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