Abstract
In the material handling industry, productivity is a vital driver of profitability. Efficient operation of a forklift fleet is a significant factor in determining overall warehouse productivity. Traditionally, lead-acid batteries have been the best choice for forklifts operated indoors where emissions are restricted for health and safety reasons. More recently the application of fuel cells in this type of activity has emerged, also guaranteeing operational and environmental benefits (Elgowainy et al., 2009), and it is also shown as a possible solution to increase the productivity of a warehouse (Ballard, 2013). Withing the material handling industry the increased productivity comes through range extension enabling operation of the forklift with quick refuelling, without the need for battery recharging, as well as the existence of a constant power throughout the whole work cycle (Ballard, 2013). The performance of a forklift truck powered by PEM fuel cell or a lead acid battery is modelled and investigated by conducting a parametric study (Hosseinzadeh et al., 2013). In this study as a function of the number of daily trips of a forklift is characterised its energy expenditure, with the purpose of dimensioning, in an intelligent way opt for the most efficient propulsion system. Note that the two systems currently have a very different development stage, because the use of batteries is a technology implemented much more than the fuel cells. Our objective is, according to the workload that the company demands its forklifts to adapt the propulsion system that allows obtaining a greater productivity. In this model is studied several kinds of forklifts of Class I, II and III of the 1000 to 9000 kg in a wide range of loads.

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The increasing urban development is being accompanied by increased mobility in transport and by the increasing of greenhouse gas (GHG) emissions. The European Union (EU) projects that, in the next forty years, transport activity will increase around 57% (2010-2050) and it will be the largest source of CO2 (Margaritis et al., 2016). To reduce these prospects, the EU has been looking for a more sustainable and decarbonised transport system (European Commission, 2011). The entry of electric vehicles (EVs) into the European markets is seen as an important aspect for low-carbon mobility (Morton et al., 2016). However, EVs have characteristics that condition their entry into the markets, such as their high cost, the limited network of charging infrastructures, their maximum reach, the lack of information dissemination (Labeye et al., 2016), and also the risk of the investment (McDowall, 2014). Global governments have been using a wide variety of incentives to facilitate the entry of EVs, including subsidies and public investments in loading stations (ICCT, 2016). The primary objective of this article is to evaluate the expansion of EVs in Europe, including the assessment of drivers' benefits. Additionally, this study allows interpreting the effect of policies implemented by the European Union and chosen individual members. For this theoretical assessment, the policies of incentives to the EVs of each country are comprehensively analysed. This study shows that, in a global incentive scenario, electric battery vehicles (BEVs) can be cheaper than other car technologies (Hagman, Ritzen, Stier, & Susilo, 2016) and that they are clearly the best choice for a low emission transport system. It is also concluded that there are still many targets to be achieved until internal combustion vehicles (ICEs) are no longer the primary choice of drivers and we may reach optimal GHG values in transportation.

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Global warming and the depletion of fossil fuels suggest the need to reduce our dependence on fossil fuels in the production of electricity worldwide, as well as to intensify the study and application of sustainable renewable energy technologies. Solar energy is very promising due to: (i) its enormous energy potential; (ii) its clean nature; (iii) the fact that it is available and abundant in large areas of the planet. Therefore, projections for solar electricity generation are very good, considering that the systems' performances are improving sharply, while prices go down. In this paper, the potential of concentrated solar power (CSP) for electricity generation in Portugal is evaluated. After analysing solar radiation data for Portugal mainland and the Portuguese national electricity grid, it is shown that one of the most favourable locations for the installation of a CSP plant is the region of Tavira, in the south of Portugal. Subsequently, the simulation of a 20MW parabolic trough concentrator (PTC) plant is performed and the obtained results are discussed. Results prove that Portugal has adequate solar resources to implement CSP despite the intra annual variability. Finally, it is shown that a CSP energy project may be economically competitive in Portugal, with the advantage of creating jobs and increasing research and industry in this field.

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