Home-grown firm Sunseap has said that the solar power it generated last year made a huge impact on the environment - equal to planting nearly a million tree seedlings over a decade.

In total, Sunseap's business of generating solar energy for corporate and retail customers helped offset over 58,000 tonnes of carbon emissions, or greenhouse gases, the company said in its sustainability impact report released yesterday.

This is equivalent to planting about 960,000 trees over 10 years for its customers, according to the United States Environment Protection Agency's Greenhouse Gas Equivalencies Calculator.

Sunseap allows customers to reduce their carbon footprints by switching to certified solar energy through the open electricity retail market.

It also leases solar panels to corporate and government customers, and currently accounts for 168 megawatt-peak (MWp) of solar systems across 1,500 buildings islandwide.

This is more than half of the installed solar capacity in Singapore, Sunseap said.

Sunseap chief executive Frank Phuan said the sustainability report signalled the firm's desire to be as transparent as possible in how it operates its business, even in the midst of the Covid-19 pandemic.

"The Covid-19 pandemic has caused unprecedented challenges for many companies wanting to go green as their businesses are impacted by the current economic climate," he said.

"However, we encourage companies to press on and look ahead at a greener future. The sustainable changes we take now will have a positive impact in the long run, environmentally and financially."

Yesterday's report, which also tallied the company's own carbon emissions last year, was done in conjunction with local sustainability consultancy Paia Consulting.

Air travel by employees made up the bulk of Sunseap's 47 nett tonnes of carbon emissions.

Sunseap won a government tender last year called SolarNova 4, which involves installing more than 170,000 solar panels across buildings in Singapore, including 1,218 Housing Board blocks and 49 government sites.

The tender was followed by the HDB announcing plans to more than double its capacity for solar power to 540MWp by 2030, enough to power about 135,000 four-room flats with clean energy.

Sunseap raised $203 million in Series D funding earlier this year for its continued regional expansion, following investments from Singapore's investment company Temasek, and Thai energy group Banpu.

It currently has solar farms in Vietnam, India and Cambodia.