Siam Cement Group expands Onnex solar power focus amidst declining technology costs

Siam Cement Group (SCG) is shifting its focus to its Onnex solar energy brand, aiming to expand its power generation capacity from 200MW to 1000MW between 2025 and 2029, driven by decreasing solar technology costs. This move includes new solar projects totalling 400-500MW, which will feature solar farms, floating solar farms, and carports, according to Wachirachai Koonamwattana, head of SCG Smart Living's living solutions business.

SCG’s solar business currently operates a solar farm in Saraburi on 1600m² of land. The firm’s focus on solar energy solutions, provided through Onnex, is growing as households increasingly seek to install rooftop solar panels to offset rising electricity costs. A large home typically installs systems of 7-10KW at a cost of THB300,000-500,000. Solar farm development costs remain at THB20m per megawatt, with solar carports costing THB28m per megawatt.

SCG’s solar arm is proving highly profitable, with an internal rate of return of 34 per cent, noted Suchart Nokputsa, associate director for rooftop solar at SCG Smart Living. Expansion beyond Thailand is planned, with the Philippines as a key target due to favourable renewable energy investment conditions.

"The demand for solar energy is rising, particularly in sectors like deep tech and data centres, where clean energy is vital for operations," said Dusit Chairat, director for smart home living solutions at SCG Smart Living.

This strategy strengthens SCG's domestic solar business before exploring further international opportunities.