Solar Water Heating System

In today’s world, we use electricity very extensively. The convenience in using electricity has made our life simpler and also very much dependent on electricity. The energy sources in the world are depleting at a phenomenal rate and we need to apply any and all means to conserve these conventional sources of energy. Moreover it is also becoming expensive to use these sources. The cost of electricity is continuously on the rise. If we look at our electricity bills, a major portion of it is related to water heating or heating of other medium as the case may be.

Solar energy is abundantly available. Solar thermal collectors can be effectively employed to convert the energy from the sun into useful heat. The collector panel consists of number of fins made of thin copper sheets, welded to copper tube. These tubes are connected to two common pipes known as headers. This entire assembly is put into a metallic box with insulation between the assembly and the box. On the topside, the box is covered by toughened glass in order to protect the fins from the dust, dirt, water etc., and yet allow the solar radiation to fall on the top surface of the fin.

The fins are coated on the top with special material. This is called as solar selective coating. It allows maximum absorption (typically over 90%) of solar radiation in the visible spectrum and limits the thermal emission (to below 5%) in the infrared regime. Thus, maximum energy from the sun is retained in the fin, as heat. This heat can now be transferred to any fluid passing under the fin or through the tube welded to the fin.

The fabrication of solar collector panels is standardized as per the rules of the Bureau of Indian Standards (Std No. IS 12933:1992). ISI marked panels can be procured from a number of fabricators in India.

EnergieSolar specializes in engineering solar heating systems based on the needs of the application and the design requirements. We design, procure, fabricate, assemble, install and commission these systems. The exact work content may vary from case to case and our role would also vary accordingly. The controlling logic and the hardware for the control is also selected, procured and integrated with the system by us.

For large application (over 5000 liters per day), it is our experience that the system economics works out to be very attractive. Typically, the savings in electricity bills adds up to bring the system pay back close to 3 years. In a few cases it is even better. Moreover, there are several fiscal incentives offered by the Government of India for using renewable energy sources. This includes soft loans with moratorium and extended repayment payment periods as well as benefits by way of accelerated depreciation for the system.

The typical life of the solar water heating systems is considered to be over 15 years. There are minimal operating expenses. Maintenance requirements are also very low. The quality of water used in the system, however, needs to be checked. Hard water is to be avoided at all costs as it generates deposits on the inside surface of the pipes and retards heat transfer. Sometimes the deposits may even obstruct the flow of water in the system.

Solar water heating systems are reliable and are time tested. In domestic applications they have been put to use for more than a decade now. The users as well as the manufacturers are therefore very confident about the performance of the system. Hence, we give five years limited warranty against manufacturing defects. We can also take up maintenance and service contract for solar water heating systems.

The systems can be designed for any requirements such as 125 liters per day to a few 10’s of thousands liters per day with temperature requirement ranging between 40°C to 100°C. Of course, the entire heat may not come from the sun and as such the system may partially use electricity, depending on the specific application.

The solar water heating system consists of

Basic System

1 Solar collector selectively coated
2 Collector Stand
3 Stainless Steel (SS 304) hot water storage tank, with outside insulation, with stand
4 G.I. 1” insulated system piping

Additional scope as per customers’ requirement

1 Cold water tank
2 Electrical Heaters
3 Extra pipe line cold / hot

Other Technical Details

1 Insulation – Rockwool (k = 0.029 w / mk, 48 kg / cu.m, R = 1.67)
2 Insulation cladding – 22 swg for tank and 26 swg for piping