When I am asked to help districts save money or financially justify the paradigm shift to One to One computing, one of the first things I suggest they do is audit their technology energy use. Shifting from traditional desktop PC’s to laptops, netbooks, or thin clients can save significant amounts of money, to say nothing of it being the environmentally correct thing to do.
A typical desktop computer uses between 65w-250w of electricity. A typical CRT monitor uses 80w and an LCD monitor 35w of electricity. You can get the actual amount of energy usage by checking the label on the specific device, or you can use a watt-meter to measure real energy consumption.
So, if we use 158w as an average for desktops and 58w as an average for monitors our total energy use is 216w per computer.
Let’s compute the energy cost of running just ONE computer for a typical school year.
1. The computer is in use 6hrs per day. (6hrs x 216w = 1296w) 2. The computer is left in power saver mode over night. (18hrs x 35w = 630w) 3. The computer is in use 200 days per year. (200 days x (1296w+630w) = 385,000w) 4. The computer is in power saver mode on weekends and holidays, approximately 100 days. (24hrs x 35w = 840w) x 100 days = 84,000w) 5. The computer uses no energy 65 days of the year.
Total yearly energy cost for ONE computer is 469,000w or 469 kilowatt hrs.
Estimated yearly cost for ONE computer @ .17 per kw hour = $80.
Energy cost for ONE computer over a (5) year lifespan = $400.
Total annual energy cost for ONE THOUSAND computers = $79,730.
Total energy cost of ONE THOUSAND computers over (5) years = $398,650.
Now, lets look at alternatives to the energy hungry desktop PC approach that is so prevalent in our schools today.
A laptop or netbook averages about 30w, most of it related to the display.
A thin client and display also averages about 30w.
Thus replacing a standard desktop with a laptop, netbook, or thin client device theoretically produces an 86% reduction in energy consumption.
Estimated yearly cost for ONE device @ .17 per kw hour = $11 (Savings =$69) Energy cost of ONE device over a (5) year lifespan = $55 (Savings =$345) Total annual energy cost of ONE THOUSAND computers = $11,000 (Savings=$68,530) Total energy cost of ONE THOUSAND computers over (5) years = $56,000 (Savings=$342,650)
Even if we take the ‘best case’ desktop scenario: a 65w computer and 35w display, the energy savings for shifting to laptop, netbook, or thin client devices is 54% resulting in a savings of $227,230.
In One to One implementations, if students use battery power during the day and are required to charge their devices at home, the energy savings can be more than 95% and a cost savings of $378,717.
The yearly $68,530 savings in energy costs (ONE THOUSAND computers) can purchase:
An additional (228) netbooks, or thin clients per year. (@$300 per device) Over (5) years a school can DOUBLE the number of devices available to students (1140) based on energy savings generated by switching to netbooks or thin clients. If you are more interested in the traditional route you can purchase laptops and add an additional (86) devices per year (@$800 per laptop) and increase your network by (430) devices over (5) years.
Anyway you look at it there is a good case to be made for going “Green”.
It’s time to shift our technology energy paradigm.
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