Open AccessPOLYSOL – Thermal and electrical performance assessment of a cost-effective polygeneration system
Author(s) -
João Soares,
B. Shahzamanian,
Szabolcs Varga,
Ana I. Palmero-Marrero,
Armando C. Oliveira
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/352/1/012052
Subject(s) - trnsys , thermal energy storage , zero energy building , renewable energy , environmental science , electricity , heat pump , energy consumption , automotive engineering , process engineering , engineering , thermal , mechanical engineering , meteorology , heat exchanger , electrical engineering , ecology , physics , biology
Buildings are responsible for a large portion of the energy consumption and harmful emissions to the environment. To change this situation, the European Performance of Buildings Directive requires new buildings to be nearly Zero Energy Buildings. To achieve this goal, energy saving measures combined with large use of renewables on-site must be applied. In this paper, a reliable and cost-effective polygeneration system for an existing test building, able to provide electricity, cooling and heating needs is presented, modelled and assessed. The system relies on solar energy as the primary source (PV and solar thermal collectors). Building heat and cooling demand is achieved with a variable geometry ejector heat pump. To reduce the mismatches between generation and consumption, it includes different types of storage (electrical and thermal). For the test building energy needs assessment, the electricity consumption of all test building consumers was measured. Thermal energy demand evaluation required the development of a dynamic numerical model using TRNSYS software. The building thermal performance was validated using experimental data. The numerical model also includes the solar field, thermal energy storage, ejector cycle subjected to know meteorological conditions and operation control. To model and simulate yearly electricity production PVSyst commercial software was applied. Regarding the thermal energy, it was found that on a yearly basis the energy supplied by the thermal collectors about six times the demand. Nevertheless, on the hourly and daily levels, there are thermal energy shortages, due to the lack of solar radiation or mismatch between production and demand. Regarding the electric energy consumption, the potential electric energy production is about 1.6 times the demand. Like for the thermal energy, on the hourly and daily levels, there are energy deficits mostly in winter, for which an electrical energy storage unit will be used. Additionally, the highest peak occurs in summer because of low solar radiation at the end of the day and high demand due to the high cooling load of the test room.