The construction of a new entrance, cycle hub and platform canopies at a popular south London train station is being hailed as the network’s first ‘Carbon Positive’ project, with arrays of integrated AluPlusSolar PV panels being installed as part of a roofing package featuring products from the Kalzip range.
The £7.5 million Denmark Hill project has been led by BAM Nuttall Ltd with Invvu Construction Consulting being responsible for the design and project management on behalf of Network Rail.
London based roofing contractor, Gribben Solar Roofing was the specialist installer of the AluPlusSolar roofs which total 260m2 across three platform canopies, the station building and an access ramp: generating an output of 35 kWp.
Located some four miles from Victoria on the South London and Catford Loop lines, Denmark Hill is flanked by two of the capital’s major teaching hospitals and has seen passenger numbers triple in the past 15 years: causing crowding with pressure on both the platforms and access routes.
Work began on site in September 2020 with the construction of a retaining wall alongside Platform 4, ready for the installation of the new canopies on Platforms 2, 3 and 4 during a Christmas possession – requiring Gribben Solar Roofing and its suppliers to complete this phase of the work in a very tight time period. All of the materials were delivered to site a week in advance of the Christmas deadline. Crucially, the redevelopment of the station facilities, and its transformation in terms of energy performance has had to fully respect the heritage status of the original Victorian structures.
Commenting on the specification process, Adrian Hartridge, the senior M&E engineer for Invvu Consultants on the project said: “We offer a full range of disciplines including structural engineering, architecture, civils and project management, with a high percentage of our work related to the rail industry and train operators. On Denmark Hill, which stands out both because of the sustainability angles and because it is Grade II listed, we were the main designer for the project.
“The design work was carried out in close consultation with the local planning authorities and the listed building authorities. Our architects have specified Kalzip on a number of projects before and when the initial approach was made here, the manufacturer put us in touch with BIPVco as the manufacturer of the PV laminates, and Gribben Solar. Together we pulled together a proposal which was successful, in part because AluPlusSolar is such a discreet system.”
MD of Gribben Solar Roofing, Paul Gribben added: “In the last 10 years I’ve overseen the installation of over 35MW of solar photovoltaic systems, across hundreds of commercial/industrial rooftops here in the UK – and the Kalzip AluPlusSolar system stands out as my most favoured system to date, because it’s so lightweight, versatile in terms of output and so quick to install.
“Denmark Hill Station was a highly complex project that had to be delivered to the highest and most precise standards and under the tightest of time constraints, which did not allow room for any errors. Some of the key challenges included the complex design of electrical cabling and components housed in a specially designed cabinet on each of the platforms. Plus, access was complicated, and we were often working after dark, as well as running electrical cables from five different canopies/solar arrays to two central points.”
Andrew Wood, the Senior Commercial Scheme Sponsor who led the project on behalf of Network Rail, reflected: “The enhancement project at Denmark Hill station was designed to alleviate overcrowding at the existing platform entrance on access routes and on the station’s platforms.
“Network Rail is committed to ensuring its developments are sustainable, and at Denmark Hill the project was designed to maximise roof/canopy space and thus maximise potential energy generation, to meet this commitment. The electricity produced by the installed PV system is greater than that used by the development, thereby making it ‘carbon-positive’ from an operational standpoint.
“We were very pleased with the attractive and unobtrusive finish of the PV installation on the canopies and rooves, especially given Denmark Hill station’s Grade II listed status. Network Rail was also pleased that this project could be delivered with its contracting partners in just 32 months from project inception to opening, which sets a new benchmark for SPEED delivery. Network Rail is now developing other projects where it hopes to employ the same sustainable system.”
The new facilities at Denmark Hill Station became operational in September 2021 and the project has since won the 2021 Award for the best roof under 1500m2 at the annual Kalzip awards.
AluPlusSolar is a versatile and highly energy efficient lightweight system that has been developed in conjunction with BIPVco who supplied the panels for bonding onto the Kalzip roof sheets: in this case the AF 65/537 1.0mm option in aluminium with a RAL 7012 Basalt Grey PVF2 finish.
The Kalzip AluPlusSolar profile can be produced in the full range of RAL colours as well as a variety of forms, including concave and convex to suit a wide variety of roof structures. Also being integrated and low in weight, they therefore offer architects and engineers greater flexibility compared to conventional PV arrays while delivering similar power output. With very low future maintenance implications, this all results in a far lower whole-life cost for a development.
The Sales Director for Kalzip, John McAllister, reflected: “This highly complex regeneration project had to be delivered to the highest and most precise standards, and under the tightest of time constraints, meaning it was vital all delivery deadlines were met.
“Aesthetically the refurbishment was ground-breaking in terms of an upgrade to a landmark Victorian structure: in many ways fusing the modern with the old, and above all making it accessible and user-friendly for passengers.
“The Kalzip AluPlus solar PV system ticked all the boxes to achieve the sustainability improvements for the refurbishment: making it the first carbon positive station development in the UK. And although the Kalzip AluPlusSolar system used on the project is not bespoke, it adopts a building integrated PV solar solution that is a genuine innovation for the roofing industry.”
