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To satisfy the increasing demand for energy and potable water, large-scale cogeneration is widely integrated. However, in remote locations, the lack of power system infrastructure limits the integration of large-scale systems. Consequently, a large portion of inhabitants has no access to electricity and the pressure on groundwater resources increases drastically. To address this power and water scarcity, a distributed cogeneration system consisting of a solar-powered micro Gas Turbine and desalination system is considered. Since the integration of solar energy in distributed cogeneration systems is uncertain, we performed a feasibility study. This paper covers the modelling, sensitivity and exergy analysis and 3 desalination systems designs, each making a trade-off between smaller plant size and higher performance. Introducing solar energy in the micro gas turbine results in an increase in electrical efficiency by 3.2% absolute. The proposed designs achieve a levelized cost of water between 1.78$/(m3/d) and 1.92$/(m3/d), which is comparable with conventional solar-powered desalina-tion plants. Therefore, these designs demonstrate the feasibility of integrating solar energy in distributed cogeneration systems and provide a promising solution towards cost-efficient, renewable-based power and water cogeneration in remote locations. The future work will enhance the economic analysis by including an intermittent solar energy supply. • An increase in efficiency of 3.2% absolute is acquired by integrating solar energy. • Varying feed water flow rate regulates brine salinity and thermal driving force. • Entrained steam flow rate and motive steam pressure maximize water production. • Levelized cost of water lies in range of conventional desalination systems. [ABSTRACT FROM AUTHOR]

• The optimal levelized cost of hydrogen ranges between 6.3 €/kg and 10.5 €/kg. • The technical robust design decreases the hydrogen production variation by 43%. • A high yearly solar irradiance is beneficial for mean and robustness of the cost. • Bulk manufacturing and more realizations further improve cost robustness. To match intermittent solar energy supply with energy demand, power-to-hydrogen is a viable solution. In this framework, designing a directly coupled photovoltaic-electrolyzer system assuming deterministic parameters (i.e. perfectly known and fixed parameters) is widely studied. However, considering deterministic model parameters in optimization disregards the inherent uncertainty of the system performance during real-life operation (e.g. due to unexpected costs or ineffective maintenance), leading to a fragile, suboptimal direct coupling of the photovoltaic array with the electrolyzer stack. To avoid a suboptimal coupling, we performed a design optimization under parameter uncertainties (i.e. robust design optimization). This paper provides the deterministic designs, robust designs and a global sensitivity analysis on the hydrogen production and levelized cost of hydrogen. The technical robust design provides a 43% reduction in hydrogen production standard deviation compared to the deterministic design, while the robust, cost-efficient design achieves a mean levelized cost of hydrogen of 6.4€/kg and standard deviation of 0.74€/kg. The discount rate and capital expenditure parameters dominate the standard deviation by 52% and 39% respectively. Therefore, bulk manufacturing of these technologies and more demonstration projects are the main actions to improve the robustness. Future works will focus on including accurate probability distributions, a demand load, the grid and batteries to the system. [ABSTRACT FROM AUTHOR]

Wind and solar energies present a time and space disparity that generally leads to a mismatch between the demand and the supply. To harvest their maximum potentials, one of the main challenges is the storage and transport of these energies. This challenge can be tackled by electrofuels, such as hydrogen, methane, and methanol. They offer three main advantages: compatibility with existing distribution networks or technologies of conversion, economical storage solution for high capacity, and ability to couple sectors (i.e., electricity to transport, to heat, or to industry). However, the level of contribution of electric-energy carriers is unknown. To assess their role in the future, we used whole-energy system modelling (EnergyScope Typical Days) to study the case of Belgium in 2050. This model is multi-energy and multi-sector. It optimises the design of the overall system to minimise its costs and emissions. Such a model relies on many parameters (e.g., price of natural gas, efficiency of heat pump) to represent as closely as possible the future energy system. However, these parameters can be highly uncertain, especially for long-term planning. Consequently, this work uses the polynomial chaos expansion method to integrate a global sensitivity analysis in order to highlight the influence of the parameters on the total cost of the system. The outcome of this analysis points out that, compared to the deterministic cost-optimum situation, the system cost, accounting for uncertainties, becomes higher (+17%) and twice more uncertain at carbon neutrality and that electrofuels are a major contribution to the uncertainty (up to 53% in the variation of the costs) due to their importance in the energy system and their high uncertainties, their higher price, and uncertainty. [ABSTRACT FROM AUTHOR]