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Tuesday, May 19, 2026 

7th Grade Science Classes
Brandywine Springs School
5/18/2026

Dear Brandywine Springs School Administration,

I am writing to share the results of an energy audit of the Pepsi vending machine located in the Staff Faculty Room at Brandywine Springs School. This machine has had an “Out of Order” sign on it since at least September 10, 2025, and the sign was still posted on May 7, 2026. Even though the machine has not been working properly, it has remained plugged into the wall, continuing to refrigerate drinks and light up the beverage display.

To collect evidence, we used a Kill A Watt electricity usage monitor. The measurement began on May 6, 2026, at 3:10 p.m. and ended on May 7, 2026, at 7:16 a.m. The total measurement time was 16.1 hours. During that time, the vending machine used 4.81 kilowatt-hours of electricity. This means the machine used about 0.299 kWh per hour, or about 7.17 kWh per day.

The machine was out of order for 239 days between September 10, 2025, and May 7, 2026. Based on the measured daily energy use, the vending machine used approximately 1,713.67 kWh of electricity during that time. At an electricity rate of $0.105 per kWh, the total cost to operate this broken vending machine was about $179.93. In other words, the school spent almost $180 powering a machine that was not available for normal use.

Our recommendation is to unplug the vending machine immediately until it is repaired, removed, or replaced. Unplugging the machine costs nothing and would stop the waste of electricity right away. Since the machine is currently out of order, there is no clear benefit to keeping it plugged in. The drinks could be removed, and the machine could remain unplugged until a final decision is made. This is the fastest and least expensive solution.

If the school decides to repair the vending machine, I recommend also installing a programmable timer. A timer could turn the machine off when the school is closed, such as overnight, on weekends, during holidays, and over long breaks. If a programmable timer costs about $20, the school could recover that cost in energy savings in a short amount of time. Since the machine costs about $0.75 per day to operate, a $20 timer could pay for itself in about 27 days if it helped eliminate unnecessary energy use.

Another possible solution is to install a Vending Miser. A Vending Miser is designed specifically for vending machines and can reduce wasted energy by using sensors to power down the machine when people are not nearby while still keeping drinks cold. If a Vending Miser costs about $180, it would cost about the same amount as the electricity already wasted while this machine has been broken. Based on the current energy cost of about $0.75 per day, the return on investment would be about 240 days if it significantly reduced or eliminated unnecessary operation. This option would make the most sense if the vending machine is repaired and expected to stay in use for a long time.

The evidence shows that leaving an out-of-order vending machine plugged in wastes both electricity and money. It also sends the wrong message about energy conservation. Brandywine Springs School has opportunities to model responsible decision-making, sustainability, and smart use of resources. Unplugging the machine now and using a timer or Vending Miser in the future would save money, reduce unnecessary energy use, and show that our school uses data to solve real problems.

Thank you for considering this recommendation. I hope the school will take action by unplugging the vending machine immediately and then deciding whether to repair it with an energy-saving device or remove it from service.

Sincerely,

7th Grade Science Students