Submitted a project report in partial fulfillment of the requirements for the award of Bachelor of Engineering. I declare that this project report entitled "COMPARATIVE COST-BENEFIT ANALYSIS OF ENERGY-EFFICIENT LIGHTING IN RETROFIT BUILDINGS" was prepared by LIOW SHII YIN and has met the required standard for submission and partially meets the requirements for the award of Bachelor of Engineering (Honours ) Electrical and Electronic Engineering at Universiti Tunku Abdul Rahman.
General Introduction
Importance of the Study
Problem Statement
Aim and Objectives
Scope and Limitation of the Study
Contribution of the Study
Outline of the Report
Introduction
Lighting Technology
Performance
According to the EPA, energy in incandescent light bulbs and 80% of energy in CFL bulbs is released as heat.
Environmental Impact
Lighting Retrofit
Review of Lighting Retrofit
As previously mentioned, buildings account for 33% of the world's total annual energy consumption, and lighting is one of the highest, accounting for approximately 30% of total electricity.
Building Retrofit Process and Decision Making
Lighting Design
- Illuminance Level
- Uniformity of Illuminance
- Glare
- Colour Rendering
- Maintenance Factor (MF)/ Light Loss Factor (LLF)
- Malaysia Standard and Code of Practice for Lighting Design There are some standards and guidelines on lighting design released by the
RSMF is the reduction in reflectivity due to dirt and dust buildup on the surface of a room. LMF is the reduction in the light output of a luminaire due to dirt and dust accumulation on the luminaire.
Life Cycle Cost Analysis (LCCA)
Life Cycle Analysis (LCA) and LCCA
LCCA in Building Retrofit
In addition, the environmental impact can be determined through LCCA by determining the consumption in the life cycle of the retrofit system, thereby previewing the amount of greenhouse gas released during the life cycle. The results also show that through extensive retrofitting to the passive house standard, carbon dioxide emissions can be reduced by almost 90%.
Introduction
DIALux Simulation
In DIALux, the lighting levels were measured on the work surface, which was determined according to the function of the space as shown in Table 3.2. Moreover, according to the SIRIM standard, the MF is set at 0.8 to ensure that the illuminance level can be maintained during the service life. The MF is considered because the lighting level will decrease after a period of use due to the fixture factors such as lamp degradation, failure and dust and dirt build-up; environmental factors such as reduced reflectivity due to dirt and dust build-up on room surfaces.
Finally, the DIALux software will calculate the illuminance level, uniformity and brightness and generate a report for reference. Value charts, isolines and false color reproduction of the calculation surface (work plane) can also be examined with DIALux after the calculation.
DIALux Modelling
Case 1: Existing Building Installed with Energy Inefficient Lighting System
The lighting system of the existing building was designed using energy-inefficient CFLs, and the details of the lamps are shown in Table 4.1. In addition to the illuminance and uniformity levels listed in Table 2.5, the maximum illuminance (LPI) is 5 W/m2 according to MS1525. This ensures that the illuminance variation (ie uniformity) of the entire work plane is acceptable.
The brightness of the entire area is acceptable, and there is no sudden drop in brightness on the work surface between the two lighting points. Based on Table 4.2, the lighting system has a good uniformity of 0.49, which is very close to the 0.5 required by SIRIM.
Case 2: Existing Building Retrofitted with Energy Efficient Lighting System
It can be seen that the light distribution in Case 2(b) is wider than in Case 2(a) because there is a large drop between the two lighting points near the ceiling as shown in Figure 4.9. The polar curve of the 14W LED tube used in case 2(b) is wider, which means that the distributed light coverage is larger. Since the difference between the minimum and maximum values for Case 2(a) is larger, the uniformity is only 0.42, which is lower than 0.48 in Case 2(b) as shown in Table 4.4.
This means that the light distribution in Case 2(a) is not as good as in Case 2b, this is also consistent with the previous discussion about the ray trace model in Figure 4.9 and Figure 4.10. This means that the lighting system in Case 2(a) consumed less power per unit floor area of illuminated space.
Case 3: New Building Installed with Energy Efficient Lighting System
Based on the isolines and value plots in Figure 4.15, the illumination level on the working plane is in the range of 68 to 130 lx and the uniformity is 0.51 (based on Table 4.6), which met the requirement of 0.5 in the SIRIM standard. A lighting power intensity of 1.67 W/m2 means that 1.67 W is consumed per unit of floor space illuminated.
Comparative Luminaires Analysis for All Cases
Based on Figure 4.17, the power consumption (420 W) and the number of fixtures (15 points) in Case 1 are the highest among all cases because the inefficient 28W CFL bulb has the highest power and lowest light output. For retrofit Case 2, with the same number of fixtures as in Case 1, the total power consumption is only 50% of that of Case 1. Comparing cases 2a and 2b, the power consumption for both retrofit systems is the same as the lamp power. are almost the same (13W in case 2(a) and 14W in case 2(b).
The power consumption in Case 3 is the lowest of all cases, with a value of 182 W due to fewer light points (13 points). According to the illuminance required by the standards, the use of LED in retrofit will not exceed the LPI limits.
DIALux Modelling
Five scenarios with different degrees of lighting retrofit were considered in this study as shown in Table 5.3. Different types of CFLs with different power ratings and models were used in the modeling to achieve the required illumination level in MS1525. The retrofit lighting systems were modeled by replacing the different amounts of the existing CFLs with different types of LED lamps with different power ratings and models to achieve the required lighting level in the MS1525.
