1. Savings Report
A spanish City Council with 3000 computers where
they were previously used in a controlled way

2. Workings
On
Active
Stand
By
Off Inactive
• The software measures the PC energy
state and the user activity each second.
• After a certain amount of inactivity time,
the PCs are put in low power state

3. Math
90W
5W ∑ Tiempo
1W
• The power used in each state is inserted in
the software, and the program does the
calculus aggregating data.

4. Data capture
This date started
the policies
The effect is noticed by the
appearance of stand-by
states (yellow bars)
• A database stores historic data and allows us
to make comparisons
• Analysis tools allow us to do a tight project
tracking during the lifetime of it (in real time)

5. Comparative criteria
• Both periods: without holidays or
reduced working hours.
• 1) Initial period:
• without applied policies
• 2) Final period
• with applied policies
• with the platform stabilized

6. Compared periods
• Data from 'Period 1' were captured
from 06/09/2010 to 6/22/2010. On
average, 1.845 PCs were connected
daily.
• Data from 'Period 2' were captured
from 09/01/2010 to 09/14/2010. On
average, 1.789 PCs were connected
daily

7. Results
• 53,9 kWh saved per PC and year

8. Graphic comparative

9. Objectives met :-)
• The savings were anticipated on July 13 by
using simulations
• Formula required by the customer:
(projected savings - real savings) / projected
savings)* 100 < 20% of deviation.
• Results: (54,5 - 53,9) / 54,5)*100 = 1,1 %

10. Recommendations
• Do not take this information to the letter. The software estimates are
conservative: when used data from the PC without considering the load of
CPU, peripherals, disk, etc, the usual consumption power is much greater
than estimated and therefore the savings are higher.
• As the result depends on the use of people and their behavior (not a
laboratory testing out of reality), and no one works the same from day to
day or week to week, it is impossible to consider the conditions between 2
periods as 100% equivalent . To accomplish this we should clone two people
´s behaviors, or put two subjects in a laboratory (one with software and one
without it) and force them to use the PC in EXACTLY the same way.
• Wait a few months and see the electricity bill. The result will be visible
where most noticeable (comparison from year to year).