“It’s the smartest thing we’ve done,” says Aron Hoff, Meyers Fruit Farms Inc.’s manager as he describes the company’s decision to undertake an energy curtain retrofit for its greenhouse in Niagara-on-the-Lake, Ontario. The $100,000 investment is well on its way to saving the company nearly $40,000 a year in energy costs.

Meyers Fruit Farms Inc. is a greenhouse and fruit farm operation producing seasonal and holiday flowers in its greenhouse. In operation year-round, the 37 000 square metre (m²) greenhouse maintains a daytime and nighttime temperature of 19°C. Prior to the retrofit, the greenhouse consumed about 39 000 gigajoules (GJ) in natural gas and about 2300 GJ in electricity, for an annual energy bill of about $560,000.

Hoff explains that a 4100-m² portion was considerably older than the rest of the greenhouse, which already had energy curtains. Given the energy savings Hoff had calculated for the newer greenhouse sections, he knew that energy curtains were a valuable investment. With incentives from Enbridge Inc. and Natural Resources Canada’s (NRCan’s) ecoENERGY Retrofit Incentive for Industry, the business case was there for a retrofit with a net simple payback of under 2.5 years.

In winter 2009, a heat retention fabric was added to the older greenhouse’s inflated double polyethylene roof to reduce the energy required for nighttime heating. Although the savings are difficult to isolate given fluctuations in weather and other energy costs, Hoff estimates that projected annual savings of about 3070 GJ, equating to just under $40,000, will be met easily. When the energy curtain is completely closed, Hoff has calculated energy savings of about 60 percent.

The benefits of the curtain go beyond the monetary and energy efficiency aspects. “In terms of quality, you can feel the heat reflecting off the new fabric,” says Hoff. The energy curtain diffuses 64 percent of the incoming light, enabling the company to grow crops with different light requirements in the retrofitted area. Prior to the retrofit project, the shading was controlled manually. However, a pulley system with a drive line has been installed, and the greenhouse computer controls the amount of shading desired. “We can program it to suit the requirements of a particular crop, taking the demand off the boilers to some extent,” notes Hoff.

The retrofit allows Meyers Fruit Farms not only to gain significant energy savings but also to maximize greenhouse space and increase the company’s capacity to grow different crops.