Options (and audits) for energy efficiency

by Courtney Llewellyn

It’s about so much more than just the final product in farming. Before there is a gallon of milk or a colorful display of vegetables on a farm stand, there are major inputs – the most important being time, money and energy. Fortunately, there are ways to reduce energy consumption, which in turn can save farmers some of that other precious resource: money.

Adam Boese of the Daylight Savings Company recently led a session on “Energy Savings – Ways to Cut Costs” at the Empire State Producers Expo. His company performs energy audit on farms around New York State. The USDA-NRCS notes that the purpose of farm energy audits is to “identify opportunities to reduce energy use and costs; change current behavior; and use energy efficient equipment.” That information can lead to recommendations on ways to reduce energy usage while maintaining or even increasing farm production.

The USDA-NRCS stated that it makes sense to have an energy audit done when a farm has minimum fossil fuel usage, has a high likelihood of installing energy-saving recommendations and will have a long lifespan. There are things farmers can do before they have someone complete an audit, however.

“Step one is to find your electric bill and look at the monthly usage comparisons,” Boese said. “Look for trends, or if there are spikes, figure out why they occurred.” He also recommended checking your bill for estimated readings versus meter readings. Estimates may be over actual usage, and you can read your own meter instead of relying on your utility company’s estimates.

Boese said every New York farmer should consider signing up for the Residential Agricultural Discount Program, which he called “the best discount in the country.” Those eligible sign up once a year (usually around July 1) by applying through your utility company. The biggest caveat is that your residence needs to be on the same property as the farm and use the same meter. Other states may offer similar programs.

Additionally, Boese noted that sales tax should not be included on a farmer’s electric bill. If it is, you should call your utility to have it removed.

In many states, users are permitted to seek out their own utility providers, rather than relying on what is typically provided in an area. If you decide to go this route, Boese warns to be wary of locked-in rates versus variable rates. “A locked-in rate may be stable, but it also may be a lot higher than something that only varies a little month to month,” he said. “That variable rate might also be worth it if it’s low 10 months out of the year and only jumps for two months.”

Boese told farmers to be diligent about checking rates and renewals. “It’s a job. It’s another job,” he said. “But you have to check it on a monthly basis.”

When it comes to the actual investigation, auditors look at anything that uses energy. “They offer more than just saying ‘switch lights to LEDs, install high-efficiency fans.’ People know that,” Boese said. “These audits help you plan for the future and help with the present.” He added they also help you compare what you are doing to what’s being done on other farms.

An energy audit will show every energy cost reduction opportunity. They look at billing, equipment fuel usage, lighting, heaters, pumps, high efficiency motors, heat reduction, coil defrost systems, refrigeration, renewable energy options – everything. They can even help farmers find net zero strategies, if that is something they wish to achieve.

Reconsidering Your Refrigeration

A very big portion of energy usage on a farm can be sunk into refrigeration, especially for those growing and storing fruits and vegetables. Michael Mager, co-owner and technical consultant with Arctic Refrigeration Company, spoke about proper refrigeration for storages as well.

“There are no rules of thumb. Everyone is different,” Mager stated. “The most important question to ask is ‘How much refrigeration do I need?’”

How does a producer figure that out? The first thing you need to do is a kind of “self-audit.” Consider what product you’ll be storing – for example, sweet corn versus apples. Mager noted that sweet corn gives off 10 times the heat of apples, so it takes a lot more energy to bring its temperature down. You also have to look at the amount of the product in pounds, its entering temperature, what your goal pull-down time is (usually 24 hours) and your goal final temperature (since every product has a different one).

Other considerations include the placement of your cooler. Is it inside or outside? What is the size of the door? Are there plastic strip curtains (which can cut your infiltration load by half)? “They are a pain in the ass but a necessity,” Mager stated bluntly. How many door openings per hour occur?

You also have to look at how the product is packed. Mager mentioned a study of cabbage in which the producer couldn’t get its temperature to drop. They looked at and compared wire, wood and cardboard packing options. The cardboard packaging kept the product 10 degrees warmer, and lowering the temperature of the cooler didn’t make a difference – only time did.

“From the time a product is harvested, it starts to deteriorate. Our goal is to slow that process,” Mager explained. He said producers need to do their homework gathering all the numbers necessary to determine their refrigeration needs: the size of the cooler, its insulation and how airtight it is, its door openings per hour, what external temperatures it’s surrounded by, etc. The biggest factor is the product load, though. That can take up more than 50% of your energy needs.

Fruits and vegetables also need humidity.

“Humidity is the toughest thing to control. It is only the moisture in the air,” Mager said. “And when you open your door, you can lose it just like that. The high will always flow to the low. You can lose all your humidity that way.”

He looked at a few examples of different crops growers deal with. Carrots are difficult, he said. They need about 32º F but almost 100% humidity. Cabbage and onions are very easy. Potatoes vary by use, but producers need to watch for soft rot and late blight before putting them in.

Newer refrigeration and humidification systems offer better efficiencies than older models, including new digital controls that are better at setting temperatures and handling defrost timing. One thing Mager stressed was that multiple systems tend to be better than one.

“You want to buy BTUs, not horsepower,” he stated. “Two 7.5 [horsepower] systems can be better than one 20 because of BTU. They provide good redundancy and better temperature control. Multiple rooms with different temperatures are also becoming more popular.”

2020-01-31T15:23:56-05:00January 31, 2020|Grower, Grower East|0 Comments

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