Siam Piwat Simon and GUNKUL Advance ‘Solar + Battery’ Model Transforming Siam Premium Outlets Bangkok into Thailand’s First Fully Renewable-Powered Premium Outlet, Setting a New Benchmark for Green Retail
Siam Piwat Simon Company Limited, has joined forces with Gunkul Engineering Public Company Limited, or GUNKUL, a leader in Thailand’s integrated renewable energy business to expand the Solar Rooftop project at Siam Premium Outlets Bangkok into a Solar-plus-Battery model. Covering more than 54,400 square meters and reducing greenhouse gas emissions by over 2,540 tonnes of CO₂ equivalent annually, the project strengthens the outlet’s position as one of Thailand’s leading renewable-powered retail destinations. The collaboration also reinforces GUNKUL’s role as a Net Zero Partner, helping businesses unlock the full potential of renewable energy while advancing Thailand’s ambition to become a regional Green Destination.
Ms. Naruechon Dhumrongpiyawut, Chief Executive Officer of Gunkul Engineering Public Company Limited (“the Company”), said that this collaboration reflects the shared vision of GUNKUL and Siam Piwat in driving the first shopping center in Thailand to use 100% renewable energy in its common areas (RE100) by 2030 through the ‘Solar-plus-Battery’ model. Previously, the installation of a solar rooftop system could help reduce electricity costs only during the daytime. However, an integrated model incorporating a battery energy storage system can enable businesses to achieve significantly greater electricity cost savings by managing clean energy and deploying it at times when it is needed by the business. According to a report by BloombergNEF, the cost of solar combined with energy storage is beginning to enter a competitive range. In addition, global energy storage installations in 2026 are expected to increase by 41% from 2025, reflecting the rapid growth and potential of battery technology at every scale, from households and commercial and industrial sectors to utility-scale applications.
The Company sees its role as a Net Zero Partner that helps businesses transition toward carbon neutrality through a variety of clean energy strategies and solutions that respond to the different Load Profiles of customers, within the context of Thailand’s evolving energy market policies and the continued drive toward sustainability goals. The Siam Premium Outlets Bangkok project, covering more than 54,400 square meters, comprises solar rooftop systems installed on buildings and parking areas, as well as a battery system. The project represents a new model for energy use in commercial buildings—moving beyond solar alone to integrate renewable energy generation and storage more effectively, unlocking the full potential of clean energy and helping turn RE100 ambitions into reality for Thailand’s business sector.
Mr. Michael Tang, Managing Director of Siam Piwat Simon Company Limited, said that the Phase 2 development of the solar rooftop system at Siam Premium Outlets Bangkok in collaboration with GUNKUL—which includes the installation of solar panels together with a 250 kWh Battery Energy Storage System (BESS) on the roof of the parking area—represents an expansion of the project to further advance the full-scale adoption of renewable energy. This reinforces Siam Piwat Group’s commitment to sustainability and its target of achieving Net Zero by 2050 through the reduction of Scope 1 and Scope 2 greenhouse gas emissions.
Siam Premium Outlets Bangkok has been Thailand’s first premium outlet to use renewable energy since 2022, reflecting its commitment to driving the business toward sustainability while simultaneously creating benefits for communities and society and protecting the environment.Through this collaboration, Siam Premium Outlets Bangkok was able to achieve its target of using 100% renewable energy in its common areas ahead of schedule, in the second quarter of 2026. Covering more than 54,400 square meters, the solar installations operate under an Direct PPA (Direct Power Purchase Agreement) and generate more than 5,115,000 kWh kWh of electricity annually, reducing greenhouse gas emissions by over 2,540 tonnes of CO₂ equivalent per year—equivalent to the annual carbon absorption of more than 267,200 trees. This collaboration will help strengthen long-term energy security and provide tangible support for businesses in progressing toward Carbon Neutrality, while helping enhance Thailand’s potential to become an important Green Destination in the region.
The collaboration between GUNKUL and Siam Piwat reinforces their shared vision to accelerate renewable energy adoption across Thailand’s retail and commercial sectors—from solar generation and energy storage to energy management and Direct PPA. This integrated approach also marks an important step toward a more liberalized electricity market. Backed by more than 40 years of experience and end-to-end capabilities across the energy value chain, GUNKUL is positioned to help businesses turn environmental ambitions into practical energy solutions that support sustainable growth, while strengthening Thailand’s competitiveness in the region and across the global supply chain.
Symbol: GUNKUL