Tracking the Sun (PDF) is an annual report from Berkeley Lab on installed solar panel prices and other trends among grid-connected, distributed solar photovoltaic (PV) systems in the United States. Primary authors of this year’s report were Galen Barbose and Naïm Darghouth.
The focal points are on systems installed through year-end 2018, with some emphasis also on preliminary trends for the first half of 2019. The scope of 1.6 million systems, representing 81% of all distributed PV systems installed in the United States through the end of 2018, accurately feeds the analysis based on project-level data.
The annual report, published this year in October of 2019, came to the following key findings:
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 systems 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 facts.
Prices sometimes reflect differences in system design, market, and installer characteristics.
The report shows technological improvement with declining costs. Along with the diminishing prices, as median module efficiencies experience a significant rise from 2002. The rise from 12.7% in 2002 to 18.4% in 2018 in module efficiencies indicates that engineers continue to succeed with improvements to technologies. (In a word, algorithms, and more algorithms.)
The report clearly emphasizes that substantial differences in pricing remains across states, even after controlling for other pricing drivers, which is an interesting finding.
One positive note for the future is that the wide variability in installed pricing may indicate the potential for further installed price declines in many places. The U.S. DOE’s Solar Energy Technologies Office, involved from the start, aims to reduce the cost of PV-generated electricity by about 75% between 2010 and 2020, and by an additional 50% from the 2020 goal by 2030.
Solar-plus-storage systems were up considerably in 2018 compared to previous years in several states, reaching approximately 5% of the solar PV market in California most notably.
Third-party-owned solar remained far from their peak of a few years ago, but it still accounted for 38% of the residential solar PV market. The option is apparently also useful for nonprofit organizations or other tax-exempt hosts that can’t take advantage of solar tax credits — companies owning the solar can do so, though, and then pass the savings on.