Combating the urban heat island effect

As a tropical nation, Singapore experiences a phenomenon known as the urban heat island effect, causing temperatures to vary up to 7 degrees between morning and the evening.

It is especially pronounced in housing estates located near construction sites where noise pollution causes the quality of indoor living environment to deteriorate.

Construction projects are plentiful in Singapore, cover a slew of major developments  such as new rail lines, hospitals, shopping malls and housing estates.

Household electricity consumption is growing at an alarming pace in tandem with rapid urbanization and electricity tariffs are rising

While such construction is for the greater good of the nation – more convenient transportation, better environment for the elderly and more medical services – they are an audible nuisance.

In 2014, the National Environment Agency (NEA) received 16,000 complaints of construction noise. Although it found the vast majority of such complaints not substantiated, perception is reality. As long as people consider the construction noise as noisy, it is noisy.

So, how do people respond to noise pollution? Some may be passive by adjusting their lifestyle and hoping that the noise will end soon. Or as most do, they take a pro-active option against construction noise by shutting windows and turning on air-conditioning to cool their homes.

But rising energy consumption is a global concern. Household electricity consumption is growing at an alarming pace in tandem with rapid urbanization and electricity tariffs are rising.

According to The World Bank Group, Singapore uses 8,845 kWh of electricity per capita, more than other industrialised Asian countries such as Japan (7,820 kWh) and Hong Kong (6,073 kWh).

Residential electricity consumption accounts for 15 percent of Singapore’s overall electricity demand, the third largest user after industry (40 percent) and the commerce and services (37 percent) sectors.

On average, a Singaporean household consumes about 50,300 kWh per month, the bulk of which is for ventilation and cooling purposes, accounting for nearly two-thirds of household electricity bills.

At the National University of Singapore Business School and School of Design Environment, we investigated differences in electricity consumption between housing blocks located near to or far from construction sites.

We studied over 5,300 HDB blocks over a three-year period where there were 322 construction projects. Using monthly consumption data provided by the National Environment Agency (NEA), we found that construction work increases electricity consumption by almost seven per cent for blocks near the project sites compared to those farther away.

Exposure to construction noises raised monthly electricity consumption by an average of 3,015 kWh per block. This translates into an annual figure of 36,184 kWh per block. Using April’s tariff of 0.2139 cents per kWh, this works out to an additional $7,740 spent per block or $77 more per household each year when there is a nearby construction.

Permanence in behaviour

More critical is the permanence in this behaviour. We found that when the construction was over and there was no more noise pollution, households affected by the construction still used more electricity and were less likely to switch back to natural ventilation compared to households that were not affected by the construction noise in the first place.

It appears that there is habit persistence. Households became less adaptable to a lower level of comfort after construction ends as they have been become used to the conditions when construction was underway.

While the increased energy consumption may seem miniscule on a household basis, there are over one million public housing flats in Singapore. With many construction projects underway, the numbers in electricity consumption can quickly add up.

The lesson drawn is to try avoid giving households reason to switch to a ventilation strategy that affords comfort whenever there is construction. For example, the NEA’s Quieter Construction Fund should be pushed further to reduce noise and in turn reduce associated energy conservation.

From the homeowner’s perspective, simply telling them to conserve is insufficient.

Consumers need to be shown in real-time how much each appliance is costing as they use it, so that the relationship between usage and cost becomes more concrete. Measures such as smart electricity devices attached to high-energy consuming appliances may be considered.

  • Author Profile

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    Sumit Agarwal is a Visiting Professor in the Department of Finance at NUS Business School. He is Professor of Finance at the McDonough School of Business at Georgetown University.

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