In 2023, the global rooftop solar installation market experienced explosive growth. From large-scale industrial plants in China to residential homes in Australia, from the Alpine regions of Switzerland to gigafactories in the United States, rooftop photovoltaics have become a critical force in the global energy transition. Below are major news events in the global rooftop solar installation sector in 2023.

China: Industrial Decarbonisation and Architectural Aesthetics Advance Together

Chongqing’s Largest Rooftop PV Project Grid-Connected

February 23, 2023, Chongqing – State Grid Chongqing Electric Power Company announced that the city’s largest rooftop PV project (by installed capacity) was completed and commissioned on a trial basis in Liangjiang New Area. The project covers a total area of over 250,000 square metres, with a total installed capacity of approximately 36 MW. It is expected to generate 26 million kWh of electricity annually, reducing carbon emissions by more than 20,000 tonnes per year.

Built in two phases on the rooftops of Chongqing BOE Display Technology Co. and Chongqing BOE Optoelectronics Technology Co., the project took five months to complete. It operates under a “self-generation, self-use, surplus to grid” model. According to a BOE energy manager, the rooftop PV system not only significantly reduces electricity costs but is also expected to lower average temperatures on the top-floor office areas by 1–2°C compared to previous years.

The project is of great significance for the energy supply and summer peak-shaving capacity of the Beibei district of Chongqing.

Gansu: Rooftop PV Brings Benefits to Rural Homes

February 27, 2023, Chongxin, Gansu – In Taopo Village, Baishu Town, workers were busy installing solar brackets on the rooftops of farmers’ homes. This distributed PV project makes full use of idle rural rooftops to build small-scale solar power plants. Electricity generated is first used by households, with surplus sold to the grid for income.

“Using idle space, waterproofing and heat insulation, generating power for self-use, and selling surplus for money” — local villager Wang Luxi summed up the benefits of rooftop solar with a doggerel he composed himself. The project offers advantages such as wide adaptability, short construction periods, and stable expected returns, and is gradually becoming a livelihood project that promotes rural revitalisation and intensive resource use.

Beijing’s New Workers’ Stadium: Dressed in a High-Tech PV “Coat”

June 27, 2023, Beijing – The newly renovated Beijing Workers’ Stadium was unveiled, featuring a major highlight: LONGi Green Energy Technology’s LONGi Longjin Building-Integrated Photovoltaics (BIPV) product.

Installed around the perimeter of the stadium roof, the system covers a total area of 3,712 square metres with a total installed capacity of 351 kW, resembling a “golden necklace.” This is currently China’s largest stadium BIPV roof, using customised PV modules that meet architectural aesthetic requirements while providing clean electricity for the venue. According to estimates, the system will reduce carbon emissions by 4,930 tonnes over 25 years.

As a landmark building in Beijing, the successful application of BIPV on the new Workers’ Stadium not only gives the building new vitality but will also lead more urban landmarks toward low-carbon transformation.

Wuxi: “Dragon Scale” Roof Composes a Green Symphony

August 27, 2023, Wuxi, Jiangsu – The main roof of the under-construction Wuxi Symphony Hall will be covered with tens of thousands of solar PV panels shaped like “dragon scales,” a technology that is a domestic first.

Developed by China Construction Eighth Engineering Division and partners over more than a year, the “dragon scale” PV panels use a unique polymer-coated tempered glass with perovskite quantum dots to improve power generation efficiency while also being anti-glare. The panels overlap like dragon scales and are installed on an irregular curved roof designed to capture sunlight from all angles.

Covering an area of 7,000 square metres, the “dragon scale” roof will feature about 12,000–13,000 solar panels, with an installed capacity of 1,240 kW. It is expected to generate 1.2 million kWh annually, saving 479 tonnes of standard coal and reducing CO₂ emissions by 1,043 tonnes per year.

The only building in the world that has successfully achieved a “dragon scale” solar roof is Google’s California headquarters (completed in 2022), which uses a regular curved design. The Wuxi project is more challenging because the roof is an irregular curved surface. Related technologies have been patented.

