Frequently asked questions

What is solar energy?

The solar thermal energy is produced by the effect of the sun rays. They emit a certain radiation that reaches the Earth's surface. This radiation can be used for heating, using thermal collectors, or for production of electricity using photovoltaic cells (active way of using solar energy).
This kind of energy also can be used in a passive way, without a mechanical system as an intermediary. Passive uses of the solar energy is the basis for the bioclimatic architercture, which consists on using the sunlight in houses, studying their ideal location, in order to use the heat of the sun.

What can we get with solar energy?

Basically, collecting the solar radiation in an adequate way, we маy get heat, electricity and lighting. The heat is produced by means of thermal collectors, and the electricity by means of the so-called photovoltaic modules. Both processes are totally different, as regards technology and also as regards their application.

Which are the advantages of the use of the solar energy?

It is an ecological source of energy (no pollution), as well as inexhaustible and free for use. In addition, it contributes to sustainable development, improving our standard of living, and it represents other option to the use of fossil fuels, which are pollutant and finite.

What's a solar thermal system ?

Roughly speaking, it is a system that allows the heat of the sun to be used for heating water or other liquid. This system can contribute to heat up to 80% of the water needed in a house. It consists of a collector (often located on the roof of the house), a tank to store hot water and a system of pipes that make flow the water which will be used in the house.

How does it work?

In the solar thermal system a specific liquid flows between the collector and the intermediary. This liquid is heated in the collector's absorber and then it transmit heat to the water in the storage tank.

How much heat can give a collector?

The intensity of solar radiation is not constant throughout the year. Although in the summer months there is solar radiation greater than 1000 W/m2 that comes to the collector, it entirely can not be used. Due to losses in the collector, pipelines, absorber, etc., to the water that is heated in the tank, collector will transmit approximately 600 W/m2. In other words, Euroterm ESK 2.5 SB collector will transmit to the water in the tank about 1500 W. This applies to the sunny summer day.

Does the new collectors affect to my normal consumption of hot water?

When the hot water generated by this system is used rationally, most of the time does not need to be used additional energy for heating tank. However, higher consumption of hot water will chilled the tank, and in this case additionally heating should be used from a secondary system (boiler, geothermal pump, electricity, etc.).

How does my house need to be in order to install modules of these characteristics?

Let begin that you need to have a minimum surface to install collectors (more than 5 square meters). Collectors are mounted with certain incline and orientation (often to the south). The area where you want to install collectors must not be blocked by obstacles that cast their shadow on them.

Is there a "template" for determining the required number of collectors, ie dimensioning the system?

No. The solar thermal system is sized in relation with many factors that affect on its functioning. All these factors, designer takes into account and use them in further calculation and dimensioning of the system. For systems that use Euroterm ESK2.5 SB solar collectors, orientation value can be obtained by using the calculator that is placed on our website.

Which are the cares for these installations?

Solar thermal system is almost self - sustainable. However, just like your car, you should perform regular controls. Usually is tested solar fluid - glycol, whose life, depending on the system, ranges from 2 to 4 years. There is no risk of breaking of the collectors glass by strong winds or hail (with the exception of natural disasters and accidents). The outer transparent cover is made of tempered solar glass, similar to those used in car windshields. Therefore, the need for maintenance is minimal.

What happens with the frosts?

The liquid that flows through the collectors is not water. Collectors circuit is treated with ecological antifreeze - glicol, so that it can bear low temperatures. Then, this heat-bearer liquid transfers the heat to the water that we consume. In summary, there is no risk of freezing in case of frost.

Will I have hot water on a cloudy or rainy day?

The collectors are absorbing not only direct radiation also diffuse radiation. There is both kind of radiation on sunny and cloudy days. Of course, during cloudy days, direct radiation is less and less will be taken by the collector. Anyway, our region has ideal conditions in relation with the average number of suny hours. In principle, there would not be any problem to have hot water everyday.

Which are the expenses?

There are no expenses (except investment). The solar system not require maintenance costs. Solar radiation is free, and it does not pollute the environment.

What can solar thermal system be used for?

Domestic hot water heating or swimming pools heating. Also, in combination with thermal storage heater, heated water can be used for support in central heating system, of course, with larger investments.

What happens if it is cloudy?

The tank has an additional source of energy ie. heat exchanger, electric heater or similar. However, after more than three cloudy days, if there is not water consumption, only 90 minutes of sunshine are needed for water to be heated up at the temperature before shutting the pump, ie. 85ºC.

How long have hot water without sunshine?

The temperature in the tank goes down 10 ° C, after 72 hours without sun.



Click to enlarge