What are solar water heaters? How does it work and what components are in the system. So in this article we are talking about the solar water heater.
A solar water heater is not the same as your daily water heater. Instead of using pure electricity that is sent to your home from a power plant that uses fossil fuels to fuel it, your energy comes straight from the sun.
In other words, your energy is 100% natural. To make your water hot, it does not have to pass through electrical wires.
Solar water heaters have solar thermal collectors instead of electricity and a device that consists of fluid that transfers heat from the thermal collectors to the point of use.
In order for the fluid system to operate, the system will have to use electricity, but the amount of electricity that is required is very small. If the whole machine worked off of electricity itself, it is even less than what will be used.
There will also be a tank in the solar water heater which will store the heated water for use. Solar water heaters may be used by households, firms, and industrial environments to heat their water. Systems may be built to vary in size to match the specific structure of the heat.
So what are the advantages using of solar water heaters?
- By using less energy, you are doing a great service to the world. Minimal energy means the use of less fossil fuels. It means a better environment for you, a safer environment for your neighbors, and animals will continue to enjoy their natural environments if they do not use too much fossil fuel.
- You should take advantage of tax benefits. When you build something that uses renewable energy in your home or company, you can find that on your next tax return, you will get a tax credit.
- You can save cash because you don’t use as much energy. Electricity is starting to become very costly. Power providers tend to be trying to raise their prices more frequently now than they used to.
Your solar water heaters is going to more than pay for itself between the tax benefit and the money saved by using too much energy. You would always feel good about what you do for the world.
Often, when you see the tax benefits and can take advantage of them, you will feel very nice. Not only is the world getting a little more beautiful, but your wallet is also more beautiful. Your wallet can actually actually expand from the use of renewable energy.
Component of solar water heaters
Solar Water Heaters Collector
Solar thermal collectors absorb heat from the sun and store it and use it to heat a liquid. The technology of solar thermal collectors is governed by two significant physical principles:
Owing to heat loss from conduction, convection and radiation, every hot object eventually returns to thermal equilibrium with its environment. Efficiency (the proportion of heat energy retained for a predefined period of time) is directly linked to the loss of heat from the surface of the collector. The most important causes of heat loss are convection and radiation. To slow heat loss from a hot object, thermal insulation is used. The Second Law of Thermodynamics (‘equilibrium effect’) follows this.
Flat Plate Collector
Flat plate collectors are an extension of the principle of positioning a collector directly facing the Sun in a ‘oven’-like box with glass. Many flat plate collectors have two horizontal pipes, called headers, at the top and bottom, and several smaller vertical pipes, called risers, connecting them. The risers are welded to thin absorber fins (or similarly connected).
Heat-transfer fluid (water or water/antifreeze mix) is pumped into the collectors’ bottom header from the hot water storage tank or heat exchanger, and it flows up the risers, absorbs heat from the absorber fins, and then exits the collector from the top header.
Serpentine flat plate collectors vary slightly from the nature of this “harp” and use a single pipe that moves up and down the collector instead. However, because water cannot be adequately drained, it is not possible to use serpentine flat plate collectors in drain back systems.
Low-iron, tempered glass is almost always the type of glass used in flat plate collectors. Without cracking, such glass can withstand substantial hail, which is one of the reasons why flat-plate collectors are considered the most robust type of collector.
Un glassed or shaped collectors, except that they are not thermally insulated or physically covered by a glass sheet, are identical to flat-plate collectors. Consequently, when water temperatures surpass ambient air temperatures, these types of collectors are much less effective.
The water to be heated is always cooler for pool heating applications than the ambient roof temperature, at which point the lack of thermal insulation allows extra heat to be drawn from the surrounding area.
Evacuated tube collectors
Evacuated tube collectors (ETC) are a way of reducing the inherent heat loss of flat plates. Since a vacuum can not be crossed by heat loss due to convection, it forms an important insulation system to hold heat inside the collector pipes. As two flat glass sheets are normally not strong enough to withstand a vacuum, between two concentric tubes, the vacuum is formed.
The water piping in an ETC is therefore usually enclosed by two concentric glass tubes separated by a vacuum that admits heat from the sun (to heat the pipe) but restricts the loss of heat. A thermal absorber is used to cover the inner tube.
Solar Water Heaters Pump
A photovoltaic (PV) panel is one way to power an active device. The (DC) pump and PV panel must be suitably matched to ensure proper pump efficiency and longevity. The controller must ensure that the pump does not work while the sun is out, but the collector water is not hot enough, as a PV-powered pump does not operate at night.
The following advantages are provided by PV pumps:
- Simpler/cheaper repair and installation
- Excess PV output may be used or placed back into the grid for household electricity use.
- Living room can be dehumidified
- Can work during an electricity blackout
- Prevents the consumption of carbon by using grid-powered pumps
A bubble pump is suitable for both flat panel and vacuum tube systems (also referred to as a geyser pump). The closed HTF circuit is under reduced pressure in a bubble pump system, which allows the liquid to boil when the sun heats it at a low temperature.
A geyser is formed from the steam bubbles, creating an upward surge. At the highest point in the circuit, the bubbles are separated from the hot fluid and condensed, after which the fluid flows downward into the heat exchanger caused by the difference in fluid levels. Usually, the HTF arrives at 70 °C at the heat exchanger and returns to 50 °C at the circulating pump.
Solar Water Heater Controllers
Temperature variations between water leaving the solar collector and the water in the storage tank near the heat exchanger are sensed by a differential controller.
When the water in the collector is approximately 8-10 ° C warmer than the water in the tank, the controller starts the pump and stops it when the temperature difference exceeds 3-5 ° C.
This means that when the pump runs, stored water still gains heat and protects the pump from unnecessary cycling on and off. (The pump can be activated in direct systems with a difference of about 4 ° C since they have no heat exchanger.)
Solar Water Heater Tank
In a sunny spot, the simplest collector is a water-filled metal tank. The tank is heated by the sun. This was how the first devices functioned.
Due to the balance effect, this setup will be inefficient: as soon as the heating of the tank and water starts, the heat gained is lost to the atmosphere and this continues until the ambient temperature of the water in the tank is reached. The challenge is to minimize the loss of heat.
- The storage tank can be positioned lower than the collectors, facilitating greater device design freedom and allowing the use of pre-existing storage tanks.
- It is possible to conceal the storage tank from view.
- It is possible to position the storage tank in a conditioned or semi-conditioned space to minimize heat loss.
- Drain back tanks can be used.