56
MAR 2017
FOOD FOCUSTHAILAND
SOURCE OF
ENGINEER
fans, an inverter systemwould require the installationof 1more fan;
and all fanswould need to operate simultaneously in order prevent
power surges.
Theoretically, using an inverter will help save electricity only
when themotor isoperatingatnotmore than80percentofmaximum
RPMs. Therefore, a fan’sminimumRPMmust be set no lower than
30 percent, while the maximum is not over 80 percent. Normally,
the fans are started at 80 percent of maximumRPM, andwhen the
temperature cools down, the system automatically decreases the
motor’sspeed. For example, a fan’sspeedcanbeadjusted from80
percent down to50percent; or in thecaseof littlepigletswhoneeda
warmer environment, fanspeedscanbeadjusted toaslower speed
equal to30percent of RPMs.
Frommonitoring of the energy savings from the use of inverter-
controlled fanmotors andpumps on52pilot pig farms, it was found
that therewas a 50 percent savings in electricity for fan use, and a
33 percent reduction in electricity used for water pumps. In 2016,
thepilot farmswereable to reduceelectricity costsbyup toTHB22
million, or 21percent compared to thepreviousyear. Moreover, use
of the inverter system doublesmotor life. Inverter systems can also
reducemaintenance expenses for motor bearings and belts, which
meanadditional cost reductions. Installing the inverter system costs
about THB 60,000 per building, with the costs being recouped in
approximately 2 years.
At this time,88CPFpig farmoperationsnationwidehave installed
inverter systems, and CPF encourages farmers in the company’s
farmingcontractorprojectwhohaveaconsistentandadequatesupply
ofelectricity touse invertersystems to reduceelectricityconsumption
further. And this is in addition to the current use of biogas systems
which change pigmanure into cleanpower onmany pig farms.
This isanother exampleofmaximizing theuseof limitedenergy
suppliesbyusing technology tohelp reducewasteand increase the
efficiency in electricity usage, while promoting Thailand’s energy
sustainability.
Currently, energy-saving technologies which utilize
invertersystemsaregainingpopularitybecause theyallow
electronicapplianceusingmotorssuchasairconditioners,
fans, pumps, or washing machines to consume 35–55
percent less electricity.
Inverter systems are electronic devices used to control electric
motors and efficiently adjust the speed of themotor to suit operational
requirements, therebyconsuming lesspowerandsavingelectricity. Not
onlyare invertersusedwithelectricalappliances tohelpsaveonenergy
costs,but inverter technologieshavebeen incorporated into thedesigns
of dual-system cars by the auto industry toprovidepower savings.
The pork industry in Thailand has the potential to utilize inverter
technology to substantially reduce electricity use in pig farm, and
Charoen Pokphand Foods Public Company Limited (CPF) has been
a pioneer in this field.
CPF’sporkbusiness linehasadopted inverter systems tomake the
mostefficientandeconomicaluseofelectricity. Notably, thecompany’s
pig raising operations use evaporative cooling systems (EVAP) which
require the installation of ventilating fans at the end of buildings to
circulate theair. Somebuildingsneed10 to15 fans, dependingonsize
of the facility andweight of the pigs. In general, the fans are activated
by ambient temperatures and the requirements for raising the pigs in
each age group. But every time a fan is turned on, electricity use will
immediately increase 2–3 times greater than normal, thereby causing
a power surge.
Thismajor challenge thus led to the trial programof using inverters
in pig farming operations over the last 10 years. It was found that the
operationofa fanwith the invertersystemwillhave thesameoperational
efficiency even if the fanmotor’sRPM drops. The principle of inverter
systems reliesonanadequateandconsistentelectrical current,making
its use in remote areas or at the end of the power line not feasible. In
addition, using inverters requires installing 20 percent more fans to
have the sameair circulation. For example, withanexisting set upof 5
SuccessCase
“InverterSystems”
ReduceEnergyCosts inPigFarm
