Until the 1980’s Scotland had a thriving tomato industry in the Clyde Valley region, near Lanark. These relatively small family businesses supplied the local Scottish markets in nearby Glasgow and Edinburgh, but the buying power of supermarkets, increasing fuel prices and cheap competition from Europe gradually undermined their viability and one by one they were either forced to grow another crop or cease trading. Eventually, none were left.
So, some might be surprised to learn that tomatoes are in production in Scotland again, but this time with a business plan that is set to change the old economics.
Jim Shanks, whose family have been dairy farmers at Standhill Farm near Hawick in the Scottish Borders for over 60 years, started to look at renewable energy more than 4 years ago. The first step was to install an Anaerobic Digestion plant to recycle farm waste and create biogas to fuel a CHP system. Initially, the CHP was used to generate all the electrical power for the dairy operation, export surplus power to the grid and use the heat to dry woodchip for biomass, but Jim also felt that building a glasshouse heated by biomass would complete the renewable energy cycle.
After much research, Jim chose turnkey specialist Certhon and their UK partners CMW Horticulture to design and build the project. ‘Certhon and CMW had a different approach than other potential suppliers – from the outset, they were keen to focus on the financial viability of the project and gave me great confidence that it could work out’ says Jim. That was particularly important because the technical requirements of successful modern tomato production were completely new ground for him.
Certhon and CMW supplied and installed everything required for a long season tomato crop: Glasshouse, heating, screens, irrigation and water treatment, ready for planting in January 2017.
The completed 16,000 m2 glasshouse with 6m gutter height and diffused glass consists of two compartments and a work area/irrigation room controlled by a Priva Connext computer. Heating is provided by two RHI compliant 1MW Herz biomass boilers connected to two 121 m3 horizontal heat storage tanks. Notwithstanding the revenue generated by the boilers through the RHI, energy saving is a high priority, so Svensson 1347 FR overhead screens and Bonar Phormium Phormitex Crystal V gable screens have been installed.
The focus on sustainability at Standhill Farm doesn’t end with heating and electrical energy, as rainwater collected from the greenhouse roof and stored in two 1,100 m3 water tanks is the main water source, with a further two 90 m3 tanks to store water from the farm’s borehole.
The crop is grown in Cultilene rockwool on Formflex hanging gutters with Priva air tubes for air circulation through the crop underneath, and all the drain water is collected, recycled and sterilised by a Priva C-Line Vialux UV system. ‘The Vialux has been crucial, as it massively reduces the volume of water needed’ says manager Mark Wilkinson. We aim for 28-30% drain and by using the Vialux we always have sufficient for the crop, we know it’s safe to re-use, and at the same time our fertiliser cost is substantially reduced. The nutrient solution is precisely controlled by a Priva Nutriflex.