Energy Project 2008

Questions:How much energy do we use in a week

making copies?

How much energy does the copier use when we’re NOT making copies?

Copier in question Its little brother

(we’ll get back to him)

Methodology• Turn the copier on each time we need it.

• Turn the copier off when we’re done.• Keep track of how long it’s on.

Then, using data supplied by the manufacturer:

• Calculate the energy used over a one week period.

Data Collection• Simple clipboard with pen and paper to record on/off times.

Problems with Data CollectionFriday of sample week was an In-Service day. This led to atypically low results for a Friday.

The copier was left on for a extended period after copying was finished on Thursday.

This led to atypically high results for Thursday.

Data AnalysisData was analyzed twice:1.As raw data2.As adjusted dataThursday adjusted with “sleep value.”Friday adjusted with “average value.”

In both cases, data supplied by the manufacturer was used to move from “up-time” to “energy.”

(Many assumptions used for adjusting – see endnotes)

Raw vs. Adjusted

Total KiloWatt Hours for the week:4123 KW-H

Total KiloWatt Hours for the week:3731 KW-H

But what about……?

…how much energy it would have used if we left it on?

• Turned on and left in sleep mode all week would use 4032 KW-H (not an interesting option – and still more than turning on/off for each use.)

• Turned on, left on, and used would use 6988 KW-H (more assumptions here)

• Turned on, used, and turned off at night (4pm to 7am) would use 4468 KW-H

Comparisons

For our current usage pattern, turning the copier on each time uses the least, while turning it off at night, predictably, uses less than leaving it on all night

(about 36% less).

In Plain Words• Turning the copier on for each use uses a little

over half the energy compared to just turning the copier on and leaving it on. (3731 KW-H)

• Even just turning the copier off at night can save about a third of the energy. (4468 KW-H)

What next?• Adjust timers between “Ready” and “Sleep”.

• Modify usage habits to consolidate “on” times

• Check some of the assumptions (warm up times??)

• Energy saved by using copier for ALL printing needs (instead of “little brother” printer)?

Assumptions and Sources:Assumptions:

1. Warm-up power requirement is same as max published value – 620 Watts

2. Copier takes 5 minutes to warm-up.3. No decrease in energy usage to warm up from Sleep than from

cold-start.4. “Average use” includes weekends (for In-Service adjustment).5. Copier was actually used for 30 minutes on Thursday’s

extended on-time.6. “Daytime” means 7a.m. to 4p.m.7. Additional students we had during the week did not make a

significant difference in copying energy.8. Manufacturer specifications are correct.

Sources:1. Technical data from:

http://h10010.www1.hp.com/wwpc/pscmisc/vac/us/product_pdfs/2512333.pdf

2. Clipart from standard PowerPoint Library