Conserving Energy is the effort and process of reducing our energy consumption. This is usually facilitated with the usage of renewable energy, in replacement of non-renewable sources. By conserving energy, we are able gain cost benefits; improve the quality of the environment around us, while also provide the most economical solution to our common energy shortages at home. High demands for fossil fuels such as coal, oil and natural gas could also be reduced, resulting in lower emissions of carbon dioxide, one of the primary contributors to our earth's growing problem, global warming.
A household's interior lighting system is a dominant consumer of electrical energy. Electrical lights are efficient, convenient and easy to use yet the vast energy usage of it contributes to a quarter of our monthly electrical bill. Although climate-responsive building techniques are able to help reduce light energy consumption by situating residential homes and buildings in a way that allows a more frequent use of natural light, many existing buildings are unable to benefit from the efficient positioning of homes, thus continuing their uses on artificial lighting. However, building occupants are also able to utilize other alternatives of energy efficient lighting systems to help reduce carbon emissions and maximize the profit of their use of household lightings.
2The different uses and choice of light bulbs we choose as our main source of household lighting are able to have impact on our monthly energy consumption. The typical incandescent light bulb that are used in most residential homes lasts from 750 to 1000 hours, while more expensive long-lasting bulbs can last for around 2500 hours. Incandescent bulbs consist of a thin, frosted glass that houses the filament, which is commonly made out of element tungsten as well as an inert gas (argon). Inert gases such as argon are gases that do not combine with other elements. Tungsten atoms that evaporate from the filament doesn't affect this as the atoms are able to bounce off the argon and are redeposited on the filament, enabling the bulb to last for a longer period of time. Inert used to fill light bulbs since gases such as oxygen cannot be contained in light bulbs; otherwise the intense heat of the filament would set the bulb on fire. There are many advantages of incandescent lights that results in the frequent use of these bulbs in residential homes and buildings. Incandescent lights are inexpensive and easy to use, yet the light produced are of good quality. [3] A major disadvantage of these lights is that they are not energy efficient, with approximately 95% of the energy output as heat energy and 5% useful energy of visible light. This results in the incandescent light bulb only having a 5% energy efficiency, as shown in the Sankey Diagram below.
Sankey Diagram showing the energy efficiency of an incandescent light bulb:
5% Light Energy (useful energy)
For a light bulb
95% Heat Energy (wasted energy)
Electrical Energy in Light bulb
4This is caused when electricity heats the filament to temperatures of around 2,500oC (4,500oF), causing the surface of the light bulb to be hot in a brief period of time. During hot weather climates, this poses as a greater problem since homes and buildings have to be air-conditioned, as the heat produced from the incandescent light bulbs contribute to the building's interior heat, it also places greater demands on the household's air conditioning system. Not only does heat energy is wasted through the inefficiency of the bulb, unnecessary uses of the air conditioner also require more electricity and energy consumption.
Fluorescent Light bulbs are more commonly used in commercial buildings rather than homes. These light bulbs are tubular shaped, with the sealed glass tube containing mercury and an inert gas (argon). Phosphor powder, a substance that emits light when electricity flows through is coated on the inside of the tube. At each end of the tubular shaped bulb, an electrode is wired to an electrical circuit, allowing the voltage across the electrodes to cause electrons to move around the tube when the current is turned on. The energy generated by the atoms is able to convert liquid mercury into a gas form. The electrons then collide with the mercury atoms, exciting them so that the electrons move in a higher orbit and energy level. As the electrons move back to their original orbits, light is emitted. The main advantage of fluorescent light bulbs is that it is energy efficient. In comparison to Incandescent bulbs, fluorescent lamps are around 3 to 5 times as efficient and can last around 10-20 times longer, often up to 10,000 hours or more. In measuring light efficiency, a distinction is made between watts and lumens. A watt is defined as one joule of work per second of time or 1/746 horsepower while a lumen measures the light output. One lumen is equal to the amount of light that is produced by a candle flame. However, fluorescent bulbs take around one fourth to one sixth the amount of wattage to produce the same amount of lumens as incandescent bulbs. [5] Moreover, the carbon emissions produced in an incandescent bulb is also 5 times more than a fluorescent one. When compared to the incandescent bulb, fluorescent bulbs have greater energy efficiency as they do not produce as much waste energy (heat). So of every watt of electricity consumed, fluorescent bulbs produce more lumens than incandescent bulbs.
6Traditional fluorescent bulbs have a long tubular shape, creating a strong disadvantage as it is unsuitable for use on floors, table lamps as well as many wall and ceiling fixtures. However, these shortcomings were resolved in the 1980s, with the development of the compact fluorescent light bulb (CFB). Compact fluorescent light bulbs works the same way as traditional fluorescent lights, however the tube is smaller and is able to be folded to be as compact as a traditional incandescent bulb. This enables fluorescent lighting to be used throughout residential homes and buildings, with more potential for energy conservation and savings. The California Energy Commission also estimates that a single 20-watt compact fluorescent bulb used in place of a 75-watt incandescent bulb is able to save 550 kilowatt-hours of electricity over its lifetime.
Figure 1 - Solar Panel Diagram [7] Apart from the use of energy efficient light bulbs, residents could also use renewable energy from the sun, as it is the world's most available source of light and energy. [8] Solar panels are normally placed on the roof of a house in order to effectively capture sunlight throughout the day. Solar panels are made of several individual solar cells which are composed of layers of phosphorous (provides negative charge), silicon (conducts electricity) and boron (provides positive charge). When solar panels are being struck with sunlight, silicon, a substance that conducts electricity in the photovoltaic cells produce an electrical current, converting the photons from the solar radiation into useful potential energy, which is then stored in a storage system as liquid or air, allowing the energy to be distributed around the
Household.
http://www.027ws.com/what-is-a-solar-panel.html
9Researchers state that if every American used compact fluorescent bulbs, the entire nation could save 31.7 billion kilowatt-hours of electricity annually, showing the great impact the usage of compact fluorescent light bulbs. Although Compact fluorescent bulbs have an average cost of HK$25, and Incandescent bulbs cost around HK$5, this poses as an early economic disadvantage in using compact fluorescent bulbs, the significant energy savings over the life of the bulb, as well as the cost reduction in electricity bills is able to benefit economically in a long term case. [10] The average residential lighting energy use is around 1,800 kWh per year per household. [11] Since Hong Kong Electric Holding's basic charge for each unit (kWh), is HK$0.63 this would result in spending HK$1134 (as seen in the equation below) per year for household lightings.
HK$0.63 x 1800kWh = HK$1134
Although the environmentally friendly ways of reducing light energy consumption in homes might seem to have a higher cost than our frequent use of electrical lights, it is able to help reduce several global environmental factors such as carbon emission and pollution, while it also prevents global warming. Also, looking from a long term perspective, the installation changes to a compact fluorescent light bulb is able to allow your bulb to have a longer life, while installing solar panels can help you generate electricity each day for around 15-20 years. [12] Hong Kong's greenhouse gas emissions are rising rapidly, carbon dioxide emissions recorded in 2005 have increased 10% as compared to the emission level in 1990. Not only does reducing your household's energy consumption help your community, it is able to contribute globally. [13] An average American produces around 40,000 pounds of carbon emissions each year. Together, the world uses billions of dollars worth of energy and electricity each day. By just contributing through your household's energy consumption, the society can help reduce environmental impacts that are affecting our world globally, enhance light quality as well as promote health and work productivity while having economical benefits to your own well being.
