Greenhouse Canada

Features Efficiency Energy
Inside View: June 2010

March 9, 2012  By Gary Jones

B.C. growers can plug into ‘Power Smart’ savings

In Canada, commercial floriculture and vegetable greenhouse growers face an extreme marketing disadvantage each winter. Low ambient light levels here mean growers face a severe production disadvantage compared to growers in the southern U.S., Mexico or South America. Daylength and cumulative illumination from ambient solar energy is deficient across Canada for as long as five months each winter. This creates a problematic “production gap” for Canadian growers.

Energy-efficient greenhouse lighting helps Canadian greenhouse growers fill this gap. The benefits are not only savings in energy costs (including natural gas and other fuels in addition to electricity), but also help the business cases submitted by growers wanting to grow “all year round.”


Houweling’s Nurseries is a leading vegetable greenhouse grower in British Columbia. They were the first British Columbia grower to work with B.C. Hydro to qualify for “Power Smart” incentives.

B.C. Hydro identified conservation as the most effective option to meet the province’s growing energy needs. The “Power Smart” program not only helps customers conserve, but also enhances economic growth and prosperity through new technology and processes. Houweling’s case provides a great example of a partnership with an energy provider that other growers may be able to emulate.

Houweling’s took advantage of the benefits of energy efficiency in its new “Phase 6” lighting project. They deployed electronic ballasts and adopted advanced greenhouse lighting controls. These energy conservation measures saved significant amounts of electricity, and having significant incremental cost, enabled B.C. Hydro to offer an incentive of $459,220 – some 23 per cent of the entire project cost.

“Working with B.C. Hydro partners who were knowledgeable about our industry was key to this application,” said Ruben Houweling, a senior manager with the company. Houweling also noted that the company has future intentions to work with B.C. Hydro on retrofits and work with an energy manager funded in part by the utility.

Houweling’s decided to use PL SE 1,000W HPS electronic ballast luminaires to help conserve electricity and manage residual 68W “heat spill” from conventional reactor ballast systems.

Argus Controls (a B.C. specialist greenhouse control company) provided improved lighting control management of larger numbers of breakers, as well as customized software for enhanced computer controls.

The installed lighting control system reduces annual lamp burn hours by about 1,007 hours a year, which offers huge electrical savings. It saves energy in two ways:

Ambient Daily Instantaneous Solar Intensity Set Point Lighting Control – The new lighting control system uses ambient lighting sensors with set points at about 160W/m2 for measuring instantaneous ambient solar intensity. When ambient solar lighting reaches 160W/m2, after about 15 minutes the computer control system shuts down the main growing area’s 1,760 x 1,000W lighting luminaires. This form of control reduces lighting by 764 hours each year.

Zone Compartmental Control for the Tomato Propagation Area and Time – Houweling’s new computer lighting control system saves electricity by zone controls for lighting in the propagation areas during the 45 day/year propagation period. In the past, unoccupied parts of the propagation area had to be lit because there were no compartment lighting control zones. The new system enables only the areas of the greenhouse occupied by young plants to be lit, reducing electrical consumption by about 30 per cent (243 hours) each year.

The end result was that Houweling’s saved 2,281,000 kWh/yr in energy. This equates to about $185,000/year in reduced electrical energy savings. Together with the B.C. Hydro incentive of $459,220, this brought the payback from electrical energy savings alone to less than eight years. When improved crop production is factored in, together with reductions in natural gas requirements (the lighting systems provides additional heating), the payback for this project is expected to be four years or less.

Such a project demonstrates the potential energy and financial savings that are possible from evaluating energy conservation opportunities in a greenhouse setting. If year-round production is a goal and would help increase the business bottom line, it’s worth contacting your energy provider to discuss the technical options that may be available. There may even be financial incentives similar to the B.C. “Power Smart” program for your region. ■

Gary Jones is chair of production horticulture at Kwantlen University, Langley, B.C. He serves on several industry committees and would welcome comments at .

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