Structures & Equipment
Inside View – March 2015
By Gary Jones
By Gary Jones
The 2015 Pacific Agriculture Show has wound up and with it another series of fascinating presentations of the Lower Mainland Horticultural Improvement Association “Grower Short Course.”
The Agri-Energy and Waste Management forum has become a perennial session. The main energy focus this year was anaerobic digestion (A.D.), culminating in a tour of Seabreeze Farm’s A.D. system in Delta. Industry speakers presented useful background on many different and new technologies that have contributed to the advancement of A.D. for producing energy over recent years in Canada.
But discussion of renewable energy was not limited to the Energy Forum session. Elsewhere, in the BCGGA-sponsored “Greenhouse Vegetable” session for example, Alison Thompson of the Canadian Geothermal Energy Association (CanGEA) shared her views on “From the Depths of the Earth…to your Greenhouse.”
Starting with an explanation of the difference between “geo-exchange” and “direct geothermal,” Thompson described that while the latter is new to Canada (nobody uses it as yet!), it was actually first commercialized some 100 years ago in Italy. Commercial horticultural examples include:
- Oserian Flower Farms in Kenya (http://www.oserian.com/index.html ).
- A 12-hectare greenhouse project at Kirchweidach in Germany.
- A seven-hectare greenhouse vegetable business at Schlattengin in Switzerland.
Closer to home, Thompson noted that direct geothermal has potential for numerous horticultural benefits including energy cost reduction, providing dissolved CO2, season extension, increased yield, production in otherwise un-economic geographical locations, soil sterilization and food processing.
Further, B.C. resources have enough energy to heat up to 750,000 homes or provide heat to 1,200 hectares [of greenhouses], and is especially suited to greenhouse enterprises because of the concentrated and high heat demand. It is now easier than ever to implement because there is no longer need for expensive drilling to establish geothermal potential: detailed drilling maps are available in many areas from the mining industry, and the new technique of using a “geo-chemical thermometer” allows interpretation of plant characteristics to show detailed geological DNA (depth and temperature of geo-thermal energy) of the ground in which plants grow.
Legislation that covers geothermal power [in B.C.] is the “The Geothermal Resources Act,” which essentially states that if the water supply is warmer than 80 C, use of it is permitted just like any other energy utility, but at lower temperatures its use is less restricted. More information is available in a 60-page report from CanGEA entitled “An Assessment of the True Value of Geothermal Energy (for B.C.).”
Elsewhere, a number of greenhouses in B.C. are now showing significant interest in Combined Heat & Power (CHP) systems, otherwise known as “cogen.” If the fuel is used for combined power generation, heating and cooling, it is often referred to as “trigen,” and at least one grower in Ontario has already implemented this.
While this has been a common route for growers in Europe to take for their greenhouse energy needs for several decades now, it hasn’t really caught on in Canada – at least not in B.C. This is due in large part to the different energy markets. In Europe and Ontario, growers can basically sell whatever energy they like into the local grid, but in B.C., it is based on “net metering,” so it is oftentimes less attractive. According to Reg Renner of Vancouver-based Atticus Financial group, the recent shift is due to a number of reasons, including:
- At least a 25 per cent rise in costs of electricity (only set to continue!).
- Reduction in the cost of natural gas to power the turbines for CHP.
- Advances in the application of LEDs mean more growers looking to install lights, so increasing electrical energy demand.
The energy market at the start of 2015 is an interesting place. Throw the energy needs of the new LNG venture into the BC mix, and we have a whole other story. Until then…
Gary Jones is co-chair of Horticulture at Kwantlen Polytechnic University in Langley, B.C. He welcomes comments at Gary.Jones@kpu.ca.