Feasibility study of a combi-pv panel for greenhouse energy supply and water recovery by nightly radiation towards the sky

In southern European areas, characterized by high irradiation, the use of water for both evaporative cooling systems and hydroponic fertigation, represents a serious drawback for crop cultivation under cover. Water recovery systems seem to be an attractive solution, especially when they are integrated in the greenhouse construction. In this research, a feasibility study of applying a water recovery system driven by a combi-PV panel, in a semi-closed greenhouse was carried out. The prototype combi-PV panel was made by coupling an amorphous silicon panel with a sump stacked on the rear PV panel surface and filled with saline water. The system is driven by a cold-heat sink which is the PV panel itself. During night, the combi-PV panel exploits the radiative cooling of a ‘gray’ surface towards clear sky, chilling the water in the sump. In opposition, during day-time, the water in the sump is heated at a temperature higher than the environment. Thus, the water vapour will be condensing on the rear panel surface during night, being the warm air circulation facilitated by bouyancy effect. The evaluation of the system is in progress in order to assess the real amount of energy irradiated and consequently the water-drips to be collected on a proper surface inside the sump. The condensed water can be mixed with saline water to reduce the salinity and be used for fertigation

Impact of wolf (Canis lupus) on animal husbandry in an Apennine province

Predation has always been an important problem in extensive sheep farms, causing serious economic losses to the farmers. In the Province of Lucca, the presence of reproductive wolf packs has already been confirmed in natural reserves, but occasional signs of presence of the predator have been reported also in neighbouring areas. The present research has been carried out in this Province (between the Orecchiella Natural Reserve and the medium Serchio Valley), in order to obtain more complete information on the location of the wolf (with transects, wolf- howling and snow-tracking), and to verify the real impact and risk factors of predation on live- stock (by means of on-farm surveys carried out in 42 semi-extensive farms) in this area. The presence of wolf was confirmed in the study area with a minimum of four adult individuals and at least one pup: this pack lives around the peaks of the Apennines in the municipalities covered by this investigation. A growing conflict between the wolf and the sheep and goat farms was observed: since 2007 there have been 25 attacks and three farms can be considered subject to chronic predation. The major risk factors are high altitude, large flock size and lack of fences and of guardian dogs. An accurate knowledge of wolf presence and the identification of the farms mostly at risk can be useful for future planning of interventions aimed at prevention and support of farmers, in order to mitigate the conflict caused by predation

Sustainable greenhouse horticulture in Europe

The European greenhouse horticulture represents one of the most intensive energy sector in agriculture and strongly contributes to increase the energy and environmental vulnerability within regions having a large greenhouse farming systems. Specifically, the European greenhouse farming sector is facing a trend that responds to the changing consumer’s demands in a society that, globally, is increasingly affluent but more aware about some negative consequences, such as high energy-demand processes, and CO2 emissions. About 200,000 hectares of greenhouses in Spain, Italy, The Netherlands and Greece is the estimated covered surface, with not less than 3.4 MTOE of energy consumption and 9.2 MtCO2eq, and an yearly economy value of 7 billions of Euros. The installed energy power load of greenhouses in Europe depends on local climate conditions, and varies from 50-150 W/m2 (Southern regions of Europe) to 200-280 W/m2 (Northern and Central regions), while complete conditioning could even reach an energy load of 400 W/m2 (heating, lighting, cooling). Nowadays, the proportion of renewable use in the total energy consumption of greenhouse farming in Europe is very low, and there are no clear priorities set in this area, yet. Comprehensive and complete studies that evaluate the opportunities of renewable options in greenhouse sector are still not completeted. This, strongly hinders the process of setting concrete goals and legislative targets to support a wider introduction of sustainable energy technology, and appropriate legislation in greenhouse regions of Europe. This paper deals with the proposal of supporting the organization of a sustainable greenhouse agriculture, based on renewable energy sources, i.e. geothermal energy at low temperature, photovoltaic solar energy and solid biomass, in tune with the specific local assets, the local geo-climatic conditions and the protection of landscapes rather than with a careless perspective for local environment and potential societal costs

Quantification and characterization of the environmental impact of sea bream and sea bass production in Italy

While the production of fish from aquaculture has grown steadily over the years worldwide, some environmental concerns have emerged. In this study, the environmental impacts and main hotspots of a typical Italian sea bass and sea bream offshore farm were analysed. The Life Cycle Assessment (LCA) methodology was applied with a “cradle to farm gate” perspective and 1 ton of fish at harvest size as the functional unit. The results confirm that feed is the main hotspot and contributes across impact categories always at least 60%, with the exception of marine eutrophication driven instead by nutrient emissions. In some impact categories, infrastructure and farm operations also have a relevant impact (about 30%). The impacts of this case study are slightly lower than those found in the literature, and this is mainly due to prior attention of the company to feed formulation. An alternative scenario was also explored, by reducing the amount of uningested feed, showing a reduction in the Global Warming Potential by 6% and in marine eutrophication by up to 10%. The application and evaluation of new technologies (e.g., automated feed dispenser, use of alternative cage materials) could be explored in future research

Multi-Criteria DEXi Analysis for the Selection of Crop Species for Saltwater Aquaponics

