More than 21,000 solar panels will be installed on the rooftops of six CapitaLand buildings by the year end, in a partnership with Sembcorp Industries, both groups said separately yesterday.

When completed, the installation will form the largest combined rooftop solar facility in Singapore by a real estate company.

Sembcorp will install, own and operate the solar panels, and the energy generated will be used to power the properties. There will be no installation cost incurred for CapitaLand, making the initiative "a good business case for sustainability", the property developer said.

The six CapitaLand properties - located at 1 Changi Business Park Avenue 1, 9 Changi South Street 3, 2 Senoko South Road, 40 Penjuru Lane, Techpoint and LogisTech - are held under the Ascendas Real Estate Investment Trust (Reit), CapitaLand's business space and industrial Reit.

Together, the solar farms, comprising 21,240 panels, will be able to generate around 10,292MW hours of energy annually. This is equivalent to powering about 2,300 four-room Housing Board flats each year. In addition, any surplus solar power generated will be channelled to the grid.

The solar energy system will help eliminate over 4.3 million kg of carbon dioxide emissions a year, which is akin to taking 937 cars off the road or planting over 52,000 trees.

Sembcorp Solar Singapore, which is under Sembcorp, owns and operates solar assets at more than 1,500 sites across the island. These include rooftop solar projects on public housing blocks, schools, government sites, and private commercial and industrial facilities.

Sembcorp said the agreement is not expected to have a material impact on the earnings per share and net asset value per share of the group for the financial year ending Dec 31, 2019.

CapitaLand said these efforts will bring it closer to new sustainability targets to generate at least 20 per cent of its energy consumption from renewable energy for its enlarged global portfolio by 2025.

The group's chief sustainability officer, Ms Lynette Leong, said that following its recent integration with Ascendas-Singbridge, it can now leverage a wider network of properties to "contribute meaningfully towards sustainability".

The group will explore the use of renewable energy certificates resulting from excess energy generated by the solar panels at the six properties to offset carbon emissions from its corporate operations at its Singapore headquarters in Capital Tower and Galaxis.

"We will further review opportunities within our enlarged global portfolio to deploy clean energy technologies to power our real estate operations," Ms Leong said.

Separately, CapitaLand announced it has raised a total of $300 million in new sustainability-linked loans with Credit Agricole Corporate & Investment Bank, Natixis Bank and Societe Generale. The group will have the flexibility to use the loans on green projects and for corporate purposes.

Through the five-year multi-currency sustainability-linked loans, interest rates may be reduced based on CapitaLand's achievements of environmental, social and governance metrics.

This makes CapitaLand the first company in Asia to partner Societe Generale for a sustainability-linked loan, and the first real estate partner in Asia for Credit Agricole Corporate & Investment Bank and Natixis for a sustainability-linked loan.

CapitaLand group chief financial officer Andrew Lim said: "Together with Credit Agricole Corporate & Investment Bank, Natixis Bank and Societe Generale, we hope to demonstrate that financial returns can be in sync with the interests of the environment and community."

Sembcorp Industries shares closed at $2.39 yesterday, down 0.83 per cent. CapitaLand shares closed at $3.69, up 0.27 per cent.