Designing for zero energy waste

In the United Arab Emirates (UAE), a resident will typically consume 45,162 GWh (DEWA-Annual Statistics 2017) annually. Yazen Saleh discusses the implementation of green building and sustainability concepts, principles and techniques in the UAE, and the steps being taken at the design stage to reduce energy consumption and avoid environmental pollution.
 

Renewable energy in the Dubai built environment.
Renewable energy in the Dubai built environment.
  • Updated: 21 December, 2018
  • Author: Yazen Saleh, civil engineer, GMICE
In 2011, the UAE introduced Green Building regulation, which focused on energy reduction to avoid environmental pollution. This included the implementation of green building and sustainability concepts, principles and techniques, such as the “Renewable Energy” Tools, to assist with the reduction in energy waste.
 

Reducing energy waste

Significant amounts of energy waste can be lost at the operational stage of a built asset. The main causes of this energy waste have been cited as the inefficient architectural design; working without categorisation steps and without planning; incorrectly calculating the estimated energy consumption; poor material selection; and, of course inefficient use at the operational stage.

Types of energy waste can be divided into two principal groups: direct energy waste; and, indirect energy waste. The direct waste relates to our daily energy consumption (see fig 1.), while the indirect waste relates to the waste process (see fig 2).  


                                                                                                                          
The UAE construction industry has been set the goal of minimising its energy waste to 30% by 2030 (Saifur Rahman).  It plans to achieve this by using the renewable energy system instead of the traditional system.

By adopting green building design and sustainability at the design stage of construction projects, this can overcome the negative environmental and monetary impacts of energy waste.
 

Green material selection principle, prerequisites and techniques

Addressing these issues at the design stage has been rightly identified as the essential step toward sustainability.



To protect the natural environment from any hazard/threats from the construction industry, the following issues must be considered to avoid energy waste:
  • At an early design stage, forecast energy waste and identify the top opportunities for specifying the renewable energy system. (Home Energy Manager, Solar Photovoltaic, Small Wind system, Smart Meter, Demand Response Appliances) 
  • At a later design stage, focus attention on reducing energy wastage rates by considering the most efficient material to achieve zero energy waste, (LED light, Solar Insulating glass, etc.)
  • Zone scheduling – Permits defined sections of a building to have HVAC and lighting reduced or shut down on a schedule. Zone scheduling means that a whole building does not need to run at a 100% comfort setting if on only a few occupants are in the facility.
  • Night/unoccupied setback – Changes the comfort settings (set points) of HVAC so that space temperature decreases in winter and increases in summer, thereby reducing demand for heating and cooling during unoccupied hours. This feature can also be done using a programmable thermostat, but with only a few schedules and no flexibility to more aggressively change setback temperatures.
  • After-hours override – Allows temporary changes to comfort settings after-hours. This eliminates the need to modify schedules, which can sometimes become permanent by accident. This also avoids having the entire building run in occupied mode to meet the needs of a small group.
  • Occupancy Sensors – Detect motion or infrared signatures in the space, and trigger lights or HVAC accordingly. The BAS also enables scheduled overrides or triggers based on card access to an area of the building.
  • Daylight harvesting – In zones of the building near exterior walls and windows, lighting can be dimmed or shut off based on specified minimum lighting levels detected by photocells. Controlled use of motorised shades can also optimize the availability of natural light without compromising energy efficiency.

Adoption of BIM for energy waste management


 
The adoption of BIM for improving collaboration on energy waste management in construction and operation needs to be considered and implemented at the design stage.

This use of BIM will assist in adequate collaboration and effective communication. In this regard, BIM plays a key role in ensuring that all stakeholders are actively involved in decision-making right from the conception of the building project through its entire lifecycle.

The main benefit of adopting BIM for energy waste management is that it enables the creation of a federated model that could be evaluated and updated by all the project team.

The use of BIM will also engender design coordination, task harmonisation, clash detection, and process monitoring of energy waste management activities.
 

“Renewable Energy” tools for minimising energy waste

The tool used to help eliminate energy waste during the design stage is the Renewable Energy tool.
This is a technique whereby the design team, at the earliest stage, identifies where a renewable energy technique can be used to minimise energy waste

These techniques include using solar energy, wind power or solar-insulating glass.

Solar energy can be collected and converted in a few different ways, ranging from solar water heating with solar collectors or attic cooling with solar attic fans for domestic use to using mirrors and boilers or photovoltaic cells to convert sunlight into electrical energy.

Wind can be used to pump water or to generate electricity – but the challenge is the need for a large open space to produce significant amounts of energy.

Solar insulating glass, which allows sunlight to pass through a window, while radiating and reflecting a large degree of the sun’s heat, allows indoor spaces to stay bright but much cooler than if normal glass were used.

The UAE construction industry is growing year after year, which can lead to large volumes of energy waste if not monitored, controlled or minimised through the design and operating stage.
 

Government initiatives

Government bodies have been proactive in their approach to minimising energy waste by issuing various guidelines and implementing solar energy systems.

For example, the Mohammed bin Rashid Al Maktoum Solar Park is the largest single-site solar park in the world, based on the IPP (Independent Power Producer) model, and is instrumental to the Dubai Clean Energy Strategy 2050.

The solar park’s production capacity will reach 5,000MW by 2030 with investments totaling AED 50 billion. It will eventually save over 6.5 million tonnes of carbon emissions every year.
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