A significant percentage of energy consumption in buildings is devoted to the production of domestic hot water. Researchers are now proposing a solution that could reduce the associated greenhouse gas emissions. Thanks to a system that takes advantage of available solar energy.
In the residential sector, the production of domestic hot water consumes a lot of energy according to this Facebook page. More than cooking, for example. It represents about 12% of the total energy consumption of a home. Hence the importance of finding efficient and clean solutions. And this is what researchers from the University of Cordoba (Spain) are proposing today. They have designed a photovoltaic solar device that uses some 95% of the energy available to it to heat water.
We are not talking about a solar water heater or a solar thermal system that requires a special hydraulic installation. We are talking about photovoltaic solar heating, which only requires the installation of solar panels and a very conventional electric water heater. All that is needed is the “very simple and low-cost” electronic conversion system developed by the researchers. Enough water can then be heated to around 80°C to cover 85% of a household’s annual needs.
A system that works even with little to no sunlight
The system designed by the researchers makes it possible to keep a fixed reference voltage and thus to operate permanently at its maximum power point. Thanks to a microcontroller and a metal-oxide gate field-effect transistor (Mosfet) that conducts or cuts the current according to the voltage. This is similar to the MPPT (Maximal Power Point Tracking) technology on which the similar solution marketed by the Belgian start-up Wanit is based.
The whole system allows solar photovoltaic panels to be connected directly to the water tank to be heated. The solar energy is then converted into heat. The researchers promise that this can be achieved with only a small number of solar panels and at any level of radiation.
The device is still in the experimental phase, but it could soon be commercialised. Scientists are working on integrating artificial intelligence, which could improve performance and safety.
Here is a little guide to help you learn more about solar energy and panels:
What is a solar thermal panel?
Thermal solar panels convert solar radiation into heat energy. By means of solar collectors – metal tubes – this type of solar panel transfers the heat from the sun’s rays to a heat transfer fluid. A pump sends the heat transfer fluid to an exchanger circuit. The solar energy transformed into heat is transferred to a hot water tank, a boiler or any other heating system.
What does the solar thermal panel look like?
The solar thermal panel is a product in the form of a rectangular panel made up of parallel vertical tubes. The “water” type of solar panel, the solar thermal panel, has metal tubes with fins to transfer the sun’s radiation to water. The heat transfer fluid solar panel is based on the same principle, with the heat transfer fluid replacing the water. The most common type of solar thermal panel is the roof-top solar panel for domestic hot water production. It is also called a solar water heater.
What are solar thermal panels used for?
Thermal solar panels with water or heat transfer fluid allow the self-consumption of up to 50% of domestic hot water. They also provide energy for a heating system. Solar thermal panels with water or heat transfer fluid often complete a primary installation. This type of solar panel is then called auxiliary solar panels. In winter, the electric resistance of the hot water tank or the gas boiler takes over to ensure the operation of the installation.
What is a photovoltaic solar panel?
The photovoltaic solar panel is made up of photovoltaic cells. When sunlight hits the surface of the photovoltaic cell, it captures photons of sunlight. It then converts them into energy and electricity. Photovoltaic cells are based on silicon (gas or physical). There are three types: amorphous, monocrystalline and polycrystalline. Photovoltaic solar panels are the most widespread solar panels. This type of solar panel is installed on the roof, on the ground (solar farm), and also equips mobile electronics.