Integral analysis of environmental and economic performance of combined agricultural intensification & bioenergy production in the Orinoquia region.

Agricultural intensification is a key strategy to help meet increasing demand for food and bioenergy. It has the potential to reduce direct and indirect land use change (LUC) and associated environmental impacts while contributing to a favorable economic performance of the agriculture sector. We conduct an integral analysis of environmental and economic impacts of LUC from projected agricultural intensification and bioenergy production in the Orinoquia region in 2030. We compare three agricultural intensification scenarios (low, medium, high) and a reference scenario, which assumes a business-as-usual development of agricultural production. The results show that with current inefficient management or with only very little intensification between 26% and 93% of the existing natural vegetation areas will be converted to agricultural land to meet increasing food demand. This results in the loss of biodiversity by 53% and increased water consumption by 111%. In the medium and high scenarios, the intensification allows meeting increased food demand within current agricultural lands and even generating surplus land which can be used to produce bioenergy crops. This results in the reduction of biodiversity loss by 8-13% with medium and high levels of intensification compared to the situation in 2018. Also, a positive economic performance is observed, stemming primarily from intensification of cattle production and additional energy crop production. Despite increasing irrigation efficiency in more intensive production systems, the water demand for perennial crops and cattle production over the dry season increases significantly, thus sustainable management practices that target efficient water use are needed. Agricultural productivity improvements, particularly for cattle production, are crucial for reducing the pressure on natural areas from increasing demand for both food products and bioenergy. This implies targeted investments in the agricultural sector and integrated planning of land use. Our results showed that production intensification in the Orinoquia region is a mechanism that could reduce the pressure on natural land and its associated environmental and economic impacts.

Spatiotemporal assessment of farm-gate production costs and economic potential of Miscanthus × giganteus, Panicum virgatum L., and Jatropha grown on marginal land in China.

Spatially explicit farm-gate production costs and the economic potential of three types of energy crops grown on available marginal land in China for 2017 and 2040 were investigated using a spatial accounting method and construction of cost-supply curves. The average farm-gate cost from all available marginal land was calculated as 32.9 CNY/GJ for Miscanthus Mode, 27.5 CNY/GJ for Switchgrass Mode, 32.4 CNY/GJ for Miscanthus & Switchgrass Mode, and 909 CNY/GJ for Jatropha Mode in 2017. The costs of Miscanthus and switchgrass were predicted to decrease by approximately 11%-15%, whereas the cost of Jatropha was expected to increase by 5% in 2040. The cost of Jatropha varies significantly from 193 to 9,477 CNY/GJ across regions because of the huge differences in yield across regions. The economic potential of the marginal land was calculated as 28.7 EJ/year at a cost of less than 25 CNY/GJ for Miscanthus Mode, 4.0 EJ/year at a cost of less than 30 CNY/GJ for Switchgrass Mode, 29.6 EJ/year at a cost of less than 25 CNY/GJ for Miscanthus & Switchgrass Mode, and 0.1 EJ/year at a cost of less than 500 CNY/GJ for Jatropha Mode in 2017. It is not feasible to develop Jatropha production on marginal land based on existing technologies, given its high production costs. Therefore, the Miscanthus & Switchgrass Mode is the most economical way, because it achieves the highest economic potential compared with other modes. The sensitivity analysis showed that the farm-gate costs of Miscanthus and switchgrass are most sensitive to uncertainties associated with yield reduction and harvesting costs, while, for Jatropha, the unpredictable yield has the greatest impact on its farm-gate cost. This study can help policymakers and industrial stakeholders make strategic and tactical bioenergy development plans in China (exchange rate in 2017: 1€ = 7.63ï¿¥; all the joules in this paper are higher heat value).

Re-assessment of net energy production and greenhouse gas emissions avoidance after 40 years of photovoltaics development.

Since the 1970s, installed solar photovoltaic capacity has grown tremendously to 230 gigawatt worldwide in 2015, with a growth rate between 1975 and 2015 of 45%. This rapid growth has led to concerns regarding the energy consumption and greenhouse gas emissions of photovoltaics production. We present a review of 40 years of photovoltaics development, analysing the development of energy demand and greenhouse gas emissions associated with photovoltaics production. Here we show strong downward trends of environmental impact of photovoltaics production, following the experience curve law. For every doubling of installed photovoltaic capacity, energy use decreases by 13 and 12% and greenhouse gas footprints by 17 and 24%, for poly- and monocrystalline based photovoltaic systems, respectively. As a result, we show a break-even between the cumulative disadvantages and benefits of photovoltaics, for both energy use and greenhouse gas emissions, occurs between 1997 and 2018, depending on photovoltaic performance and model uncertainties.

Biomass production in agroforestry and forestry systems on salt-affected soils in South Asia: exploration of the GHG balance and economic performance of three case studies.

This study explores the greenhouse gas balance and the economic performance (i.e. net present value (NPV) and production costs) of agroforestry and forestry systems on salt-affected soils (biosaline (agro)forestry) based on three case studies in South Asia. The economic impact of trading carbon credits generated by biosaline (agro)forestry is also assessed as a potential additional source of income. The greenhouse gas balance shows carbon sequestration over the plantation lifetime of 24 Mg CO2-eq. ha(-1) in a rice-Eucalyptus camaldulensis agroforestry system on moderately saline soils in coastal Bangladesh (case study 1), 6 Mg CO2-eq. ha(-1) in the rice-wheat- Eucalyptus tereticornis agroforestry system on sodic/saline-sodic soils in Haryana state, India (case study 2), and 96 Mg CO2-eq. ha(-1) in the compact tree (Acacia nilotica) plantation on saline-sodic soils in Punjab province of Pakistan. The NPV at a discount rate of 10% is 1.1 k€ ha(-1) for case study 1, 4.8 k€ ha(-1) for case study 2, and 2.8 k€ ha(-1) for case study 3. Carbon sequestration translates into economic values that increase the NPV by 1-12% in case study 1, 0.1-1% in case study 2, and 2-24% in case study 3 depending on the carbon credit price (1-15 € Mg(-1) CO2-eq.). The analysis of the three cases indicates that the economic performance strongly depends on the type and severity of salt-affectedness (which affect the type and setup of the agroforestry system, the tree species and the biomass yield), markets for wood products, possibility of trading carbon credits, and discount rate.

Potential of bioethanol as a chemical building block for biorefineries: preliminary sustainability assessment of 12 bioethanol-based products.

The aim of this study is to present and apply a quick screening method and to identify the most promising bioethanol derivatives using an early-stage sustainability assessment method that compares a bioethanol-based conversion route to its respective petrochemical counterpart. The method combines, by means of a multi-criteria approach, quantitative and qualitative proxy indicators describing economic, environmental, health and safety and operational aspects. Of twelve derivatives considered, five were categorized as favorable (diethyl ether, 1,3-butadiene, ethyl acetate, propylene and ethylene), two as promising (acetaldehyde and ethylene oxide) and five as unfavorable derivatives (acetic acid, n-butanol, isobutylene, hydrogen and acetone) for an integrated biorefinery concept.