9
Energy & environmental
Energy Consumed – graph (kWh)
The calculated energy used annually with the existing control method and
using a frequency converter for flow control are both illustrated in two-column
chart.
Saving percentage %
The reduction in electricity costs in percents. This is also, of course, the energy
saving in percents.
Annual energy consumption (kWh)
These are shown for both with existing control method and improved control
method.
Annual energy saving (kWh)
This is the energy difference in favor of frequency converter control.
Annual CO
2
reduction (kg)
The reduction in carbon dioxide (CO
2
), which results from the reduced energy
consumption due to variable speed control. Carbon dioxide CO
2
is the primary
greenhouse gas causing global warming.
The CO
2
reduction depends on the
CO
2
emission per unit
, which should
reflect the way and emissions the electricity used has been generated with. The
per unit emission is given in kg/kWh consumed, and it can be altered by the
user.
Economic results
Annual money saving
This is how much money you save thanks to the variable speed control by AC
drive. Money saving comes in the form of smaller electricity bill.
Payback period
This direct payback time shows how many years the investment has paid itself
back.
Net present value
Net present value (NPV) is a more advanced method for analyzing investments
than the payback period rule. If the NPV is positive, then the investment should
be accepted.
