Variable speed savings, well, vary


SALEM, Ohio – Every milk producer wants to save money, particularly now as low milk prices linger.

But the concept, “you have to spend money to make money” is particularly true with new variable speed drives, also frequently called variable frequency drives.

Pump it up. On most farms, the milking vacuum pump is oversized to accommodate the demands during peak milking. These maximum-capacity pumps are usually operating at full speed, regardless of vacuum needs, and that means dairymen are spending money on extra energy they don’t always need.

In the mid-1990s, Cornell researchers developed a new component for controlling the vacuum and getting electronic feedback. These controls were linked to a variable speed drive on the pump motor.

In the new system, the capacity of the vacuum matches the actual air flow needs of the milking system, with energy savings of at least 50 percent.

“The concept behind it is ‘vacuum on demand,'” said Tom Wilson, Crawford County (Pa.) extension agent who also has an ag engineering focus.

If a producer needs to replace a vacuum pump, and will be making the investment anyway, it’s worth taking a look at it, Wilson said.

Payback for a new system depends on the size of the herd, the size of the existing pump (how much ‘overcapacity’ you’re currently paying for), and how long the pump is in use every day. Every farm varies, but the payback typically ranges between two and three years.

“The economics are good,” Wilson said.

An added plus is that the system is a whole lot quieter than vacuum motors running at full speed all the time.

Rebate in Pa. A Vermont company is offering $1,000 cash rebates to the first 20 eligible farms who apply in Pennsylvania’s Eric, Crawford and Mercer counties.

Farmers in those counties should have received a promotional mailing on the rebate deal the first week of May.

If eligible, you must install a variable speed drive on your milking vacuum pump before the end of August. Funding is allocated on a first come, first served basis.

EnSave Energy Performance received a $50,000 Pa. Department of Environmental Protection grant for the pilot program. Of that, $20,000 is slated for the rebates; the remaining $30,000 is for administrative costs and program development, according to Helen Hossley, director of program operations at EnSave.

The company has conducted similar programs in California, Minnesota, Wisconsin and Michigan.

New York rebate. EnSave is also currently conducting a rebate program to 300 New York milk producers, offering a $500 or $1,000 rebate, depending on the amount of electricity saved.

The deadline for that program is the end of June.

Eligibility. After it receives an application, EnSave calculates the producer’s kilowatt hour savings based on information on the application. If below a certain savings level, and if the payback would be more than five years, the application will be denied, Hossley said.

Hossley said there is an immediate turnaround on the application and producers should know within a week of sending the rebate application whether or not they have been accepted.

No strings. EnSave offered a pilot on-farm energy audit and pollution prevention audit in Pennsylvania earlier this year, but the variable speed drive rebate is not connected to that program.

Milk producers in the three participating Pennsylvania counties, or in New York, interested in learning more about the rebate offer can call EnSave at 1-800-732-1399 and ask for Hossley.


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