Deep freezers powered by the sun conserve two billion seeds

A total of 270 solar panels have been installed on the roof the of the Millennium Seed Bank, at Wakehurst Place at Ardingly, near Haywards Heath, as part of a commitment by the Royal Botanic Gardens, Kew, to reduce electricity consumption and move to renewable energy.

On the longest day of the year (June 20) for example, the panels will have produced up to 400 kWh (kilowatt hours) of electricity, depending on weather conditions. Since the beginning of February, when the panels were installed, they have generated 21,860 kWh.

The panels have been carefully arranged to blend in with the curved roof of the iconic building which stands in an Area of Outstanding Natural Beauty on the 500 acre country estate of the Royal Botanic Gardens, Kew. Image attached, please credit Wolfgang Stuppy RBG Kew.

Over the course of a year they will generate an estimated 48,500 kWh of free electricity– more than enough to power the freezer units that currently store some 2 billion seeds from more than 30,000 species at temperatures of -20 °C in the vaults of the Seed Bank .

The Millennium Seed Bank is the largest wild seed collection in the world and is helping to safeguard the world’s most endangered plants. Kew and its partners have already collected and conserved seed from 11% of the world’s wild flowering plant species and aim to conserve 25% by 2020.

Tom Parrott, Energy Manager for Kew and Wakehurst Place, said: “Previously the electricity used in Kew’s Millennium Seed Bank came from the National Grid and our target for the Seed Bank is for 100% of its energy needs to be met from renewable sources by 2020.

“The solar panels are an important first step towards this and their installation is the largest project of its kind undertaken by Kew. The panels will produce enough energy to power all of the bank’s seed stores.”

He added: “The system is performing well and we hope to reach our annual target, weather permitting.”

The solar panel installation is expected to generate 1,200,000 kWh of renewable energy over the next 25 years. This figure is equivalent to a reduction of 654 tonnes of carbon dioxide* over the lifetime of the project.

The Millennium Seed Bank is open to the public and visitors can see a display showing how much energy is being generated and how much carbon is being saved, along with information about the project and solar power in general.

Energy consumption at the Seed Bank has already been reduced by measures such as introducing low energy computers and incubators, installing intelligent boiler controls, and changing behaviour – for example making sure computers and monitors are switched off at the end of the day.

Experts from Kew worked closely with both the Department for Environment, Food and Rural Affairs (Defra) and Mid Sussex District Council planners in the run up to seeking planning permission to minimise visual impact of the solar panels.

* All Carbon dioxide (CO2) emission savings are calculated using the current DEFRA CO2 conversion factors.