The capacity for solar photovoltaic (PV) systems to generate electricity here has nearly quadrupled in the past three years as solar panels have mushroomed all over Singapore.

The total installed capacity of such systems has swelled from 33.1MW peak (MWp) in 2014 to 129.8MWp in the first quarter of this year, according to data released by the Energy Market Authority (EMA) yesterday.

In 2010, the Economic Strategies Committee set a target of having renewable energy sources like solar energy contribute to 5 per cent of Singapore's peak electricity demand or 350MWp by 2020.

Dr Thomas Reindl, deputy chief executive of the Solar Energy Research Institute of Singapore, said Singapore is on track to exceed the 350MWp target.

Under the SolarNova scheme, which aggregates solar demand, agencies such as the Housing Board provide rooftop space for firms to install panels. In return, town councils enjoy discounted electricity rates.

The private sector, town councils and grassroots units were major contributors to the expanded solar capacity from 2014. The newly upgraded Bukit Panjang Community Club, for example, has about 150 solar panels installed on its roof.

Non-residential installations of solar panels in the private sector accounted for 45.9 per cent of the total installed capacity, while town councils and grassroots units such as the HDB contributed 44.7 per cent towards the figure.

589 Number of solar panel installations by the residential sector - primarily private homes - as of the end of the first quarter of this year.

A spokesman for the EMA said it has made it easier for consumers to be paid for supplying the excess energy they generate to the grid.

Residential users account for less than 5 per cent of total installed capacity. As of the end of the first quarter of this year, there were 589 installations by the residential sector, which comprises primarily of private homes.

Cost remains one of the obstacles, experts have said, since larger rooftop systems tend to be more economical compared with smaller systems. But residential use may increase as the cost of solar panels is expected to drop further.

Research is being done to see how Singapore can overcome its space constraints to have more solar panels installed. This includes the setting up of the world's largest floating solar PV cell test bed at Tengeh Reservoir last year, which will test and evaluate the performance of 10 different systems.

Singapore's total electricity consumption rose by 2.3 per cent from 47.5TWh (terawatt hours) in 2015 to 48.6TWh last year, according to the EMA report.