Advanced materials solutions for next generation high efficiency concentrated solar power (CSP) tower systems

Project Information

NEXTOWER

Grant agreement ID: 721045

DOI

10.3030/721045

Project closed

EC signature date 14 December 2016

Start date 1 January 2017

End date 30 June 2021

Funded under

• INDUSTRIAL LEADERSHIP - Leadership in enabling and industrial technologies - Advanced materials

Total cost

€ 6 221 105,19

EU contribution

€ 4 981 304,32

Coordinated by

AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILE
Italy

Periodic Reporting for period 3 - NEXTOWER (Advanced materials solutions for next generation high efficiency concentrated solar power (CSP) tower systems)

Reporting period: 2019-07-01 to 2021-06-30

Summary of the context and overall objectives of the project

NEXTOWER proposes to investigate a set of innovative materials to boost the performance of tower solar power (CSP) systems and explore a new technology for higher-temperature thermal storage based on liquid lead.
Tower systems are relevant to society for their great environmental compatibility and offer tremendous potential for efficient (electrical and thermal) power generation. Yet, their industrial exploitation has been so far hindered by limitations in the materials used for the central receiver - the core component - and for thermal storage. Such limitations in materials performance determine in fact the maximum working temperature and the overall in-service durability. Improving the efficiency of a tower system entails necessarily improving the central receiver upstream and possibly re-engineering the whole systems downstream to work longer and at much higher temperature, especially in the thermal storage compartment.
The development of a new generation of CSP materials in NEXTOWER, allowing both an increased working temperature of the solar receiver and a new storage concept based on liquid metal as heat storgae fluid, contributes to the next-generation of CSP towers. The objectives of NEXTOWER are to deploy a comprehensive conceptual and manufacturing approach to optimize structural materials for durability, while designing a new storage strategy based on liquid metal to go beyond molten salts (limited to 550°C heat storage). Our concept entails, indeed, the pursuit of two important achievements:
(i) the making of better ceramics for high temperature receivers capable of extended service operations (20-25 years) vs. thermal fatigue and thermal shock;
(ii) the usage of liquid lead as high-temperature heat transfer fluid (HTF) and heat storage fluid (HSF) in CSP up and above 750°C, for the very first time.
NEXTOWER demonstration foresees the making of prototypes intended for full-scale CSP testing, with demonstration activities finally split into two parts: a SOLEAD#1 demonstration campaign with the new NEXTOWER ceramic receivers to be installed and tested on the CESA-1 solar tower at the Plataforma Solare De Almeria (PSA) in Spain, and a SOLEAD#2 brand new installation at ENEA Brasimone in Italy, entailing a storage block with two heat exchangers filled with 32 tons of liquid lead and tested at 750-800°C, which is an unprecedented experience.
Assessment of market potential, societal impact and industrial viability of all proposed solutions, along with a strong standardization effort, was perfromed.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

From the beginning of the project to the end, the project evolution has been very coplex, partly due to the inherent ambition of the action and partly due to extrinsic factors, such as the COVID19 oandemic. The main results achieved are summarized as follows:
• development, manufacturing and delivery of advanced SiC based receivers, benchmarking different state of the art low cost ceramic manufacturing routes;
• demo activity SOLEAD#1: field tests on final receivers done at PSA;
• conceptual and executive engineering design of the SOLEAD#2 demonstrator implemented at ENEA Brasimone;
• new steels capable of resisting liquid metal (pure lead) corrosion up to 900°C, fully tested in lab-scale condition on both bulk and welded coupons, for thousands of hours ;
• scaling up of alloy production (batch-size of tons od alloy) and welding qualification by authoritative manufacturers and welding Institutes;
• procurement of such steel materials in all the form factors needed for the making of SOLEAD#2 demonstrator (with several formats, e.g. wire, welding strip, slabs, tubes), included an innovative compound tube made of a core of structural alloy covered by a FeCrAl shell
• demo activity SOLEAD#2: delivery and installation at ENEA Brasimone of the new installation, compring a main vessel S200 equipped with two heat exchangers and supported by one storage vessel S100 and a melting tank to perform sustained field testing (daily thermal cycling) at 750°C after loading S200 with 32 tons of high purity lead;
• benchmark of several new coating or surface treatment on the base ceramic receiver to reduce emission losses at high temperatures;
• modelling of liquid lead–steel interaction and engineering modeling of life-predicition of ceramic receivers to support the experiments and the design activities, with validation aimed by non-destructive evaluation (NDE) tests via x-ray tomografy;
• computation of LCOE computation for the intended CSP system with respect to some relevant scenarios;
• streamlined LCA analysis and critical raw material assessment;
• active dissemination of results through journal papers (with final special issue on Materials , MDPI), conferences and dedicated workshop, also with other sister-projects from HORIZON2020 (IEEE, COST Academy, IN-POWER, ETN peridoci meeting, etc.)
• production of leafleats, posters, linked-in channel and final project video, all available though our project website https://www.h2020-nextower.eu;
• received CEN-CENELEC award 2020 for Innovation+Standardization for the contribution made for a revision of a ISO18755 and the proposal of a new CWA at CENELEC related to a new testing procedure for ceramics receivers by LFA;
• fueled innovative technology into a new project, SISAL SLAG VALORIZATION ( https://eitrawmaterials.eu/project/sisal) where NEXTOWER materials are tested in a full scale demonstrator for CO2 looping.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Progress brought by NEXTOWER from diverse angles are :
1) New solar receivers are substantially superior to the older generation, in terms of refined engineering and manufacturing of SiC-based components, encompassing 3d printing as well as best in class processing at high temperature (above 2000°C);
2) The new storage compartment designed, fabricated and installed at ENEA Brasimone is the innovative peak of NEXTOWER, representing a tangible manufact emboding all the advances in terms of new engineering, new materials, new processing, new full scale manufaturing. The NEXTOWER thermal storage solution is indeed radically new. While in the temperature range of 500-600°C, Molten-Salt heat storage systems have proven efficient and reliable, NEXTOWER contributes to a new storage solution in the temperature range of 600-800°C , to deploy solar energy in many industrial processes, traditionally energy demanding and with a heavy carbon footprint. The technological leap in NEXTOWER accrues precious know-how to advance beyond the state of the art, with the new liquid lead storage concept underpinned by an entirely new class of functional FeCrAl alloys, which can be explored furthered in follow-up projects and bear cross-cutting benefits in the energy sector beyond CSP (e.g. CO2 looping, GEN-IV nuclear fission, etc.).
3) The new CWA proposed within CEN-CENELEC and the subsequent I+S 2020 award are the expression of a progres beyond the state of the art for the broader interest of society.
These achievements are factual and reinforce the European leadership in advanced materials, fostering the deployment of solar power as a mainstream renewable option within the new green deal .

NEXTOWER resistant to liquid lead corrosion up to 800°C

CEN-CENELEC 2020 award

a complex compoenent of SOLEAD#2 - main top flange in alloy800

passivating layer of alumina formed in high T corrosion tests in liquid lead above 750°C

Nextower solar receivers - two prototypes mass produced for field tests

SOLEAD#1 demo installation for solar receiveres at PSA

SOLEAD#2 demo hall at ENEA with S200 and S100 intalled in final position

NEXTOWER concept at a glance

NEXTOWER team - a sample