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.