If we want to make the transport sector more sustainable, it will have to place a firm focus on electric or hydrogen-powered driving. This is the emphatic recommendation of PhD candidate Bunyod Holmatov of the University of Twente. The usual focus of the sector is on biofuels, as they would reduce the greenhouse gas emissions. But they come at a hefty price for land and water, while the biofuels can replace only a small part of the energy consumed in the transport sector. On 26 November, Holmatov obtained his doctoral degree with this topic.
The results of Holmatov’s research demonstrate that the land, water, and carbon footprint of alternative fuels and electricity vary greatly, depending on many factors. For example, the type of output energy, the raw material used, the country, and the assumptions on the availability of the raw material. Though biofuels can have a small CO2 footprint and can help reduce greenhouse gas emissions, their water and land requirements can make them unsuitable for large-scale production or inferior to other alternatives that are already available.
The overarching objective of this research is to make a contribution to the public debate about the energy transition – in particular the use of low-carbon fuels in the transport sector to achieve the climate targets, while taking the land and water implications of alternative fuels into consideration. This is done in two steps: by means of a calculation of the land, water and carbon footprint of biofuels, and by an estimate of the regional and worldwide production potential of biofuels based on various sustainability criteria.
Water, land, carbon and energy are interconnected. Ambitious climate targets and a fast transition to renewable energy sources mainly focus on carbon emission (footprint) reduction. However, the need for land and water (footprint) of renewable energy systems becomes more and more a determining factor for the sustainability and acceptability in the long run, as society already experiences the impact of renewable energy systems such as biogas digesters, biofuel refineries, solar parks, and wind turbines.
Sources such as land and water are scarce. This is why it is important to understand the land and water footprint of renewable energy systems, in order to compare it to the energy generated from fossil fuels. We have to ensure that one problem is not exchanged for another.
Currently, fossil fuels are the dominant energy sources in all sectors of the global economy, and the use of them results in greenhouse gas emissions causing the climate change. Among the various sectors, the transport sector is a unique case. This sector emits a quarter of all greenhouse gases. Because of the great energy density requirement and the difficult infrastructure, the transition to low-carbon technologies presents a huge challenge.
Bunyod Holmatov was a PhD candidate in the Multidisciplinary Water Management (MWM) research group. His thesis supervisor is M.S. Krol PhD of the Faculty of ET. He is working as a postgraduate researcher at the CSTM (BMS) since 1 August.