Solar energy is all the rage these days. As interest in solar energy increases, people are investigating new applications every day. Many innovations in this field are actually quite old, they were simply cost prohibitive until now.
Solar energy can be used to achieve a wide variety of functions. One function is using the thermal properties of solar energy. A common way this is achieved is using a solar collector. A solar collector can be a great way of utilizing thermal solar energy.
The question then arises, what is a solar collector exactly? You may also wonder how it works and why it’s preferred over solar panels. In this article, we’ll go over these points for you. So, read on!
What is a Solar Collector?
A solar collector is simply a device that uses solar radiation, and uses the greenhouse effect to heat water pipers or air. Solar collector designs can range from simple to complex depending upon their purpose.
For domestic uses, the design is rather basic. It is normally a flat box with a transparent casing. Inside the box are pipes that carry a coolant. The bottom contains an insulated backplate for maximum heat retention.
For commercial uses, that is large buildings and industries, the designs are completely different. These may include mechanical parts such as sun tracking glass that concentrates heat onto the pipes. The average consumer won’t need such technical variants.
How Do Solar Collectors Work?
As previously mentioned, solar collectors use the greenhouse effect to carry out their job. Sunlight enters the flat box through the transparent casing. Keeping the content of the box exposed allows the transfer of solar radiation.
The depression in the box and the transparent lid on top essentially trap heat. Unable to escape, the heat begins to transfer to the coolant pipes within the collector box. The pipes are made of copper to maximize conduction.
The box contains an insulated backplate that has been painted black. This is just another means of retaining heat. The entire box is also insulated for the same purpose.
Types of Solar Heating Systems
How a solar collector works depends on the type of solar heating system you’ve utilized. As previously discussed, the exact design of the collector will vary based its purpose. There are two main types of solar heating systems, active and passive.
Passive space heating systems are used to heat space. They utilize a variety of design principles based on a building’s geographical location. That means windows face the sun, and materials have heat absorbing qualities.
The design features of a passive space heating system, allow the space to remain warm even in cold climates. Solar collectors don’t come into play here.
Solar collectors are utilized in active solar heating systems. They collect heat from the sun, and transfer it to pipes that contain a coolant. The fluid is helped along the pipes via fans or pumps. The pipes themselves can lead inside the building heating it centrally.
Conversely, they can lead to a storage tank to be released. Once the pipes release their heat, the fluid is moved along again back to the collector for reheating. A water tank is one of the key characteristics of an active solar heating system.
Types of Solar Collectors
We’ve answered what is a solar collector. We’ve also shown you that the type of solar collector depends on the solar heating system. Now let’s look at these types. Broadly speaking, solar collectors can be either concentrating or non-concentrating.
Concentrating Solar Collectors
Concentrating solar collectors are used for commercial and industrial purposes. The collection area is much larger than the absorption area.
The collectors concentrate solar energy onto an absorber. They also have mechanical parts to track the sun’s movement throughout the day. This property ensures that they are useful thorough the day.
Non-Concentrating Solar Collectors
In non-concentrating solar collectors, the absorber and the collector are built into the same area. As such they are equivalent in size. The description of how a solar collector works mentioned in our guide, is based on these.
Non-concentrating solar collectors are normally modest in size, and hence perfect for residential usage. They do not have any moving parts, and have a simple yet effective design.
Solar Collectors vs. Solar Panels
Although the focus of this guide is largely on solar collectors, you may wonder how they stack up against solar panels. Solar panels receive far more press than solar collectors but each has its advantages and disadvantages.
Advantages and Disadvantages
Both Solar panels and collectors are eco-friendly. However, solar panels can produce electricity. As a result, they offer cost savings and increase your independence. Solar collectors cannot do so.
The flip side of this is that solar panels are expensive to install. Solar collectors on the other hand are a cheap and efficient alternative. Solar collectors can use low-cost mirrors to increase their surface area.
Solar panels may be cheap to maintain, but their high initial cost makes them inaccessible to most people. The cost rises with the area you want to cover.
Both solar panels and collectors are highly dependent on the sun. Inclement weather can reduce the usefulness of both.
Our Final Thoughts
At the beginning of this guide you wondered “what is a solar collector?” Well, now you know. Not only that but you’ve learned a lot more. We hope this guide has been helpful in answering your questions.