From The Straits Times Archives: Resolving Singapore's green energy tri-lemma

Singapore’s options for clean and green energy could include electricity from solar panels installed on rooftops and wind turbines. The lack of physical space is one inhibiting factor but new technologies could eventually make the renewable energy
Singapore’s options for clean and green energy could include electricity from solar panels installed on rooftops and wind turbines. The lack of physical space is one inhibiting factor but new technologies could eventually make the renewable energy sources more attractive for Singapore.PHOTO: ST FILE

This article appeared in the print edition of The Straits Times on November 10, 2012.

SINGAPORE - LAST month, the Government made two major decisions about the future of Singapore’s electricity.

First, it announced that it had ruled out nuclear power for the country at the moment.

A two-year study by government agencies and independent analysts had found that existing nuclear plants were still too risky for the Republic’s small size and dense population.

Energy experts agreed, saying that while there were designs for safer nuclear plants, these would not be commercially viable for at least another 20 to 30 years.

The Government then announced later last month that it would build a fourth storage tank for the new liquefied natural gas (LNG) terminal, which is slated to begin operations here next year.

The new tank will boost the terminal’s capacity by 50 per cent to nine million tonnes a year. It will also help diversify the country’s LNG sources and make it less reliant on imports from Malaysia and Indonesia.

When asked, the Energy Market Authority (EMA) said natural gas is expected to make up more than 90 per cent of Singapore’s electricity fuel mix in the future, up from the current 80 per cent. The rest of Singapore’s electricity comes from sources such as fuel oil, waste and renewable energy.

Natural gas can be costly as its price has been linked to that of oil, although this may change in the future. Is such an overwhelming reliance on this energy resource desirable?

Nuclear energy has been ruled out for now, but can Singapore entertain other clean energy options?

There are already established technologies worldwide for tapping natural resources such as the sun, wind, water and the earth’s heat for power.

The initial set-up cost, such as solar panels and wind turbines, is expensive but the resources are effectively free.

They are also better for the environment and could lead to cheaper electricity in the long run.

Yet the EMA has consistently said that Singapore’s natural conditions make such green energy sources difficult to use here.

Singapore’s energy ‘tri-lemma’

ACCORDING to the EMA, Singapore has to maintain a balance across three objectives – energy security, environmental sustainability and economic competitiveness.

This “tri-lemma” limits the potential of renewable energy sources here. 

For example, solar energy scores high on environmental sustainability but low on energy reliability.

“The heavy cloud cover in Singapore means that solar energy would be intermittent,” said EMA. 

The National Climate Change Secretariat, which coordinates Singapore’s climate change policies, and the National Research Foundation have also noted that harnessing solar power requires a lot of physical space. 

In a report last year, they said the sun could potentially meet about 15 per cent of Singapore’s electricity needs, but this would require putting solar panels on top of 65 per cent of commercial building rooftop space, 48 per cent of HDB housing block rooftop space, 25 per cent of inland water bodies and 20 per cent of the ground.

Singapore is already short of land, and these panels could compete with other green rooftop uses such as gardens or skylights to reduce the need for lighting.

Another example of how the “tri-lemma” works is tidal energy. It is both environmentally sustainable and secure because Singapore is surrounded by the ocean, but it comes at a cost to Singapore’s economic competitiveness.

Mr Timothy Cornelius, chief executive of Atlantis Resources Corporation which sells tidal turbines and has headquarters in Singapore and London, said Singapore’s waters are too busy to support large turbines.

The Republic is surrounded by shipping lanes and some of them are the busiest in the world. “It is simply not practical to install turbines in shipping lanes” because of safety, said Mr Cornelius.

Biomass power, which uses biological materials such as plant, wood and paper waste to generate electricity, also fails the economics test.

“We understand that the main biomass produced in Singapore is around half a million tonnes a year. But even if all of these were used to produce energy, it would meet only 1 per cent of the country’s energy demand,” said Dr Geng Anli, president of the BioEnergy Society of Singapore.

“Transportation of bulky biomass from other countries to Singapore is very impractical,” she added.

Promising options

OTHER energy experts said that there is some potential in wind and geothermal power in Singapore.

Dr Grahame Oliver, a senior lecturer at the National University of Singapore (NUS) who teaches geoscience, said power could be tapped from underground hot water near springs in Sembawang and on Pulau Tekong, an offshore military training area.

His theory suggests that shafts could be drilled into the earth at spots near the springs.

Hot water would emerge as steam, which could drive a turbine to produce electricity. The water would then be channelled back into the earth. This technique has been used in other countries such as the United States.
Dr Oliver said the Singapore spring waters are likely heated by hot rock in the earth.

