(Bio) Ethanol - the Sustainable Alternative for Non-renewable Fuels?

-- an SWMTHiNKTANK article

Started officially in 2003 with a capacity of 33.5 Mio l world-wide, today bio-ethanol has emerged towards a vital alternative in the market of energy carriers [1]. Of the more than 110 Mio l of bio-ethanol most of it is produced in the USA [2], [3] followed by Brazil [2]. Asia is currently not considered as a major player in this sector [2] but developments to follow the technology trends are going on [4]. In addition, new technological developments seem to provide for a more efficient extraction/refining of ethanol from the plant fibres [5], [3] that may help to reduce the energy impact per hectare. 

However, the number of arguments increase that call for a more critical/comprehensive consideration of the production of bio-ethanol. Two issues are addressed: the different energy efficiency in the production of bio-ethanol in different regions and the water demand of the (mono culture) plantation, e.g. [6]-[9]. Accordingly, Southern-America (in particular Brazil) would be the favorite region to produce bio-ethanol. Whereas the energy balance of bio-ethanol produced in Brazil results in factor of about 9 the factor for bio-ethanol produced in the USA results in a factor of about 1-2 [3], [5], [10], [11]. With regard to water the result is similar. Whereas in Brazil about 90 l of water are used to irrigate the plantations in the USA about 400 l of water are needed [12], [13]. Further studies also underline the issue of water when it comes to bio-ethanol production, e.g. [14]-[16]. In all, a trend is notable that the production of bio-ethanol needs to be considered more comprehensively and that wrong incentives may result in detrimental situations not only on regional but on global levels. Once more, in terms of economy, diversification of energy supply is considered as robust alternative to one-sided weighting.

Further readings: [0], [1], [2], [3]*, [4], [5], [6], [7], [8], [9], [10], [11], [12], [13]

* German only