Optimising greenhouse environment and energy inputs for sweet pepper production in the UK - a commercial demonstration of the use of thermal screens and advanced climate control

Escalating energy costs, the Climate Change Levy (CCL), and increasing pressure to reduce the environmental impact of energy use mean that energy saving continues to be an important issue for all producers of protected crops. The Horticultural Development Council has funded a number of energy saving projects for the protected cropping sector. This project used knowledge gained from trials with other crops to demonstrate how it can be applied in sweet pepper production.

Trials undertaken on a commercial sweet pepper nursery in Essex showed that a modern design of moveable thermal screen delivered additional energy savings of 52kWh/m² compared to a temporary screen. It was also shown that temperature integration can save energy when applied to a sweet pepper crop. However, yield can suffer if the correct crop balance is not maintained. Investment in energy saving technology and constant attention to climate control set points delivered an energy saving of 24% and a payback on investment in less than 18 months.

Specific objectives were:

1. To establish (and successfully apply) a range of environmental control set points that would fully exploit the energy saving potential of temperature integration whilst optimising crop response.
2. To establish the energy consumption (and energy cost) that could be realistically achieved on a commercial pepper nursery by introducing energy saving technologies.
3. To quantify any effect of these techniques on crop yield, quality, scheduling and disease levels.
4. To stimulate commercial uptake of advanced climate control techniques and thermal screens in the pepper sector by communicating the results of the work to growers in the UK.