Proposals wanted for 6MW energy storage system test-bed

SINGAPORE — Renewable energy sources such as solar power are increasingly being harnessed here, but how and where to store these energy resources is becoming the next focal point for Singapore as it moves towards energy independence and reducing its global carbon footprint.

In a joint press release yesterday, the Energy Market Authority (EMA) and Singapore Power called for proposals to implement a test-bed for a grid-level energy storage system.

Projected to be six megawatts (MW) in size — enough to power 500 four-room public housing flats for a day — the test-bed will allow the government agencies to better understand the performance and facilitate the deployment of large-scale energy storage systems in Singapore.

Mr Stanley Huang, Singapore Power’s chief financial officer, said: “This is the first and largest energy storage system test-bed to be conducted on Singapore’s national grid. With more solar energy initiatives, (the storage system) will address the challenge of intermittent solar (photovoltaic) energy due to clouds and rain, and smoothen the power flow at all times of the day and night.”

Solar photovoltaic technologies convert energy from sunlight directly into electricity using solar panels, and a storage system has the potential to allow the authorities to better manage electricity demand.

Technologies capable of storing electricity on a large scale may include lithium-ion batteries, chemical-based redox flow batteries, and mechanical spinning flywheels.

Proposals submitted to the agencies would have to factor in operating conditions such as Singapore’s hot and humid climate, which could affect battery performance, space constraints, as well as safety concerns given the highly built-up and urbanised environment here. The test-bed could be deployed over three substations in Singapore.

Professor Subodh Mhaisalkar, executive director of Nanyang Technological University’s Energy Research Institute, said that it was “timely” for Singapore to look at such technologies: “The key opportunity in Singapore is solar (energy), and as you put more solar panels, you have issues of intermittency, (in times of) rainy or cloudy weather … This could create a lot of disturbances on the power grid.”

An energy storage system could ease such fluctuations, he said, and it is crucial to find ways to collect the energy and stabilise the grid to ensure a continuous supply of power.

Mr Koh Leong Hai, programme manager for sustainable building technology at the Energy Research Institute, said that the effectiveness of this test-bed would depend on which technology was used. The safe use of lithium-ion batteries could be a big issue, while flywheels need a lot of space as well as enough energy output to compensate for the power needed to keep them running, he added.

And while redox flow batteries could be a large store of energy, they are still new to the market and can be quite costly.

“Each solution has its own pros and cons, and all of them behave differently … And if ... they are not tested thoroughly, it could also be a challenge,” Mr Koh said.

Even then, Mr Niels de Boer, senior scientist at the Energy Research Institute, lauded the efforts to divert resources into this, noting that the 6MW test site is a “reasonably large” one, showing that Singapore is serious about testing its long-term usability. He warned though that experimenting with a test-bed may hold some risks because Singapore is a high-tech city with facilities that put a high demand on grid availability and grid power.