Science Faces

Geothermal energy 'never turns off'

The boiling river in the Central Peruvian Amazon. Although it is more than 700km from the nearest active volcano, its temperature can go up to 94 deg C.
National Geographic explorer and geothermal scientist Mr Ruzo, who was here late last year for the Green Carpet Awards, said he expects that passive geothermal cooling systems would be a more exciting and realistic option in Singapore.PHOTO: SOFIA RUZO
National Geographic explorer and geothermal scientist Mr Ruzo, who was here late last year for the Green Carpet Awards, said he expects that passive geothermal cooling systems would be a more exciting and realistic option in Singapore.
The boiling river in the Central Peruvian Amazon. Although it is more than 700km from the nearest active volcano, its temperature can go up to 94 deg C.ST PHOTO: ALICIA CHAN

While many are looking up at the sun for clean, renewable energy to stem the emission of greenhouse gases, one scientist has suggested looking underground instead.

Geothermal energy, says National Geographic explorer and geothermal scientist Andres Ruzo, 28, is another source of clean energy.

"Compared to wind and solar energy resources, which are intermittent, geothermal energy is a resource that never turns off," he said.

There are two types of geothermal energy systems, active and passive.

Active systems are large power plants that harness heat from the Earth to produce electricity, and are often associated with volcanos.

Passive systems, on the other hand, do not require large plants. They help to conserve energy by tapping stable underground temperatures to regulate temperatures above ground. Such systems usually consist only of an indoor handling unit and a buried system of pipes, which help to conduct heat away from a building when it is hot, and vice versa when it is cold.

"There is very limited research on this, but my expectation is that passive geothermal cooling systems will be a more exciting and realistic option in Singapore," he told The Straits Times while in Singapore late last year for the Green Carpet Awards - an initiative organised by Singapore's World EduCorp, a social enterprise to promote green causes.

A spokesman for Singapore's Energy Market Authority said that solar energy is the most promising renewable energy source for electricity generation for the Republic.

However, she added, the Government "remains open to all generation sources and technologies that meet our need for energy security, price competitiveness and environmental sustainability".

Energy sources such as geothermal heat are considered environmentally friendly as electricity can be generated without burning fossil fuels.

According to the United States Environmental Protection Agency, most greenhouse gases come from burning fossil fuels to produce energy. They create a bubble around the planet that traps energy in the atmosphere and heats up the planet.

Global research body World Resources Institute said that in 2012 alone, 9.7 billion tonnes of carbon were emitted into the atmosphere through the burning of fossil fuels and producing cement, which involves burning vast amounts of pollutive coal. This is equivalent to the carbon emissions from more than 10,000 coal-fired power plants.

Mr Ruzo pointed out: "There are more than seven billion people in the world, but we have a limited planet.

"There have been estimates that if everyone were to live to the same level as the average American, we will need the resources from four planet earths to meet that demand - and that's a lot of resources."

His book on geothermal energy, The Boiling River: Adventure And Discovery In The Amazon, was published last month.

In it, he details his adventures in the Central Peruvian Amazon while pursuing a PhD in geophysics at the Southern Methodist University in Texas, United States.

In 2011, he became the first geoscientist to receive the blessings of the shaman of the indigenous people to study the sacred boiling river, previously thought to be just folklore.

Although more than 700km from the nearest active volcano, the temperature of the river - which reaches depths of about 5m, and a maximum width of about 25m - can go up to 94 deg C.

"It starts off as a small, cold stream, then heats up. It flows hot for over 6km, hot enough to kill you over most of this distance, especially during the dry season," Mr Ruzo said.

Because the boiling river is huge, hot and yet so far away from the nearest volcano, it is the focus of numerous studies from various fields, from the geological to the biological and anthropological.

"The river is super-charged by fault-fed hot springs, some of which are boiling, which increases the temperature," explained Mr Ruzo.

"As we have hot blood running through our veins and arteries, so, too, the Earth has hot water running through its cracks and faults," he said earlier in a public speech.

"Where these arteries come to the surface, these earth arteries, we'll get geothermal manifestations... hot springs and in our case, the boiling river."

Beyond looking at ways to provide green energy to meet the world's hunger for electricity, Mr Ruzo believes it is important to teach children about the earth, and why it should be protected.

"Our challenge as environmentalists is to make people care. And the way you make people care is by tapping into that gift of awe," he said.

He pointed to a Spanish saying, "hay que tener el don del asombro" which means, "you need to have the gift of awe".

"It is what will make you care, it is what will make you realise that you are a part of a greater world, and that the stuff that you're doing makes a difference."

A version of this article appeared in the print edition of The Straits Times on March 18, 2016, with the headline 'Geothermal energy 'never turns off''. Print Edition | Subscribe