Expert urges govt. to ensure that at least transport sector uses renewable energy

By Rathindra Kuruwita

Sri Lanka needs to establish fast charging stations to promote the use of electric vehicles, Engineer K.M.YS. Konara, senior lecturer at the department of electrical and information engineering at the University of Ruhuna said.

“When we consider long trips, we don’t consider electric vehicles because of problems with charging. If we can have fast charging stations, this becomes a non-issue. If we use slow charging (AC on board charging – level 01 – 120v, 1.4 kW) it will take about 1, 332 minutes to charge an electric vehicle to go 200 kilometres. But it only takes 4.7 minutes if we use ultrafast charging (800V, 400kW),” he said.

Surveys have shown that motorists only like to spend about 15 minutes charging their vehicles, from 20 percent to 80 percent, during long trips, he said. If charging takes longer than that, they prefer not to use their electric vehicle, Konara said.

“Fast charging stations are not recommended to be connected to low voltage grids. They must be connected to medium-voltage grids. The widespread deployment of fast charging stations also adds some stress to the grid. When we establish a large number of fast charging stations, it exerts a lot of stress on the power grid because EV charging is an extra load. This might lead to some issues with network capacity, power system stability and power quality. A DC fast charging station is a power electronic based microgrid, and whenever you have these microgrids, there will be issues like voltage fluctuations, especially drops. Then it’s linked to power grid stability problems and power quality issues. These are well known problems,” he said.

Dr. Konara added that a country needs to reinforce the existing grid to accommodate fast charging stations.

“We need to find the optimal setting and size for fast charging stations to maximize profits, minimize the impact on the power grid and energy market, and provide a quality service to electric vehicle users,” he said.

Commenting on the drive for renewables, he said Sri Lanka can achieve 80 percent of its energy needs from renewable sources.

“This has been achieved in other countries, and if we can’t get our transport sector to run on renewable energy, we are in trouble,” he said.