Italian Financial and Energy saving policies: Cost-Benefit Analysis based on the Enea Reports issued within the survey span 2007- 2010

The aim of the present research is to assess the cost-effectiveness of mixing and combining different energy retrofit measures for the several geographical areas of Italy. The research work is based on the analysis of the results supplied by the several Reports drawn up by ENEA - the Italian National Agency for New Technologies, Energy and Sustainable Economic Development - year by year since 2007. The work is centered on finding out a criterion, based on simple and available data, that is able to identify the most cost-effective retrofit measures to improve dwellings’ energy efficiency. With the final objective of adjusting and addressing the subsidies and the policy makers’ decisions in the most profitable way, there were developed some comparative cost-effectiveness analyses and there were highlighted the most consistent kinds of renovation, both with the current economic outlook and depending on the specific geographical and climatic background. This paper presents and discusses the consequences of the Italian government leaders' policies and purposes of reducing the energy demand in the residential sector, in order to facilitate the development of a consistent plan and extention of public incentives and tax deductions for dwellings’ energy-saving retrofits. Thence, it’s designed to represent a reference point to help decision-makers and relevant stakeholders appreciate how targets have been used till now and how effective they could be, also providing evidence to be used in the upcoming policy development discussions. Actually, as this paper proves, the earlier outcomes connected with the current National Energy Strategy reveal that some such adjustments and refinements are needed, in order to make it really effective and worthwhile. Although the praiseworthy initiative and aim that underlies such a political-economic venture, it shows several gaps and faults that should be offset and filled up

Performance Simulation and Evaluation of Net Zero Energy Buildings in an Australian Coastal Climate

Net zero energy buildings (NZEB) are becoming more common, and as new energy saving designs and technologies become available, the ability to estimate overall energy use and understand the impact on operation of building appliances will become important. This paper outlines simulation results of performance improvements achieved by modifying various components (glazing, lighting, thermal comfort settings) of two tertiary education NZEBs and a typical modern commercial building. The DesignBuilder models\u27 thermal performance and energy consumption were validated using real data from case study buildings. The work shows validating models of smaller, less conven-tional, buildings is more difficult than for larger conventional ones. Performance of NZEBs was benchmarked against the typical commercial building, and subsequently the impact of alterations to overall energy savings established. Results illustrate that NZEBs appear more sensitive to design changes. The work indicates significant savings are achievable in NZEBs and conventional buildings if suitable glazing is selected, lighting controlled according to daylight, or comfort band settings adjusted appropriately. Poten-tial savings are quantified using models developed and validated in simulation

Design of a nearly zero energy one-family house in North-Centre Italy

The thermal design of a nearly zero energy one-family house, in North-Centre Italy, is described. The house has a timber frame, a wood-fiber thermal insulation for the roof and a wood-fiber plus YTONG blocks thermal insulation for the lateral walls. Forced ventilation with high efficiency heat recovery is employed. Heating and cooling is provided by an air-to-water heat pump connected to floor radiant panels. Domestic Hot Water is supplied by a thermal solar collector and a heat pump for DHW. The electric energy for the heat pumps and for the forced ventilation system is supplied by PV collectors, which provide also most of the electric energy for lighting and appliances. The thermal design is based on dynamic simulations performed through the code TRNSYS 16

The assessment of the relevance of building components and life phases for the environmental profile of nearly zero-energy buildings: life cycle assessment of a multifamily building in Italy

Purpose: Since the construction sector is a considerable energy consumer and greenhouse gas (GHG) producer, the EU rules strive to build nearly zero-energy buildings, by reducing the operative energy and yearning for on-site energy production. This article underlines the necessity to go beyond the energy evaluations and move towards the environmental assessment in a life cycle perspective, by comparing the impacts due to building materials and energy production devices. Methods: We compared the operational energy impacts and those of technologies and materials carrying out a life cycle assessment (LCA; ISO 14040, ISO 14044, EN 15643–2, EN 15978) on a nearly zero-energy building (ZEB), a residential complex with 61 apartments in four buildings, situated near Milan (Italy). We consider all life cycle phases, including production, transport, building site activities, use and maintenance; the materials inventory was filled out collecting data from invoices paid, building site reports, construction drawings and product data sheets. To make the assessment results comparable, we set a functional unit of 1 m2 of net floor area in 1 year (1 m2y), upon a lifespan of 100 years. The environmental data were acquired from Ecoinvent 2.2. Results and discussion: The results highlight the important role of the pre-use and maintenance phases in building life so that in a nearly ZEB, the environmental impacts linked to the use are no longer the major proportion: the pre-use phase accounts for 56 %, while the operative energy is only 31 % of the total. For this reason, if the environmental assessment of the case study was shrunk to the operational consumption, only one third of the impacts would be considered. The consumption of non-renewable resources after 100 years are 193,950 GJ (133.5 kWh/m2y); the GHG emissions are 15,300 t (37.8 kg of CO2 eq/m2y). In the pre-use phase, structures have the major impacts (50 %) and the load of system components is unexpectedly high (12 %) due to the ambition of on-site energy production. Conclusions: Paying attention to the operative energy consumption seems to address to only one third of the environmental impacts of buildings: the adoption of LCA as a tool to guide the design choices could help to identify the solution which ensures the lowest overall impact on the whole life, balancing the options of reducing the energy requirements, the on-site production from renewable sources and the limitation of the impacts due to building components (simpler and more durable)