The course covers 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 have a good knowledge of the main technologies for exploiting the solar source through thermal conversion. The 2 fields of application considered will be the civil construction sector, where Low-medium temperature (<100°C) systems (LTS) are used to meet heating, domestic hot water and cooling demands, and the concentrating solar power generation (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 LTS (56h) • Solar source: position of the Sun in the sky; atmospheric models for clear and average skies; data bases of horizontal solar radiation energy; solar spectrum; solar irradiance components. • 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 diagrams. Control, regulation and safety components. • Practical laboratory exercise with microcontrollers (like Arduino). • 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. • Recent research trends. Introduction to Concentrating Solar Power (CSP) 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 tramite PC con l'utilizzo della piattaforma di ateneo; Elaborato progettuale in gruppo;

The final mark is the sum of project evaluation (up to 7 points) and written exam (25 points). Full marks of 32 corresponds to 30 cum laude. The project report must be submitted by the end of the course, the exact deadline will be announced. The written exam consists of 2 parts. Part 1 : Low Temperature Solar systems 20 questions true or false (5pts) 1 numerical exercise (5pts) 1 open question (5pts) Part 2: CSP 8 open questions (5pts)

Modalità di esame: Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo; Elaborato progettuale in gruppo;

The final mark is the sum of project evaluation (up to 7 points) and written exam (25 points). Full marks of 32 corresponds to 30 cum laude. The project report must be submitted by the end of the course, the exact deadline will be announced. The written exam consists of 2 parts. Part 1 : Low Temperature Solar systems 20 questions true or false (5pts) 1 numerical exercise (5pts) 1 open question (5pts) Part 2: CSP 8 open questions (5pts)