Lawrence Berkeley National Laboratory

Berkeley Lab’s annual Tracking the Sun report summarizes installed prices and other trends among grid-connected, distributed solar photovoltaic (PV) systems in the United States. The latest edition of the report focuses on systems installed through year-end 2018, with preliminary trends for the first half of 2019. The analysis is based on project-level data from approximately 1.6 million systems, representing 81% of all distributed PV systems installed in the United States through the end of 2018. Key findings from this year’s report include the following: -Distributed PV Systems Keep Getting Bigger, More Efficient. Median system sizes in 2018 grew to 6.4 kW for residential and roughly 50 kW for non-residential systems, though the spread in system sizes is also quite wide—especially for non-residential systems, with 20% larger than 200 kW. Increasing system sizes over time partly reflect a steady growth in module efficiencies, which rose a full percentage point to a median of 18.4% among systems installed in 2018. The report also details trends among other system design and project characteristics, including panel orientation, inverter loading ratios, solar-plus-storage, use of module-level power electronics, third-party ownership, and non-residential host customer segments. -Installed Prices Continued to Fall through 2018 and into 2019. The report focuses its analysis of installed prices specifically on host-owned distributed PV systems. Among these systems national median installed prices fell year-over-year by 5-7%, depending on the specific distributed PV customer segment. Those declines are broadly in-line with trends over the past five years. National median installed prices in 2018 were $3.7/W for residential, $3.0/W for small non-residential, and $2.4/W for large non-residential systems. Considerably lower prices are observed among many systems, however. -Installed Prices Vary Widely Across Projects. For example, among residential system installed in 2018, prices for host-owned systems ranged from $3.1/W to $4.5/W between the 20th and 80th percentile levels, and prices for small and large non-residential systems varied across similarly wide ranges. The report explores sources of that pricing variability, including differences in system size, module- and inverter-type, mounting-type, location, installer, host customer-type, and new construction vs. retrofits. This year’s report also contains a multi-variate regression analysis to isolate the effects of individual pricing drivers, including characteristics of the local PV market related to market size, competition, and installer experience, among other factors.