Energy supply systems for buildings based on PV panels

In Europe, buildings are responsible for 40% of the energy consumption and 36% of CO2 emissions. Water heating accounts for around 16% of the energy consumption. A completely renewable, central energy supply for all buildings is not possible. Therefore, decentralized solutions with individual storage tanks and solar energy collectors will be needed in the city of the future, interacting with existing grid infrastructures in the best possible way.

In the past years, wind and photovoltaic technologies have taken over the dominant position of solar thermal water heaters in terms of installed renewable capacity globally.

Direct electric heating with PV panels is a robust technology because there is no pumped circulation and the requirements for maintenance are minimal. Reduced installation costs are expected because of a lower complexity of the system than of traditional solar thermal water heater systems. Further, smart and adaptive control systems can interface with the household’s energy consumption for water heating, lighting, household machinery and possible electrical vehicle, and optimize the use of the produced energy and maximize the efficiency and the profitability of the system.

A new IEA task within the SHC Program: Solar Hot Water for 2030 is under preparation. A Task definition meeting will take place in September 2021 and the Task is expected to take off in the start of 2022. The overall aim of the task will be to elucidate which solar hot water technologies are most suitable for the future. Investigations on hot water systems heated by solar collectors, PV panels and heat pumps are included in the task. One subtask will be focused on PV domestic hot water systems, due to the rapid PV market growth with strongly decreased PV costs seen in the last couples of years. A paper presenting the task [3] will be presented at the Asia Pacific Solar Research Conference, held in December 2021 in Sydney, Australia.

The solar group at DTU Civil Engineering has great experience with heat storages and all kinds of solar energy collectors from numerous projects. International partners have asked if the solar group can serve as a subtask leader for the coming IEA Task.