The Green Schools Approach at Poolesville

High School

Starting Small…Starting Small…ComputersComputers Soda MachinesSoda Machines

Using The Tools

Computers…Computers…Best approach?

•Leave on

•Sleep mode

•Shutdown

Cost of One Computer…Cost of One Computer…

During During School School Hours:Hours:

E=Pt E=Pt

=100W(8h) =100W(8h)

=800Wh=800Wh

=.800 kWh=.800 kWh

.8 kWh($.08/kWh)= .8 kWh($.08/kWh)= $.06$.06

Outside Outside School School Hours:Hours:

E=Pt E=Pt

=37W(16h) =37W(16h)

=592Wh=592Wh

=.592 kWh=.592 kWh

.592kWh($.08/.592kWh($.08/kWh)=$.05kWh)=$.05

Total: $.11 for one computer per day during the Total: $.11 for one computer per day during the School YearSchool Year

For One School Day

Cost of One Computer…Cost of One Computer…

During The During The

Summer/Summer/

Weekends:Weekends:

E=Pt E=Pt

=37W(24h) =37W(24h)

=888Wh=888Wh

=.888 kWh=.888 kWh

.888 kWh($.08/kWh)= .888 kWh($.08/kWh)= $.07$.07

Total: $.07 for one computer per day during the Total: $.07 for one computer per day during the summer/weekendssummer/weekends

For One Non-school Day

Cost of One Computer…Cost of One Computer…

During The School During The School Year:Year:

($.11/day)(180 school days/year)=($.11/day)(180 school days/year)=

$19.80 for one computer during the school year$19.80 for one computer during the school year

During The During The

Summer/Summer/

Weekends:Weekends:

($.07/day)(185 non-school days/year)=($.07/day)(185 non-school days/year)=

$12.95 for one computer during the summer $12.95 for one computer during the summer and on weekendsand on weekends

Total for the entire year for one computer: Total for the entire year for one computer:

$19.80 + $12.95 = $19.80 + $12.95 = $32.75$32.75 for one computer per year for one computer per year

During the Entire Year

Total Cost of Computer System…Total Cost of Computer System…

($32.75 per computer/year)(220 computers)=($32.75 per computer/year)(220 computers)=

$7205.00 for all 220 computers over the course of one year$7205.00 for all 220 computers over the course of one year

($.06 during school hours/day)(180 days/year)(220 computers)= ($.06 during school hours/day)(180 days/year)(220 computers)= $2376.00 for all 220 computers during school hours over the course $2376.00 for all 220 computers during school hours over the course

of one yearof one year

Total amount saved: $4829.00Total amount saved: $4829.00

Soda Machines…Soda Machines…

Asset or Liability?Asset or Liability?

Per Machine:::Per Machine:::

- MCPS: $300 per year- MCPS: $300 per year

- Must make at least $48.68 per month- Must make at least $48.68 per month

In total:::In total:::

- 12 machines = $3600.00 per year- 12 machines = $3600.00 per year

DATE 2002 20038/25 – 9/23 192,977 kWh 148,179 kWh

9/24 – 10/22 135,829 kWh 124,712 kWh

10/23 – 11/23 135,804 kWh 134,340 kWh

11/24 - 12/23 167,628 kWh 153,431 kWh

TOTAL 632,238 kWh 560,662 kWh

Comparison of Savings Before and After Green Schools Initiative

632,238 kWh632,238 kWh

kWh kWh - 560,662 kWh- 560,662 kWh

SAVED SAVED 71,576 kWh71,576 kWh

71,576 kWh($.068/kWh) =71,576 kWh($.068/kWh) =

Money Saved $4,867Money Saved $4,867

First Semester Savings