According to a provincial government study called the Potential for Solar Power in British Columbia: 2007 to 2025, BC’s climate is much more amenable to solar than either Germany’s or Japan’s. The average production of a PV solar array in Kamloops, for example, is 1160 kWh/kW of PV installed. Even Vancouver (1009) has much more solar potential than Tokyo (885) or Berlin (only 848). Ben Giudici, of Kamloops-based Riverside Energy Systems, provided a copy of the study.
“I believe a modestly equipped sustainable home, utilizing solar to produce 50% or more of its own operating electricity, can be built with little or no increase to the building budget if the owner and builder base key construction details on reduction of energy consumption, and are willing to trade off some aesthetics for renewable energy equipment,” said Giudici.
“Construction practices and results in our building industry suggest BC residents are more inclined to equip their homes with granite counter tops, hot tubs, swimming pools, cobblestone driveways and/or other features devoid of monetary pay back, than with grid-connected solar arrays which do offer a return on investment,” he added.
Riverside was founded in 1995 and will have completed more than 20 grid-connected solar PV installations by the end of this year. It also provides off-grid solar, wind and micro-hydro systems.
In 2010, Riverside designed and installed the solar PV system for what was meant to be a zero-net-energy home. Though PV produced almost exactly as expected, the building’s other operating systems consumed more than estimated and solar hot water production fell short of projections.
“During the year CMHC monitored the home, it self-produced about 75% of the energy it consumed,” Guidici said. “That is about 25% short of the net zero target.”
The design of a net-zero home begins with an ultra-insulated and very air tight building envelope. Every construction detail revolves around the goal of reducing energy consumption. After everything else — every electrical, heating, and cooling need — is reduced as much as possible, “then and only then are renewables such as solar PV, solar thermal, etc added.”
“The design and building process is arduous, requiring builders and homeowners to be very committed to the process and the desired net-zero outcome,” he said. “Zero net energy homes, like many other high performance systems, are dependent on their owners to reach full potential. (eg. a Ferrari will safely reach much higher speeds with a professional driver at the wheel than if I were driving.) Thankfully sustainable building practices do not need to be ‘net-zero or nothing’ in order to have significant impact.”
Jim and Cathy Brown agree. They are retired teachers who purchased a 5.8 kW system from Riverside in 2012. This provides more than 100% of their energy needs during the summer months, but not nearly enough from November through February. Cathy estimated it supplies 1/3 of their power needs then. They intend to purchase another 5.8 kW array and try to get that up to 2/3.
“You wouldn’t get anything near this rate of return if you left your money sitting in a bank account,” Cathy said. “And it makes you feel good to know you are doing something to help the environment.”
Guidici emphasized the fact it is all about choice. If a new homeowner decided to live with a a $30,000 kitchen instead of a $45,000 kitchen, and chose an asphalt driveway instead of cobblestone, “… renewable energy systems would soon be paid for.”
“If all else fails, construction and operating costs can be reduced by making the home a little smaller. This is a paradigm shift which may not come naturally for many of us, but fading perceptions of ‘forever cheap’ electricity in BC seem to be moving more people in this direction.”
Photo at top of page: Rooftop of almost zero net energy home in Kamloops, courtesy Riverside Energy.