An assessment of the techno-economic viability of rooftop residential solar photovoltaic systems in Canada and U.S. cities with similar solar irradiation

We present the first comparative techno-economic analysis of 7.22 kW rooftop solar photovoltaic (PV) systems in U.S. and Canadian cities with similar solar irradiation levels along the 49th parallel north, from the Pacific to the Atlantic coast. Of the 26 Canadian cities analyzed, 11 had a positive net present value (NPV) before incentives, and 14 had a positive NPV after incentives. Similarly, among the 26 U.S. cities studied, 11 had a positive NPV before incentives, and 18 achieved a positive NPV after incentives. At the aggregated level, both countries exhibit negative NPVs before incentives (Canada: −$12,027; U.S.: −$5574), but incentives shift total NPV to $83,468 in Canada and $162,962 in the U.S., increasing profitability indices from 0.97 to 1.24 and from 0.99 to 1.32, respectively. The aggregated net present value (NPV) for Canadian and U.S. locations therefore shows similar negative values before incentives, but the post-incentive improvement is substantially greater in the United States. The 30% federal investment tax credit (ITC) is a key U.S. incentive that significantly increases the NPV of rooftop solar PV systems. Our analysis indicates that this incentive is more effective than those currently available in Canada. These results highlight the importance of incentive design, particularly the ITC—which has been in place since 2005—in promoting solar PV deployment in the U.S. These findings suggest that policy mechanisms similar to the U.S. ITC may warrant further evaluation in the Canadian context as a potential means of enhancing residential solar adoption.