Chicken House Energy Audit Results in Ideas to Improve Efficiency

The Problem

Demand for better climate control, especially ventilation, has increased over the past decade as poultry companies have moved to require fully enclosed chicken houses. These houses must support the genetics of today’s meat chickens, which grow faster and with higher feed conversion ratios than ever before.

Many farm electric accounts are charged not only for total energy usage but also extra charges for power used during periods of peak demand, according to Yi Liang, Associate Professor of Biological and Agricultural Engineering for the Division of Agriculture. Her study used 15 minutes as its peak demand period — the amount of time that utility companies use to compute the most power within a billing cycle.

Liang’s previous published research showed that peak demand charges can account for close to 50 percent of the monthly electricity bill for some farms.

The Work

A modern broiler chicken house’s electric load pattern was monitored for 11 months. Equipment monitored included sidewall fans, end-wall fans, circulation fans, compact fluorescent lamps, dimmable LED lamps, feed-bin cross-auger motors, feed-line motors, blowers on radiant-tube heaters, and well-water pump motors for an entire farm. The sump pumps used to deliver water to the cooling cells were not monitored since their electricity consumption was small. Due to the difficulty in obtaining real-time measurements, the researchers did not measure fuel usage to heat the production houses.

The Results

Over the monitoring period, which included four flocks of broilers, a single broiler house consumed 29,068 kVAh of apparent power. KVAh (Kilovolt-ampere hour) is the measure of the total power consumed by an electrical system, including both the useful power (kW) and reactive power (kVAR). The maximum usage of 6,938 kVAh per calendar month occurred in August 2022. April 2022 and January 2023 had two of the lowest usages of about 600 kVAh, during which brooding occurred.

Ventilation fans used 25,480 kVAh, or 88 percent of the total energy, partitioned between 5,545 kVAh (19 percent) for sidewall fans and 19,935 kVAh (69 percent) for end-wall fans. End-wall fans create high air speed through the house, typically referred to as the “tunneling effect,” to help cool the chickens.

Due to the adoption of energy-efficient lamps, lighting used just 3 percent of the total energy. Motors that delivered feed, water and heat to the house used 1.7, 1.0 and 0.9 percent of electricity, respectively, over the four-flock, 11-month period.

The highest total demand happened when birds were 43 days old, and the daily maximum of the outside temperature was 91.4 Fahrenheit. The end-wall fans had been in operation for a long period of time, with the peak demand taking place when multiple feed motors and the well-water pump motor started while the fans were on.

Quantified by price, electricity costs over the 11-month production period ranged from $5 per metric ton to $22 per metric ton of live weight produced for winter and summer flocks, respectively.

The Value

The results of this study could help target energy conservation efforts in the nation’s largest meat protein sector. Researchers and producers may be able to develop peak-demand reduction strategies and characterize the value of dynamic excess energy supplied to the grid by broiler farms that adopt on-site renewable energy generation technologies, like solar panels.

The long-term monitoring of a modern broiler house provided insight into the impact that load management could have on costs by increasing the diversity of load and lowering peak demand. Liang hypothesized that pausing the operation of some fans while the feed motors and water pump take time to refill. The critically needed fans could then be quickly restarted in succession. Liang said that control hardware exists, but a control algorithm would need to be developed.