Solar Panels – Direct Absorption with CPC Insulated Mirror
Solar panels equipped with the new direct absorption technology produce the thermal energy needed for domestic hot water and for the preparation of the thermal agent used to heat homes, public institutions, businesses, and swimming pools.
The main advantage of the new direct absorption solar panels is that the hot glycol comes into direct contact with the glass tubes and the heat transfer is maximized. Compared to heat pipe panels, where heat is transferred through several exchangers, this system significantly improves efficiency.
Due to the lack of damageable components, direct absorption panels benefit from a 25-year warranty, which can be extended according to each distributor’s policy.
The efficiency of direct absorption solar panels is up to 30% higher than heat pipe panels and up to 50% higher than flat panels. For maximum efficiency, the solar panel should be mounted on the south side.
Solar panels equipped with direct absorption technology and CPC insulated mirrors represent a state-of-the-art solution in solar energy systems. The CPC insulated mirror layer is applied directly to the back of the outer glass tube and helps recover solar radiation that would otherwise be lost while also reducing heat loss through the shaded surface of the tube.
In summer, simply rotating the tubes can reduce or stop the operation of the solar panel by shading the CPC insulated mirror, which is oriented towards the sun.
Main Advantages
- By attaching the CPC insulating mirror directly to the glass tube, dust and impurities cannot accumulate on the mirror surface and block solar radiation.
- By attaching the CPC insulating mirror directly to the outer glass tube rather than the inner one, heat loss through the shaded surface of the tube is reduced.
- The extremely simple assembly allows installation by any authorized installer.
- The expansion vessel ensures the condensation of overheated glycol and its reintroduction into the circuit, eliminating the risk of evaporation.
These solar panels, together with a solar boiler and an automation station, create a complete solar system that works all year round regardless of outside temperature. The solar system can be connected to any type of heating system in the building.
Construction Variants
- 18 tubes – product code TMC18 – 1.55 m x 1.85 m
- 25 tubes – product code TMC25 – 2.15 m x 1.85 m
- 30 tubes – product code TMC30 – 2.55 m x 1.85 m
The Solar Panel Consists Of
- Vacuumed glass tubes
- Horizontal heat exchanger
- Fixing bracket made of duralumin / stainless steel
- Expansion vessel
- Fasteners, accessories, screws, nuts, silicone, and rubber gasket
The glass tubes have a double-walled, thermos-type construction with a vacuum level between the glass walls of 5 x 10-3 bar. The outer tube is 58 mm in diameter and 1800 mm long.
The inner glass tube is coated with two selective layers. One Al-N-Al type layer increases the absorption level of infrared radiation in the visible range of solar radiation up to 95%. The second layer is designed to refract thermal radiation inside the tube so it can be taken up by the thermal agent and produce up to 810 kWh/mp/year.
The glass used to manufacture the tubes is borosilicate type 3.3 and is hail resistant.
Functions of the Glass Tubes
- Absorb infrared radiation in the visible range of sunlight
- Refract thermal radiation toward the inside of the tube until it is taken up by the thermal agent
- Insulate the thermal system very well by limiting heat transfer with the external environment
- Allow the thermal agent inside the tubes to convert solar radiation into usable thermal energy even under overcast skies
The position of the evacuated glass tubes on the support structure is always inclined, which gives them high resistance to hail impact. It also supports thermosiphon circulation, with the hottest thermal agent remaining at the top and heating the heat exchanger efficiently.
The heat exchanger is made of stainless steel and is designed to capture the thermal energy produced by the solar panel tubes. Its housing is 2 mm thick and resistant to harsh outdoor conditions. The thermal insulation of the heat exchanger is made of high-density polyurethane with a thickness of 50-60 mm, which reduces heat transfer and increases the mechanical strength of the equipment.
Due to the high capacity of the heat collector, direct absorption panel systems have very low hydraulic losses and can be sized in groups of up to 200 tubes per installation, unlike heat pipe panels which are limited to 120 tubes per installation.
The inlet and outlet of the heat exchanger use 22/28 mm diameter pipe. Connection to external equipment is made using a removable elastic connector, which absorbs expansion and movement.
The solar panel support is made of duralumin or stainless steel U-profiles, giving it mechanical strength and corrosion resistance. The profile thickness, shape, structure, and fixing system provide stability in difficult atmospheric conditions such as strong wind and heavy snow.
The tilt angle of the support can be between 20° and 90°.
The solar panel works all year round regardless of outside temperature. There is no danger of frost during operation because glycol is used in the system circuit and can withstand temperatures down to -40°C. To reduce heat loss on the connecting pipes, they are insulated with high-temperature-resistant materials.
The solar panels meet all the requirements of national and international legislation and environmental standards. By using solar panels on each building, fuel consumption is reduced and significant quantities of pollutant emissions, especially CO2, are eliminated.
Solar panel with 25-year warranty.