European Directives 2010/31 and 2012/27 require that the energy performance of buildings in the civil sector be progressively more efficient and make greater use of renewable energy sources. In particular, at national level, Legislative Decree no. 28 of 3 March 2011 stipulates that the thermal energy production systems (heating, cooling, hot water) of new buildings or those undergoing major renovation must be designed in such a way as to ensure that the use of energy produced from renewable sources covers a percentage of the building’s thermal needs that increases over the years: 20% by the end of 2013, 35% in 2014÷2016, 50% from 1 January 2017. In order to meet these requirements, it is therefore necessary to provide for the use of technologies that use renewable energy sources, in particular heat pumps (HP) and solar thermal, because of the need to satisfy the demand for indoor climate control and domestic hot water.
RSE has developed two experimental activities on these topics.
The first, carried out at the BIC Umbria in Terni – managed by the public company Sviluppumbria – is an integrated system of solar panels and a heat pump that allows the efficient use of solar radiation to heat buildings and produce hot water. In particular, the system incorporates different types of solar panels – hybrid, photovoltaic, thermal – a heat pump with storage and a waste water heat recuperator. The hybrid, photovoltaic and thermal panels are the focus of particular attention, as they are components that are not yet widespread but show great promise. The system is equipped with an acquisition and control system that allows remote management of the system and evaluation of the performance of the system as a whole and of its main components, in particular hybrid panels compared to traditional ones.
The second activity was carried out at the RSE experimental area in Milan, where a system – for residential and tertiary applications – was created using parabolic solar collectors and a double-effect absorber. The highly efficient system uses solar radiation indirectly, through the absorber, for cooling.
A series of simulations of the two plants were carried out in the TRNSYS software environment in order to obtain important indications of their operation and performance, to be verified with the experimental data obtained from the monitoring.
Both projects are characterized by the use and optimization of solutions using components available on the market, in order to be able to hypothesize replicable business cases using real data derived from tests carried out on prototype systems, and thus contribute to a subsequent phase of development of commercial lines of high-efficiency products for indoor climate control.