Conducting research on energy loss in beehives and its effect on honey production

The loss of energy in beehive is closely related to heat management and the ability of the beehive to maintain heat. When assessing honey production as one of the quantitative indicators, it is also necessary to take into account the impact of environment. In an effort to maximize honey production, leaving out quality of the beehive as an important environmental factor and instead seeking a solution in quality of the genetic component (breeding), the goal is usually unreachable. Especially in common, non-laboratory conditions.

Why is it important for a beehive to be well insulated?

  • Spring development
    In case of a long, cold Spring, there is a delay in development in beehives without sufficient insulation and colonies cannot collect abundant nectar because they are not ready to forage
  • Heating the beehive at the time of brood rearing
    It is indeed heating the beehive at the time of brood rearing that represents the highest demand on energy. Honey consumption for heating is very high and these losses significantly affect the profitability of beekeeping. Colony in an insulated beehive is more efficient in collecting nectar because the majority of its foragers do not need to maintain necessary temperature for developing brood
  • Sudden temperature changes
    Honey stocks are not used even if there is a wave of cold weather after a period of heavy foraging, unlike in poorly insulated beehives

"There is also a difference in the consumption of food of adult bees, which is affected by living and working conditions; the more unfavorable environment in which the bees live and the more and harder they must work, the higher the consumption. E.g. in poorly insulated beehives where there are large heat losses, bees use more stock to produce thermal energy than in well-insulated beehives. The consumption of glycid stocks, i.e. honey, or sugar is high, especially when brood roaring, because the brood needs a stable temperature of 34-36°C for its development."

Čavojský et al., 1981, p.52

Having insulated walls does not automatically guarantee thermal insulation

General opinion exists that a beehive with insulated walls of any kind is indeed thermally insulated. It does not need to be true. Of course, thermal insulation of a beehive is not only a matter of used materials, but also the construction. If the construction is unfit and the craftsmanship is poor, a wall made of an insulating material of any kind will not ensure thermal insulation. We think, and our measurements prove it, that a beehive with a 20 mm polystyrene insert in walls is a beehive with insulation, however we cannot even speak about thermal insulation here. It is proved by measurements, where a beehive of such construction performed even worse than a wood beehive of 22 mm wall thickness.

Measuring beehive energy losses

Why did we do it?

Areas which have been researched before such as:

  • temperature in beehive during season
  • temperature in swarm in winter months

were out of our scope.

Instead, we focused on areas which are not researched much:

  • energy losses and rating of beehives in Spring and Summer months

It is possible and practically doable to measure the energy consumption needed to heat up a beehive.

How did we do it?

We have developed a simple but fairly accurate way of measuring heat loss in different types of beehives. Reproducing the process, you can make your own measurements.

Tools and material used in measurements:

  • 250W heat lamp
  • power consumption meter
  • thermostat with thermometer
  • 2x polystyrene board with a thickness of 80 mm
  • supers of various constructions and materials

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The measurements were carried out in a room at a set temperature with no air flow. During the measurements, each super was covered from the top and bottom by a 80 mm thick polystyrene board. Heat losses were measured by the consumption of electric current in kWh, so that the temperature inside the super has reached 35°C. The results, therefore, show energy losses through beehive walls.

Table 1: Energy losses

Beehive walls

March, April, ... , September

average outside temperature 12°C

May, June, July, August

average outside temperature 14°C

Wood 7 mm/polystyrene 20 mm/wood 7 mm 233 kWh 137 kWh
Wood 22 mm without knots 187 kWh 103 kWh
Polystyrene 40 mm 137 kWh 72 kWh
Polystyrene 80 mm 84 kWh 30 kWh

The table shows the results measured in the room at a set temperature with no air flow. In nature, windlessness is a rather rare situation. Further outdoor measurements have shown that energy losses with insufficient thermal insulation due to wind are approximately another 10%.

Conclusion

Better thermal insulation results in low energy losses lead to the conclusion, that it is far less demanding for a colony to reach and maintain the required temperature in a beehive.

Knowing the range of energy losses measured in supers, let's now go back to the individual reasons why it is important to have a high level of thermal insulation.

  • Spring development
    It is imperative to say that an early Spring development not only ensures collecting of abundant nectar. More important is the replacement of winter bees with new bees capable of taking over the Spring development
  • Heating the beehive at the time of brood rearing
    As we have already mentioned, it is the heating of the beehive at the time of brood rearing which represents the greatest energy demand. Autumn and winter months are the heating season in our homes, with bees it is exactly the opposite. The temperature does not move around 20°C as in our homes, but reaches up to 35°C. Honey consumption for heating is very high!
  • Sudden temperature changes
    Beehives with a sufficient thermal insulation level out the temperature oscillation and the colony does not need to react to it. Honey stocks are not used to reach the required tempearteure unlike in beehives with poor thermal insulation

Our solution

HiveTD beehive with its construction and materials used ensures a high level of thermal insulation. Energy losses are minimized to the lowest possible levels, and therefore the honey production is higher. Colony development is early and massive, and the colony is ready to collect abundant nectar in Spring.

We recommend reading an article about our research about energy loss and its effect on varroa mites.

Bibliography:

ČAVOJSKÝ, Valent a kol. 1981. Včelárstvo. [Beekeeping] Bratislava : Príroda, vydavateľstvo kníh a časopisov, n.p., 1981. p. 628.