The CTI Solar Collector
Costs considerably less than an equivalent parabolic dish
Can be built with multiple focal points enabling:
- One concentrator to be used for several different purposes at the same time, OR
- Allows collected solar energy to be spread out over a predetermined area
Solar concentrators are made with a large surface to reflect sunlight onto a focal zone where a converter, receiver or absorber is located. This converter or receiver is part of a system that converts the solar energy into another form of useful energy such as electricity or heat. The surface is curved or parabolic in shape so that the incident sunlight is directed towards the focal zone. The reflective surface is usually formed of a single mirror or an array of curved mirrors fixed on a dish or a trough shaped frame.
- Has a low side profile – providing less wind resistance.
- Is constructed of concentric rings on a simple spoke frame.
- Easy to erect and maintain.
- Is manufactured using polished stainless steel rather than glass mirrors.
- No more expensive replacement parts and less prone to damage.
- Has a higher optical efficiency, translating into more usable concentrated heat.
To achieve a usable energy output the surface area obviously needs to be larger than 2 meters in diameter and due to the large size an equivalent parabolic mirror is difficult to fabricate with added difficulty in the skill and care required to shape the parabolic dish to achieve efficient solar collection making the cost of manufacturing these solar concentrators generally high.
The reflective materials or mirrors used are often coated with a clear polymer material to protect the surface from the environment. The ultra violet rays affect this coating over a period of time and cause degeneration. Glass mirrors are susceptible to damage by hail and cracking due to expansion and contraction of dissimilar materials. If the mirror or some of the mirrors are damaged the concentrator would be required to be removed from service.
All solar concentrators presently on the market are relatively high (side on profile) in form and the parabolic shape makes them susceptible to damage from high winds and storms. They collect dirt and need regular cleaning. Also, because of their shape, the larger concentrators are heavy, requiring major support structures and powerful motors to move them.
The newly designed solar concentrator designed, built and tested by CTI has overcome these disadvantages.
In addition, the concentrator can be built with one or multiple focal points thus allowing one concentrator to be used for several different purposes at the same time or allowing the collected solar energy to be spread out over a predetermined area so that the concentration ratio can be altered to suit the application.
The CTI concentrator can be manufactured using polished stainless steel with a reflective index of 82% or a newly developed polished aluminium with a reflective index of 87% with a clear ceramic coating to protect the highly polished surface from the elements and to maintain its reflective surface for many years. The concentrator is constructed of concentric rings cut to emulate sections of a parabolic mirror and set on a simple spoke frame. This costs less than a quarter of that required to manufacture a traditional parabolic dish of similar collection area.
Assembly can be done on site thereby making it possible to transport a concentrator as a “Flat Pack”.