B010608 - RENEWABLE ENERGIES

Italian

- The concept of renewable energy sources
- Renewable energy statistics and trends at national and international levels
- HYDROPOWER
- GEOTHERMAL ENERGY
- SOLAR ENERGY (Photovoltaic, Solar thermal, Concentrating solar power and solar cooling)
- WIND ENERGY
- ENERGY FROM BIOMASS
-

Parts of different textbooks and documentsm (including web), suggested at the beginning of each subject

Provide to the Mechanical and Energy engineering students the base knowledge regarding the 5 main renewable energy sources and their exploitation, including the ability to make quantitative assessments inherent to the various sources and the related technologies.

Robust basic knowledge of thermodynamics, energy conversion systems and their components

Classroom lessons and exercises on the course subjects

Oral exam on the topics and exercises of the course

INTRODUCTION (estimated time): 3-4 hours
The concept of renewable energy sources. The energy at national and international levels: contribution of different energy sources to primary production and the role of renewable energy. Trend of recent decades and future prospects. Introductive data sheets on various renewable energy sources that will be covered during the course: role, technological state of the art and development prospects. Nod to the economic aspects.

HYDROPOWER (estimated time): 10 hours (2,5 weeks)
Introduction and basic schemes of large and small hydroelectric plants. The resource, the scope and hydraulic jump. Duration curve. Losses and net head. Energy production and overall performance. Electric power and energy capability. Utilization curves. Planting schemes (small and large hydro). The hydraulic machines: energy equation, specific speed, specific speed and classification machines (slow and fast). Selection of turbines in function of flow rate and net head. Specified speed and escape velocity. Classification and types of hydraulic turbines, machine concept Action and reaction: Pelton turbines, Turgo, Francis and Kaplan. Distributors stator. Velocity triangles. Discharge diffusers. Curves. Regulation of turbines. Bulb turbines. Applications to small plants (mini hydro). Nod to plant and production costs.
GEOTHERMAL ENERGY (estimated time): 10 hours (2,5 weeks)
Geothermal energy: distribution and temperature, geothermal gradient. Distribution of thermal energy and heat flow. The hydrothermal geothermal system. Extraction and reinjection wells. Classification of geothermal resources. Application of geothermal resources and mention to its investment costs and incentives. National and international distribution of geothermal resources: potential exploited and maximum expected potential installed and new explorations. Integration of geothermal energy in energy mixes virtuous. The geothermal exploration: pre-feasibility study and surveys. Work systems and drilling technologies: profiles well. Drilling, well testing and models. Typologies of wells and producibility: water and vapor-dominated. Thermodynamic conversion of geothermal energy: the geothermal power plants: plants in single double and multiple flash: features, technologies and performance. Dry steam plants directly (direct dry steam). Case studies and examples of calculation. Binary cycles using ORC. Hybrid solutions binary/single flash. Examples of calculation and optimization. Combined production of electricity and heat from the geothermal resource (CHP), examples with binary cycles. Motioned to advanced cycles (Kalina). Technologies to reduce the environmental impact of geothermal power plants: systems for the capture of H2S and mercury (AMIS) and SO2. Possible integration of geothermal energy with other energy resources. Low temperature geothermal energy: use for the combined production of electricity and heat. Heat uses: geothermal heat pumps and district heating. Applicative examples and calculation. Motioned to innovative exploitation of geothermal resources: engineered geothermal systems (EGS) and supercritical fluids.

SOLAR ENERGY (estimated time): 10 hours (2,5 weeks)
The solar resource. Solar radiation: insolation and radiation, solar constant. Spectral distribution of solar radiation. Variation in irradiation depending on the position of the sun in relation to earth: concepts of latitude, altitude solar declination: fundamentals of solar energy. Radiation on a tilted and horizontal plane. Direct and diffuse radiation. Curve of daily radiation on a tilted surface. Seasonal optimization. Measurement of solar radiation. Solar maximum energy on unit horizontal and tilted surface area.
Systems of harnessing solar energy
Photovoltaic
Photovoltaic effect. Band energy and maximum utilization of radiant energy. The concept of semiconductors and doped semiconductors, pn junctions. The photovoltaic cell. Characteristic curves of a solar cell and equivalent circuit. Electric power generated by a cell. Influence of temperature on cell performance. Connections between cells: analysis of a photovoltaic panel. Typologies of cells and modules: monocrystalline, polycrystalline and amorphous materials and their performance. Inverters: function and characteristic. Composition of a photovoltaic system: major components. Batteries, structure of a plant. Grid connected and off grid plants. Insulated systems for water pumping. Examples of conceptual design of grid connected and off grid systems. Costs and economic analysis: investments and electric productivity, incentives.
Solar thermal
Basic concepts, technologies and their classification. Coupling to heating and sanitary hot water production: examples of system configurations. Unglazed collectors, flat plate glazed collectors and vacuum collectors. The solar thermal collector: characteristics and components. Flat plate collectors. Concentrating collectors. Flat plate collectors: basic scheme and thermal flows, losses and energy balance of the collector. Useful heat absorbed by the collector. Expression of performance and construction of characteristic curves. Interpolation of the characteristic curves: polynomial parameters of commercial collectors. Generalization of the flat plate collector performance curve and parameters to the other collector types. Comparison of performance and operational limits. Fundamentals of sizing glazed and unglazed collectors. Examples of conceptual design of systems with thermal solar collectors: integration in heating plants and production of hot water. Solar fraction and seasonally energy saving. Investment costs, incentives and economic return.
Concentrating solar power and solar cooling (nod)
Solar thermal and photovoltaic concentration: principles and basic concepts. Linear parabolic mirrors. Independent parabolic concentrators, concentrator towers. Combination with thermal power plants (CSP). Solar cooling. Photovoltaic concentrators. Tracking: solar trackers.

