Lighting and Energy Efficiency
Lighting your residence has become very familiar and routine in our modern age. As the Gas Lights faded, and our world became lit by electric light, our societies energy usage grew and grew.
To obtain electric light, we need to generate electric power. Using various lighting methods, i.e. LED’s, incandescent, Tungsten, Florescent and others we can generate lumens. Lumens are the real visible light output that illuminates the area in the region of the light source. So it may generally be said that we pay for lumens in order to light our environment. Let’s examine what the costs are and what efficiencies we might expect from LED based lighting devices.
Early developments in lighting produced the Edison Bulb which was his invention for generating light from electrical current. After years of trial and error , he finally found the ideal “element” tungsten for generating electricity inside a bulb that has inert gases inside. Early on Edison was in favor of using direct current (DC) to light homes and factories. Tesla on the other hand was an advocate of alternating AC current for powering homes and factories. Eventually Tesla won the battle, as AC electricity was easier and less costly for wide spread distribution via AC transformers.
Tungsten bulbs produce a very nice type of light which emits a wide spectrum of white light. The more power we put into the light, the higher the electrical power usage and the more lumens we get out. But unfortunately we get more than lumens. We also get a lot of heat generated as well! This heat generation may cause us additional costs, because in the summer if we are running air conditioning , the additional heat generated will make a room warmer. In addition, we are paying for ALL the electrical energy going into the light bulb, both heat and light.
A typical 100 watt incandescent light bulb will generate about 1600 lumens. Some more efficient LED lights can also produce a nice warm type of white light that is similar to incandescent lighting.
What does it Cost To Run a 100 Watt Bulb all Year Long?
For example let’s assume that you are paying 20 cents/kilowatt hour for your electricity. Computing these costs for a year gives us:
Watts/Day – (24hours ) x 100 9watts/day will become, 2400 watts-hours/day x 365 days/year x 1kilowatt/1000 watts = 876 kilowatts/year. At the proposed cost of $0.20 (twenty cents/kilowatt-hour) your yearly cost will be $175.20. At 10 cents per kilowatt-hour your costs will be $87.60 per year. Costs for electricity in your area will of course vary, and quite often you may be charged different costs/ kilowatt hour, depending on how much you use per month. These blocks are sometimes called “tiers”. Tiers typically result in much higher costs for energy, the more energy that you consume in one month. In order to calculate your average cost of electricity per kilowatt, you must average the amount and cost for each tier each month. It is not uncommon in parts of the USA to see tier charges of over 50 cents per kilowatt hour!
What are the advantages of using LED lighting for your Home?
LED lighting can put out the same lumens as a 100 watt incandescent bulb at a much lower cost. To get our typical 1600 lumens, we can use an energy efficient LED type bulb.
According to the US Energy Department, LED lights with the ‘ENERGY STAR’ rating, use at least 75% less energy, and last at least 25 times longer than incandescent bulbs. So if we use these facts in the example above our costs for a 100 watt bulb/year will be about $45.80 and $21.90 respectfully. A great savings!
How do LED (light emitting diodes) lights work to provide light at lower heat and cost?
LED’s came into being in the 1960’s and were used for indicator lights at first. They are made from semiconductor materials like transistors & diodes, and are quite low in power and run off of DC voltage. These LED’s have no filaments or glass bulbs inside, but instead are semiconductor chips that emit visible light when energized by an electric supply circuit. The color of the LED varies depending upon the type of chemicals used in the bulb. Early lights were red, green and blue in color. When these RGB colors are combined, or mixed a light similar to white light is produced. This light can be easily focused with lenses or diffusers. As semiconductor technology advanced over time, the cost of these LED lights continued to tumble. Very cost effective LED lighting solutions have been achieved today. Using LED technology, a home or business owner can improve lighting and energy efficiency, and lower electricity costs to a very significant extent.