Consumer Willingness To Pay for Proenvironmental Attributes of Biogas Digestate-Based Potting Soil

Abstract

Biogas from anaerobic digestion has become an important element in the renewable energy portfolio of many countries. In anaerobic digestion, digestate is produced as a byproduct. This could be used to produce fertilizers and potting soils for home gardeners substituting mineral fertilizers or peat-based products. However, this depends on consumer willingness to pay (WTP) for such products, which we investigate in this study. To this end, we conducted a discrete choice experiment (DCE) with 507 private consumers. From the 6084 decisions made, we derived Bayesian part-worth utilities using a preference share model and so calculated the WTP for different proenvironmental attributes of potting-soil products. We also assessed the influence of proenvironmental attitudes on the WTP. We discovered five distinct consumer groups in our respondents. Some show a significant WTP for proenvironmental attributes such as “organic”, “peat free”, and “without guano”. Three descriptions of digestate as a “renewable resource”, a “fermentation residue”, or a “biogas residue” elicited three markedly different WTP responses across all classes, with “renewable resource” garnering the highest WTP and “biogas residue” the lowest. Consumers with a stronger proenvironmental attitude exhibited a higher WTP for proenvironmental attributes. Our results can help marketers of digestate-based potting soils discover suitable price points for their products and design differentiated pricing strategies across consumer groups.

Synthetic natural gas in the private heating sector in Germany: match or mismatch between production costs and consumer willingness to pay?

“…When DCEs were first introduced, it was only possible to evaluate these experiments on an aggregate level [35], but the development of Hierarchical Bayes (HB) estimation techniques has opened new and more sophisticated possibilities. Using HB allows a researcher to calculate part-worth utilities on a pseudo-individual level [36][37][38], even if there is little data for each respondent [39].…”

“…Although this might seem unrealistic given current market prices, this level was included to cover unreserved aversion toward a renewable gas product (opting against it although there is no price increase). The upper limits had to be chosen at a level that would include all accepted price premia in order to avoid under-coverage (as, e.g., in [39]). For biomethane, market prices from [49] were used and varied; for SNG, the calculated production costs came from [58].…”

“…After a quality check, another 11 cases had to be removed from further analysis due to random answer behavior which would have impaired the estimation of part-worth utilities by creating more noise in the data. Eliminating cases after a quality check is common when conducting DCEs, as it improves the quality of the HB estimation model [39,59]. Each respondent had to complete eleven choice sets (see Fig.…”

Is the information sufficient to create a new market for digestate?

“…Moreover, Pappalardo et al (2019) noted that the willingness to pay (WTP) for the digestate depends on how much information is available among farmers. Although past studies have shown that farmers and/or consumers are willing to entry the digestate market (Dahlin et al, 2015;Herbes et al, 2020b), and purchase it (Selvaggi et al, 2021), understanding what drivers play a relevant role in the digestate purchasing process remains an open question, especially regarding the motivations that may influence its purchase instead of other soil conditioners like manure traditionally used and already well-known among consumers.…”

Correlations between the Composition of Liquid Fraction of Full-Scale Digestates and Process Conditions

“…This policy aims to achieve a 32% share of renewable energy from total energy consumption by the year 2030 [1][2][3]. In consequence, this leads to a huge production of biogas plant byproducts, digestate, a renewable resource [4] which requires post-treatment for nutrient recovery to meet the latest European Union regulation proposal on fertilizers [3,5].…”