What is quality in a glazed solar panel? How should glazed panels be built? Does your solar panel tick all the boxes?
Homepage for Genersys solar in the UK  
Thermosolar AG
 
Genersys solar in Chile Genersys solar in Mexico Genersys solar in New Zealand Genersys solar in South Africa Genersys solar in the USA Genersys Solar YouTube video blog
Search our website:
What is quality in a solar panel?
Updated: 21st February 2007
 
  Download this file  

Contents

  1. General principles
  2. Panel box construction -light but strong, as strong as a roof
  3. Glazing -strong, low reflection, high absorption and low emmissivity
  4. Absorber plate should have a long working life
  5. Heat pipe should have a long working life
  6. Panel absorber surface should use environmentally friendly material
  7. The ability to stagnate without causing damage to the solar panel
  8. The ability to produce controllable hot water
  9. Internal condensation issues your solar hot water system should be designed to avoid such problems
  10. The ability to withstand high pressures and work at high pressures
  11. How long is the guarantee from the manufacturer?
  12. The connection design should be solid and easy to fit
  13. There should be minimal maintenance requirements
  14. The frames and other fittings should be strong, light and easy to fit
  15. Quality of other components, such as heat exchangers, pump stations and controllers should all be built to the same high standards of engineering excellence as the panels
  16. Heat exchange liquid should be "food safe"

 

1. General principles

Solar panels are a safe and environmentally friendly way of producing heat. It makes no sense to us at Genersys if the panels need to be regularly changed, maintained or serviced.  We at Genersys think that they should be built strongly, they should have a very long working life and should require no maintenance producing versatile controllable heat for homes and industry.

They should be designed for use as a sealed system through heat exchangers rather than directing potable water through the panels so that they can be used for maximum efficiency with more than one heat circuit if needed. Solar systems built with our panels should be very low maintenance structures with as strong and nearly as long lasting as the building they serve.

The materials used should be recyclable and environmentally benign but strong long lasting and of the highest quality. Genersys panels are built to these standards.

Return to top of page

2. The panel box should be light but strong –as strong as a roof

Genersys panels 

The panel tray is stamped from a single sheet of aluminium manganese alloy, anodised for corrosion protection. This seamless method of construction is not only very strong, but there are no rivets to come undone and no seams which can act as weak point in the structure.

Other Panels

Most other panels are made up of a tray constructed by welding aluminium profile together and then welding a back sheet, to form a box. This generally means that the panels have to be thicker and heavier without being stronger.

Return to top of page

3. The glazing should be strong low reflection high absorption and low emmissivity

Genersys Panels

The glass is safety solar low iron tempered glass 4mm thick. It is TUV tested to withstand golf ball sized hailstones. It is highly transparent and allows more than 93% of available light to reach the absorber plate. This glass will not let you down.

Other Panels

Some use environmentally unfriendly plastic (which discolours and decays over time) and others use low iron tempered glass but without the TUV hailstone resistant testing.

Return to top of page

4. The absorber plate should be of long working life

Genersys Panels

The absorber plate is made of a single sheet of aluminium and using a specially patented technique is folded around the heat pipe. This means that there is virtually a 360° contact between the heat pipe and the absorber plate. This method of fixing enables the sheet aluminium and the copper pipe to expand and contract while holding their shape and full contact with each other so that heat can conduct efficiently with minimal loss. There is no welding, soldering or bonding used.

Other panels

Most panels use aluminium or copper absorber sheets but spot weld, solder or laser welded together from fins. The welding is a potential point of failure with the heat stresses. In addition the heat pipe is soldered, welded or laser welded to the absorber plate. The point of contact between the absorber and the heat pipe is only a few degrees. Over a period of time due to the heat collected on the absorber surface and the heating and contraction of the heat pipe and the absorber plates the heat pipe tends to become detached in places causing less heat to be transmitted to the heat pipe and the panel to perform less effectively and with less efficiency.

Return to top of page

5. The heat pipe should be of long working life

Genersys panels

In the Genersys 1000-10 the heat pipe is a continuous copper pipe without joints (except at the two connections to the manifold pipe). This is a robust form of construction preventing leaks, weeps and avoiding liquid loss in the collector which tends to condense on the glazed surface, thus preventing optimum efficiency and over a period of time decaying the absorber surface.

Other Panels

Most panels weld or solder a series of parallel heat pipes to the manifolds, creating the necessity for at least ten or twelve joints in the heat pipe to and from the manifold, making failure much more likely.

