Global rooftop solar photovoltaic (PV) installations are expected to jump to almost 95 GW by 2025 from 59 GW in 2021, according to a recent analysis.
In the last five years, Rystad Energy analysts reported rooftop installations have surged 64%, and currently represent 30% of total global solar capacity.
Much of the global growth results from increased adoption in China, where rooftop solar PV capacity pre-2017 sat at 4 GW. In 2021, installations in China reached 27.3 GW, according to the analysts.
“Small-scale solar PV, including residential, commercial and industrial, and off-grid projects, are gaining momentum supported by economics and policies, with China, Japan, Germany, the U.S. and Australia emerging as key markets,” said Rystad’s Gero Farruggio, head of renewables research.
“Key drivers” for residential sector growth include high retail electricity costs, low solar system costs, high feed-in tariffs (FiT) and the available roof space. FiT policies are designed to accelerate renewable energy investments by ensuring customers will receive a set price from a utility for all the electricity they generate and provide to the grid.
Among the top 10 countries for total installed rooftop capacity is the United States, where most rooftop systems power residential properties. The popularity among homeowners is the result of incentives including FiTs and grants. Many U.S. homes also have rooftops with enough space to support solar panels.
The U.S. Energy Information Administration (EIA) recently noted that the annual share of domestic electricity generation from renewable energy sources is forecast to rise to 22% in 2022 and to 24% in 2023 from 20% in 2021. The gains would result from “continuing increases in solar and wind generating capacity,” it said in the latest Short-Term Energy Outlook.
The gains by solar and wind would lead to an “expected decline in natural gas generation, which falls from a 37% share in 2021, to 36% in 2022 and to 35% in 2023,” EIA’s researchers noted. EIA sees utility-scale solar capacity rising by 22 GW in 2022 and 24 GW in 2023.
“We expect solar additions to account for nearly half of new electric generating capacity in 2022,” the EIA researchers said. “In addition, in 2021, small-scale solar capacity (systems less than 1 MW) increased by 5.4 GW to 33 GW. We project that small-scale solar capacity will grow by 4.0 GW in 2022 and 4.3 GW in 2023.”
According to a report by Wood Mackenzie and the Solar Energy Industries Association, solar installations in the United States have increased as costs have dropped. The cost of installation has fallen by more than 60% since 2010.
For an average-sized residential installation, the cost has decreased by around half, from a pre-incentive price of $40,000 in 2010 to about $20,000 in 2021. Meanwhile, residential installations nearly reached 25 GW in 2021, compared to 667 MW in 2010, according to the report.
California, Florida and Texas have led the United States in solar PV installations since 2019, with Texas overtaking California with the most solar installations last year. Current solar capacity sits at about 6.1 GW in Texas, 3.6 GW in California, and 1.7 GW in Florida.