European Energy Efficiency Evaluation Based on the Use of Super-Efficiency Under Undesirable Outputs in SBM Models

Examples of the first approach can be found in Seiford and Zhu (2002), where original data was transformed and traditional DEA models were then applied; in Ramanathan (2005), where undesirable outputs are treated as inputs and desirable inputs as outputs; and in Färe et al. (2004), where the DEA model is transformed into a non-linear problem in which normal outputs are maximised and undesirable outputs minimised. With respect to the second approach, the most representative example is Färe et al. (2004). In this study, using the original data, the authors make the assumption of weak disposable reference technology originally suggested by Färe et al. (1996) (this technique has been denoted as environmental DEA technology in Färe et al. (2004)). Nevertheless, it is worth noting Førsund’s Førsund (2009) suggestion that the assumption of weak disposability for undesirable outputs has serious formal weaknesses, and, additionally, it does not account for abatement, and he recommends modelling the generation of undesirables as a function of the same set of inputs as in the production of good inputs. In a recent publication (Førsund 2018), he has developed the multi-equation modelling of desirable and undesirable outputs satisfying the physical principle of conservation of material balance.

The use of a Malmquist approach can also be applied to determine the effects of changes other than time. For example, we may use it to evaluate two different ways to organise production, or two technologies, or two different managerial alternatives (see for instance Cooper et al. 2007, p.231).

The cases (l = 0, u = ∞), (l = 1, u = 1), (l = 0, u = 1) and (l = 1, u = ∞) correspond to the constant (CRS), variable (VRS), non-increasing (decreasing) (NIRS) and increasing (IRS) returns to scale, respectively (see, for instance, Bogetoft and Otto 2011).

Regarding the specific objectives, the sixth Environment Action Program (EAP), adopted in 2002, is a policy program for the environment in the EU for the period 2002–2012. This program has four key priorities, the first one “Tackle climate change” with two objectives: (i) to achieve the EU target of reducing greenhouse gas emissions by 8% by 2008–2012 and (ii) to target more radical global emission cuts in the order of 20% by 2020. These long-term objectives require efforts from EU countries in terms of efficiency improvement and energy saving, and the evaluation of energy and environment efficiency in the EU member countries allows references to be identified for dissemination and provides evidence of the results achieved.

In this study, we account for the electricity and derived heat generated from conventional thermal plants (fossil fuels) and nuclear plants

An approach with several similarities has been considered in (p.375–376 Cooper et al. 2007) in the context of US electric utilities.

A metric measure used to compare the emissions from various greenhouse gases (i.e. methane, carbon dioxide, fluorine gas, HFCs, nitrous oxide, PFCs, and SF₆) based upon their global warming potential (GWP). Carbon dioxide equivalents are commonly expressed as “million metric tons of carbon dioxide equivalents (MMTCO₂Eq)”. The carbon dioxide equivalent for a gas is derived by multiplying the tons of the gas by the associated GWP. Nevertheless, the most important greenhouse gas linked with the energy sector is CO₂, although most of the literature lacks a precise definition of this term.