# Final Energy Consumption Conclusions

Total Rooms on campus: 2,458

Energy Cost per kWh: \$0.102

kWh per day calculations:

(.25h x  .0139kW) + (.25h x .0236kW) + (9h x .0196kW) + (5h x .0336kW) = 0.353775 kWh/day

Student Average Usage per Day

(0.1491 kWh/day) + (0.353775 kWh/day) / 2 = 0.25144 kWh/day

0.25144 kWh/day x 220 days = 55.3168 kWh

Student cost to the college

55.3168 kWh x 0.102 \$/kWh = \$5.64

All students’ use per day

0.25144 kWh/day x 2,458 rooms = 618.03952 kWh/day

All students’ use per academic year

618.03952 kWh/day x 220 days = 135,968.6944 kWh

Approximate cost to the college

135,968.6944 kWh x 0.102 \$/kWh = \$13,868.81

Our project attempted to estimate the amount of energy used in the dorm rooms of Vassar students, and the cost to the college for that usage. In order to do this, both Irene and I measured the wattage of the electronic devices in our rooms, which can be seen here and here. We then tracked the time these devices were active over the course of three days to determine our average energy usage in a day. This average was then used to calculate the cost to the college for this use over the course of an academic year, which amounted to a surprisingly low total of total of \$5.64. Given our original premise to determine what percentage of our room and board fees goes towards electricity, we found that our actual usage costs amount to 0.054%.

We then used the same average to approximate the cost of all the students on campus, which amounted to 135,968.6944 kWh at a cost of \$13,868.81. While these numbers do not take into account the energy consumed by the original overhead lights in place on the dorm rooms, the cost to the college is still less than expected. An interesting feature that developed out of our study was the realization that refrigerators do not use a constant amount of energy to maintain their temperature. While initial readings gave extremely high wattage values (many times greater than all other electronics totaled), this level was not constant. Had the highest level of wattage been the energy used by the fridge constantly over a 24 hour period, we would have seen a staggering 2,162% increase in energy use! While we didn’t get the opportunity to study the refrigerators over a longer period of time, it would be interesting to see how often the high level of energy output is keep constant temperature.

Overall, our project demonstrated the extremely high energy usage at Vassar College. Without even measuring the light bulbs in our own rooms, let alone the lights in every room of campus (many of which are on 24-7) we approximated that we consume 135,968.6944 kWh in an academic year. While the cost of this usage may seem manageable, especially given the high cost of room and board, it does shed some light on how much we’re costing on the grand scale.

# Energy consumption of Irene’s room

The energy consumption of my room turned out to be less than I thought. As expected, the refrigerator took up a large amount of my overall consumption. I was surprised at how little power my computer ended up using as I waited for the Watt’s Up Pro’s value to level out. One thing that surprised me was that the power strip and my chargers did not show a reading when tested while not in use. I had thought that the lights on the power strip and charger may have used some energy, but I guess the amount is negligible.

An interesting thing to note is how the wattage appeared to change when measurements using the Watts Up Pro were taken from devices plugged directly into the Watts Up versus when the values were taken from the power strip connected to the wall. In addition to this preliminary data, I will be recording how long I am using these appliances over the next 3 days to determine my average energy consumption.

 Appliance Wattage Notes laptop 21-22 Increased from average of 17-22W after extended use, high 43 when turned on phone charger 4.1 alarm clock 1.1 phone + power strip 4.7 laptop + powerstrip 23-24 Started at 32, slowly decreasing, flatlines around 23-24 laptop+ phone+powerstrip 26.9 fan- high setting 30 fan-low setting 20.1 fan-medium setting 23.5 fridge 283 Slowly decreasing over time camera charger 3.5 camera + powerstrip 3.9