The course is devoted to present the main technologies for exploiting low-medium temperature and concentrating solar systems, the methods to correctly design the installations, and to estimate their performance in terms of energy and economics outcomes.

At the end of the course, the students should know the main technologies for exploiting solar thermal renewable sources. The fields of application considered will be mainly the buildings sector, where renewables are used to meet heating, domestic hot water and cooling demands, and the concentrating solar power (CSP) plants. A core knowledge acquired will be to understand the coupling of transient and intermittent availability of the sources with the temporal profile of the demand, by the application of heat storage and automated controls. The students who successfully complete the course will be able to correctly design the main parts of the systems, evaluate the useful energy which may be produced, and make a cost-benefit analysis, also taking into account environmental impact issues.

Good knowledge of heat transfer and thermodynamics; basic knowledge of renewable energy sources.

LOW-MEDIUM TEMPERATURE SOLAR THERMAL SYSTEMS (56h) Solar source: position of the Sun in the sky; atmospheric models for clear and average skies; data bases of horizontal solar radiation energy. Calculation of global (direct, diffuse and reflected) irradiance and global solar irradiation on a tilted surface using decomposition and transposition models. Solar collector typologies and definition of efficiency. Thermal balance of a solar collector and analysis of temperature profile of the plate. Hottel equation. Thermal and optical characterization of plate, glazed cover, ducts, and insulation. The role of thermal storage and sizing criteria. Installation typologies, components and applications. Production of hot water for domestic and space heating uses. Methods for the evaluation of seasonal performance of solar thermal installations. The f-chart method. Software for the dynamic simulation of solar thermal installations (Polysun). Analysis of as-built technical schemes. Control, regulation and safety components. Solar cooling through absorption/adsorption refrigeration. Solar DEC (Desiccant Evaporative Cooling) system. Cost-benefit analysis. Some hints on solar district heating network and seasonal storage systems. INTRODUCTION TO CONCENTRATING SOLAR POWER TECHNOLOGIES (24h) In this module an overview of the main CSP technologies (Parabolic Trough, Central Tower, Linear Fresnel, Stirling Dish) will be presented, with particular emphasis on the first two. The state of the art of each technology will be discussed, as well as the main physics principles, features and technical characteristics, together with an analysis of current and future R&D lines and trends. An overview of the commercial experiences worldwide will be given. In detail: • Motivation • Principles of concentration of Solar Radiation • Analysis of the most successful technologies so far - Parabolic Trough - Central Tower • Principles of energy storage in CSP plants • Modeling & Design tools: Optics – the open-source Tonatiuh code, Thermal fluid dynamics – commercial CFD codes at component level and tools for system-level modeling, Integration • Thesis opportunities

Experimental activity at laboratories (3h) Guided technical visit to real plants (3h) Project: Large domestic hot water production and solar cooling system analysis and design (18h). The project is a team work (3-4 people). Each team must write a final report, to be discussed before the end of May.

• Notes from the teachers • Duffie & Beckman, Solar Engineering of Thermal Processes, John Wiley & sons, 4th edition, New York 2013. • Tiwari G.N., Solar Energy - Fundamentals, Design, Modelling, and Applications, CRC Press, 2002 • Bent Sorensen, Renewable Energy: Physics, Engineering, Environmental Impacts, Economics, Elsevier Associated Press, London, 2004. • Notes from the EnerMENA lectures on CSP

Modalità di esame: Prova scritta (in aula); Progetto di gruppo;

Exam: Written test; Group project;

... Final evaluation is based on an oral discussion of the project and a written exam. The project discussion is part of the final mark and weights as 7/30 points. The project is developed during the course and 15 minutes discussion for each group is held before the end of May. The discussion is a team one, but individual scores will be assigned. The written examination consists of open questions and/or short exercises concerning Low-medium temperature solar thermal systems (LTS) (including the experimental exercise and the guided visit) and Concentrated Solar Power (CSP). The details of the grading of the different parts are: 7 points for the project, 25 for the written exam (15 LTS and 10 points CSP), to reach a total of 32 points, corresponding to "30 cum laude".

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.