The economic benefit is prominent. Once-off investment and long-term profit is the prominent character of solar water heater system. After our many years¡¯practice and test, in general solar water heaters can win all investment during 2-3 years. Generally speaking, per square meter of collector of solar water heater can generate 50~60 liters of hot water above 40~50¡æ every day and can generate heat about 600000~700000 kcal. in a whole year. The contrast between solar energy and common energy sources (counting according to average 300 days of sunlight all year): taking heating 14 tons water to up net 30¡ædaily by the solar water heater project of 245,000 Yuan as comparative object. Industrial electricity is 0.80 Yuan/kw., the efficiency of electric water heater is 95%; natural gas is 2.5 Yuan/m3, when the quality of heat is 37000KJ/ m3, the efficiency of gas-fired water heater is 85%; diesel oil is 4.5 Yuan/kg, when quality of heat is 46040KJ/kg, the efficiency of oil-fired boiler is 80%.
From the comparison of the results in the above table, all of the investment on solar water heater can be got back in 2~4 years. After 2~4 years, we can use hot water free. That¡¯s to say, we can save 123120 yuan from expense of electricity, or we can save 42000 yuan from expense of expenses of gas fuel, or we can save 64800 yuan from expense of oil fuel.
Another kind of way also can show the same result:
1, only use coal boiler water heater:
If the demand of the hot water is 8000KGS every day and the unit price of coal is 600RMB/T, the hot water supply fee will be 1172360¡Â4300¡Â60%¡Á0.6¡Á365=99514.2RMB per year.
2, only use fuel gas water heater:
If the demand of the hot water is 8000KGS every day and the unit price of gas is 2.2RMB/M3, the hot water supply fee will be 1172360¡Â8600¡Â75%¡Á2.2¡Á365=145954.3RMB per year
3, use solar water heater add fuel gas water heater:
In changzhou, there are about 280-300 days available for us to choose solar water heater to supply hot water each year, so that other about 85 days depend on fuel gas water heater., the fee is 1172360¡Â8600¡Â75%¡Á2.2¡Á86=33989.4RMB
The solar water heater project price for 8000KGS hot water is 120000RMB
We can see from the above calculate that the cost of using solar water heater add fuel gas water heater is the lowest, then the coal boiler water heater, and the cost of the fuel gas water heater is the highest. Since the recycling time of using coal boiler and gas water heater system making hot water is about 1-2years, while the life time of the solar water heater is 15years, as a result, install and use the solar water heater system is both economical, energy save and environmental? protection. 1.SC Glass Vacuated Tube
All glass evacuated tubes are the key component of solar collectors. The evacuated tube is similar to a conventional Dewar flask and consists of two borosilicate glass tubes, a glass with high chemical and thermal shock resistance. The outer side of the inner tube is coated with a sputtered solar selective surface. This coated inner tube is closed at one end and sealed at the other end to the outer tube. The annular space between the outer tube and inner tube is evacuated to virtually eliminate heat loss by conduction and convection.
We use the tubes which use the successfully developed innovative Advanced Solar Selective Coatings in commercial scale, which achieve the highest thermal efficiency and good thermal stability. Solar selective coatings absorb most solar radiation while simultaneously suppressing the thermal emittance loss from coating surfaces. They vary mainly in their optical property and thermal stability.
Excellent results have been obtained by using DC magnetron sputtering technology. A solar absorbance of 0.94 - 0.96 with an emittance of 0.04 - 0.06 at 100 centigrade has been achieved.
