As I mentioned already, solar power comes in many forms. To better illustrate what I mean, consider the world’s current energy sources – not just the oil and coal we use to run our computers and cars, but the food, water, and wind that’s around us every day.
It’s all because of the sun. Trace the food chain to its lowliest members and you’ll find plants and algae – both life forms that can transform the sun’s rays into energy sources through photosynthesis.
That energy allows plants to reproduce and in turn transfers to the animals and people who eat them. All energy in our food comes from the sun, even if it goes through five or six steps of the food chain before it gets to your belly.
Even the current forms of energy we use are merely old, super high-density containers for solar energy. Coal is compacted plant matter. Oil is compacted algae matter. Natural gas is the by-product of both of them.
It’s all a cycle, so it’s no surprise that technology has developed in recent years to take advantage of the sun’s rays in as many ways as possible, not just through silicon based solar cells, but through solar collectors, insulated tubes, and more.
Solar Collectors
First thing’s first – how do we take all that energy being pumped out by the sun each day and convert it into viable power for your home? It’s done with solar collectors – special panels that you place in your roof, on your walls, or beside your pool to collect and trap the radiation given off by the sun and use it to produce heat. We’ll get into the systems used to convert that energy into a useful form in your home soon, but for now, let’s take a look at how the collectors actually work.
Sometimes called solar thermal collectors, collectors are used in many installations – most notably solar hot water and space heating setups. They may also be used for solar towers, solar power plants, and solar conversion for warehouses or commercial outlets.
Think of it this way. Roughly 52% of all electricity generated in the United States is done with the use of Coal. However, coal doesn’t generate electricity on its own. Usually, it is burned or broken down in a way that releases energy. That energy is then used to heat water which turns turbines. Those turbines then produce electricity which is stored and transferred to homes and businesses throughout the region.
A solar collector is taking on the same role as the coal – it’s trapping energy and preparing it for conversion to a form we can actually use. Where and how you use those collectors will depend largely on what kind of energy you need. Instead of the highly unstable and generally not very useful solar radiation that comes from the sky every day, a solar collector converts the sun’s energy into something that can be used to heat water or recharge a battery.
Heating Collectors
The first type of collector is used for heating. Solar heating collectors come in flat plate or evacuated tube collectors. Basically, a flat plate will heat a tank of water while evacuated tubes will transfer heat to various tubes of coolant which can be transferred to a tank for later use. The latter is more often used in commercial settings or for homes that experience freezing winters.
? Flat Plate – A flat plate collector is an insulated box that contains a plate designed to absorb solar energy – usually protected beneath a set of glass or plastic layers when installed in your home. If you use the same collector plate for your pool, it may be uncovered.
? Integral Collector Storage – The Integral collector storage (ICS) system is often known as a “batch system” and will usually have multiple tubes or tanks contained within a single insulated box. The system will pump cold water into the tubes or tanks to heat it. The water is then transferred to your standard hot water heater which is heated by gas or electricity.
This ensures that, if your region freezes in the winter, you always have a source of hot water. The hot water heater can be set to only turn on when the water drops below a certain temperature coming from the collector. In most situations, this reduces your traditional energy use by up to 70%.
? Evacuated Tube – The third type of solar collector is the evacuated tube, which encapsulates each pipe in the collector with numerous clear tubes made of glass. Each tube will have metal absorbers to trap the solar energy and heat the water.
Due to the scalability of this option, it is used often for businesses and large buildings. Another benefit here is that the evacuated tubes are not affected by things like air temperature due to the insulation. These collector types will vary greatly depending on whether you are installing a heating system, a hot water system, or a different thermal solar system.
Electricity Collectors
The collectors you’ve probably seen more often are the ones used for generating electricity -? the panels, dishes, pyramids, and towers that dot the landscape in secluded areas or in industrial parks. Different types of collectors include:
? Parabolic Trough and Dish – Troughs are used by solar power plants to concentrate the energy collected from the sun to heat a pipe filled with coolant, which is then used to power boilers in a station. Parabolic dishes look like giant foil wrapped satellite dishes. They focus all of the sunlight received onto a single point where it is converted into a more useful form of energy.
? Power Tower – Like something out of a scene in a science fiction movie, the power tower is surrounded by small mirrors that focus on the central point of the tower. The tower then transfers heat gathered to the base of the tower where a power station is located.
? Solar Pyramid – A pyramid uses air as the conductor to turn the turbines. They require a lot of space and are covered in solar collectors that transfer heat to the air that is pushed through them.
There are a number of reasons why these systems tend not to show up on your neighbour’s roof or at the local grocery store. They’re expensive to implement and require a complex system to ensure the mirrors and collectors remain concentrated in the right location throughout the day.
The amount of heat generated and collected, however, is immense. This makes them perfect for power plants where cost can be outweighed by the long term benefits of a productive power plant.
The biggest issue that keeps concentrating and collecting systems from being used residentially is that they generally don’t work in sub-prime conditions. If the sun is invisible or simply diffused for any period of time, they don’t work well, whereas photovoltaic systems continue gathering power. So, instead of focusing on what you can’t use, let’s take a look at how solar collectors can be integrated into your home for thermal collection.
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