Return of Investment

Investment cost = SGD 45,000

Eletricity cost reduction per months = SGD 2,000

Assume the piezoelectric carpet last for 5 years, and maintenance cost for 5 year is SGD 12,000
hence, the total saving is SGD 120,000- 12000 = 108,000

ROI = (108000-45000)/45000 =140%

Payback period = 25 months