CPC - solar collector

Every ingenious invention is based on a simple idea

Take advantage of sunlight with a SOLARFOCUS CPC solar panel collector. Transform the sun’s rays into free heat for your premises to reduce your energy costs and impact on the environment. Our solar CPC collectors can be used all year round and are especially effective in the spring and autumn, when the sun’s rays fall at a low angle. 

The CPC collector – not just for the summer

  • Perfect exploitation of light at a low incident angle
  • No condensation means no wet insulation in the collector; 10-year guarantee
  • No condensation means no film of dirt on high selective coating of absorber
  • Large format: 2,400 x 1,155 x 65 mm, aperture area 2.5 m²
  • For vertical or horizontal installation

Save Money & Energy with Solar CPC Collectors

Different sizes of CPC solar collector are available to suit all applications. A system lifetime of 25 years and the ability to supply at least 70% of domestic hot water requirements makes solar CPC collectors an investment in the future of your home and the environment.

To find out more, please contact your local SOLARFOCUS representative.

No ventilation holes - no plastics - no wood - no insulation - no rubber seals

Why the structure of the collector should be important to you: because environmental influences such as wind, rain, dirt, UV radiation, snow loads and extreme variations in temperature are active on the collector over a period of decades.

Collector tray - the 'foundation'

  • The 1.5 mm leak-proof welded aluminium tank without vent holes forms the “foundation”.
  • Air and waterproof design without air holes and rivets protect the interior of your collector for decades.

Absorber – the 'heart' of the collector

  • High-selective coated copper absorber with ultrasonic welded heat transfer medium pipe.
  • The floating absorber which is coated on both sides guarantees you the best energy yield.

Reflector – the crucial difference

  • The cylindrical, high-gloss rolled, galvanically anodized pure aluminium reflector concentrates the penetrating solar radiation onto the vertically
    installed absorber ship.
  • The reflectors are protected in the casing from environmental influences, which guarantees a long service life.

The solar safety glass

  • 3,2 mm low-iron, prism-structured solar safety glass.
  • Highest light transmission, impact and hail resistant.

Special seal – robot-produced

  • Flexible, UV protected special seal.
  • Connects the tray, the glass and the glass strip.
    Diffusion proof.
    Prevents the penetration of moisture and contaminants.

Aluminium glass holding strip

  • Anodized special aluminium section.
  • No rubber seal, but a UV and weather-resistant aluminium strip provides protection for the glass edges.
    Guarantees permanent adhesion between the glass and the tray.

Surface-sealing joints

  • 1/2” external thread with flat-faced gasket.
  • The surface seals contacting the interior and exterior side of the tray are screwed in plane-parallel with brass nuts and hermetically seal the tray.
  • No environmentally vulnerable rubber or plastic seals.
  • Allows simple connection of the collectors.

Negative pressure relief valve

  • Negative pressure relief valve for pressure compensation. The air expands at the first warm-up of the interior of the collector - and excess pressure develops. The valve opens and the air can escape. When the air cools, the valve closes and a vacuum develops in the interior of the collector.
  • No corrosion of the interior of the collector due to aggressive outside air. 
  • No exchange between interior and exterior air - therefore no heat losses due to convection.
  • No condensation, therefore no degradation of the high-selective absorber coating.

Every ingenious invention is based on a simple idea

It would be ideal if the collector always faced south

  • The angle of the sun on the collector surface changes continually with the earth's movement. This means that the main proportion of the sun's rays will strike the collector at an angle.
  • The positioning of the collectors plays an important role when designing your solar energy system. You should aim for collector orientation towards the south (the optimum would be 10° south-west) and an angle of inclination of 30 to 45 °.
  • But even when facing west and with a roof pitch of 30°, the CPC collector from SOLARFOCUS still offers 80 % of the yield produced with optimum orientation.

Concentration with flat, weak solar radiation

  • Due to its CPC geometry, the collector can still achieve usable temperatures even with weak sunlight at a low angle of incidence.
  • The reflector concentrates the power of the sun's rays by a factor of up to 3. This ensures effective exploitation of even sunlight with a low angle of incidence.
  • This is important in the transitional period (spring/autumn), when up to 80 % of the sun's rays fall at a low incident angle.

