Like arteries and veins that keep the body alive with a constant flow of blood, close to 26,000km of cables, more than 3,240km of gas pipelines and a 3,000-strong team of people work around the clock to keep Singapore's lights on and air cool.
IN 2004, when Mr Peter Leong oversaw the engineering division at Premas International, which provides property management services, Singapore was hit by one of its worst blackouts in history.
Piped gas supply from Indonesia to Singapore's power stations was disrupted by a technical fault and most turbines were unable to switch to the backup source of fuel. It caused a two-hour outage affecting more than 300,000 homes.
In one home in Jurong, a man had a heart attack and needed to get to a hospital. The lifts did not work. At the time, Premas managed the Jurong Town Council, to which Mr Leong provided engineering support.
"I had to send our contractor up to carry him down. I saw how the residents were affected. Failure can be very serious and I know how important continuity is. I remember that even now," recalled the 57-year-old, who joined Singapore Power (SP) PowerGrid as general manager about five years ago.
That image remains with him, and has served as a constant reminder in his current role as managing director of SP PowerGrid - he has to ensure "the lights are always on" for the company's 1.4 million customers.
"Singapore is like a copper mine. There is 26,000km of copper underground because everything needs power. Just like blood needs to flow to every part of the body, electricity needs to flow to every corner of Singapore. And like the human heart, we cannot afford to fail, so we do everything we can and put every effort into ensuring nothing goes wrong."
The three main areas Singapore Power covers are: planning and strategy, that is, planning ahead for energy needs; network development, that is, building the transmission and distribution network; and network management, that is, operating and maintaining network equipment.
"The team works 24/7 to ensure the health of the system. We respond immediately to any system distress," Mr Leong said.
Temperatures of transformers are taken, insulating oil is checked, and other parameters are continuously measured - whether online or off - to ensure that the power paramedics can be sent in for swift and often pre-emptive responses.
Exercises are conducted for everything from network management to billing, so that if anything goes wrong, everyone knows what to do.
In the last 20 years, Singapore has achieved one of the most reliable grids in the world - the average amount of outage time has gone from 27.44 minutes per person a year two decades ago, to less than half a minute now.
But just like Singapore has evolved, so must the power superhighways. Mr Leong says that energy demand has increased dramatically between the pre-war period and now.
Power is pumped through some 26,000km of cables to more than 10,000 transmission and distribution substations that convert electricity into the necessary voltages for various uses.
"As power demand grows, it becomes more efficient to push through power with higher-voltage cables. It is not unlike Singapore's highways. Where two lanes used to do the job, we now have the Marina Coastal Expressway, which is 10 lanes wide. As energy intensity grows, we need a bigger highway," said Mr Leong.
The North-South and East-West Electricity Cable Tunnel Project is part of that expansion. Its two 60m-deep tunnels will span 35km way below the MRT and even the sewerage system and, when completed in 2018, will reinforce Singapore's power grid as one of the most reliable in the world, said Mr Leong.
The company has been looking into how new technologies and energy sources, such as solar photovoltaic power, could impact the grid.
As Mr Leong listed some of the major infrastructural projects in store for the nation - Changi Airport's Terminal 5, Project Jewel at Changi Airport, the redevelopment of the southern waterfront and new container ports at Tuas - his eyes lighted up.
"We have to plan now for tomorrow," he said with a smile.
Mr Leong, who studied electrical engineering at RMIT University in Australia and did his master's at the National University of Singapore, began his career at the then-Singapore Institute of Standards and Industrial Research, which eventually merged with the National Productivity Board to become Spring Singapore.
There, he spent 18 years with safety on his mind, operating the nation's test lab for equipment and accessories that connected to the electricity network, then regulated by PUB, the national water agency.
He did product testing and also participated in investigations into electrical deaths.
When he moved on to Premas, he oversaw the maintenance and operation of equipment such as chillers, lifts and switchboards in commercial buildings and techno parks, and several town councils.
But it is at Singapore Power that he has found a "better sense of purpose", he said.
"I love being able to look at how to do things differently, and I can never say that my job is done. This is a journey without a finish line."
Get a copy of The Straits Times or go to straitstimes.com for more stories.