Pigs – Save energy use

Save energy use

System: Pigs

Mainly applicable for: Intensively rearered indoor pig herds with a high energy demand.

Not applicable or effective for: Less applicable for outdoor pigs

Description

Saving energy use for on-farm processes by installing energy-efficient techniques or reducing energy-demanding activities. Energy can be saved in various on-farm processes, such as ventilation, heating and feeding animals. Besides more energy-efficient machinery, it is important to use properly sized machinery.

Options for saving energy use are, for example:

Localised heating in the creep area of farrowing houses can reduce energy by heating only the area occupied by the piglets, possibly using renewable heat from slurry cooling or other renewable energy.
Heat exchanger to cool slurry, providing hot water which can be used for heating rooms with young pigs or for washing;
Heat pumps, using significantly less electricity than conventional heating systems;
Ventilation in intensive pig farming can use a lot of electricity so ensuring efficient operation can reduce electricity consumption and hence emissions;

Mechanism of effect

Saving on energy use for on-farm processes means less CO2 is emitted due to less fossil fuel combustion. Depending on the specific action this can concern either reduction of on-farm fossil fuel combustion, or reduction of purchased electricity or fuel. This solution will be less effective when renewable or low carbon energy is used in the reference situation. Using a heat exchanger to cool slurry also reduces the methane emissions from the slurry (and ammonia) due to less methanogenesis at lower temperatures.

Reference situation

Average European grid mix. No energy-efficient techniques installed.

Legend

● – Small effect (<5%)	o – No effect	o – no effect
●● – Medium effect (5-20%)	● – Unfavourable effect	? – unknown effect
●●● – Large effect (>20%)	● – ● – Variable effect (depending on farm characteristics or way/level of implementation)

Effect on total greenhouse gas (GHG) emissions (kg CO2-eq)

	per kg product		per farm (absolute)		Level of evidence
	Mean	(min-max)	Mean	(min-max)
Slurry heat exchange	●	●–●	●	●–●	High
Heat pump	●	●–●	●	●–●	High
Economic ventilation	●	●–●	●	●–●	High
Localised heating in the creep area	●	●–●	●	●–●	High

Effect per emission source

	Source	Manure storage		Animals	Feed and forage production			Barn
	Gas	CH₄	N₂O	CH₄	CO₂	N₂O	LUC	CO₂
Slurry heat exchange								●●
Direct expansion heat pump								●●
Economic ventilation								●●
Localised heating in the creep area								●●

*risk of an adverse effect (see ’cause of variable or unfavourable effect’)

Explanation of variable effect

Slurry cooling

Effect depends on the initial slurry temperature and the slurry storage time and on the use of the renewable heat.

Direct expansion heat pump

Depends on the demand for heating, which depends on the climate.

Economical ventilation

Depending on the efficiency of the original system and the demand for ventilation. Most benefit should be gained in hot climates where significant ventilation is needed.

Localised heating in the creep area

Depends on the original method of providing heat for piglets.