A 4.84 kWp SolaX system on the upper roof of Block A, a new build high-rise at 840 Old Kent Road, Southwark, London. 11 Jinko Tiger Neo panels on a K2 S-Dome ballasted south-facing array. Projected 3,887 kWh per year for the landlord's communal supply.
A new build high-rise on Old Kent Road in Southwark, London. Here is what we delivered.
| Property Type | New Build Mixed-Use Residential High-Rise |
| Location | Block A, 840 Old Kent Road, Southwark, London SE15 1NQ |
| Completion Date | April 2025 |
| System Size | 4.84 kWp |
| Panels | 11 × Jinko Solar JKM440N-54HL4R-BDV (440W Tiger Neo N-Type All Black Mono) |
| Inverter | 1 × SolaX X1-BOOST G4 3.0 kW (single-phase string inverter) |
| Mounting System | 19 × K2 S-Dome Ballast Mounted, zero penetration |
| Orientation | South facing, 34° from due south, 10° tilt |
| PV Array Area | 32.79 m² |
| Grid Connection | Three-phase supply, single-phase connection at communal distribution board |
| Certification | MCS Zone 1, Permitted Development |
| Generation Meter | Emlite ECA2.nz, MID approved |
| Client | HG Construction |
Block A at 840 Old Kent Road is a 21-storey new build on the Old Kent Road in Southwark, London, delivered by HG Construction as part of a wider mixed-use residential scheme. EV-ON was brought in to design, supply, install, and commission the solar PV system on the Block A upper roof, serving the building's landlord communal electrical supply. Our remit ran from the initial roof survey and structural load calculations through to grid connection approval, commissioning and MCS certification. The scope throughout was collaborative. We worked to the HG site programme, to the architect's roof drawings, and to the energy strategy the building had committed to at planning.
Block A was a live 21-storey construction site when we arrived. Panel delivery had to fit around the main contractor's crane removal, after which all rooftop access was via the building's service lift. We shared the roof and the cable routes with the mechanical and electrical, roofing, fire alarm and lift teams through the final phase of the programme. Every delivery, access window, and commissioning step had to sit inside HG's wider programme without disrupting the trades working below.
The Block A upper roof was brand new and carried a full waterproofing warranty from the main contractor. Any mounting method that penetrated the membrane would have compromised that warranty and created ingress risk across every apartment below. For a 21-storey residential high-rise, a water damage claim from compromised roof fabric is costly, disruptive, and entirely preventable with the right mounting specification.
The design needed one clear, easy to reach point where the solar system could be switched off in an emergency. The obvious option was to run the high voltage cabling from the panels all the way down the full height of the building. That would have added risk for the fire service and made future maintenance harder than it needed to be. Whatever we chose had to satisfy building control, HG's mechanical and electrical team, and our own installation standards.
We used the K2 S-Dome system, which holds the panels down with weighted trays sitting directly on the roof surface rather than bolts drilled through it. Nothing penetrates the waterproofing, so the warranty stayed intact in full. Before installing we ran the numbers against the structural engineer's design loading to confirm the roof could take the extra weight. It could, with no reinforcement needed. The whole array comes to around 725 kg spread across 24 square metres, comfortably inside the design limits. The finished system sits low at a 10 degree tilt to keep wind loading down, with clear walkways left around the abseil anchor points on the roof edge.
We worked with the HG design team to fit the array into the roof zone marked on the architect's drawings, clear of the plant and service equipment already up there. Eleven all black Jinko panels face broadly south at a shallow 10 degree tilt. The roof is almost entirely free of shade, which is unusual in central London and means the array runs close to its full potential. Estimated generation is 3,887 kWh a year, which hit the figure the building had committed to for the landlord's communal supply.
We went through the options with HG's mechanical and electrical team and with building control. Rather than run high voltage cabling from the panels down the full height of the building, we put a dedicated shutdown switch in the Level 12 lift lobby and a second one on the outside wall at the same level. The inverter, meter and remaining switchgear all sit together on the upper roof. Building control were satisfied, the fire service has a shutdown point they can actually reach, and no high voltage cabling runs through occupied floors.
Block A at 840 Old Kent Road now has a 4.84 kWp SolaX solar PV system on its upper roof, projected to generate 3,887 kWh per year for the building's landlord communal supply. The system was commissioned April 2025, certified under MCS Zone 1, and installed under Permitted Development Rights with Building Regulations self-certified through the MCS Competent Persons Scheme.
Projected annual CO₂ offset is 774 kilograms. The roof is almost entirely clear of shade, which is rare in central London, and the array sits cleanly inside the unshaded zone marked on the architect's drawings. Output is landing where we expected it to for a roof of this size, direction and tilt.
The landlord's communal supply now runs partially on solar during daylight hours. Every kilowatt-hour generated on the roof offsets communal electricity cost. The system delivered the on-site renewable generation target committed to in the planning energy statement under London Plan Policy SI 2 and Southwark Local Plan Policy 11 (Climate Change).
For more on solar panels for apartment buildings as the new standard on London new build schemes, and what the 2028 Future Homes Standard will mean for main contractors and developers, see our solar for new build apartments page.
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