MAILBOX: Address Efficiency First—Then Tackle PV


This energy conundrum we find ourselves in makes me chortle. I live in Alberta—the Canadian version of Texas, just smaller. We are in a battle with OPEC and, of course, the United States, for energy to market. That said, I’ve been involved with solar—including net-zero and Passive House programs—for the past five years.

During that time, I’ve found that folks who want to take their existing stick-built home to net-zero energy seem to feel that if they install a PV system (grid-tied, of course), they have done their part to working toward net-zero.

However, when they find out that the PV system is unable to offset their winter loads, reality sets in. Without addressing their consumption…well, the laundry list gets very big very quickly in a conventional stick-built home that’s built to the code minimum.

I agree with Pete Gruendeman in his recent letter (HP175) about addressing the envelope first. I advise anyone to start first with the shell of the home. Insulate, seal, and be sure to provide proper ventilation to the newly sealed-up home. Second, I advise them to upgrade all windows and doors to triple-pane, thermally broken, multipoint turn-and-tilt systems. I also advise them to reduce the size and number of all north-facing windows to reduce exposure. Most of all, this change helps to improve the whole-wall R-value.

I then advise people to examine their appliances and, if necessary, upgrade to more than “energy-wise” appliances, with the overall goal of reducing their carbon footprint and lowering energy consumption. Next, I suggest that they monitor their consumption habits for a month. At the end of that month, a review helps determine energy consumption habits. Then we examine what can be addressed/changed to reduce the load.

It’s only then that a PV system is discussed and sized to the new reduced energy usage.

Steven Bell • Calgary, Alberta

Comments (3)

Todd Cory_2's picture
Todd Cory_2 (not verified)

job one is decarbonizing your lifestyle:

Edward-Dijeau's picture

Great little article. Reducing the load through LED lights or "energy Wise" appliances is less expensive than adding more solar. At night, when solar is not available and your utility is burning coal, oil or natural gas to supply your home, the lower nightime or winter footprint is doing your part for the air we breath and for the planet. Next will be "energy storage" for on grid systems that allows us to save up energy we do not use durring the day first before sending the rest of it on to the utility and using the stored electricity first, at night, before using fossil fuels and the utility credits. Utilities are going to be slow about this because their Billon Dollar investment in power plants and infrastructure that has made North America the industrial power it is, needs to be supported as well. Solar and wind now cost less per Megawatt to build and distribute but can not be stored for nightime use so right now, the best a utility can do is 50% renewable energy but as a homeowner we could do better with energy storage but that comes at a personal cost. Reducing the load is the most cost effective way to do this.

Ed Kelly_3's picture

Our company's philosophy is exactly this"it is less expensive to reduce demand than create supply. Don't forget your light bulbs

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