Details of the distribution of luminaires for each renovation case are described in Tables 5.4 to Table 5.8.
Energy and Climate Impact Analysis .1 Analysis Method
Climate impact = Annual CO2 emission, kg CO2/year Annual = Annual electricity consumption, kWh/year Emission factor = CO2 emission factor, kg CO2/kWh. The project is located on Peninsular Malaysia; therefore, the emission factor based on the electricity generation from Peninsular Malaysia can be used. It can be observed that the emission factor is related to the fuel share of non-renewables (i.e. coal and gas).
Therefore, regardless of the emission factor fluctuations, the average emission factor over the study period is estimated to be 18% lower than the 2017 emission factor, or 0.48 kgCO2/kWh.
GENERATION FUEL MIX FOR PENINSULAR MALAYSIA (2010 - 2019)
Energy Saving and Emission Reduction Analysis
A large amount of CO2 emissions are due to the high electricity consumption of the CFL lighting system, with a consumption of 1404MWh/year. For the cases of retrofit lighting systems, the general trend, shown in Figure 5.6, is that electricity consumption and CO2 emissions savings increase with the percentage of LED used in retrofit, with 100% LED retrofit being the highest reduction in emissions and consumption. This huge savings is due to the use of energy-efficient light sources (i.e. LEDs) that require lower energy consumption for the same level of illumination.
For Cases 3, 4 and 5, the retrofit lighting systems consist of mixtures of energy-efficient and inefficient light sources (i.e. LEDs and CFLs), therefore the savings in electricity consumption and CO2 emissions cannot reach the maximum. In order to be more environmentally friendly and energy-saving, a retrofitting alternative with a higher proportion of energy-efficient light sources should be chosen.
Economic Analysis .1 LCCA Method
Operating expenses consist of annual electricity consumption multiplied by the TNB energy tariff rate, as shown in equation (5.5). The daily operating hours of luminaires for all areas in the building are shown in Table 5.11. Since the building is a 40-story building, the supply voltage will be 11kV, which belongs to the medium voltage level by referring to Table 5.12, so the tariff category is tariff C1 as shown in Table 5.13.
Since the lamp operating times are different for all areas of the building, the time for lamp replacement is different in each case, which is summarized in table 5.15. Based on market research, the replacement costs and installation costs for different types of lamps are shown in Table 5.14 (Kristal Maya, 2020) (JKR, 2021).
100% CFL)
100% LED)
- Economic Analysis of Percentage of LED Retrofit
The NS for an alternative relative to a given base case is the difference between the LCC of the alternative and the base case, which can be calculated using equation (5.9). NS = Net savings for an alternative relative to the base case, RM LCCbasecase = Life cycle cost of the base case, RM. The alternative is cost-effective compared to the base case if NS is greater than zero.
The CAPEX for Case 2 is the highest, which is about 15% of the LCC, but the LCC is the lowest, with NS can reach up to 20%, which is the highest among all renewal cases. Based on Table 5.17, the longer operating hours of the luminaires, which are 24 hours installed on the scale, have shortened the life of the lamp.
25% LED
- Economic Analysis of Lighting Retrofit Sequence Based on Operating Time
- Economic Analysis of Lighting Retrofit using LEDs with Different Lifespans
- Comparative Analysis of Energy, Climate Impact and Economic Table 5.20 to Table 5.22 present the comparative analysis of electricity
- Break-even Analysis
- Sensitivity Analysis
- Critical Inputs Identification
The LED unit prices of different lifetimes of different brands are examined and the final selection is shown in Table 5.18 and Table 5.19. According to Table 5.22, retrofitting with longer life LEDs should be considered first, as this results in more NS, and the NS of a LED system with a lifespan of 50,000 hours can be as high as 20%. Because the most effective method for energy-efficient retrofit has been determined in the previous section, the base case scenario and the retrofit cases will be modeled on the basis of the selected retrofit methods, as shown in Table 5.23.
The sensitivity analysis was performed by obtaining the LCC of the base case and retrofit cases based on the selected retrofit methods as shown in Table 5.23. The critical input values for the LCC of the retrofit alternatives were identified by increasing the uncertain input values such as CAPEX, OPEX and REPEX as shown in Table 5.24 by a certain percentage (10% in this case) and then recalculating the LCC based on the equation (5.3).
75% LED)
Sensitivity analysis is used to determine the criticality of the input variables and the lower and upper bounds of the LCC or any other economic evaluation metric for the alternatives. At LCCA, the cost-effectiveness of lighting upgrades depends on expected costs and selected key economic variables such as discount rates, electricity tariffs, lamp prices, etc. The percentage changes in LCC resulting from the change in input values were then compared.
50% LED)
25% LED)
- Degree of Uncertainty and Feasibility Determination
- Conclusions
- Recommendations for future work
For the same reason, in terms of net savings, the feasibility of retrofit alternatives and the scope of NS can be determined based on the most likely or lowest OPEX and CAPEX. This can be shown in Figure 5.19 that with an increase of about 70% in the price of LEDs, the lower LED retrofit percentage will become more economical than the higher LED retrofit percentage . When the discount rate is below 20%, the higher percentage of LED retrofit cases is more economical.
On the other hand, a lower percentage of LED retrofit housings have better NS after that point. The sensitivity analyzes showed that the change in LED prices is unlikely to negate the net savings from the retrofit systems.