Return to top of page

6. The Panel absorber surface should be selectively coated with an environmentally friendly material

Genersys panels

These are selectively coated (creating a series of microscopic ridges to present a greater surface area to the light) with Genersys’ own formula aluminium oxide coating, which is designed to produce only useful heat for the application rather than to produce all possible heat. This coating is 100% safe.
BOX

Other panels

These are sometimes coated with black paint, which performs in hot direct sunshine conditions but not in cloudy light conditions or on cooler days. Some panels are selectively coated in black chrome. We at Genersys think this is an area of potential environmental danger as well as potential health risks. See U S Environmental Protection Agency’s note at  http://www.epa.gov/ttn/atw/hlthef/chromium.html.

Return to top of page

7. The ability to stagnate without causing collector damage

The ability to hold heat stresses over a prolonged period of time. The owner of the collectors should be able to leave the property vacant and unattended knowing that the panels will safely stagnate and will not require covering in times of high insolation and low heat requirements. This overcomes the problem of having to “dump” the heat. Genersys 1000-10 panels are designed stagnate at 347 Fahrenheit (175 degrees Celsius) – in other words they will not get hotter than that regardless of insolation conditions. If panels are required for continuous heat processes which will always draw the heat and which require more heat than the solar system can produce then the end user should specify Genersys 1200 panels which stagnate at around 464 Fahrenheit (240 degrees Celsius).

Return to top of page

8. The ability to produce controllable hot water

Genersys panels are controlled by the DC12 or the DC 22 digital controller; this controller is installer programmable (to enable high efficiencies to be achieved by reflecting the end user’s life style and living requirements) and by regulating the heat precisely. The DC22 can divert heat to two separate hydraulic systems according to the installer’s programmed requirements.

Return to top of page

9. Designed to avoid internal condensation issues

Many panels are permanently covered with condensation; while some condensation is inevitable Genersys panels are designed to remove any internal condensation with an hour of light striking the absorber surface making the panels last longer and work better.

Return to top of page

10. The ability to withstand high pressures and work at high pressures

In Genersys systems the heat circuit is pressurised to ….psi. This means that the Glycol does not evaporate until the temperature of the heat circuit is in excess of 120 degrees Celsius thus ensuring that in very hot daylight conditions all heat requirements will still be met. The heat circuit is a Tichelmann system which ensures that pressure is equally maintained in all parts of the system.

Return to top of page

11. How long is the guarantee from the manufacturer?

Genersys panels installed by an approved installer are guaranteed for 10 years and guaranteed against corrosion for a further ten years. For details of the all conditions attaching to the manufacturers’ warranty please contact your Genersys supplier.

Return to top of page

12. The connection design should be solid and easy to fit

The patented connection kits, which connect panel to panel and panel to the heat circuit are robust easy to fit and will last longer than brazing connections without leaks or weeps; these connections have been used in Europe in hundreds of thousands of systems over many years without any problems.

Return to top of page

13. There should be minimal maintenance requirements

There are no significant maintenance requirements; the panels are designed to be maintenance free and should last for over 35 years. In larger systems the glycol should be tested for anti-freeze properties every year. The testing can be carried out thru a pipe in the pump station without switching off the system by a suitably trained pool maintenance person.

Return to top of page

14. The frames and other fittings should be strong light and easy to fit.

The frames re built of anodised Aluminium which is both strong and light and corrosion proof. They will not interfere with the integrity of the roof structure provided that the correct roof fitting is used; Genersys produce over 15 types of roof fittings so that tiles, slates, pan tiles, bitumen and flat roofs can all be quickly and safely fitted.

Return to top of page

15. The other components, such as heat exchangers pump stations and controllers should be built to the same high standards of engineering excellence as the panels

Genersys heat exchangers are built from cast iron with the internal parts in cupro-nickel which will not stain or be degraded by pool chemicals or salt water. The heat exchanger design is the same as used in many power boats. The pump station prevents simple plumbing errors and its components are made from single pieces of brass drilled and engineered to the appropriate tolerances. Dials on the pump station enable the installer to see the status of a system at a glance. The pump station incorporates a high quality UL approved pump, flow adjuster and glycol draw off testing pipe; the system is filled through this pipe.

Return to top of page

16. The heat exchange liquid should be “food safe”

Genersys systems are designed to be used with Tyfocor L, a non toxic hydroscopic fluid based on propylene glycol, used in food industries and water purification applications. It contains corrosion inhibitors, protecting the system and heat exchangers. It can be used in concentrations that protect against frost down to – 50 Celsius. The corrosion inhibitors also prevent any sludge building up in the heat pipe.

In places where freezing is never experienced the heat pipe can be filled a very low glycol concentration to enable the corrosion inhibitors to keep the system in optimum condition.

Return to top of page

 

 

  Can't find what you're looking for?  
    Our sitemap gives you a complete list of every page on our website. It's really helpful if you can't find what you're looking for.  We also have a great search page that searches our entire library of content and even lists pages by keyword, click here to start searching.