5% of the UK’s consumption of tomatoes comes from one large-scale environmentally friendly greenhouse project completed last year.
Located in East Anglia, near Norwich, the greenhouse area consists of 16 hectares of growing space (two greenhouses of 7 and 9 hectares each). Whereas a typical greenhouse burns fossil fuels to produce heat, this system takes waste heat from the nearby water treatment works and uses this instead of burning fossil fuels to heat the vast greenhouse area, cutting carbon emissions for crop production by an estimated 75%.
Heat is extracted from the local water treatment works and transferred in a closed-loop system to heat pumps located at the greenhouses. Electricity for the ground source heat pumps is provided by the grid and Combined Heat and Power units. These CHPs have the added benefits of providing waste heat which further supplements the greenhouse heating and provides the supplementary carbon dioxide to enrich the atmosphere inside the greenhouses and increase yields.
The main greenhouse is planted with 378,000 tomato plants growing using a vertical hydroponics system and biocontrol methods (such as the release of the predatory insect Macrolophus pygmaeus) to protect the crops. The adjoining greenhouse using the same technology is producing an estimated 14 million cucumbers and 22 million peppers.
Visit Low Carbon Farming for information on the project.