Solar water heating system - Thermal energy from the sun

Solar water heating system types and Thermal energy from the sun. A renewable energy source is the heat of the sun. Do you want to heat your pool, jacuzzi or domestic water on thermal energy? That is possible with a solar water heater combination or thermic panels. You can heat your water objects in an environmentally friendly way.

Solar water heating system - Thermal energy from the sun

Many different possibilities are to heat water or another liquid with the heat of the sun. You can purchase a PVT system. Also called combination panels. PVT means Photovoltaic Term = Sun and Heat. They are hybrid panels that provide both electricity and heat. Panels for electric power, combined with a thermic water heater for hot water.

Wikipedia is us telling about it.

Solar water heating

From Wikipedia, the free encyclopedia
Solar water heating (SWH) is the conversion of sunlight into heat for water heating using a solar thermal collector. A variety of configurations are available at varying cost to provide solutions in different climates and latitudes.

Thanks to the operation of a thermic collector, you can benefit from hot water every season. Even in the winter, the thermic collector can still produce heat. Although the efficiency of the two types of collectors is not far apart, the collectors perform better in different seasons.

The flat plate thermic collector, for example, works well in warm and sunny weather thanks to the large absorber plate. The absorber then absorbs light over the entire surface, while the vacuum tube collector between the tubes by a lot of sunlight goes wrong.

The vacuum tube collector, however, works perfectly in colder weather, for example in winter. The vacuum tube solar collector then loses fewer heat thanks to the excellent insulation. Besides, this thermic collector heats up very quickly, which means that the vacuum tube collector performs well even in cloudy weather.

Electricity and hot water.

The PVT panel looked like a typical thermic panel but equipped with a water circuit at the rear. The roof surface is therefore used twice. The water provides additional cooling, which means that the board delivers up to 10% more energy. Storing the heat in a thermal storage unit with heat exchangers.

A thermal storage unit is often a solar boiler

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A thermic boilermaker makes use of the heat instead of the electromagnetic properties of the sunlight. This heat transport is a piping system to the hot water tank or heat exchanger. Solar water heaters will increase in popularity thanks to the recently introduced subsidy on thermal boilers.

With a thermic water heater, you can quickly save up to half (average 45%) of your energy costs for heating water. Besides, you are also extremely environmentally friendly, because a water heater prevents CO2 emissions (on average 280 kg per year!) Due to the sustainability of solar energy.

Solar water heating system - Thermal energy from the sun

Solar collector.
Is a collective term for a type of device in which either heat or thermo electric energy is converting. Sunlight converts into heat in thermic collectors. In contrast to photovoltaic systems, thermic collectors do not use electromagnetic properties of sunlight.

The heat from the collector is applied directly to heat an object (think of the solar cooker) but it is also usable for electricity through a turbine.

The flat-plate collector.

The flat-plate collector is the type of collector that you usually find in people's homes in combination with a thermic water heater. As the name already indicates, the heart of this collector is a black plate, also known as the absorber.

This plate is surrounded with insulating material and can thus absorb heat very efficiently. To allow the temperature to rise further, we find a transparent (glass) cover plate above the absorber. At the bottom of the absorber, there are pipes through which water flows. These pipes are placed in such a way that the heat can bring the water to a higher temperature.

Vacuum tube solar collector.

The operation of the vacuum tube collector differs slightly from the flat plate solar collector. The vacuum tube collector consists of several tubes, fixed in a frame. These tubes, made of double glass, are vacuum-formed and have a special coating on the inside.

The operation of the vacuum tube collector is thus comparable to the principle of a thermos flask. As a result, the tubes have a very well insulation. In the collector, there is a copper absorber, also known as a heat pipe, which gives off the heat to the tap water.

The sun dish.
The solar dish is a large dish-shaped parabolic mirror that brings the incident light together to one focal point. This focal point is a few meters in front of the centre of the mirror.

Because the sun starling is very concentrated, the temperature in the focal point can reach very high values. A Stirling engine (hot-air motor) placed at this location, which converts the heat generated into movement.

A dynamo generates it into usable electricity. Another possibility is that a particular heat-resistant cell with high efficiency in the focal point.

Solar water heating system - Thermal energy from the sun

The parabolic trough.

The technology of the parabolic trough is already quite old (1984), but has changed in recent years. Research focuses on the stubbornness and durability of the relatively expensive montage, but also on improving the mirror itself.

The Heat Collection Element (HCE), the steel tube on which the sunlight focus, is covered with a layer that improves absorption. This part is also subject to change, and modern material can absorb about 20% more than older variants.

A parabolic trough consists of a long parabolically curved mirror with a tube in the focal plane through which a liquid flows. Because the mirrors concentrate the incident sunlight on the liquid pipe, the liquid present (natural oil) is heating up.

The heat of this liquid (sometimes up to 500 degrees Celsius) to boil water, after which the steam obtained and passed through a steam turbine. The tube itself is surrounded by a vacuum (glass), to minimise the loss of heat. The advantages of the parabolic trough system include that it is efficient (between 15 to 20%) and that only one axis is rotating to follow the sun.

The disadvantage of this system is that after cooling it is impossible to keep running at night and is very dependent on the weather. For the system to operate after sunset, it is possible to feed the hot liquid through heat storage. It's a tank with (mostly) nitrate salt, a material that has excellent storage qualities. After sunset, the still hot salt will keep the oil in the tube warm enough to produce steam at the generator.

Solar updraft tower by wikipedia

The solar tower.

A solar tower or updraft tower is a tall building around which a large number of mirrors. These rotatable mirrors all reflect the sunlight at one central point at the top of the tower, which is enormously warming up. At this point, a storage medium is chosen, which transmits the heat to a water boiler.

The water is flowing to a boil, and the resulting steam is producing electricity through a steam turbine. The surplus goes into a storage medium so that it can also give off enough energy at night to bring water to the boil. Nowadays, sodium is the prefered product to use, because this soft metal has a high heat capacity. If the sun does not shine, this system hardly works.

Solar water heating system - Thermal energy from the sun

The solar chimney.

Not to be confused with the different working solar tower, the solar chimney makes use of the fact that hot air rises. The air is heating up in a large circular greenhouse-like collector. However, there is a very high chimney in the middle of the greenhouse.

Because hot air has a lower density, the air heated up to the ground will rise at high speed through the tower. By placing a turbine in the tower, electricity can from this air flow.

The chimney is a concept by the German engineer Jorg Schlaich that is still under development. In the 1980s a prototype was build in Spain. The test showed that the system is very inefficient (around 0.5%), but also very cheap to keep running.

Solar boilers.

Solar boilers generally consist of a collector, a pipe system, a pump, a storage tank, electric heater and various sensors. The electric heater is necessary because the sun does not always provide enough energy to keep the water warm (think of the winter and cloudy days).

If the temperature is too low, the electric heater will ensure that the water is at least 60 degrees hot on a colder day by conventional means. This is necessary to kill the Legionella bacteria.

The pump starts as the temperature inside the collector is higher than the temperature in the storage tank. If this situation is reversing, the pump will stop.

Many companies here in Portugal Algarve are selling electric solar panels with a combination of one mentioned above.

Look here to find the best solar energy Portugal companies.