Enhancing the performance of temperature integrating climate control strategies – a commercial demonstration

Following introduction of the Climate Change Levy (CCL), protected edible growers were increasingly focused on improving the efficiency of energy inputs. For salad crop production in the UK, energy can account for up to 40% of the total costs of production. Any further increase in the cost of energy will therefore pose a serious threat to the future profitability of this sector of horticulture in the UK.

A number of approaches and technologies are available to help reduce energy costs. The key deliverable from this project was to identify the most promising methods and highlight the economic viability of these techniques.

Findings:

A number of key technologies were identified that could allow growers of protected edible crops reduce energy costs and assist them in meeting the energy efficiency targets set by the Government.

The most promising technologies identified were:

• Improved humidity control;
• Temperature integration;
• Thermal screens.

A temperature integration (TI) based control strategy was applied to the production of a commercial crop of classic round tomatoes and compared to a more conventional approach to temperature control over two cropping seasons in 2002 and 2003.

• Energy savings of 8.4% and 5.9% were recorded in 2002 and 2003, respectively.
• Using 2003 energy prices, the average annual energy saving over the two years of the project were worth at least £4,485/ha.

The objectives of the commercial demonstration were to:

• Demonstrate the level of energy saving that can be achieved by applying temperature integration (TI) on a commercial nursery.
• Quantify any crop related effects. (disease, yield, etc.)
• Determine the overall economic impact of TI strategies on the production of a commercial tomato crop.
• Give guidelines on the application of TI for a commercially grown crop of tomatoes.