Emerging Technologies to Improve Building Energy Efficiency
Singapore has committed to reduce its Emissions Intensity (EI) by 36% from 2005 levels by 2030. In order to meet this target, it is paramount to ensure that buildings become more efficient as they account for about one-third of Singapore’s total electricity consumption. The Building and Construction Authority (BCA) has been working closely with industry and stakeholders to implement new technologies and innovation to help achieve these goal and has set a target of greening 80% of the building stock in Singapore, also by 2030.
Several strategies have been mooted and they include utilising passive building design elements, incorporating active technologies, integrating smart energy management system and adopting renewable energy technologies.
Passive design elements could reduce the energy needed for cooling by up to 12 percent. These elements should be incorporated from the very start of the project and be a recurring theme through the entire building design and construction cycle. For instance, buildings could be designed using a double skin façade which would reduce the cooling load, resulting in lower use of air-conditioning.
Another method is to incorporate daylight redirecting technologies such as light shelves. This technology reduces the use of artificial lighting by increasing the depth of penetration of useful daylight into buildings. Developers can opt to use solar heat shielding film, which is effective in blocking both UV and IR without affecting visible light transmittance.
Examples of active systems that are installed in buildings are air conditioning, mechanical ventilation, lighting and vertical transportation. They take up the bulk of energy consumption in buildings. In order to reduce energy used for these systems, strategies such as demand controlled ventilation, radiant cooling panels and utilising a non-compressor air-conditioning system could be implemented.
Non-compressor air-conditioning, which uses water as a refrigerant in combination of membrane and evaporative cooling techniques, achieves more than 30% energy savings compared to conventional vapour-compression refrigeration. It is also cheaper to manufacture does not use harmful refrigerants that contribute to global warming.
An automatic air balancing system could also be implemented to provide accurate air distribution for every zone while evaporative cooler that produces chilled water for a two-stage cooling process can also help to reduce energy consumption. In terms of lighting, developers can utilise ambient and task lighting, which will provide more accurate lighting levels for different tasks.
Dedicated outdoor air systems, such as those manufactured by Bry-Air Malaysia, can also help to improve energy efficiency. “By separating the sensible and latent load of the building using a Bry-Air Dedicated Outdoor Air System (DOAS), the building owner can greatly improve upon the building energy efficiency,” said Datuk Umang Sharma, Director & CEO, Bry-Air Malaysia.
Smart Energy Management Systems
Another strategy of increasing building efficiency is to incorporate smart energy management systems. Building management system (BMS) is a control system that can be used to monitor and manage the mechanical, electrical and electromechanical services in a given facility. Such services can control, among other appliances, power, ventilation, air-conditioning, physical access control, pumps, elevators and lights.
The Southeast Asian Building Energy Management Systems market is expected to grow strongly at a compound annual growth rate of 10 to 15% from 2015 and 2020. The market is expected to be worth more than $180 million by 2020.
“Modern Building Management System (BMS) must evolve to encompass and integrate the energy management factor seamlessly to continuously provide greater cost saving and efficiency boosts in buildings and facilities. The key to bring about greater cost saving is the BMS’s ability to connect, control, monitor, and strategize energy plans across all physical devices in the building,” said Philip Loh, Managing Director, LEFA Technologies Pte Ltd.
BMS systems can also be integrated with IoT. For instance, advanced sensors can be used to collect real-time information so that energy consumption from the various fixtures can be optimised. In general, smart technologies have a potential to save an estimated 8-18% of total building energy consumption.
“Apart from energy management, the modern BMS also controls and optimize power strategies for all other aspects in the building, such as HVAC, Lighting, Surveillance, Access and Controls, Water Management, and more,” Philip added.
Renewable Energy Technologies
The most feasible source of renewable energy for Singapore is solar due to the country’s abundance of sunlight all year round and the country maintains its target to have over 2,400 public residential buildings fitted with solar panels by 2020. Singapore receives an average irradiance of 1636 kWh/m2 per year, and the solar energy can be converted into electricity through photovoltaic conversion.
Developers can utilise perovskite PV technologies, which utilises perovskite solar cells that are flexible and easy to manufacture. These cells can be used on almost every surface as they can be painted or sprayed from an ink solution or churned out of a printer like a newspaper.
In addition, developers could also consider co-locating solar PV and greenery on the same roof space, introduce anti-degradation system to slow down the degradation of PV panels over time to make it more durable and efficient or develop innovative structures that can be deployed easily on rooftops.
Written by: Hairul Borhan