Saltwater aquaponics is a sustainable alternative system for food production. The success of this system largely depends on the selection of both fish and plant species, for which several features and criteria must be considered. This paper aims to identify the most suitable plant species for saltwater aquaponics by using a multi-criteria decision-making method also based on current literature. One simple model that contained one root criterion, four aggregated criteria, and four sub-criteria was created using DEXi software. The same model was evaluated considering two different salinity levels in the recirculating water: 10 (brackish water) and 35 (sea water) g L-1. The relevance of the model structure was evaluated by the sensitivity analysis, through the 'plus/minus-1 ' analysis. Our results suggest that Salicornia europaea L. and Portulaca oleracea L. were suitable species for saltwater aquaponics at 35 g L-1. Moreover, at 10 g L-1, the suitable candidates were: Salicornia bigelovii Torr, S. europaea L., Beta vulgaris ssp. maritima (L.) Arcang, Atriplex hortensis L., and P. oleracea L. The DEXi analysis resulted in being an easy and effective tool to select proper species in similar contexts. DEXi can help to identify the hotspots of production processes, according to our results. Since the selected species are wild edible species or minor crops, the availability of their seeds is one of the main constraints of their cultivation in saltwater aquaponics

Green roofs and green façades for improving sustainability of towns

Nowadays, buildings in Europe account for a consumption of 40% of total energy use and about 65% of total electricity consumption. According to the European Directive on the energy performance of buildings (EPBD Directive), solutions such as green roofs and green walls can help to reduce energy consumptions and the greenhouse gases emissions by buildings. The installation of plant systems covering some surfaces of the building allows to reach an improvement of the building's energy efficiency mainly by reducing the energy demand for cooling in warm periods. The green layers used for buildings contribute to improve thermal insulation, since they reduce the direct solar radiation while the evaporative cooling contributes to create a better local microclimate. This paper provides the first data collected by a green wall prototype in progress at ENEA Casaccia Centre to investigate the effects of this natural green solution on the energy efficiency of buildings. The project was funded by the Programme Research of Electrical System, and is being carried out in cooperation with the Universities of Pisa, Bari and Viterbo

Vertical Greenery as Natural Tool for Improving Energy Efficiency of Buildings

The European Construction Sector Observatory outlined that green building envelopes as green roofs and walls contribute to the reduction of energy demand and CO2 emissions due to the air conditioning in summer periods, and the mitigation of heat islands in urban areas. For this reason, the understanding about the contribution of urban greening infrastructures on buildings to sustainable energy use for air conditioning is urgent. This paper focuses on the analysis of a vertical surface provided with a Parthenocissus quinquefolia (L.) Planch., a winter deciduous species, as green cover of a building, assessing the reduction of the solar radiation energy absorbed by the facade and, consequently, the heat flux (HF) transmitted into the internal ambient. This research shows that, in July, surface temperatures (STs) on the vegetated facade were up to 13 degrees C lower than on the unvegetated (bare) facade. Under the climate and environmental conditions of the green wall located at ENEA Casaccia Research Center, a saving of 2.22 and 1.94 kWh(e)/m(2) , respectively in 2019 and 2020, for the summer cooling electricity load, was achieved. These energy reductions also allowed the saving of 985 and 862 g CO2/m(2) emissions, respectively, in 2019 and 2020. Ultimately, a green factor named K-v* was also elaborated to evaluate the influence of vegetation on the STs as well as on HFs transmitted into the indoor ambient and adapted to the case of a detached vertical green cover. Measurements of K-v* factor lasting three years showed the suitability of this index for defining the shading capacity of the vegetation on the building facade surfaces, which can be used to predict thermal gains and effects in a building endowed of a vertical green system

Impact of wolf (Canis lupus) on animal husbandry in an Apennine province

Predation has always been an important problem in extensive sheep farms, causing serious economic losses to the farmers. In the Province of Lucca, the presence of reproductive wolf packs has already been confirmed in natural reserves, but occasional signs of presence of the predator have been reported also in neighbouring areas. The present research has been carried out in this Province (between the Orecchiella Natural Reserve and the medium Serchio Valley), in order to obtain more complete information on the location of the wolf (with transects, wolfhowling and snow-tracking), and to verify the real impact and risk factors of predation on livestock (by means of on-farm surveys carried out in 42 semi-extensive farms) in this area. The presence of wolf was confirmed in the study area with a minimum of four adult individuals and at least one pup: this pack lives around the peaks of the Apennines in the municipalities covered by this investigation. A growing conflict between the wolf and the sheep and goat farms was observed: since 2007 there have been 25 attacks and three farms can be considered subject to chronic predation. The major risk factors are high altitude, large flock size and lack of fences and of guardian dogs. An accurate knowledge of wolf presence and the identification of the farms mostly at risk can be useful for future planning of interventions aimed at prevention and support of farmers, in order to mitigate the conflict caused by predation

Fishmeal replacement with hermetia illucens meal in aquafeeds: Effects on zebrafish growth performances, intestinal morphometry, and enzymology

Fishmeal (FM) is still the most important protein source in aquafeeds. However, due to the reduction of wild fish stocks used for FM production, its manufacturing it is now unsustainable. Insect meal represents a valid alternative to FM, due to the low carbon footprint of its production and its high nutritional value. The aim of this study was to investigate the potentials of replacing FM with black soldier fly (Hermetia illucens) meal (HIM) in aquafeeds, using zebrafish as the animal model. Four diets were formulated with increasing HIM/FM replacement rate (the control diet contained 20% FM). Mortality rates, growth performances, and feed consumptions were measured, and fish intestine samples were collected for histological and enzymatic analysis. After 49 days, all groups almost tripled their initial body weight (cumulative body weight gain ranged between 143.9 and 155.2 mg), and no statistically significant differences among treatments were observed in relation to growth performances and histological traits. Contrarily, trypsin, alkaline phosphatases, and alpha amylase–glucoamylase activities were significantly reduced when the FM replacement rate was increased. In conclusion, HIM may represent an alternative to FM, since no adverse effects were observed when it was included up to 20% in the zebrafish diet, even when replacing 100% of the FM