Alvaro Marucci

The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology

Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called “Mediterranean greenhouses” and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect.

Feasibility of the electric energy production through gasification processes of biomass: technical and economic aspects

Biomass is one of the main sources for energy production, indeed, due to its chemical and physical peculiarities, it can be used very well in thermo chemical processes such as combustion, pyrolysis and gasification. Furthermore, the considerable variability of bio fuels that can be produced allows the experimentation of new technologies that with a higher performance are able to produce not only heat but also electric power. On the other hand, due to problems in supplying and technology, the main disadvantage of such energetic system consists in its difficult application in a large scale production. The present study aims to highlight the possible use of biomasses in small energetic districts such as Viterbo area: the exploitation of wood and cellulose biomasses are described and the possible application with flowing bed technology is considered. This study wants to technically test the feasibility of a biomass supplied system, taking care of stocks availability and amount, use of gasification process based on flowing bed technology, chemical characteristic of syngas and energy power production.

Energy Efficiency of a Greenhouse for the Conservation of Forestry Biodiversity

Forest biodiversity conservation is one of the most interesting and crucial problems in forestry world. Currently, the conservation methods are based on two phases: the conservation of seeds at low temperatures and the multiplication of vegetable material. This latter operation can be successfully developed in properly designed greenhouses. The aim of this paper is to define a type of greenhouse which is particularly suitable for plant material propagation in order to preserve forest biodiversity in the area of the Central Italy. Some general parameters were first defined for a correct planning of the structure, such as: the shape of the section, volume, cover material, systems for heating and cooling, and those for the control of the internal microclimate parameters (light, air temperature, and relative humidity). Considering the construction characteristics and the climatic conditions of the place, the internal microclimatic conditions have been later determined by the useful implementation in TRNSYS in order to analyse the energy efficiency of the greenhouse.

Energy-Aware Control of Home Networks

Home networks have become heterogeneous environment hosting a variety of wireless and wired telecommunication technologies. Currently there no exist any intelligent energy saving mechanism to control the home networks. In this paper we propose an energy-aware strategy that integrate Wireless Sensor Network (WSN) with a convergent digital home network. We aim to demonstrate that a WSN can act as a dependable control plane to manage the high speed home network. While the home network nodes can be deactivated, the WSN is always on and, due to the low data rate required to properly work, it consumes a very limited quantity of energy. This mutual interaction leads to a substantial reduction of the energy consumptions. Simulation results show that this strategy is effective in different scenarios and provides a tangible economic benefit.

Use of Semi-transparent Photovoltaic Films as Shadowing Systems in Mediterranean Greenhouses

In Mediterranean greenhouses, active and passive cooling systems are almost always needed due to high values of solar radiation (nearly 1000 Wm− 2) -especially during summer season- and high values of air temperature (near 40°C). Nevertheless, the use of the above-mentioned systems imply the increase of the operating costs of greenhouses.

Characterization of Biomass Emissions and Potential Reduction in Small-Scale Pellet Boiler

In recent years it has been proved that residential biomass combustion has a direct influence on ambient air quality, especially in the case of cereals. The aim of this study is the characterization of the emissions in small-scale fixed-bed pellet boiler (heat output of 25 kW) of beech and corn, and of its potential reduction to an addition of calcium dihydroxide. In the biomass combustion test 7 fuel mixtures were investigated with regard to the particulate content (PM10), gaseous emissions and combustion chamber deposit.

Photovoltaic Pumps: Technical and Practical Aspects for Applications in Agriculture

The paper deals with a series of tests conducted on a PV-DC pump in Viterbo (42°24′ North, 12°06′ East). The tests lasted from January 2003 up to November 2004 and involved measurements of solar radiation, on both a horizontal surface and the tilted module surface, flow rates, volumes, and total dynamic heads. In total, up to 3000 data were collected every day whose analysis allowed us to find empirical relationships among system efficiencies, solar radiations, and total dynamic heads. In the second part of the paper we develop a simple method that allows both the assessment of performances of the whole system when installed in a different site from that in which the tests were performed and the optimal inclination angle of the panel to be determined in relation to annual or seasonal use (see irrigation).