Reducing Energy Consumption

Solar Panels

HDB is the largest driver for the installation of solar photovoltaic (PV) systems in Singapore today. Under the SolarNova programme, HDB aggregates public sector demand for the installation of solar panels across HDB blocks and government sites. This generates more clean energy and helps to reduce carbon emissions, thereby mitigating the effects of climate change.

In December 2019, HDB announced a new solar target of 540 megawatt-peak (MWp) by 2030. The new target could potentially generate 648 GWh of clean energy annually, reducing carbon emissions by 324,000 tonnes per year. This can generate enough energy annually to power 135,000 4-room HDB flats. To-date, some 5,500 HDB blocks have been fitted with/ identified for solar panel installations, bringing clean energy to more than 50% of housing blocks islandwide. Through the SolarNova programme, HDB aims to commit 70% of HDB blocks for solar panel installation by 2030.

On average, the solar energy generated by a typical HDB block is sufficient to meet the energy demand for the common services (e.g. lifts, lights and water pumps). This enables the blocks to achieve net-zero energy consumption for the common areas, and can help town councils to moderate increases in operating and maintenance costs. Excess solar energy is channelled back to Singapore’s electrical grid.

Smart LED Lighting

HDB has been exploring innovative solutions to reduce energy consumption in the common areas of HDB estates. One such solution is smart lighting, which comes equipped with smart motion sensors and analytics capabilities that can automatically adjust the luminosity of the LED lights depending on the motion detected. Since 2014, HDB has progressively implemented this solution in the common areas (such as carparks, stairwells, link-ways, common corridors, playgrounds, void decks etc.) of new Build-to-Order (BTO) projects. HDB will work with Town Councils to install this in all common areas of blocks built prior to 2014 when their existing LED lights are due for replacement.

Using smart sensing control, the LED lights progressively dim and brighten according to whether motion is detected:

• When motion is detected, lights along the user’s path ahead will be brightened in advance so that the user does not experience a sudden brightening effect. Smart analytics also enable the LED lightings to remain illuminated when there is a higher need for lighting, eg during certain periods of the day when there is heavier human traffic.

   

• When there is no motion, the lights will dim automatically, thus conserving energy. In this way, the use of Smart LED lighting can reduce energy used for lighting by up to 60% compared with conventional LED lighting.

Data collected from the sensors can provide insights on the pattern of residents’ space usage in HDB estates, enabling HDB planners and designers to better design spaces to meet the needs of our residents.

With the data, service providers can also monitor and analyse the performance of the lighting. This enables them to predict potential faults and carry out proactive maintenance before a breakdown occurs.

Recycling Rainwater

Urban Water Harvesting System

As part of its efforts to conserve water, HDB developed the Urban Water Harvesting System (UWHS) to harvest rainwater for non-potable uses like washing of common areas. HDB has piloted the system in selected housing precincts, and will be scaling up the pilot to more precincts.

The UWHS collects rainwater and stores it in an underground harvesting tank. The harvested rainwater is treated before being recycled for washing of common areas and irrigation. In this way, the use of potable water (drinking water) for washing of common areas and irrigation can be reduced by more than 50%.

The UWHS also slows down the discharge of storm water to the drainage system, thus helping to mitigate flood risk.

Cooling HDB Towns

Cool Coatings

To mitigate Urban Heat Island effects due to climate change, a key consideration in creating a more liveable and sustainable living environment is to improve thermal comfort for residents. One such solution is the application of cool coatings (i.e. cool paint containing pigments that reflect the heat of the sun), which can be applied on building facades, roofs and pavements.

Typically, building and pavement surfaces absorb heat during the day and emit the stored heat in the night, hence heating up the environment. Surfaces treated with cool coatings absorb less heat during the day. As a result, they emit less heat at night, leading to a cooling effect on the environment.

A large-scale pilot on the application of cool coatings involving several neighbourhoods will be conducted. In this pilot, we target to reduce ambient temperature by up to 2^oC. With the learning points and data collected from the pilot, the application of cool coatings can be extended island-wide.

Greenery Intensification at Multi-Storey Carparks

Over the years, HDB has provided a myriad of green spaces in every housing development so that residents can enjoy greenery at their doorsteps.

To further green HDB blocks, HDB will introduce greenery to the top decks of more Multi-Storey Carparks (MSCPs), by repurposing them for urban farming, skyrise greenery (i.e. using the Prefabricated Extensive Green (PEG) Roof Tray system^[1]), or for community gardening where feasible.

Besides offering visual and spatial relief for residents in our high-rise living environment, the greenery also helps to cool and enhance the liveability of our estates.