APS Salads has revealed how it uses ‘tomato power’ to generate enough electricity to power the Kent town where some of its glasshouses are based.
The firm, which supplies Tesco with a range of tomato varieties from cherry to beef, uses combined heat and power (CHP) units at its glasshouses near Sandwich, Kent to provide electricity to the national grid.
According to the company’s owner Philip Pearson, the units produce enough electricity to power Sandwich itself, with over 211,500 mWh of electricity supplied to the national grid each year. This powers over 200,000 homes.
CHP systems are also used at APS Salads' production sites in Alderley Edge, Cheshire; on the Isle of Wight; and in the Tees Valley, Teeside, where the technology was installed this year.
The units use natural gas to produce electricity, which is then fed into the local electricity grid. Waste heat helps warm tomato plants in the glasshouses, while waste carbon dioxide helps nourish them.
The CHP systems operate in the day when demand for carbon dioxide is highest and more electricity is required by the national grid. But since the tomato crop doesn’t require heat during daylight hours, thermal storage tanks are used to store energy for when the sun goes down.
During the night, the stored hot water is then pumped back into the glasshouses to keep the crop warm without the need to run a boiler.
APS Salads was the first UK grower to introduce CHP systems and CO2 extraction in tomato production, beginning in 1998. In 2008 it also became the first tomato grower in the world to install a fully closed loop Anaerobic Digestion system.