WIND ENERGY (estimated time): 10 hours (2,5 weeks)
Background. The wind resource: physical principles of wind generation. Power of the wind resource: its dependence on the speed. Influence of soil characteristics: roughness, dependence of speed and power on height above the ground (power law method). Standardized wind speed classes. Acceleration of flow: influence of soil characteristics. Effect of obstacles and turbulence. Measurement of the resource (anemometry): speed and wind direction (wind rose), anemometric towers. Assessment of the potential of a wind site. Wind atlas, the wind resource: Weibull distribution. Power curve and efficiency. Estimation of energy production for macro and micro wind. Estimation of productivity through the power curve. Betz theory: maximum exploitable wind energy. Machinery and wind turbines. Aerodynamics of profile and determination of the forces generated by the wind (lift and drag). Performance curves vs tip speed ratio. Wind turbines: types and characteristics. Horizontal and vertical axis wind turbines. Control of the wind rotor as a function of wind speed (pitch and stall regulation). Mechanical and aerodynamic brakes. Horizontal and vertical axis wind turbines features and their applications. Electric generators and network connection. Mini wind: micro siting for the evaluation of the characteristics and potential of the resource. Examples of mini wind turbines. Outline of the development of a wind project, costs and incentives.
ENERGY FROM BIOMASS (estimated time): 10 hours (2,5 weeks)
Definition and characteristics of biomass. Chemical composition - the physics of biomass: analysis and ultimate analysis as it is: moisture, chemical composition and ash (metals). Types and characteristics of the ashes: behavior and melting point. Heavy metals. Basics about the supply chain of biomass and related costs.
Technologies for the use of biomass for heat and electricity. Please notice: This course teaches the basic concepts of this topic. Insights on these and other technologies (biofuels, biogas, sustainability and life cycle etc..) Can be acquired in the next course "technologies and processes for energy conversion of biomass" (B019243).

Biomass combustion: principles. Fixed-bed combustors: fixed and mobile grids, horizontal and sloped grids, vibrating and rotating grids, cigar combustors. Examples of combustors for the production of thermal energy and as boilers of external combustion powerplamts. Fluidized bed combustors: basic principles. Types of combustors: boiling and circulating fluidized beds, combustors for pulverized biomass. Domestic burners: main types. Wood stoves. Reverse flame burners. Boilers for wood chips. Pellet burners. Costs and economic evaluations.

Pyrolysis of biomass: basic principles. Pyrolysis processes and their products. Fast pyrolysis: liquid, solid and gas. Pyrolysis oils: properties and energy characteristics. Thermal characteristics and residence time of the reactors. Types and examples of reactors.
Thermochemical gasification of biomass: history and principles. Possible gasification processes. Chemistry and gasification reactions. Equivalence ratio. Nod to chemical equilibria. Composition and characteristics of produced syngas. Thermodynamic balance and reaction temperature of gasifier. Types of gasifiers: fixed bed (downdraft, updraft, crossdraft) and fluidized bed (hot, dragged and circulating). Cleaning the syngas: removal of particulates, alkali metals, nitrogen, tars, sulfur and chlorine. Hot and cold gas cleaning. Applicative examples: biomass cogeneration plants. Calculation of the resource required to supply a plant. Conversion technologies in comparison. Outline of costs, economic analysis and incentives.

Gaseous and liquid biofuels. Basic principles of anaerobic digestion process, gas composition and yelds. Liquid biofuels: basic principles of transesterification process starting from raw materials. (acid fats and alcohol). Yeld and costs of process. Basic reactions for the production of methanol.