On the use of latent thermal energy storage to cut the energy costs in space cooling: from lab to home

According to IEA report, about 37 Gton CO2 were estimated having been released in the atmosphere during 2019. A similar value was obtained for 2020. It is absolutely essential to reduce this figure, calling the researchers to focus on finding and developing innovative solutions. A huge amount of the energy is used for space heating and cooling and, in the last decades, energy management and indoor thermal comfort have become challenging issues.

Gagliano et al. reported that in the European Countries the total cooled floor area is destined to grow up to 2 billion m2 in 2020 (it was 1000 million m2 in 2012). Therefore, more than 100 TWh year-1 will be required for building cooling only. Future smart and efficient energy management systems for space cooling and heating in building applications call for novel solutions to store heat in order to decouple the energy demand and the availability of renewable energy sources.

Latent thermal energy storages represent one of the most promising solutions; however, their cost-effective implementation in terms of energy and cost savings, payback time needs to be verified case-by-case. Thus, simplified though accurate performance simulations during both charging and discharging phases are strongly needed to be implemented into the different dynamic simulation tools.

Starting from accurate experimental test campaign on a novel 18 kWh latent thermal energy storage which uses the roll-bond technology to efficiently store and release cold energy exploiting the solid/liquid phase change process of 300 kg of a bio-based phase change material having a melting temperature of 9 °C, a numerical study is carried out to investigate the potential benefits on a 150 m2 single dwelling in three potential locations: Venice, Kuala Lumpur, and Brisbane.

The model is developed using TRNsys and it includes a new type of the latent thermal energy storage based on the experimental results. The results will explore the interactions between the single dwelling and the A/C system as a function of the photovoltaic field, and of the LTES to estimate the potential energy savings and the capabilities of the system to maintain satisfactory thermal comfort.