Questions/answers

Solar energy is the energy emitted by the Sun, being a source of renewable energy. The term renewable energy refers to forms of energy produced by the energy transfer of energy resulting from naturally renewable processes. Thus, the energy of sunlight can be captured by humans using various processes, including solar installations.

Solar installations are of 2 types: thermal and photovoltaic. Photovoltaics produce electricity for free. The thermal ones help to save gas in a proportion of 75% per year, being used to heat the rooms and to produce hot water.

In the Republic of Moldova, the global radiation (the sum of direct and diffuse radiation) on a horizontal surface in conditions of average cloudiness is 1280 kWh / m2 / year - in the northern area and 1370 kWh / m2 / year - in the southern area. Over 75% of this radiation falls in April-September. The global radiation in the northern area is 3.5% lower than in the central area and 2.6% higher - in the southern area.

Usually, existing solar installations allow the conversion of solar energy into 2 types of energy: 1) electrical with the help of photovoltaic panels; 2) thermal with the help of solar collectors. The project tends to demonstrate the possibility of obtaining cold in addition to the two components mentioned, based on a 10,5kWp pilot installation built at the spa resort "Bucuria Sind" in Vadul lui Voda and a 4kWp built in Răducăneni, Romania (trigeneration). It is estimated that the innovative solution to be implemented will increase the efficiency of the use of photovoltaic panels by at least 5%, and the efficiency of the use of solar energy will eventually increase. Additionally, all 3 products - electricity, heat and cold will be obtained only on the basis of photovoltaic panels.

Photovoltaic panels convert solar energy into electricity with an efficiency of about 15-20% depending on the technology used. The other 85-80% of solar energy that falls on the surface of the photovoltaic panel leads to its heating, which results in decreasing the efficiency of electricity production. We plan to install on the back of the photovoltaic panels specialized capillary systems, which will absorb the thermal energy from the surface of the photovoltaic panel. This will increase the electricity production efficiency of panels by at least 5%. In parallel, the extracted thermal energy will be stored in an insulated thermal water tank for later use or will be used to prepare domestic water for current needs. If there is no need for hot water, the thermal energy will be converted into cold by means of a water-to-water heat pump that will be used to cool the spaces.

The proposed technical solution - thermal photovoltaic panels - can be used by anyone. It is important for the investment to be effective. It can only be effective if all 3 products are used at the same time - electricity and heat or cold. Otherwise, the investment will not be recovered. This is the main reason why the installation is made at the spa where it is needed in all 3 energy products.

At the moment it is estimated that it should not exceed 1300 euro / kW. After the realization of the solar system, the exact investment will be updated.