SOLARX integrates 3 high concentration solar technologies and AI based smart resource management, to produce – either directly with high efficiencies or through storage stages for maximizing revenues – electricity, heat and green H2 in a carbon neutral way. The Key Technology Elements developed by SOLARX include:
The complementary utilization of three (or more) energy vectors opens the door to a wide range of optimization strategies but it also underlines the need for a powerful solar management algorithm that can distribute the direct normal irradiance (DNI) resource based on current demands and boundary conditions. SOLARX will develop a DNI nowcasting system combining different inputs, based on real time measurements, sky imagery-based nowcasting system and satellite based nowcasting system, all of them developed by Fraunhofer ISE.
A dynamic system model, based on AI, will be used to predict the dynamic behaviour of the SOLARX multi vector system, including dispatchability aspects related to storage capacities for heat and H2. The system, developed by Fraunhofer ISE, will provide greater flexibility in distributing the available energy to the different receivers depending on the current and near future demand of electricity, H2 and heat. SOLARX partner ACCIONA will provide the CST data for the models and the overall strategy impact and application scenarios will be assessed by SOLARX partners EMD International and Danmarks Tekniske Universitet (DTU).
The methods SOLARX will use for controlling and managing the heliostat field will extend available methods that have been used for commercial systems. SOLARX will adapt and develop them to TRL4 (technology validated under laboratory conditions) for their actual application in a multi-receiver solar tower whilst the integration of demand curves of the energy vectors and the solar resource will be developed to TRL3 (experimental proof of concept). The integration of multi-receivers on a single solar tower has never been demonstrated. Therefore, the integration into a laboratory field, simulating a multi focus will bring the TRL level from 2 to 3 and its operation will bring the TRL to 4.
Although dense array CPV receivers are commercially available, with efficiencies typically at 32% and embedded solar cell efficiencies at 40.8% there is scope to improve both cell efficiency and to reduce the gap between cell and module efficiencies. SOLARX will demonstrate a 45.9% cell efficiency and will address each source of loss at the receiver level by revising each component to improve the receiver’s electrical efficiency by 30% with respect to the state of art (from 32% to 40.7%).
Dense array CPV receivers are commercially available with 32% efficiency at 700x at 25°C with embedded large solar cells (typically 1 cm2 with efficiency of 40.8% at 25°C under 1000x concentration). The main routes to improve dense array receiver’s efficiency are to improve cell efficiency and to reduce the gap between cell and module efficiencies. SOLARX partners, CNRS and UDL will demonstrate a 45.9% cell efficiency and will address each source of loss at the receiver level by revising each component to improve the receiver electrical efficiency by 30% with respect to the state of art (from 32% to 40.7%).
At the beginning of the project, the SOLARX innovations are at TRL2 where the TCVC cells, cooling plate and interconnection concepts have been conceptualised, modelled and in some cases validated but not demonstrated experimentally. By applying proven adaption processes for dense array receiver assembly, SOLARX will bring the innovations to TRL3 and to TRL 4 when its performance will be validated in the lab.
Today, Steam Methane Reforming (SMR) produces more than 95% of the world’s H2. In conventional processes, the reaction is carried out at high temperature by burning 30-40% of the process gas and the efficiency is below 70%. Electrolysis is an alternative technology that is increasingly implemented, where renewable electricity is available. However, it suffers from high cost, up to 3 times when compared to SMR and low electricity to H2 efficiency (50-60%).
SOLARX partner CNRS recently demonstrated a unique solar-based microreactor for SMR, capturing the solar energy to supply heat to the endothermic SMR reaction achieving up to 85% efficiency, whereas producing H2 through electrolysis supplied with PV electricity has an efficiency limited to 15-25%. This can lead to a three to sixfold efficiency improvement in the use of the solar resource. Furthermore, the gas purity is very high (no burning residue), facilitating carbon capture and sequestration. In SOLARX, CNRS will modify these solar microreactors for compatibility with biogas, incorporate electrical heaters and integrate them into an H2 receiver that has the unique capability of operating either with solar or electrical energy.
The H2 receiver is based on building blocks that have been validated in conditions of high sunlight concentration, but SOLARX will upgrade these building blocks with additional electrical feed-in. Such a concept has been formulated at TRL2 but has not been demonstrated yet. The design and operating conditions will also be explored for reliable operation under dry methane reforming (consuming CO2). Through these upgrades SOLARX will increase the technology readiness levels of the innovations up to TRL 3 and TRL4.
SOLARX will demonstrate its role as a future KET for a game-changing RES through a technological, environmental, economic and social assessment
KPI-1.1: LCOE reduction by 9-18% (relative to CSP generation with thermal energy storage)
KPI-1.2: COVE improvement by 15-23%.
KPI-1.3: ROI improvement by 15%.
To achieve these assessments, the technical model with be coupled with demands scenarios, system costs and regulatory frameworks to assess the economic impact of SOLARX for varying levels of deployment, through the assessment of the relevant KPIs, identifying the relevant parameters that will characterize the optimum application scenarios (and the ones to be discarded) and the associated optimum sizing of the SOLARX components. The results of this techno-economic model will be the base for the definition of the future implementation strategies.
From the beginning of the project, on the base of the inputs from the project development, economic, environmental and social assessment will be carried out in order to analyse the SOLARX solution in a holistic way. The LCA study will include the identification of measures to promote the alignment of SOLARX with circular economy principles. Recommendations for SOLARX deployment will be supplied from technical, regulatory frameworks, environmental, social and economic perspectives.
3 specific KPIs have been defined to monitor these goals:
KPI-5.1: SOLARX 2-5%, 2-5% and 1-3% penetration potential in the energy mix for electricity, SHIP and Green H2, respectively, by 2050.
KPI-5.2: Demonstration of SOLARX low environmental impact (LCA).
KPI-5.3: Establishment of guidance for a socially acceptable system.
Innovation potential
The underlying idea of the SOLARX multi-vector energy system contributes to the main goals of the European Green Deal initiative.
- It will provide a net-zero emissions system for electricity, heat and H2, and it will facilitate the introduction of more renewable energy, such as wind or PV systems, into the energy mix due to a dispatchable power-to-X capability.
- It will help transform the EU’s economy for a sustainable future by creating new business opportunities (aligned with circular economy principles) in the energy sector (power-to-X and multi-vector energy brokers) and providing green H2, Syngas and eventually solar-derived fuels that will replace fossil-based fuels in the chemical industry and the transport sectors.
- It will provide a clean, affordable, and secure energy system, with solar-based production of heat, electricity and H2.
