Commercial Solar Panels for Marinas & Boatyards on the Solent

Walk the pontoons at Swanwick, Warsash, Hamble Point or Gosport and look up. Chandlery buildings, rigging sheds, dry-stack halls and workshop roofs — most of them large, steel-framed and unshaded, many facing the water to the south. It is exactly the roof stock a commercial solar installation is designed for.

The two biggest operators on the Solent have already committed. Premier Marinas — whose sites include Swanwick and Gosport — reports around 3,630 panels across seven marinas with more than 1,200 kWp of generating capacity, built up over roughly 15 years and about £850,000 of investment. MDL Marinas has installed over 1,000 panels across four sites, including at Hamble Point, where the first 100 panels went on the chandlery building back in 2018 and a further 230 have been added since.

That matters for two reasons. First, it is proof the economics work at marina scale in this exact coastal environment. Second, it raises the bar: independent yards, sailing clubs and smaller marina businesses from the Hamble to Lymington are now competing on berthing costs and sustainability credentials against operators who generate a chunk of their own power. The good news is that a single yard does not need a corporate estates team to do the same — a 30–100 kWp system on one good shed roof is a straightforward project for an owner-led installer.

Marinas are unusual among commercial sites in how well their consumption lines up with solar generation. The expensive loads run in daylight, and the busiest season is summer — precisely when panels on the Solent produce most.

One point marina operators know painfully well: under Ofgem's maximum resale price rules, you cannot mark up the electricity you resell to berth holders — you pass it on at the rate you paid. So the lever you actually control is your own purchase cost. Every kWh generated on your roof and used by the hoist, the workshop or the office is a kWh you never buy. The same logic applies to yards and clubs across the wider region — see my page on commercial solar in Southampton for how this plays out at city businesses too.

A marina roof is a harsher environment than an inland farm shed, and the kit list should reflect that. This is the part of the survey I care most about, because a system that is cheap on day one and corroding by year five is a bad deal.

• Salt-mist certified modules. Panels should carry IEC 61701 salt mist corrosion certification — the international test standard that exposes modules to saline fog cycles specifically to prove coastal durability. Most tier-one manufacturers certify their panels; I check the certificate, not the brochure.
• Marine-grade mounting. Anodised aluminium rails with stainless steel (A2/A4) fixings, and no mixed-metal contact points that invite galvanic corrosion in salt spray.
• Inverters and isolators out of the weather. Wherever possible I locate inverters inside the building — a rigging shed or plant room — rather than on an exposed external wall taking spray off the water. Where external mounting is unavoidable, enclosure IP rating and orientation matter.
• Wind loading. Waterfront sheds at somewhere like Hamble Point or Gosport are in exposed wind positions. Fixing schedules need calculating for the actual site, not copied from an inland job.
• Roof condition first. Many marina buildings date from the 1970s–90s. If a roof needs recovering within ten years, do it before the panels go on, not after.

I install SigEnergy, Fox ESS and GoodWe equipment, and my small team and I survey and install every job — on a coastal site, the difference between a spec sheet and a survey is exactly where problems hide.

The Solent coast is one of the better solar locations in the UK. A well-oriented, unshaded roof here typically yields around 950–1,050 kWh per year for every kWp installed — I will not promise more than that, because nobody honest can. Applied to typical marina building sizes:

For scale: MDL's Hamble Point installation — roughly 330 panels — and Premier's seven-site portfolio show what marina roofs sustain in practice.

Payback depends almost entirely on self-consumption. A yard using 70–80% of its generation on site does far better than one exporting half of it, because export earns only a Smart Export Guarantee rate — typically somewhere between 3p and 16p/kWh in mid-2026 depending on tariff — while every self-consumed unit offsets your full commercial import rate. Marinas' daytime-heavy loads push self-consumption high, which is why the sector suits solar so well. I model this from your actual half-hourly consumption data before quoting, for any site covered by my commercial solar service across Hampshire.

VAT. The 0% VAT rate you may have read about applies to domestic installations only (until 31 March 2027). Commercial marina and boatyard installations carry standard 20% VAT — recoverable in the normal way if you are VAT registered.

Capital allowances. Commercial solar qualifies as plant and machinery. Under the Annual Investment Allowance you can deduct 100% of the cost — up to £1 million of qualifying spend per year — from taxable profits in year one, which comfortably covers any single-yard installation. Note that solar is classed as a special-rate asset, so the separate "full expensing" relief does not apply to it; above the AIA cap, a 50% first-year allowance is the usual route. Confirm treatment with your accountant — I will supply the itemised breakdown they need.

Batteries. Shore power is the load solar alone cannot fully serve, because berth-holder demand runs into the evening. A commercial battery charged on midday surplus and discharged into the evening shore-power draw closes that gap, and can also blunt peak demand when the travel lift is working. For yards around Portsmouth Harbour and Gosport this pairs naturally with generation — see commercial battery storage in Portsmouth.

Grid connection. The Solent is SSEN's patch (Southern Electric Power Distribution). Anything at marina scale needs a G99 application to SSEN before connection rather than the simpler G98 notification, and busy waterfront substations can mean export limits. I handle the G98/G99 paperwork myself on every job — it is part of the install, not an extra.

Most rooftop solar on commercial buildings in England is permitted development — no full planning application — provided conditions on projection and siting are met. But the Solent has some local wrinkles worth knowing before you commit:

• Hamble river yards (Fareham and Eastleigh borough council areas): generally straightforward for rooftop PD, but conservation area designations around the old village and waterfront need checking per site.
• Gosport and Portsmouth Harbour: plenty of former naval and heritage buildings on the waterfront. If a building is listed, listed building consent applies regardless of permitted development rights.
• Lymington: planning is split between New Forest District Council and the New Forest National Park Authority depending on which side of the Park boundary a site sits — the Lymington and Pennington Neighbourhood Plan spans both authorities. Rooftop solar remains possible inside the Park with conditions, but the NPA is the authority to consult, and I verify the current position for each job rather than assume. Lymington's waterfront is serious commercial territory for this: Berthon's shipyard dates to 1877 with 280 deep-water berths, and Lymington Yacht Haven runs 500 fully serviced berths.
• Leaseholders: many yards and clubs occupy land leased from harbour boards or estates. Freeholder consent is a contractual requirement separate from planning — get it in writing early.

My base in Whiteley (PO15) puts the whole of this coastline inside my 30-mile radius — Swanwick and Universal marinas are minutes away, Hamble and Warsash just across the river, Gosport and Portsmouth Harbour twenty minutes east, and Lymington at the western edge of the patch. My small team and I survey, quote, install and sign off every job ourselves. If you run a marina, boatyard or sailing club anywhere on the Solent, send me your last few electricity bills and I will tell you honestly whether solar stacks up for your roof.

Do solar panels survive salt air at a marina?

Do we need planning permission for solar on marina buildings?

Can solar cut what our berth holders pay for shore power?

What size system does a typical boatyard need?

Which marinas and yards does Solent Solar cover?