Updated: Jun 29
To support the Government’s policies in achieving 31% of renewable energy (RE) capacity by 2025, the Kuala Lumpur (KL) Mayor Datuk Seri Mahadi Che Ngah, has imposed a mandatory requirement that all future residential & commercial developments in KL must rely on at least 30% of renewables on-site. Documents that show the system design and calculation/simulation shall be submitted prior to the approval of Development Order (DO) and all relevant documented evidence shall be attached during the issuance of Certificate Completion and Compliance (CCC).
“We recently imposed this condition in our approval process, and developers must now include this when planning their projects. We must move with the times as renewable energy is the future. Renewable energy is cleaner and helps combat greenhouse gas emissions and is better for the environment ”, said the Mayor.
This major leap from zero to 30% of RE reliance could be quite challenging for some of the projects, such as high-rise buildings or buildings with roof space constraint. Ambitious goals are essential in the transition to 100% RE, however, is this 30% RE requirement attainable? We’ll discuss further below.
RE Sources in Malaysia
RE development in Malaysia has gone a long way since the embarkment on the Four-Fuel Diversification Strategy 1980, which was formulated in the aftermath of the two international oil crisis and quantum leaps in prices in 1973 and 1979. Various types of RE sources can be developed in Malaysia, mainly are: Hydro, Solar, Biomass & Biogas while others remain their potentials.
Decentralized RE system is one of the options to cope with the challenge of balancing local energy production and energy consumption. It allows high operational flexibility that can alleviate stress from local grid system, reduce transmission & distribution losses and provides a more reliable energy supply. For buildings in Malaysia, rooftop solar photovoltaic (PV) remains as the most favored choice of RE sources. According to Sustainable Energy Development Authority (SEDA) Malaysia, there are over 4.12 million buildings with rooftop solar PV potential in Peninsular alone.
Malaysia has the advantageous values in developing solar energy due to its location in the equatorial zone that overhead sun can be obtained throughout the year. Versatility and simplicity of the installation of solar PV system is also one of the reasons that it is being adopted in most of our IEN projects to further lower the overall building energy demand.
Practical Limit of RE Offset for Different Types of Buildings
Below is the analysis of minimum solar PV capacity required to fulfil the 30% RE requirement for different buildings:
1) Low-rise residential
With reference to our previous article, the average monthly energy consumption of a two-storey terrace house in the City of Elmina is 608 kWh/month. To achieve 30% RE requirement, at least 183 kWh/month of energy shall be supplied by solar PV system. Meaning minimum 2 kWp of solar PV capacity is required, which is equivalent to 5 units of 400 Wp solar PV panels (about 10 m2 of roof space only).
2) Low-rise non-residential
IKEA Batu Kawan has a building energy intensity (BEI)* of 156 kWh/m2/year, with 1,300 kWp of solar PV system (BEI for a typical shopping mall in Malaysia is around 320 kWh/m2/year). With the use of approximately 35% of total roof space, the contribution from solar energy is 24% of total building energy consumption. Hence, 30% RE requirement can be easily achieved with the installation of an additional 360 kWp of solar PV on the building’s roof. That would require another 1,800 m2 or 8% of total roof space.
*Building energy intensity (BEI) is a benchmarking tool in monitoring building energy performance. It is calculated by taking the total annual electricity consumption (kWh/year) divide by gross floor area (GFA) excluding carpark area (m2).
3) High-rise residential
The development of KL Eco City ViiA Residences is near to completion and towards the issuance of CCC. From the simulation result during design stage, solar PV system with 49 kWp capacity is expected to contribute roughly 2.5% of the total energy consumption of all the common shared spaces. An estimation of 530 kWp of solar PV capacity is needed in order to attain 30% RE reliance, which requires an area that is much larger than the provided roof space in this project. The only option is to start placing façade solar PV on the building façade (can be wall cladding or window), which due to the vertical orientation, it can only achieve about half the annual solar yield of rooftop solar PV. The yield of façade solar PV is further diminished by shading from surrounding tall buildings. Hence, it is advised to place the façade solar PV at the highest levels and on those façades that are relatively unshaded by surrounding buildings. To reach the 30% RE goal, this KL Eco City ViiA Residences would need at least 6,500 m2 of façade solar PV, which corresponds to at least 25% of the total façade area.
