Load Management Helps Flood Irrigators
PORTAGEVILLE, MO.
Load management (LM) is
an incentive program that
a couple of electric coops
in the Bootheel area make
available to irrigators. If irrigators
agree to withhold from
running pumps during the
heat of the day, these utility
companies will lower the rate
they charge them. The reduction in costs comes
about by the companies foregoing the demand
or stand-by charge. There can be very large saving
for irrigators who choose LM.
The normal Bootheel pivot operator (135 acres,
35 PSI operating pressure, and 11 inches
pumped) using electricity pays about 40 percent
of what he would be paying if he were using
diesel or propane (D/S) instead. Load management
might save him some money, but in some
scenarios, it could actually increase the cost a
bit. The take-home fact is that electricity always
makes sense for the pivot user, although the
benefits of LM must be looked at on a case-bycase
basis. The cost per KWH for the pivot operator
is about 9 to 11 cents.
However, the case for flood irrigators is more
complicated. The overall cost for flood irrigation
is influenced by flow rate (thus pump motor size)
and the number of acres being irrigated (thus
annual hours of operation). As pump size increases
and/or field size decreases, the pumping
cost per acre for the flood irrigator using electricity
increases. However, using LM keeps this
from happening.
The flood irrigator on load management is paying
about 50 percent of what he would be paying
if he used D/S instead. His cost per KWH is
about 12 cents. However, the flood irrigator not
using LM is very likely paying more per acre
then he would be if he were using D/S! His cost
per KWH is 30 to 40 cents if his field size is 80
acres or less.
How much savings can a flood irrigator incur
from using load management? Figure 1 shows
the savings in dollars per acre based on the field
size being irrigated and the flow rate of the
pump. For example, if a 60-acre field is being irrigated
with a pump making 2,200 GPM the LM
option would reduce the per-acre costs for those
6 0
acres by $15 to $20 for each acre.
The SEMO Electric Coop and the Ozark Border
Coop have these load management programs.
They discount the charge to farmers by
dropping the demand charge. Flood irrigators
who benefit the most have large pumps and
smaller acreages.
The Pemiscot-Dunklin Electric Coop does not
currently have a load management program.
However, their stand-by rate is low, resulting in
the final charge for flood irrigators being very
close to what the other two utilities offer with
their load management programs.
If you are flood irrigator and have balked at
using LM since shutting off power means you
have to re-wet the top part of your field, think
about it as a form of surge flow. Once a furrow
is wet and slicked over the water stream moves
out fairly fast. I’ve timed one to reach the bottom
of a quarter mile field in just 20 minutes.
This is a small cost compared to the savings you
can obtain from load management. Δ
Dr. Joe Henggeler is Irrigation Specialist with
the University of Missouri at the MU Delta Center
at Portageville.