This June, we were approached by a business partner who is a leading manufacturer of security systems in the Czech Republic. For the emerging solar water heating project, they turned to SALTEK with a request for the supply of SPD DC with a maximum voltage value of 275V. Their wish was to launch the required solution on the market by the end of September this year.

We were very pleased with the interest of this partner with Czech roots in SALTEK products, and with regard to possible participation in other projects in the future, we did not hesitate in any way. During the summer months, we were able to meet their requirement and develop a brand new FLP-PV275 V/U to complement our SPD range for PVs. The FLP-PV275 V/U is derived from the existing FLP-PV550 V/U, practically it is a FLP-PV550 V/U in half width and with only two modules. Thanks to this, it was possible to use the existing base from FLP-12,5 V/2, modules from FLP-PV550 V/U and to create a new product according to the customer's requirements flexibly and in a relatively short timeframe.

Water heating using solar energy is currently a hot topic in the Czech Republic, mainly thanks to the possibility of drawing state subsidies, which is why many companies are coming to the market with their solutions. Due to the uniqueness of the project, we only briefly describe the basic principles of the issue. The solutions currently offered can be broadly divided into two groups; photovoltaic and thermal. As it follows from the previous sentence, photovoltaic water heating is not thermal heating, these terms are often misused or confused – both systems are collectively called "solar".

Solar energy can be understood as light and heat energy. Photovoltaic panels are used in photovoltaic heating, which, as in the case of today's common photovoltaic power plants in your house, work on the principle of the photovoltaic effect, where light energy is converted into electrical energy with the help of transistors or diodes with an open PN junction. This is then further used, in this case to heat water, for example in a boiler.

On the other hand, solar collectors are used for thermal heating, which have the task of collecting heat energy, which is done by a system of copper tubes, filled with a special propylene-based fluid, inside a collector located on the roof. This fluid then further heats the water in the tank with the help of a pump.

Our FLP-PV275 V/U is used in the first of the mentioned types, i.e. in PV heating. One of the ways in which PV water heating is solved is a micro PV system, consisting of a PV panel with an output voltage of 230 V DC, a micro DC/DC converter and a heating element with a water tank ("boiler"). The FLP-PV275 V/U provides protection of the microinverter on its DC side and, thanks to its parameters, especially the SPD protection class T1+T2 together with the maximum operating voltage of 280 V and the voltage protection level of 1.3/2.5 kV, meets all requirements for micro PV systems of this and similar type.