Embodied Energy and Energy Return on Investment Analyses in Maize Production for Grain and Ethanol under Center Pivot, Subsurface Drip, and Surface (Furrow) Irrigation with Disk Tillage and No-Till Practices

2016 ◽  
Vol 59 (3) ◽  
pp. 873-884 ◽  
Author(s):  
Peter Rez

It is nearly always the case that the energy used to make the materials dominates, whereas the energy used in shipping either the raw materials or the finished product is usually small in comparison. For most things that we use, the embodied energy is much less than the energy consumed in operational use. When considering energy generation, there are two energy costs that should be considered. There is the energy needed to build the system, which can be thought of as a ‘capital’ or investment energy, and the energy needed to provide the fuel. For fossil fuels, the energy needed to provide the fuel dominates; for renewables, the fuel is free, so there is only an investment energy. The investment energy for nuclear power is greater than the energy needed to make the fuel, but only by a factor of about 4.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1011
Author(s):  
Bartłomiej Bajan ◽  
Joanna Łukasiewicz ◽  
Agnieszka Poczta-Wajda ◽  
Walenty Poczta

The projected increase in the world’s population requires an increase in the production of edible energy that would meet the associated increased demand for food. However, food production is strongly dependent on the use of energy, mainly from fossil fuels, the extraction of which requires increasing input due to the depletion of the most easily accessible deposits. According to numerous estimations, the world’s energy production will be dependent on fossil fuels at least to 2050. Therefore, it is vital to increase the energy efficiency of production, including food production. One method to measure energy efficiency is the energy return on investment (EROI), which is the ratio of the amount of energy produced to the amount of energy consumed in the production process. The literature lacks comparable EROI calculations concerning global food production and the existing studies only include crop production. The aim of this study was to calculate the EROI of edible crop and animal production in the long term worldwide and to indicate the relationships resulting from its changes. The research takes into account edible crop and animal production in agriculture and the direct consumption of fossil fuels and electricity. The analysis showed that although the most underdeveloped regions have the highest EROI, the production of edible energy there is usually insufficient to meet the food needs of the population. On the other hand, the lowest EROI was observed in highly developed regions, where production ensures food self-sufficiency. However, the changes that have taken place in Europe since the 1990s indicate an opportunity to simultaneously reduce the direct use of energy in agriculture and increase the production of edible energy, thus improving the EROI.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2803
Author(s):  
Wiraditma Prananta ◽  
Ida Kubiszewski

In early 2020, Indonesia implemented the biodiesel 30 (B30) program as an initiative to reduce Indonesia’s dependency on fossil fuels and to protect Indonesia’s palm oil market. However, palm oil has received international criticism due to its association with harmful environmental externalities. This paper analysed whether an investment in palm oil-based biofuel (POBB) provides Indonesia with the ability to achieve its environmental and financial goals. In this research, we performed a meta-analysis on biofuel energy return on investment (EROI) by examining 44 biofuel projects using ten types of biofuel feedstocks from 13 countries between 1995 and 2016. Results showed an average EROI of 3.92 and 3.22 for POBB and other biomass-based biofuels (OBBB), respectively. This shows that if only energy inputs and outputs are considered, biofuels provide a positive energy return. However, biofuels, including those from palm oil, produce externalities especially during land preparation and land restoration. We also compared these EROI biofuel results with other renewable energy sources and further analysed the implications for renewable energies to meet society’s energy demands in the future. Results showed that biofuel gives the lowest EROI compared to other renewable energy sources. Its EROI of 3.92, while positive, has been categorised as “not feasible for development”. If Indonesia plans to continue with its biofuel program, some major improvements will be necessary.


2018 ◽  
Vol 22 ◽  
pp. 179-187 ◽  
Author(s):  
Zhaoyang Kong ◽  
Xi Lu ◽  
Xiucheng Dong ◽  
Qingzhe Jiang ◽  
Noah Elbot

2011 ◽  
Vol 3 (12) ◽  
pp. 2323-2338 ◽  
Author(s):  
Yan Hu ◽  
Lianyong Feng ◽  
Charles C.S. Hall ◽  
Dong Tian

2018 ◽  
pp. 387-404
Author(s):  
Charles A. S. Hall ◽  
Kent Klitgaard

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