land to be preferred over land in grades 1, 2 and 3a, the best and most versatile categories.

The published regional mapping is not sufficient. It was produced at a scale that cannot answer a field-level question, and consultees say so. What is needed is a soil survey to the Ministry of Agriculture, Fisheries and Food 1988 guidelines, carried out on an agreed grid with auger borings and pits, producing an Agricultural Land Classification map of the actual site.

Two points shape the programme. Surveys cannot be done when the ground is waterlogged or frozen, so a wet winter pushes the work into spring. And the results can change the layout, because a scheme that avoids the grade 3a fields is a different scheme from the one drawn on the constraint plan.

Where some best and most versatile land is unavoidable, the case rests on the reversibility of the development, continued agricultural use through sheep grazing, and soil protection during construction and decommissioning. Set that out as evidence rather than as assertion.

Landscape and visual effects

A 20 hectare array is low but wide, and the visual question is about extent and about the loss of open field character rather than height.

A Landscape and Visual Impact Assessment prepared to the third edition of the Guidelines for Landscape and Visual Impact Assessment is the standard document. It should include a zone of theoretical visibility, viewpoints agreed with the case officer before the fieldwork, winter and summer photography, and an assessment of effects on landscape character and on visual receptors.

Cumulative assessment deserves real work. Consented schemes, schemes under determination and schemes at appeal in the surrounding area all count, and a search radius agreed with the authority at the outset avoids an argument later.

Mitigation is mostly boundary planting and setback. New hedgerows take 10 to 15 years to perform, so the assessment should describe effects at year one as well as at year 15, and the planting has to be secured by condition with a management period.

Ecology, biodiversity net gain and the management period

Solar farms often deliver ecological improvement, and the application should show it with a metric rather than claim it in prose.

Start with a preliminary ecological appraisal and an extended habitat survey in the botanical season, roughly April to September. Protected species surveys follow from what that finds, and any survey or licence work involving bats, great crested newts, badgers or reptiles must be carried out by a suitably licensed ecologist under the relevant legislation.

Biodiversity net gain applies, and the statutory metric has to be completed by a competent person with the biodiversity gain plan approved by the authority. A Biodiversity Net Gain Assessment sets the baseline and the post-development habitat, and on a field-scale site the gain usually comes from species-rich grassland under and between the arrays.

There is a mismatch worth naming early. The statutory habitat management and monitoring obligation runs for 30 years. Solar permissions are commonly granted for around 40 years with decommissioning conditions attached. The land agreement, the management plan and the lease all need to work across both periods, and a scheme where the biodiversity obligation expires a decade before the panels come down is a problem to solve at drafting rather than at discharge of conditions.

Archaeology, drainage and construction traffic

Three further work streams sit behind the headline studies.

Archaeology is usually the one that adds time. Expect a desk-based assessment, then geophysical survey of the whole site, then targeted trial trenching agreed with the county archaeologist. Piled foundations and cable trenches are the intrusive elements, and the mitigation strategy usually turns on avoiding identified features rather than on excavation.

Drainage matters more than the panel area suggests. Ground-mounted arrays add little impermeable surface, but access tracks, substation compounds and soil compaction during construction all change run-off. A site of one hectare or more needs a flood risk assessment even in Flood Zone 1, and a 20 hectare site will need one whatever its zone.

Construction traffic is short but intense. A construction traffic management plan should cover the delivery programme, abnormal loads, the access geometry, wheel washing and the routeing agreement with the highway authority. On a rural site the access design is often the item the highway officer spends longest on.

Illustrative evidence base for a 20 ha scheme

This list is illustrative and should be checked against the authority's validation requirements and the screening outcome.

1. Screening request and the adopted screening opinion.
2. Planning statement and design and access statement.
3. Agricultural land classification soil survey with a site-specific grade map.
4. Landscape and visual impact assessment with a zone of theoretical visibility and agreed viewpoints.
5. Preliminary ecological appraisal, protected species surveys as triggered, and the biodiversity metric with a draft gain plan.
6. Archaeological desk-based assessment, geophysics and an agreed evaluation strategy.
7. Flood risk assessment and drainage strategy.
8. Construction traffic management plan and access drawings.
9. Glint and glare study, particularly where a road, a railway or an aerodrome lies nearby.
10. Noise assessment for inverters and the substation transformer where dwellings are close.

Programme the seasonal items first. Ecology surveys, the soil survey and geophysics all have weather or season constraints, and they are what set the submission date.

Grid, decommissioning and the studies PlanScope does not produce

Some of the work above sits outside what PlanScope generates, and it is better to say so than to leave a gap in the programme. Glint and glare studies, aviation safeguarding assessments and grid connection design are specialist pieces commissioned separately.

Decommissioning is handled by condition rather than by a report. Expect a condition requiring removal of the panels, frames, cabling, tracks and substation within a stated period after generation ceases, along with a soil restoration scheme. Where the landowner and the operator are different parties, that obligation should be reflected in the lease.

Grid capacity is not a planning matter, but it sets the timetable for everything else. A connection offer with a date years beyond the permission's implementation period is a commercial problem that planning conditions will not solve.

You can compare the list above with the full index of report types by category when scoping fees, and enter the site postcode on PlanScope to see which designations are recorded against the land. This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.