Solar-powered beehive coolers increase yields

The Oregon Garden, in Silverton, recently reported a harvest of 300 pounds of honey from four first-year beehives, each of which is equipped with a solar-powered hive cooler.

Part of a new bee education program at the 80-acre botanical sanctuary, the hives [first photo above] are installed and maintained by Mark Thompson, who occasionally assists with the garden’s bee education workshops and lectures.

(Mr. Thompson is a specialty coffee roaster who works with indigenous farmers to ensure that they get a fair wage for their product. He first became interested in bees about 18 years ago when a man at his church had to give up bee farming because of health issues. Thompson volunteered his labor to keep the bee farm open.)

Why the results might have been different

"First-year hives don't usually produce much of anything because the bees are busy establishing the colony," Thompson explained.

He went on to say that the Oregon Garden hives were started as "nucs" or nuclear colonies, which are smaller versions of a normal beehive, containing less than 10 percent of the workers in an established colony. This not only makes them less productive, but also more vulnerable to winter weather.

"Under ideal conditions, a nuc hive might produce 30 to 40 pounds of honey in its first year, but the hives with the coolers averaged 75 pounds," Thompson said. The Oregon Garden [see second photo above; click arrow at right base of first photo.] has an abundance of early spring flowers, which also contributes to the hives' success.

How the coolers help

During the summer months, when the bee colonies are most active, bees assign certain workers to sit at the bottom of the hives and fan their wings in order to generate airflow that cools down the hive. (Bees also fan to reduce the moisture content of the honey before they cap it off.)

Even though bees like it warm, too much heat is not good for the eggs, makes the queen lethargic, and exposes the hive to condensation, mold, and mites. But the solar-powered coolers liberate many of the bees from their fanning duties, increasing the number available to collect pollen and make honey.

When asked whether he had any concerns about the solar coolers affecting the long-term behavior of the bees or their social organization, Thompson voiced confidence in the bees' own intelligence.

"Bees are smart," he said. "I've seen them avoid fields that have been sprayed with pesticides and return only after a safe period of time has passed. Because the fans don't run all of the time, many of the bees are exposed to both conditions, so I think if they didn't like the coolers, they would either seal them off from the rest of the hive, or swarm and move to a new area."

How the coolers work

The cooler is a separate vented chamber that fits between the top of the hive and a standard top cover. The fan is powered by a solar panel mounted on one side of the chamber. A built-in thermostat turns the fan on when the temperature of the hive exceeds 90 degrees F. (32 C), drawing the air up through hive and out through the built-in vents, literally taking the heat off the bees and helping them to be more productive.

If you go:

The Oregon Garden is located 45 miles southeast of Portland. The bees are now in winter hibernation mode, and will become active once the weather warms and spring flowers are in bloom. The hives are kept in the Oregon Garden’s Oak Grove and oriented with maximum exposure to sunrise and sunset to help the bees orient themselves. The location affords visitors a good view of the hives without disturbing bees or people and gives Thompson easy access.

Interpretive signs inform visitors about the lives of honeybees, as well as colony collapse disorder, which has adversely affected bees worldwide. Binoculars are available for better viewing.

On-site lodging is available at the Oregon Garden Resort.

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Lois J. de Vries, a popular speaker at regional flower shows and garden clubs, writes from her home in rural northwestern New Jersey. To read her other posts at Diggin' It, click here. She's a field editor for Better Homes and Gardens and Country Gardens magazines and has been a contributing editor for other national publications. She was awarded the Jefferson Presidential Award for public service in environmental work. Click here and here to read about her garden design and environmental ideas and her holistic approach to gardening.You can also follow her on Twitter and Facebook