Developments in Solar Water Systems

Solar water heaters also called as solar domestic hot water systems can be used to generate hot water for your home needs. They can be a cost effective way to heat water in any climate, and the fuel they use is sunshine which is available free in the atmosphere. Solar water system includes the storage tank and solar collectors. There are two types of solar water heater systems: Active (pumped systems) which have circulating pumps and controls; and passive (compact systems), which don’t have.

A compact system, which is also known as mono bloc, consists of a solar collector and a tank for the heated water. Heat pipes are used to transfer the heat energy from collector to the tank, or by natural convection. They are more reliable since electricity powered components are not used which makes them easier to maintain with a longer life period.

Compact systems are developed in three types, which are integrated storage system, thermosiphon system and conventional heat storage system.

Integrated collected storage system:– Here the tank acts as both solar and storage collector. Batch heaters are located in the house or on roof, comprising of thin rectilinear tanks, with glass in front. They utilize gravity flow to deliver water, with no pumps, and are rarely pressurized. They are suitable in periods of good sunshine with moderate climates. With the advantage of being efficient, simple, and less expensive than other types of water heaters, they are mostly preferred.

Thermosiphon Systems:- They rely on the natural course that activates the warm water to rise. The system distributes water through solar heat collectors and subsequently into a holding tank, which is placed above the collector.

Conventional heat storage system:– These consist of intense collectors of plate type, with insulated tanks that are built-in. The unit uses convection system to move the water upward, from heater to tank. Neither electricity nor pumps are utilized in this system, which makes it more efficient than an ICS, since some water is heated by the intense collector that is constantly rising to the tank.

Pumped systems are developed in three types – direct system, indirect system and drain back system

Direct system:- These pumps are used to pump the water from the solar heat collectors. These systems are mostly used for mild seasons.

Indirect system:- Heat exchangers are utilized to pass on the heat from the fluid to the water. These are used in colder climates as they minimize the chance of damage to the solar water heater by frozen water in some parts of the system.

Drainback Systems:- In these systems, electric pumps are used to circulate water through the solar heat collectors. When the pumps stop, the heated water moves into a holding tank.

The above are the various details of all the developments that occurred in the technology of solar water systems.