Increasing importance of water treatment and desalination for the provision of drinking water and industrial water can be observed on a global scale. Simultaneously, there is an increase in energy demand for associated processes. In Vietnam, insufficient or unreliable connection to the public power grid can be a problem in rural areas. Self-sufficient energy supply is often provided by diesel generators. This leads to higher pollutant emissions to the environment. More environmentally friendly and sustainable energy supply of water treatment plants can be realized on the basis of renewable energy sources.
Facilitated by the environmental goals set by the government, wind turbines will be one of the main pillars of the future electricity production in Germany. In this paper, a comprehensive assessment of the future metallic raw material requirements for the development of the German wind energy sector was conducted, which is closely based on the current and future market conditions. Copper and dysprosium are identified as the most critical materials since they face the possibility of supply bottlenecks while being fundamental to the functionality of wind turbines. While the cumulative demand for copper may require 0.2% of the current known reserves, the demand for dysprosium may reach up to 0.6% of the reserve levels. Both metals clearly exceed the allocations for renewable energy technologies in Germany and would face strong competition from other sectors in securing raw materials. Although recycling is able to reduce the bottleneck risks, it does not completely mitigate them. More efforts are therefore required to improve material efficiency by means of alternative turbine designs, efficient production techniques, highly reliable components and material substitution.
Long-distance road-freight transport causes a large share of Germany's greenhouse gas emissions with about 20% of traffic emissions. A potential solution for an emission reduction in this sector is the use of hydrogen in fuel cell heavy-duty vehicles (FC-HDV). However, the large-scale use of green hydrogen production for FC-HDV usage comes with implications on the energy system as this would increase the local electricity demand. In this study, we use German driving data for heavy-duty trucks in a market diffusion model and a refueling station design model. Together with an electricity demand model, we determine the FC-HDV electricity demand per region up to the year 2050. In 2050, the FC-HDV stock will sum up to 176,000 FC-HDVs cumulating an annual demand of hydrogen of about 830,000 tons, which will distributed to the FC-HVD fleet via 525 hydrogen-refueling stations (HRS). With assumptions about electrolyzer efficiency, the regional electricity demand can be determined. The hydrogen demand for FC-HDVs can have different impacts in regions, depending on the existent structure and future developments for population density, industrial sites and urban areas. As a result, we find a noteworthy impact of the additional electricity surplus caused by FC-HDVs with over 50 TWh (almost 10%) of the total electricity demand per year. Furthermore, FC-HDVs amount for the highest share of total electricity demand in some eastern German regions. Our results indicate a regional diverse surplus of energy demand through FC-HDVs. Simultaneously, regions with high surplus may avoid grid expansion by either shifting hydrogen production towards periods with low electricity load (e.g. night times), make better use of local potentials for renewables (e.g. wind) or distribute hydrogen from other regions (e.g. through pipelines). For this reason, the reduction of greenhouse gas emissions through FC-HDVs seems feasible with limited challenges from a transport and energy sector perspective.