Global Perspective: Good News from Rooftop PV Around the World

Australia: Rooftop Solar Covers 11.2% of National Electricity Supply

Data released April 16, 2024 – According to the latest report from the Australian Clean Energy Council, Australia’s cumulative rooftop solar PV capacity exceeded 20 GW in 2023. The annual addition was 2.9 GW, with a total of 314,507 systems installed, making it the second-best year on record.

Rooftop solar now accounts for 11.2% of Australia’s total electricity supply, making it the country’s second-largest renewable energy source (after wind power) and fourth-largest electricity source overall. It is estimated that about one-third of Australian households and businesses have installed rooftop solar technology, giving the country one of the highest penetration rates in the world.

New South Wales set a new annual installation record for any Australian state, adding 970 MW. Queensland became the first state to exceed 1 million total rooftop solar installations.

Switzerland: Record Growth of 51%

According to the 2023 National Report for Switzerland released by the International Energy Agency’s Photovoltaic Power Systems Programme, Switzerland added 1,640 MW of new PV capacity in 2023, an increase of 51% year-on-year, reaching a record high. By the end of 2023, Switzerland’s cumulative PV capacity reached 6,374.7 MW, with annual PV generation of 4.624 billion kWh, covering 8.25% of the country’s electricity consumption.

The report highlights that PV installations in Switzerland are dominated by distributed rooftop systems, with residential rooftops accounting for 87% of systems installed, and industrial installations contributing 41% of new capacity. Switzerland is advancing its “Energy Strategy 2050,” aiming for PV generation of 34 billion kWh by 2050.

On the policy front, the “Alpine Solar Offensive” launched in 2022 offers investment subsidies of up to 60% for winter-optimised solar plants. In 2023, Switzerland also launched its first national auction programme for large PV systems above 150 kW, awarding 163 MW across 437 projects.

Notably, due to strict building heritage protection laws, BIPV is widely used in Switzerland, accounting for about 10% of new capacity in 2023, and receives higher feed-in tariffs and municipal bonuses.

United States: Tesla Gigafactory Aims for World’s Largest Rooftop Solar

November 6, 2023, Texas – Logan Grant, Senior Engineering Manager at the Tesla factory, revealed that Tesla is deploying a large number of solar panels on the roof of its Gigafactory in Austin. Upon completion, the project is expected to become the world’s largest rooftop solar system, generating about 30 MW. The first phase has already been successfully completed.

New Jersey: Largest Community Solar Project Completed

November 30, 2023, Monroe Township, New Jersey – Local authorities and community solar company Solar Landscape jointly inaugurated the state’s largest completed rooftop community solar project. Installed on the roof of a commercial warehouse with a capacity of 4.99 MW, the project will provide discounted solar electricity to nearly 830 households. Together with another site, the two installations total nearly 8.8 MW, serving 1,437 local residents.

The community solar model allows residents who cannot install their own rooftop systems to enjoy the benefits of solar power through subscriptions, particularly offering an energy equity solution for low- and moderate-income families.

Germany: Munich Launches Large Tenant Electricity Project

September 2023 – Munich launched the city’s first large-scale “tenant electricity” project. A large PV system was installed on the roof of a residential building. Phase one installed 2,336 modules with a power of 957.76 kWp; phase two installed 2,231 modules with a power of 970.49 kWp. The system generates about 1 million kWh per year, meeting the electricity needs of about 400 households.

The “tenant electricity” model allows apartment tenants to directly use electricity generated by the PV system on their building’s roof without installing any equipment themselves, providing a feasible pathway for residents of multi-family buildings to participate in the energy transition.

Technology Innovation and Policy Support

In 2023, the rooftop solar industry achieved not only breakthroughs in installed capacity but also significant progress in technology innovation and permitting efficiency.

The 2023 performance report from the U.S. National Renewable Energy Laboratory showed that the automated permitting platform SolarAPP+ significantly accelerated the installation speed of residential solar projects. Compared to traditional permitting processes, projects using the platform reduced the time from application to completion of installation and final inspection by an average of 14.5 days. Over the full year of 2023, the platform saved U.S. local governments a total of 15,400 hours of permitting review time, with 668 installers submitting 18,906 permit applications through the platform.