Uwe Fritsche, Oeko-Institut - Institute for Applied Ecology
As part of the Info Dialogue on Fracking, Oeko-Institut has analysed the cumulated energy and greenhouse gas (GHG) balances of natural gas from unconventional resources , and compared those to other energy sources. In this, Oeko-Institut cooperated with LBST (Dr. Zittel) and ESUservices (Dr. Jungbluth), both of which acted as reviewers of the study.
The study supplies information on how gas extraction from unconventional resources which ExxonMobil is planning to undertake in North Rhine-Westphalia and Lower Saxony compares to other sources of energy when key environmental indicators such as GHG emissions, air pollutants, cumulated energy demand as well as land and water use are considered.
The presentation outlines the first major outcomes of the study.
Methodology
Based on data concerning natural gas extraction by fracking, typical ranges of depth, extraction volume and post-production release of methane were determined. Next, typical data for gas processing were selected.
From this, corresponding process data for the GEMIS model were implemented in the GEMIS database, reflecting life-cycles for respective exploration, operation and disposal phases, distinguished between 2010 and 2030.
An analysis of the energy and environmental effects of these processes was conducted. This extended beyond the extraction of the gas to incorporate the other processes involved in the supply of gas to consumers (i.e. including processing and typical transport in the gas grid). The use of gas for power generation in a new combined-cycle power plant was also analyzed.
Respective data for conventional natural gas extraction in Germany, Norway and Russia in the years 2010 and 2030 were used as benchparks (comparators).
As is the case with unconventional natural gas, GEMIS was used to calculate the energy and environmental effects of “conventional” gas supply (including processing and typical transport in the gas grid to the consumers) and then the use of the power generated in a new combined-cycle power station was analyzed.
The environmentally relevant greenhouse gas balances (CO2 equivalents), acidification potentials (SO2eq), fine particle emissions (PM10) as well as total and non-renewable energy requirements are presented in the preliminary results.
Preliminary results
It turns out that drilling for exploration and production of frac fields is of great relevance for the results.
Of even greater relevance for the results are the post-production diffuse emissions of CH4, which were modelled over a 100-year period, and then related to the amount of frac gas supplied and/or the power generated from it.
Comparisons
LNG (liquid gas) from Algeria and regenerative gas (from biomass and wind-generated electricity) were incorporated (time horizon 2030) and calculations were also made of other environmental aspects such as
- acidifying air pollutants (SO2 equivalents, SO2, NOx)
- non-renewable primary energy consumption and the land balance.
The data are undergoing validation (peer review).
