S'pore looking into geothermal energy for power generation

Sembawang hot spring park is one of the two known areas with geothermal potential in Singapore. PHOTO: LIANHE ZAOBAO

SINGAPORE - The potential of using geothermal energy for power generation is currently being explored following new developments in technology, said the Energy Market Authority (EMA) in a statement on Tuesday (Oct 26).

If found feasible, geothermal energy could serve as a new and additional source of indigenous clean energy for power generation in Singapore, it added.

Currently, solar energy is the only renewable resource proven feasible for use locally. However, land constraints could limit large solar farms and restrict the amount of sunshine that can be tapped.

Therefore, Singapore has to look harder for other renewable resource alternatives to diversify its energy sources and improve its energy resilience.

Announcing this at the SG-International Renewable Energy Agency (Irena) forum on Tuesday, Second Minister for Trade and Industry Tan See Leng said: "Advancements in technologies, coupled with declining costs, have enabled policymakers and industry leaders to significantly advance the role of renewables in global energy systems."

According to Irena, 260 gigawatts of generation capacity based on renewables has been added globally. This is four times more than the capacity added from other fossil fuel-based sources, Dr Tan noted.

Exploratory studies to be conducted will focus on determining the geothermal resource potential in northern and eastern Singapore. These areas have been identified to hold geothermal potential based on their higher surface temperature measurements, said EMA.

Two known areas with geothermal potential are the Sembawang Hot Spring Park and Pulau Tekong, which is gazetted for military use.

EMA is working closely with the Nanyang Technological University (NTU) and various ministries and agencies, including the Ministry of Trade and Industry and the National Climate Change Secretariat, to carry out these studies, which aim to establish preliminary findings by the end of next year.

If the studies yield positive results, EMA will then conduct further research to determine the viability and scalability of deploying geothermal systems in Singapore.

Acknowledging that studies looking at geothermal potential have been conducted in the past, an EMA spokesman said that newer technology has opened up the possibility of geothermal applications in Singapore.

"In the past, conventional drilling technologies were a considerable limitation. However, with time, we are looking at newer, more advanced technologies that will allow us to drill deeper and at lower costs," he said.

EMA noted in its statement that conventional hydro-thermal systems, which harness heat from underground resources such as hot water or steam, may not be applicable to Singapore due to the lack of quality sources at shallower depths.

Conventional hydro-thermal systems usually have three features: a relatively shallow heat source, nearby aquifers, which are saturated bodies of rock that can hold water, and good rock permeability.

In Singapore's context, advanced geothermal systems can be considered, where heat is harnessed from deep, hot and dry rock with "minimal impacts to environment and safety", said EMA.

Advanced geothermal systems are "closed-loop" systems, where pipes constructed underground carry fluids which pick up heat by conduction to the surface. The heat can then be used for generating electricity.

Associate Professor Alessandro Romagnoli from NTU's School of Mechanical and Aerospace Engineering said: "These can allow for heat extraction and power generation which could be more scalable, cost-effective and efficient for the given heat we have here."

In Singapore, the occurrence of hot springs and fractured granite outcrops suggests that the granite is well-fractured at depth, especially along fault zones.

"Away from the fault zones, the granite could be hot, but may not be as fractured, making it possible to deploy advanced geothermal systems to harness heat," Prof Romagnoli added.

If found feasible, geothermal energy could serve as a new and additional source of indigenous clean energy for power generation in Singapore. PHOTO: ST FILE

For instance, Temasek-backed Eavor is a Canadian geothermal start-up which employs an underground, closed-loop system to generate industrial-scale electricity by absorbing natural heat from the earth.

The company has three to four commercial plants in the pipeline, with one likely to come up in Germany this year.

Another project funded by Singapore's National Research Foundation includes testing a quantum gravity sensor to understand the composition and structure of selected geological sites in Singapore.

Quantum gravity sensors have been used in projects globally to monitor volcanoes, tectonic plates and the exploration of natural resources.

Co-led by NTU Associate Professor Rainer Helmut Dumke, who is also a scientist at the National University of Singapore's Centre for Quantum Technologies, and Assistant Professor Wei Shengji from NTU's Earth Observatory of Singapore, the study can help to gauge the applicability of potential sites for geothermal power generation.

Join ST's WhatsApp Channel and get the latest news and must-reads.