Efficient use of the sun = a longer break for your boiler

  • The cylindrical shape of the CPC reflector allows it to absorb even diffuse light. Incident angle modifier at 30° = 1.1
  • The vertical installation of the absorber allows the shallow-angled light to be utilised.
  • The small absorber strip means a smaller radiating surface and thus lower heat losses. The small absorber strip also ensures quicker heating as a result of concentration.

Difference: CPC collector – flat collector

  • Unlike the flat collector, the CPC collector is equipped with trough-shaped reflectors. The sunlight is thus concentrated on the absorber which is installed vertically in the focal line.
  • Advantage: Optimum utilisation of low incidence light in the morning and afternoon through concentration.
  • Collectors always facing south would be ideal; in the case of significant deviations, the CPC collector would be a better choice!

Service life: CPC collector / flat collector

  • The basic service life of a collector is approximately 25 years.
  • The sealed construction of the CPC collector prevents contaminants or moisture penetrating into the inside of the CPC collector – even with extreme weather conditions and temperatures.
  • This largely prevents loss of performance and ageing and ensures a long collector service life.

The CPC is sealed, the flat collector ventilated – why?

  • As a result of the sealed construction of the CPC collector together with the collector valve, a negative pressure of up to 0.3 bar can arise inside the collector. The forces created would be enough to shatter the glass (implosion).

  • But as the glass is supported on the reflector in the CPC collector, these loads are no problem.

  • A flat collector needs ventilation to allow gas emission from the mineral wool insulation and condensation to escape.

  • In addition to this, there is no support (reflector) for the glass on the flat collector, so that under negative pressure, the glass would be drawn inwards and break!

No insulation?

  • Energy absorption from both sides of the absorber in CPC collectors reduces radiation losses towards the rear (which occur on normal flat collectors) to a minimum.
  • This means that no insulation is needed here and results in a very flat design
  • Heat loss factor K1 = 3.3 W/m²K

Standstill temperatures: measures

  • In summer, the solar energy system may switch to standstill if all heat requirements have been met.
  • In this case, extremely high temperatures can occur inside the solar collectors. However, SOLARFOCUS collectors are tested for their ability to withstand these temperatures.
  • The high-quality materials and workmanship ensure that such standstill temperatures are no problem.

The decisive advantages

Schematic diagram of the CPC collector

1.   The collector tray
2.   The absorber
3.   The reflector
4.   The solar safety glass
5.   The special seal

6.   The glass holding strip
7.   The surface sealing joints
8.   The negative pressure relief valve
9.   Ring-groove ventilation

The right solution for every case

Roof-integrated mounting – attractive and unobtrusive
  • Single- or multiple-row collector arrays
  • Standard or horizontal installation
  • Special flashings are also possible
On-roof mounting, parallel 0°
  • Single- or multiple-row collector arrays
  • Standard or horizontal installation
  • Various attachment methods for virtually all roof types
On-roof mounting, elevated
  • 20°, 45° or 70° elevation possible
  • Optimum for low roof pitch
  • Also available for horizontal installation
Façade installation
  • 45° or 70° elevation possible
  • Wall installation at 90° available on request
  • Horizontal installation for CPC-S1 and Sunny-28 only
Free-standing installation
  • Where there is insufficient space on the roof or adequate orientation is not possible
  • 45° or 70° elevation possible
  • For concrete foundations provided on-site
Installation on a flat roof with gravel box
  • For attachment to an aluminium tray filled with gravel
  • Where there is insufficient space on the roof or adequate orientation is not possible
  • 45° or 70° elevation possible
Installation on a flat roof with a concrete base
  • 45° or 70° elevation possible
  • Horizontal installation for CPC-S1 and Sunny-28 only
Special designs available on request
  • Special installation options
  • Range of colours for the sheet metal flashings or frame profiles

Prospect solar energy system