This paper presents the system analysis and the techno-economic assessment of selected solar hydrogen production paths based on thermochemical cycles. The analyzed solar technology is Concentrated Solar Power (CSP). Solar energy is used in order to run a two-step thermochemical cycle based on two different red-ox materials, namely nickel-ferrite and cerium dioxide (ceria). Firstly, a flexible mathematical model has been implemented to design and to operate the system. The tool is able to perform annual yield calculations based on hourly meteorological data. Secondly, a sensitivity analysis over key-design and operational techno-economic parameters has been carried out. The main outcomes are presented and critically discussed. The technical comparison of nickel-ferrite and ceria cycles showed that the integration of a large number of reactors can be optimized by considering a suitable time displacement among the activation of the single reactors working in parallel. In addition the comparison demonstrated that ceria achieves higher efficiency than nickel-ferrite (13.4% instead 6.4%), mainly because of the different kinetics. This difference leads to a lower LCOH for ceria (13.06 €/kg and 6.68 €/kg in the base case and in the best case scenario, respectively).

One of the major difficulties in the assessment of costs of desalination projects is that key investment parameters and operation-related parameters are project-specific data. This information is commonly not in the public domain and is generally available only to the general contractor. In addition, the interpretation of published data is complicated by the fact that often plant boundaries are not clearly indicated (e.g. if the intake cost and the pipeline cost to and from the plant are included in the evaluation). Finally, the analysis involves an elevate number of design parameters, such as plant capacity and configuration, metal and other material prices, and very site-specific conditions (seawater quality, feed water intake, and brine discharge). In the end, these issues result in difficult comparability of data from different sources about the cost of the desalinated water. This paper deals with the implementation of a flexible techno-economic model for the assessment of desalination plants on system analysis level. Thereby, the focus is given to units driven by different technologies (conventional steam turbines and concentrating solar power). The model is applied in a case study in order to evaluate and compare the performance and the costs of different desalination technologies (multiple effect distillation and reverse osmosis). Finally, a sensitivity analysis of the results with respect to selected key design parameters is carried out.

The increasing water demand and the impacts of climate change call for the construction of a large number of new desalination capacities, causing—besides environmental impacts—a relevant amount of additional power consumption. Consequently, new power plants need to be installed and operated as base load plants in order to supply power continuously to the desalination units. As fossil fuel prices are characterized by high volatility and a clear trend upwards, the use of renewable energies allows for saving fossil fuels and therewith reducing risks related to energy price escalation along the whole desalination life cycle. However, the fluctuant nature of renewable energies conflicts with the—ideally—continuous operation of desalination plants. In contrast to technologies such as photovoltaic (PV) and wind power, which are prone to fluctuating and intermittent power generation, concentrating solar power (CSP) is able to supply firm capacity on demand and can be fully integrated into conventional power utilities. On the other hand, CSP is currently considered to be more expensive than other renewable energy technologies. This work highlights the key importance of comparing technology options with equal quality of supply in order to obtain resilient results. Within this work, a representative site in the Middle East and North Africa Region has been analyzed by two different methodologies in order to demonstrate the potential large difference of results. The first method assumes that any variations of renewable energy supply can be compensated by the electricity grid, while the second method assumes that the addition of load to the electricity grid will require the addition of an equivalent firm power supply capacity. Hourly solar and wind data of a typical meteorological year have been used as inputs for a techno-economic simulation. Different options for CSP solar field layout, thermal energy storage, PV, and wind installed capacity, are analyzed and compared in terms of power and water cost for reverse osmosis and multieffect distillation plants.

Jordan has experienced a significant increase of peak load and annual electricity demand within the last years due to economic development and population growth. The experienced growth rates are expected to continue during the next decades, making large investments in new power plant capacity necessary. Additionally, when gas supply from Egypt was interrupted several times and crude oil world market prices increased simultaneously, recent years have shown painfully that a power supply exclusively based on fossil fuel imports is subject to a very high risk and can have a strong negative impact on the national budget. Electricity-sector authorities are therefore looking for suitable solutions to keep up with the increasing electricity demand, to make Jordan more independent from fossil fuel imports, and to provide electricity at reasonable prices in the future. This paper presents a methodology for the optimized integration of renewable energy (RE) technologies into Jordan's existing power plant portfolio. The core of the methodology is the mixed integer linear optimization program REMix-CEM, developed at the German Aerospace Center (DLR), which optimizes capacity expansion and unit commitment of RE and conventional power generation technologies simultaneously. After describing Jordan's electricity sector and the available RE resources, the developed methodology and the results are presented. The paper shows that by the year 2022, Jordan could generate at least 47% of its electricity demand by a well-balanced mix of concentrating solar power, utility-scale photovoltaics, and onshore wind power. This scenario would maintain the security of electricity supply, absorb present growth rates of power generation costs, and make Jordan significantly more independent of fossil fuel imports.

Within the MED-CSD project, feasibility studies of integrated hybrid concentrating solar power (CSP) and seawater desalination (DES) plants were carried out in selected locations in Morocco, Italy, Cyprus, Egypt and Gaza/West Bank. After a review on CSP and desalination technologies, ten typical sites within the five partner countries have been selected. For each location, a CSP-DES plant was modeled. The model bases on hourly time series of solar irradiance, ambient temperature, as well as wind speed and includes local seasonal and hourly load curves for power and water. Surplus thermal energy from the solar field is fed into the energy storage, so that operation is possible at night and during cloud transients; gaps between demand and solar power production are covered by cofiring with fossil fuel. Different plant components (solar field collectors and desalination technologies) have been compared. A techno-economic model is applied in order to analyze the economic feasibility and the required financial framework conditions of the projects. Furthermore, an analysis of the market potential of concentrating solar power for sea water desalination in the Mediterranean Region and socio-economic and environmental impact analyses were implemented.