The potential of using geothermal energy for power generation is currently being explored following new developments in technology, the Energy Market Authority (EMA) said yesterday.
If found feasible, geothermal energy could serve as a new and additional source of indigenous clean energy for power generation in Singapore, it added in a statement.
Currently, solar energy is the only renewable resource proven feasible for use locally. However, land constraints could limit the scale of 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.
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 Nanyang Technological University (NTU) as well as 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.
While 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 hydrothermal 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 fluid - which picks up heat through conduction - to the surface. The heat from the fluid can then be tapped to generate 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.
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 be up in Germany this year.
Cheryl Tan
