Exorbitant prices were also paid by some service sector customers.
"We are the highest in the region for household using lots of electricity," Tilak Siyambalapitya, a power sector analysts said.
"For medium and large commercial customers we are the highest. For manufacturing industry, we are certainly not the highest, Singapore is the highest."
He was speaking to members of the Sri Lanka Association of Economists at its annual sessions.
For households which used more than 300 units (kiloWatt hours) Sri Lanka's tariff was about 23.
87 rupees, compared to 21.09 rupees for Singapore, an analysis by Siyambalapitiya showed.
Commercial customers (which are in the service sector) were charged highest rates.
Medium size commercial customers were charged 22.09 rupees a unit, higher than Singapore at 21.09 rupees, while large commercial users had to pay an average of 20.98 rupees. In Singapore it was only 14.60 rupees for large customers.