Fewer than half of households here have switched to an electricity retailer since the liberalisation of the energy market two years ago.
The Energy Market Authority (EMA) said many of the island's 1.4 million households are still purchasing electricity from SP Group.
This was the only supplier in Singapore prior to the launch of the Open Electricity Market (OEM) in November 2018.
In the first year of the scheme, 40 per cent of households switched to OEM retailers.
This rose marginally by another 8 percentage points by the end of last month.
The OEM was set up to provide households with a choice of energy retailers. There are now 12 OEM suppliers in Singapore.
Keppel Electric has the largest market share at 23.4 per cent, followed by Geneco with 21 per cent.
In a survey of more than 7,000 households conducted by the EMA between last November and June this year, nine in 10 indicated that they were satisfied with the service provided by their OEM supplier.
Diamond Energy Merchants ranked the highest in terms of overall satisfaction while Keppel Electric ranked the lowest.
Retailer ratings are updated on the OEM website every six months. Half of the survey respondents who had renewed their contracts did not check the price plans and ratings of other OEM retailers before doing so, despite 53 per cent of them attributing their decision to "attractive price plans".
EMA chief executive Ngiam Shih Chun said customers should visit the website to compare the standard price plans from all OEM retailers.
Since the launch of the OEM, most consumers who switched to electricity retailers would have signed two-year contracts.
Many would have started receiving notification about subsequent supply arrangements after their current contracts end. The EMA said consumers should look out for these notifications.