Change is inevitable; many times it’s for the better. Updating technology, social reform, and safety improvements are all examples of good change. But change doesn’t always have a positive result. Sometimes the effect isn’t really negative, but it sure isn’t positive. We have had a recent change here at Memorial, which is of the third category. We are no longer allowed to charge our cell phones or mobile devices in the abundance of outlets located around the school, out of general concern for students’ phones being stolen, and over concern of wasting electricity and running up the electric bill. Seems like pretty logical and well-thought-out reasons, don’t they? Let’s see about that. Here I’m going to focus on the last two reasons, the first is a story for another time.
I can’t deny the noble cause of saving energy. It’s a good idea to try and not screw up everything for future generations, but the tiny portion of electricity used to charge students’ cell phones is absolutely microscopic in comparison to all the things that are wasting energy here at Manchester Memorial High School. For example, the vending machines in the cafeteria go out of order quite frequently, and when they do, they’re left plugged in. A typical soda machine like the ones in the cafe or the one in the teachers’ lounge (i.e. the Dasani® and Aquafina® machines) typically consumes 3.1 to 4.4 kilowatt hours of electricity per day for the lighting alone, and 3.5 to 4.0 kWh/day for the refrigeration. They’re definitely not the most energy-efficient machines if you ask me. Now, about your average smart phone, what does it take to power that? The answer: ~1 kWh. That is, per year. Okay, so let’s do some math. We’re only in school for 175 days out of the year, so we’ve got to divide one by 365 and multiply that by 175. In other words, 35/73 kWh used per school year. This is obviously a generous estimation, since we’re not all charging our phones at school every single day, and we don’t have a 24-hour school day.
Okay, so now you’re probably thinking, “But there’s not only one person charging their phone each day at school”, and I’m getting to that. There are over 2,000 students here at Memorial. I’m going to guess here and say that not all, but still a considerable amount, charge their phones about every day, let’s say 750. So, how much energy does it take to power 750 students’ phones for one school year? About 359½ kWh. The vending machines are always on, including weekends, so we take 6.6 and 8.4 and multiply them by 365, and we get a range of 2,409 kWh/yr to 3,066 kWh/yr. Quite a stark contrast. Oh, and don’t forget, that’s 3,066 kWh per vending machine. There are three drink machines in the cafe, one in the teachers’ lounge, and two snack machines in the cafe. Let’s be generous and say the snack machines only require the lighting. So, that’s four drink machines and two snack machines. The drink machines alone consume about 10,036 kWh/yr to 12,264 kWh/yr, plus the snack machines we get 2,263 kWh/yr to 3,212 kWh/yr (1,131½ to 1,606 each), so in total we waste 12,299 kWh/yr to 15,476 kWh/yr. 359½ kWh/yr is starting to look pretty small, isn’t it? And that’s just the vending machines.
After deep research, I still couldn’t find a source for the City of Manchester’s electric rates for its city-owned buildings (such as City Hall, schools, police stations, libraries, and other municipal/public buildings). I also scoured the U.S. Department of Energy’s website, as well as U.S. Energy Information Administration’s website, and finally the City of Manchester’s website. I found a very nice report on the EIA’s site detailing each state’s average rates for electricity consumption per kilowatt hour (see Table 5.6.A Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, October 2015 and 2014 (Cents per Kilowatt hour) on page 125). I also found some stats on Electricity Local‘s site, specifically for Manchester. We are going to use both stats, just for good measure.
According to the EIA’s yearly report, in October 2015, the average cost of electricity consumption for commercial properties in the State of New Hampshire in cents per kilowatt hour was 14.42¢/kWh. Now, I’m not certain about this, but I’m pretty sure that the City of Manchester gets at least a slight discount on their electric rates, but to avoid a large margin of error on my part, I’m going to leave it at the base price. According to Electricity Local, the average cost for commercial properties in Manchester is 9.56¢/kWh. So, let’s take a look at our costs.
For the vending machines, our estimate of 12,299 kWh to 15,476 kWh, with the EIA’s info, we get a cost range of $1,773.52/yr to $2,231.64/yr, and with Electricity Local‘s info, we have $1,175.78/yr to $1,479.51/yr. The cost for our phones? With the EIA’s info we get ~$51.85/yr, and with EL‘s info we get ~$34.38/yr. Remember, these are rough estimates—since this kind of information isn’t easy to verify—even with all the great publications from the Department of Energy and the Energy Information Administration and sites like Electricity Local. But even so, I’d imagine that the real costs wouldn’t be too far from what we’ve come up with here. Using what we’ve come up with, our cell phones are only about 2.3-2.9% of what the vending machines cost, which means they account for an infinitesimally small percentage of the school’s total budget. The city’s total budget plan for 2016 allocates $161,062,680 to education, so the final nail in this long, drawn-out coffin, is that Memorial having 750 students plug in their phones every day at school accounts for about 2.134×10-5% to 3.219×10-5% of the city’s total education budget. That’s two to three hundred-thousandths of a percent. I rest my case.
 Vending Solutions – FAQ: Visit↗
 Forbes [written by C. Helman] – How Much Electricity Do Your Gadgets Really Use?: Visit↗
 U.S. Department of Energy: Visit↗
 U.S. Energy Information Administration: Visit↗
 City of Manchester, NH: Visit↗
 EIA – Electric Power Monthly with Data for October 2015 [PDF]: View↗
 Electricity Local – Manchester, NH Electricity Rates: Visit↗