Electric energy consumption of milking process on some Finnish dairy farms

Abstract

The aim of this study was to examine the electric energy consumption of milking process on dairy farms and to evaluate the methods to improve the energy efficiency. The electricity consumption of the milking process was measured on three dairy farms in Southern Finland, and it varied between 37-62 Wh kg -1 milk. The largest energy saving potential was identified in milk cooling and the heating of cleaning water. Even simple methods, such as placing the condenser of the refrigeration system outside, may reduce the energy consumption of milk cooling by 30%. Efficient milk pre-cooling can reduce the energy consumption of the whole milking process by more than 25%. Even larger energy savings are possible with a sophisticated milk cooling -water heating systems. It was concluded that there is a significant potential to reduce the energy consumption and energy costs of the milking process, and thus to improve the profitability and sustainability of the sector at the same time.

Energy Consumption on Dairy Farms: A Review of Monitoring, Prediction Modelling, and Analyses

“…Milk cooling was found to be the second largest consumer of electricity (16.4 Wh kg −1 ) followed by water heating (3.2 Wh kg −1 ), and water pumping (2.6 Wh kg −1 ). All four studies [23,25,27,28] found milk harvesting to be the greatest consumer of electricity on AMS farms. Although none of the farms included in Table 4 are organic farms, electrical energy on organic farms is of greater importance compared to conventional farms because it represents 26% of total primary energy usage, compared to 17% on conventional farms (calculated using energy values in Table A1).…”

“…Similar to Upton et al [4] and Shine et al [8], Kraatz [22] found that milking equipment (vacuum pumps, milk bulk tanks, and water heaters) were the major electricity consumers on German dairy farms. In Finland, Rajaniemi et al [27] calculated electricity consumption associated with milk production (milk-cooling, milk harvesting and water-heating) to vary between 37 and 67 Wh kg m −1 when analyzing three dairy farms (mean herd size = 82 cows), one farm of which employed an AMS. Rajaniemi et al [27] reported milk harvesting and milk-cooling as the largest electricity consumers on the AMS farm, (29% and 22%, respectively), while on the two Conv-c farms, milk-cooling and water-heating were the two largest electricity consuming processes (22% and 16%, respectively).…”

“…In Finland, Rajaniemi et al [27] calculated electricity consumption associated with milk production (milk-cooling, milk harvesting and water-heating) to vary between 37 and 67 Wh kg m −1 when analyzing three dairy farms (mean herd size = 82 cows), one farm of which employed an AMS. Rajaniemi et al [27] reported milk harvesting and milk-cooling as the largest electricity consumers on the AMS farm, (29% and 22%, respectively), while on the two Conv-c farms, milk-cooling and water-heating were the two largest electricity consuming processes (22% and 16%, respectively). In Denmark, Brøgger Rasmussen and Pedersen [34] analyzed the electricity consumption within the milking parlor on 17 dairy farms, which each employed an AMS between June 2003 and February 2004, making comparisons with a conventional herringbone parlor and 26-stall rotary milking parlor.…”

“…With increasing electricity demand, there exists the potential for improvements in efficiency (usage per liter of milk) as dairy farm facilities may not be optimally configured for milk production increases [4,27]. For example, utilizing the MECD [38], Upton et al [53] found a farm with a herd size of 88 dairy cows had a 24% greater electricity consumption per liter compared to a farm with a herd size of 45 cows.…”

“…Rajaniemi et al [27] highlighted that milk-cooling related electricity savings of approximately 30% may be achieved through modest improvements to plant infrastructure such as: improving the ventilation of the milk tank room, placing the refrigeration condenser outside the building to improve the operational COP, and installing milk pre-cooling and heat recovery systems. However, it should be noted that these calculations were carried out through utilizing only three dairy farms, while electricity saving potential was calculated using an un-validated model.…”