The Impact of Manure Use for Energy Purposes on the Economic Balance of a Dairy Farm

Abstract

The use of methane fermentation in mesophilic conditions for the energy use of cow manure and additional co-substrates from the farm can bring a small dairy farm (140 dairy cows) financial benefits of up to EUR 114,159 per year. Taking into account the need to pay for emissions calculated as carbon dioxide equivalent, this profit could be reduced to EUR 81,323 per year. With the traditional direct use of manure, this profit would drop by as much as 60% to the level of EUR 33,944 per year. Therefore, the introduction of fees for emissions may significantly burden current dairy farms. As has already been shown, just compacting and covering the manure (which costs approx. EUR 2000 per year for 140 cows) would give almost twice as much profit—EUR 64,509 per year. Although an investment in a small biogas plant with a cogeneration unit on a family dairy farm may have a payback period of less than 6.5 years and a return of capital employed of 16%, most small farms in the world will not be able to afford its construction without external subsidies. At the same time, it would make it possible to reduce emissions by almost 270 times—from 41,460 to 154 tons of CO2eq per year—and the possibility of preserving valuable nutrients and minerals and supporting soil properties in the digestate. Therefore, it seems necessary for Europe to introduce a support system for small- and medium-sized farms with this type of investment in the near future in a much larger form than it has been so far.

Agricultural Micro Biogas Plants as a Factor in Farm Development—A Case Study

“…Various numerical methods, such as AHP [20], Vikor [21], and the numerical taxonomy method [22], can be used to assess the profitability of the investment. The payback period for the construction of an agricultural microbial gas plant is 6-7 years [23] (investments with a payback of up to 8 years are considered financially beneficial [24,25]). In comparison, the payback for a P.V.…”

Influence of the Parameters of an Agricultural Biogas Plant on the Amount of Power Generated

“…Investing in biogas plants on dairy farms, in addition to the reduction of greenhouse gas emissions and the reduction of unpleasant odours, results in an increase in the income indicators of the farm in question [52]. The revenue from electricity production in a biogas plant is approximately EUR 20/MWh higher than the average electricity price in the second quarter of 2023 [53].…”

“…Selling the heat produced in the biogas plant or using it for a farm's needs would yield an additional profit of approximately EUR 35 per GJ [54]. It should be noted that the payback period for an agricultural biogas plant is just over six years [52] (financially favourable investments with a payback of 5-8 years are considered [55][56][57]). In the case of microbial biogas plants, where no investment in land is required, a payback period of even less than five years is achieved [52].…”

“…It should be noted that the payback period for an agricultural biogas plant is just over six years [52] (financially favourable investments with a payback of 5-8 years are considered [55][56][57]). In the case of microbial biogas plants, where no investment in land is required, a payback period of even less than five years is achieved [52]. In comparison, an investment in a PV plant typically pays for itself within five to six years [58].…”

Leverage of Essential Oils on Faeces-Based Methane and Biogas Production in Dairy Cows

“…To reduce these costs, relatively cheap solutions can be employed, including compaction and heap cover [18][19][20], solid fraction separation [18,19,21,22], composting [23][24][25][26][27][28][29][30][31][32], and others [19,33,34]. At the moment, however, the most proven solution to the above-mentioned problems, although requiring significant investments, is the application of manure within methane fermentation processes [35][36][37][38]. Moreover, retrofitting a biogas plant with a cogeneration unit (CHP) will not only drastically reduce the production of greenhouse gases and other harmful impacts, but will also be a source of renewable energy as a result of methane recovery [39][40][41][42][43].…”