“An optimistic view is that one cubic kilometre of hot rock... under Sembawang or Pulau Tekong may well provide electric power for 50,000 homes,” he said. There are slightly more than one million HDB flats in Singapore. 

But he cautioned that more research is needed. “Without a new feasibility study which would include drilling, we simply don’t know how much energy is stored in the geothermal reservoirs under Sembawang or Pulau Tekong,” he said.

A research project including proof of concept drills would cost about $47 million, he estimated. 

NUS, the Economic Development Board (EDB) and a “major player in the geothermal power business” are already doing a desktop study that involves computer modelling, Dr Oliver said.

Meanwhile, scientists at Nanyang Technological University’s Energy Research Institute (ERI@N) are investigating wind energy. 

The institute has analysed the wind in Marine Parade and on Pulau Semakau, an offshore landfill and conservation habitat, for more than a year.

“The initial data suggests it could be possible to set up small wind parks on islands like Pulau Semakau... to power 5,000 HDB homes,” said ERI@N executive director Subodh Mhaisalkar.

“Small wind turbines with a diameter of less than 5m could also be deployed along Singapore’s coastlines or on top of ocean-facing homes,” he said. 

Some 250 such turbines along a 10km coastal stretch could generate electricity for 500 homes.

The studies are ongoing, and the ERI@N team is also mapping wind at other parts of the island, such as Woodlands, Pasir Ris and Jurong. It has designed and filed patents for wind turbines more suitable for low wind-speed conditions and will create prototypes in the next nine months. 

Smaller marine turbines sited on the ocean floor could also work for Singapore, but more analysis is needed, said Prof Mhaisalkar.

Future innovation

STILL, the situation isn’t static, and new trends or technologies could eventually make the renewable energy sources more attractive for Singapore, said energy experts. 

Last month, for the first time here, a decline in the cost of solar panels brought the cost of electricity from solar power on a par with that from conventional electricity sources.

The price of solar panels had been falling over the past two years due to global manufacturing overcapacity and a drop in demand in some parts of the world, noted Energy Studies Institute energy economist Tilak Doshi.

Although a decline in prices for these reasons is likely to be temporary, technological advances are also bringing prices down. 

Mr Goh Chee Kiong, the EDB’s clean technology group director, predicted that solar power’s cost will continue to fall, making it more attractive to users.

Researchers here are also working on new batteries which can store more solar power for longer periods, reducing the intermittency problem.

Electronics giant Panasonic is working on green energy solutions here. Some of its work is being tested in Punggol

The Government has also poured money into green energy projects in recent years, particularly in the field of solar power. 

Since 2010, the HDB has been testing solar panels under a $31 million, five-year scheme. Last year, the EDB and national water agency PUB unveiled plans to build a floating solar panel system on the Tengeh Reservoir.

In June, the Government’s Energy Innovation Programme Office awarded $11 million to researchers working on solar cells. It also plans to improve its understanding of nuclear science and technology.

The solutions may not always be technological.

Greater cooperation between Singapore and its regional neighbours is another way to boost the use of renewable energy here, said energy experts.

The development of an Asean power grid – in the works since the 1980s – could allow Singapore to tap wind, water and other green power generated in other countries which are not subject to the same land and economic constraints, said an international panel of experts during Singapore International Energy Week last month.

The BioEnergy Society’s Dr Geng added that, with some process tweaks, Singapore could import converted biomass from other countries.

“Singapore could convert biomass to fuels and chemicals on site first before transporting them here for further processing and consumption,” she said.

Question of impetus

IN 2010, a high-level government committee set up to chart Singapore’s economic future said renewable energy should supply 5 per cent of the country’s peak electricity demand by 2020.

NTU’s Prof Mhaisalkar said this was achievable, “and could be stretched to 10 per cent by 2030”.

But energy experts said the sense of urgency to meet such targets could be dampened worldwide by a recent development: the emergence of shale gas.

New drilling techniques have given many countries such as the United States access to vast, previously untouchable reserves of the natural gas, upending the global energy equation.

Minister in the Prime Minister’s Office S. Iswaran said during last month’s Energy Week: “The US was expected to be a large importer of natural gas. Today, it could become a major exporter of shale gas to the rest of the world.”

But some energy experts warned that relying on the reserves would be a mistake. Said a report from Britain’s Chatham House: “The anticipation of cheap natural gas could inhibit investment in renewables. 

“But if the revolution fails to deliver a lot of cheap gas, by the time this is realised, it could be too late to revert to renewables.”

Singapore’s defence must be to remain nimble.

Mr Iswaran said Singapore must be adaptable, especially considering the “great energy and economic uncertainty” worldwide. New technologies and global policies could change the local energy outlook.

“The energy landscape is continually evolving. We need to be prepared for an uncertain energy future by keeping our options open,” he said.