SNOWPURE, LLC, 2005-2018
VERSION 3.5 (XL+EXL)
–FEBRUARY 2018
PAGE 72
Appendix #8: EDI Power Consumption and Electrical Cost
The operating cost of an EDI system includes the cost of the electrical power
supplied to the EDI system. However, at all times, it can be shown that the total
operating cost is dominated by the power usage of the RO equipment. Here is a
sample energy cost calculation for an XL-500-R module:
1.
Power
used by each module is a product of the DC voltage and DC current.
DC Power (Watts) = Voltage (VDC) * Amperage (ADC)
(e.g., XL-500-R) 600 W = 300 VDC * 2.0 Amps
2. There is some
power loss
at the power supply during the conversion from AC to
DC. Power supply efficiency is typically over 85% (15% losses).
AC Power = DC Power / 90%
0.7 kW = 600 W / 0.90 / 1000
3.
Energy
used is the product of Power and Time.
Energy (kWh) = AC Power (kWatts) /1000 * Hours
6 kWh = 0.7 kW * 8 hrs
4.
Energy
Cost
depends on the local utility rate (e.g., $0.12 per kW-hr). Cost =
Energy * Rate. A typical XL-500-R module the energy costs under $1 per 8-hour
period.
Cost (8-hour period)
Energy
Rate
$ 0.72
6 kW-hr
$ 0.12 /kW-hr
€ 0.84
6 kW-hr
€ 0.14 /kW-hr
5.
Cost of energy used to produce a unit volume
of pure water:
Cost
Volume
Energy
Rate
$ 0.15
1000 gallons
1.2 kW-hr
$ 0.12 /kW-hr
€ 0.05
1 m
3
0.3 kW-hr
€ 0.14 /kW-hr