• Energy Research

Improvements in energy efficiency and production of renewable energy hold significant potential for reducing greenhouse gas emissions of housing, which accounts for 14% of global greenhouse gas emissions. In our research, we focused on the willingness of owners of detached houses to adopt renewable energy production systems of their own, and we examined perceived barriers to adopting these systems. The research was conducted using a survey and a life cycle assessment model. The survey covered three residential areas in Lahti, Finland, and the potential reductions in greenhouse gas emissions were estimated using a life cycle assessment model based on the survey results. The barriers to transformation were identified as a lack of knowledge in the following three areas: (1) the possible annual savings attained; (2) the costs of implementing energy efficiency and renewable energy production solutions; and (3) the technologies used in renewable energy production. The greenhouse gas emission reductions in the residential areas surveyed would amount to approximately 15% if the consumers implemented the solutions they considered.

Abstract Transportation biofuel production efficiencies and cruising ranges provided by one hectare of land are studied from a life cycle perspective in the boreal climate zone. Efficient biofuel production is essential in terms of sustainability – especially land use, biodiversity and GHG emissions. Grass methane produced by anaerobic digestion and synthetic natural gas (SNG) produced from willows by gasification provide the longest cruising ranges. However, electricity production by solar panels for electric vehicles is a significantly more efficient option than biofuels. Grass methane, straw ethanol and SNG require less primary energy per produced fuel energy than other options. Increasing biofuel production for passenger cars from cultivated biomass in the boreal climate zone should be very carefully considered because electricity for transportation is significantly more efficient.

Organic Rankine cycles have been identified as a suitable technological option for converting low-grade heat into electricity with relatively high efficiency, and the organic Rankine cycle technology has been successfully implemented in different power production systems and in recovering heat in industrial processes. This paper studies the greenhouse gas emission reduction potential by using organic Rankine cycles for recovering exhaust gas heat of biogas engines. The study concentrates especially on the biogas engine power plants in Europe. Life cycle assessment methods are used and various waste heat utilization scenarios are compared. According to the results, greenhouse gas emissions can be reduced significantly if the thermal energy of the exhaust gases, otherwise lost in the process as waste heat, is utilized for additional electricity production by means of organic Rankine cycle. However, there may already be use for the exhaust gas heat in biogas plants in the form of heat power. In these cases, the use of organic Rankine cycle does not necessarily lead to greenhouse gas emission reductions. The results also indicate, that the working fluid leakages and production as well as the organic Rankine cycle construction materials and production have only marginal effects on the results from greenhouse gas perspective.

This article focuses on the saving potential of butanol as regards greenhouse gas (GHG) emissions. It is known that butanol can be used as a biofuel to decrease the greenhouse gas emissions from transport and that butanol may overcome blend wall limitations better than ethanol. However, the GHG emissions of butanol are not well known. The study is based on two case studies: corn butanol production in the USA and sugarcane butanol production in Brazil. Results obtained for GHG emissions show 79–122 gCO2−eq/MJ for corn butanol and –55—18 gCO2−eq/MJ for sugarcane butanol. Our results suggest that in the cases studied, producing butanol from corn (with the current cultivation and process practices) does not lead to GHG emission savings. On the other hand, producing butanol from sugarcane seems to have potential for GHG emission reductions in certain conditions. We highlight the differences between these two production chains and discuss how GHG emissions from these biofuel chains could be reduced.

Abstract Biogas is a biofuel which can be used as an energy source for gas-operated vehicles or for electricity and heat production. This paper studies the greenhouse gas emissions from biowaste, waste water treatment plant sludge and agricultural biomass based biogas use as a transportation fuel and compares the transportation use with the electricity and heat production and composting of feedstock. The research is conducted using Life cycle assessment methods and the calculation follow the directive 2009/28/EC, ISO 14040 standard and Greenhouse Gas Protocol. The use of biogas in transportation sector led in all studied cases to reductions of GHG emissions compared to fossil transportation fuels. The GHG reductions varied from 49% to 84%. Biogas production and use in electricity and heat production also led to GHG reductions compared to composting of feedstock but the reductions are not as high as in transportation use in most of cases. In addition if biogas is already used in energy production, it should be considered carefully whether the advantages of directing biogas to transportation purposes are profitable from a GHG emission point of view. However the GHG reductions are heavily depended on local energy systems. This creates challenges for the policy makers and leads to need for system scale comparisons. The wider use of biogas as a transportation fuel has a potential for high GHG emission reductions in the transportation sector.

Abstract Energy decisions play an essential role in reducing greenhouse gas (GHG) emissions in the transportation sector. Biogas is a renewable energy source and can be used as an energy source for gas-operated cars or for electric cars. This paper compares different ways to use biogas, which is produced on a medium scale anaerobic digestion plants, as an energy source for transportation. The research is conducted from an economic and environmental point of view, and the option to deliver upgraded biogas via a natural gas grid is taken into account. Different processes for the use of biogas for transportation purposes are compared using life cycle assessment (LCA) methods in the Finnish operational environment. It seems that the most economical way is to use biogas in gas-operated cars due to the high price of methane for vehicle fuel use. A new feed-in tariff for electricity produced with biogas will, however, have highly positive economic effects on electricity production from biogas. From the environmental point of view, the highest CO2 reductions are gained when biogas is used in gas-operated cars or in CHP plants for power and heat production. During the transition stage, it might be reasonable to use biogas in gas-operated cars and most importantly in heavy vehicles to reduce GHG and local pollutants rapidly. If biogas production is located near a natural gas grid, the biogas can be delivered effectively via the natural gas grid. The use of biogas in gas-operated cars is an effective way to reduce carbon dioxide significantly in the transportation sector.

Food production processes may have both positive and negative environmental sustainability impacts. This makes decision-making challenging in the transition towards more sustainable food production systems. In this paper, a new method for presenting environmental impacts in the context of planetary boundaries is demonstrated. This will help food and agricultural producers compare the magnitudes of various environmental impacts. The environmental sustainability impacts of an organic sheep farm in the boreal climate zone in Finland are studied herein first using a life cycle assessment method. The results are then normalized and presented in a planetary boundary framework to ascertain the extent of different environmental impacts. The results show that in the planetary boundary context, there are positive impacts of sheep grazing on biosphere integrity (genetic diversity) and biogeochemical flows and negative impacts on climate change, land use or freshwater use. Magnitudes of the impacts greatly dependent on the assumptions made especially regarding biosphere integrity impacts. In the future, it is crucial that decision-making be based on the evaluation of various environmental impacts and that the focus be more on complex sustainability thinking, rather than on one single environmental impact. This research demonstrates that results from a life cycle assessment can be modified and presented in a planetary boundaries context. A planetary boundary framework approach similar to that proposed herein could be further used to identify different environmental sustainability perspectives and to help one better recognize the multifunctional aspects of the ecosystem processes.