For energy consumption by dwelling units, with assumption of 70% occupancy rate, the additional façade area required to be solar PV would be about 5,600 m2 (20% of total façade area). Thus, KL Eco City ViiA Residence needs a total of 12,100 m2 façade solar PV (that constitutes to 45% of the building façade area) to cover 30% of the energy usage for both common spaces and dwelling units.
4) High-rise non-residential
KL Eco City Mercu 2, which was designed, constructed, commissioned and fine-tuned as an energy efficient office tower, had achieved a BEI of 102 kWh/m2/year while a typical office building in Malaysia that is designed according to Malaysian Standard MS1525 has a BEI of 200 kWh/m2/year. This 40-storey office tower with a GFA of 68,605 m2, only has 1,200 m2 roof space. 85 kWp of solar PV system provided can only cover 1.35% of the total building energy consumption. To achieve 30% RE dependency, that would require approximately 22 times larger than the existing capacity and space to locate the solar PV panels. By applying the same method as above, KL Eco City Mercu 2 would require about an area of 22,500 m2 of façade solar PV, which is equivalent to 80% of the total building façade area, which would limit the amount of façade glazing for daylight and views out. Moreover, if not built as an energy efficient building, the building would not have sufficient surface area (roof + facades) to fulfill the 30% RE requirement.
Energy Efficiency as Strategy to meet 30% RE Requirement
As mandated by DBKL, at least 30% of RE shall be provided for all upcoming developments in KL to reduce carbon emissions and minimize the dependency of electricity from the grid. However, this cannot be done with merely installation of RE and without the use of energy efficiency (EE). This is because EE keeps demand growth in check and RE can begin to cut emission. RE & EE shall work in synergy. According to International Renewable Energy Agency (IRENA), RE & EE can bring faster reduction in energy intensity and lower energy costs when pursued together.
"Greater RE reduces the demand for energy from grid, and greater EE results in higher shares of RE"
Taking the Suruhanjaya Tenaga (ST) Diamond Building, which is the landmark EE and environmentally friendly office building for the Malaysian Energy Commission, as an example. The latest measured BEI of ST Diamond Building before the COVID-19 pandemic was 70 kWh/m2/year (excl. solar PV) and 63 kWh/m2/year (incl. solar PV), with multiple innovative EE measures. Thanks to the low energy demand, the additional solar PV capacity required to achieve 30% RE target is about 220 kWp only, which is 70% lower (in term of capacity, cost & required space) than a typical office building with BEI of 200 kWh/m2/year.
Simplified PV Equation for Buildings
The following formula gives a rough estimation of the PV roof area required to meet the 30% RE requirement:
In case the required roof area (Equation 1) exceeds the available roof PV area, the additional PV façade area can be estimated from this formula:
The two formulas use the fair assumption for Malaysian climatic conditions that a 1 m2 photovoltaic panel can produce 150 kWh/year (horizontal installation) and 75 kWh/year (vertical installation).
Click here for our interactive online PV calculator:
The emergence of electric vehicles and the energy required to charge them will significantly increase the energy consumption of buildings. While electric charging infrastructure should be provided for in residential and non-residential buildings alike, it is doubtful that most high-rise non-residential buildings will have sufficient surface area to meet the 30% RE requirements. As such, allowing for some degree of off-site renewables to help meet the 30% RE requirement seems like a pragmatic solution going forward.
(Note: All above estimations are based on assumptions. The solar PV yield varies, depending on various factors: weather, location, module type, installation, conversion losses, etc. We are more than happy to help if you would like to know more.)
Bavani, M. (2021, May 17). 30% Renewable Energy Rule for all New Projects. Retrieved from TheStar: https://www.thestar.com.my/metro/metro-news/2021/05/17/30-renewable-energy-rule-for-all-new-projects
Sustainable Energy Development Authority (SEDA). (2020, January 06). A Report Card (2019) Strengthens the Growth of Renewable Energy and its Industry in Malaysia. Retrieved from SEDA Malaysia: http://www.seda.gov.my/2020/01/seda-malaysia-a-report-card-2019-strengthens-the-growth-of-renewable-energy-and-its-industry-in-malaysia/
Gregers, R. (2021, June 15). Carbon-Breakdown of House @ Sime Darby Sustainability Day. Retrieved from IEN Consultants: https://www.ien.com.my/post/sime-darby-sustainability-day
International Renewable Energy Agency (IRENA). (2017, August). Synergies between Renewable Energy and Energy Efficiency. Retrieved from IRENA: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2017/Aug/IRENA_REmap_Synergies_REEE_2017.pdf