14 September 2026
Most engineering consultancies meet a solar farm at detailed design, when the land is secured, the layout is drawn and the grid connection is agreed. By then, the decisions that most affect cost and programme have already been made, often without the ground, water and access evidence to support them.
The early stages of solar project development are where civil, geotechnical and geoenvironmental engineering earns its keep: planning support, site feasibility assessments, flood risk and drainage strategies, ground investigations and geotechnical design. Alan Wood & Partners provides exactly this early-stage input, alongside the civil and structural delivery that follows, and this article explains what early engineering involves and why developers who buy in early spend less later. For the wider energy market context, see our overview article, Power and Energy Infrastructure.
Before a scheme is fixed, four strands of engineering evidence shape whether it is viable and what it will cost to build:
Site feasibility and constraints. Levels, access, watercourses, existing services and ground conditions determine buildable area and layout options. A feasibility assessment turns a promising land parcel into an evidenced development case, or rules it out before serious money is spent.
Flood risk and drainage strategy. Solar sites are frequently on lower-grade land where flood risk is a live planning issue. A flood risk assessment and outline drainage strategy, developed with the planning application rather than after it, addresses the questions planning authorities and the Environment Agency will ask, and avoids consent conditions that surprise the construction budget.
Ground investigation and geotechnical design. Foundations for inverters, transformers and substations, cable routes, and the frames themselves all depend on what the ground will support. An intrusive ground investigation, scoped by the engineers who will later design the foundations, prices ground risk before it is inherited by the construction contract.
Planning support. Engineering inputs that stand up in the planning process: drainage strategies, access arrangements and supporting technical assessments, coordinated so the consented scheme is one that can actually be built economically.
These are the strands developers most often leave until later, and they play directly to the strengths of a multi-disciplinary practice, because feasibility, flood, ground and structure inform each other rather than arriving as four separate reports — see our Renewable and Low Carbon Infrastructure service for how we bring these together under one practice.
The cost of engineering knowledge does not change much across a project's life. The cost of engineering surprises does.
Discovering poor ground at feasibility changes the layout, the foundation concept, or the site. Discovering it during construction changes the contract sum. Our energy portfolio makes the point at both ends of the lifecycle:
On a front-end engineering design (FEED) study for a 400MW battery storage scheme and substation on a confidential site, early cut-and-fill modelling, settlement analysis, comparative foundation appraisals, a peat management plan and floating road design for access over peat set the development strategy before capital was committed, exactly the work that decides whether a site is deliverable at cost.
At Llanwern Farm Solar Park in Newport, where Alan Wood & Partners delivered the civil, structural and geotechnical engineering for the 132/33kV primary substation forming the solar farm's point of connection, poor ground conditions demanded pile-supported monolithic raft foundations and chemically stabilised access roads, with critical plant lifted above predicted flood levels. Ground and flood shaped everything; knowing that early is worth real money — see our companion article, Grid Connections and Substations, for how that connection was engineered.
The pattern repeats across our wider storage and connection work: on energy sites, risk sits in the ground, in flood, in settlement and in access, far more than in the equipment, which arrives as a standard product.
Early-stage engineering is most valuable when the same practice can carry the scheme through. Alan Wood & Partners provides:
Feasibility assessments, flood risk assessments and drainage strategies for planning
Intrusive ground investigation and geotechnical interpretation
Geotechnical and foundation design for plant, substations and supporting structures
Civil design for platforms, access roads, crossings and site-wide drainage
Structural design for substation buildings, bunds and support steelwork
Interface management where schemes meet highways, railways, utilities and third-party assets
Continuity matters because the questions do not change between stages; they get more expensive. The engineer who scoped the ground investigation knows exactly what the foundation design can rely on. The team that wrote the drainage strategy knows what the planning condition means in practice.
Solar's reach is also wider than field-scale arrays. At Stourton park and ride in Leeds, described by Leeds City Council as the UK's first solar-powered, zero-emission park and ride, Alan Wood & Partners delivered the structural design for the bus terminal superstructure, where solar generation meets public infrastructure.
What engineering does a solar farm need before planning?
Typically a site feasibility assessment, a flood risk assessment with an outline drainage strategy, and early ground appraisal. Together they evidence the planning application and protect the development budget from ground and water surprises after consent.
When should a solar developer commission a ground investigation?
Before the layout and foundation concept are fixed, and ideally scoped by the engineers who will design the foundations. On energy sites the ground investigation can be a substantial package in its own right, and its findings drive layout, foundations and cost.
Do civil engineers work on solar farms in the UK?
Yes, across the lifecycle: feasibility, flood risk and drainage, ground investigation, platforms and access, foundations for inverters and transformers, and the grid connection substation that gets the power to the network.
Alan Wood & Partners is an engineering consultancy supporting the delivery of major power and energy infrastructure, combining civil, structural, geotechnical and geoenvironmental engineering under one practice. If you are developing a solar scheme and want feasibility, flood or ground risk assessed while the options are still open, contact our team at the start of the project, not the end.