The people of the US actually turn on more lights then they need and make there eyes worse from the glare. If you don’t believe me listen to this professor.
The UAF campus uses electricity. Some of the electricity is used to power fluorescent light bulbs which are much more efficient than incandescent bulbs but because they exist as a load in the power grid, use energy. How much energy is being used by these lights, is it more than is necessary, and how bright to classrooms and computer labs need to be? In 2010, UAF created its Office of Sustainability to utilize the $20 per student fee towards sustainable projects. The goal is to supply the necessary funds to make sustainable projects happen but the projects must be cost effective with realistic financial return periods. Although bright rooms are convenient, the UAF sustainability club should lobby the Chancellor and Facilities Services to implement a program that systematically removes bulbs from over-lit rooms because it will reduce the energy use of the UAF campus, make indoor conditions more comfortable, and save money.
The simplest way to reduce the energy use for lighting is to remove unnecessary bulbs. Before someone begins pulling random lights from their fixtures at will, some simple calculations can be done to get “back of the envelope” numbers for a cost-benefit analysis. The following calculations will use some simple energy units, the kilo-Watt (kW) and the kilo-Watt-hour (kWh). A kW is a measurement of Power and is defined as 1,000 joules per second, how quickly work is being done. A kWh is a measurement of energy, a fairly large amount of energy at that, being the amount of work by a one kW source for one hour. Electricity is sold in kWh, because it doesn’t matter how fast someone or something is using the electricity but how much of it they are using. Light intensity can be measured in lumens or foot-candles. A lumen is a measure of the power of light perceived by the human eye and the foot-candle can be considered as the amount of light falling on a surface, being defined as one lumen per square foot.
The first thing to be determined is whether or not rooms are over lit. If they are, then energy is being wasted. The U.S. Occupational Safety and Health Administration (OSHA), recommends that in an office setting, the light intensity be between 20 and 50 foot-candles (OSHA). As I write this essay, I am sitting in the Students of Engineering Computer Lab (SOECAL) in Duckering. The room is quite bright and approximately 20 ft by 40 ft and holds 15 light fixtures, each containing three fluorescent bulbs. The bulbs are GE Ecolux Starcoat bulbs consuming 32 Watts and producing 2800 lumens a piece (light bulb). To determine if this particular room is over lit, the following calculation is made:
It appears that the SOECAL lab is over lit by three times the amount of recommended light for a work office, perhaps other similar classrooms and computer labs are as well. Since we can assume the SOECAL lab and many other rooms are over lit, it can also be determined how much energy is being wasted and how much it is costing. The following calculations are performed considering a single bulb for a single hour.
In the room where he is writing no less. More tomorrow.