Vertical solar panels cover three walls of net zero hotel

The voco Zeal Exeter Science Park is a net zero carbon hotel with a number of unique features, not least a wrap-around vertical solar panel façade that is expected to produce more energy than the hotel needs.

The voco Zeal has been developed by Zeal Hotels in partnership with IHG Hotels & Resorts (who own brands such as Holiday Inn, InterContinental and Crowne Plaza) and Valor Hospitality.

voco Zeal Exeter Science Park has installed vertical solar arrays on three of its four exterior walls

The hotel’s design includes energy-efficient systems such as heat recovery, adiabatic cooling for guestrooms and reversible heat pumps that balance heating and cooling loads.

Triple glazing, airtight construction and fresh air ventilation enhance energy efficiency, mean that the hotel uses a third of the energy of a traditional hotel.

Needless to say, the building runs entirely on renewable energy, indeed it is the first hotel in the UK to use Solarlab vertical photovoltaic panels as cladding, with vertical solar arrays installed on three of its four exterior walls.

The black glass panels, which blend into the overall design of the hotel are expected to generate 320,000 kWh of clean energy a year, more the building is expected to use and saving 202 tonnes of CO2 per year.

The installation is projected to save around £200,000, with a return on investment inside 18 months.

The challenges of using vertical solar panels, such as uneven sunlight exposure, frequent shading and reduced energy efficiency in traditional systems, were addressed in this project by integrating SolarEdge DC-optimised inverters and S-Series Power Optimisers.

Vertical panels are more prone to shading from nearby buildings and trees and receive sunlight at more variable angles throughout the day. In traditional solar setups, panels are connected in a series (like Christmas lights), so when one panel is shaded or underperforming, it drags down the performance of the entire string. This is a major issue for vertical installations where shading is more likely and sunlight angles are less consistent.

To solve this, the SolarEdge system allows each panel to operate independently. The Power Optimisers ensure that if one panel is shaded or receiving less sunlight, it won’t impact the performance of the others. This maximises the energy output from the array, even under less-than-ideal conditions.

Currently, surplus energy is exported to the grid and imported back at night but there are plans to install on-site battery storage at the site.

Nick Spicer, managing director of solar specialist Your Eco, which installed and commissioned the vertical solar system, explains: ‘While the original plans for the hotel included a rooftop solar system, it quickly became evident that rooftop solar alone wouldn’t produce enough energy to meet the hotel’s energy demands – a common challenge in buildings with small rooftops compared to their overall size and energy consumption.

‘Rather than compromise on its sustainability goals, Zeal embraced a bold alternative: a vertical solar installation. They had a clear and ambitious vision, and we’re proud to have helped bring that vision to life.’

Tim Wheeldon, Founding Director, Zeal Hotels, added: ‘The decision to build our net-zero hotel reflects our commitment to combating climate change and reducing our carbon footprint. By harnessing renewable energy sources, implementing energy-efficient designs, and using innovative technology, we have created a space that not only provides comfort and luxury but also prioritises environmental responsibility.’