Comparative Assessments of CFLs, Incandescent and LEDs Bulbs for Energy Efficient Lighting System in Building

Compact Fluorescent Lamps (CFLs) and Light Emitting Diode (LEDs) are fast replacing incandescent bulbs in most residential buildings because they are designed to fit into most lamp holders originally designed for incandescent bulbs. The aim of this work is to look at to what extent the usage of Compact Fluorescent Lamps (CFLs) or Light Emitting Diode (LEDs) can help reduce energy demand and how energy wastage in residential buildings due to lighting can be addressed by using energy efficient lamps. Energy meter was used to measure the actual energy in kWh (kilowatt-hour) of each bulb. Lux meter was used to measure the luminance (brightness) between CFLs, LEDs and Incandescent bulbs. Lighting point calculation for a three bedroom flat was carried out and the number of lighting points required to light up the building was calculated. An estimate of energy consumed for one year by the different bulbs using the readings from the energy meter was done and the prices of the bulbs was compared to ascertain if the cost outweighs the energy consumption. The prices of incandescent bulbs when compare to CFLs and LEDs in local stores is far cheaper than CFLs and LEDs with a burden of huge cost in lighting the incandescent bulbs due to energy wastage. Lighting design calculation for a three bedroom flat was carried out using IES (Illuminating Engineering Society) recommendation for different area. It was observed that LEDs bulbs can save almost 86.4% energy consumed by Incandescent bulbs while using CFLs bulbs can save 78.8% energy consumed by incandescent bulbs. Hence, LEDs is the most energy efficient bulb, by using LEDs in every home there will be a reduction of over 80% energy consumption due to lighting when compared to incandescent. DOI: 10.7176/JETP/10-5-04 Publication date:September 30th 2020


Introduction
In Nigeria energy poverty has led to closure of many small and medium scale businesses, even the big businesses suffer from this energy poverty while the nation's hunger for electricity consumption is growing at an increasing rate. In light of this crisis, it becomes essential to educate consumers about energy and its rightful usage, and the necessary steps that consumers should take to reduce their demand for electricity as well as high energy bills. The provision of reliable, secure and affordable energy services are central to addressing energy crisis, including poverty, inequality, climate change, food security, health and education. They are also required for wealth creation and economic development. Today more than 1.1 billion people worldwide lack access to electricity supply according to International Energy Agency (IEA2017). Internationally, energy efficiency is recognized as the most cost-effective means of reducing dependence on fossil fuels as well as an essential component of sustainable energy policy. Two of the many available energy efficient lighting technological options are the compact fluorescent lamp (CFL) and light emitting diode (LED) -which can directly replace a standard incandescent lamp.

Materials/ Methodology
The experiment was conducted by obtaining CFL Bulbs, LED Bulbs and Incandescent Bulbs from open market. An energy meter was used to measure the energy consumed by each bulbs in one hour and a lux meter was used to determine the light brightness (Luminance) of each bulb. Lighting design calculations for a three-bedroom flat were carried out for each type of bulb to determine the power consumption of each bulb for one year.

Power Measurement/Power Calculations
A plug type energy meter was used to measure the voltage, current, energy consumed in one hour and the power factor. AC power = volts x amps x PF (power factor). Table 1 shows the energy consumed by the various bulbs in hour.  Corridors I00 According to IES each environment has a recommended lux level. Shown above is the recommended IES lux level used in the light point design consideration.

Calculations
Lighting design calculation of a three bedroom flat was carried out to determine the number of bulbs required to light up the building. The formula for the number of bulbs required to light up an area is given as  From calculations it could be seen that 59 bulbs are required of 18 60watt of incandescent bulbs or 18 (13-18) watt bulbs of CFL or 18 (6-8) watt LED bulbs and 41 40watts incandescent bulbs or 41 (8-12) watts CFL bulbs or 41(4-5) watt LED bulbs.

Cost of Energy
The energy consumption for a period of one year was estimated. By making assumption that the bulbs were switched ON for 11 hours (7 Pm to 6am every day). The readings from kilowatt meter were used for this calculation and diversity factor of 0.65 was applied to the load because not all the bulbs will be ON/OFF at the same time.

Cost of Bulbs
The initial cost of bulbs to light up the three bedrooms flat is taking into consideration. 59 bulbs is need based on our calculation using IES standard. From table 6 it can be seen that the cost of the various types of bulbs required is summed up to a. cost of incandescent bulbs required = N5,900 = $16.41 b. Cost of CFL bulbs required = N21,550 = $60 c. Cost of LED bulbs required = N25,400 = $70.66

Conclusion
The most energy efficient bulbs with good light output with little current consumption is LED the percentage energy saved when compared with incandescent bulbs is 86.4% which is more than the 78.8% saved by CFL. Energy saved is directly proportional to savings in energy bill. The low cost of incandescent bulbs in the market cannot outweigh the savings in electricity at the long run. The difference between CFL and LED in terms of energy savings is about 10%. Using LEDs as the standard light bulb will help to reduce energy wastage due to lighting thereby reducing energy demand and making energy available for other purposes.