SOLAR+HEATERS+-+Bruce

Solar Heaters
By 小BB

**What is Solar heating energy?**
Solar heating energy is a mature renewable energy technology. It uses the heat from the sunlight to heat the water inside it’s storage tank, which stores the hot water for mostly residential use. Solar heating energy is very common in many countries for years, and has been widely used in Israel, Australia, Japan, Austria and China.

** How it works: **
Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. Because solar heating energy relies on sunlight, therefore during winter there sometimes may not be sufficient solar heat gain to deliver sufficient hot water. In this case a gas or electric booster is normally used to heat the water.


 * Cold water moves in a pump from a water tank and travels through solar collectors in a solar panel to get heat.
 * In the process, it is heated up by the sunlight hitting the solar collectors.
 * This heat is then carried away from the solar collectors by the water returning to a heated storage tank.
 * A controller component regulates the pumping action of the water.
 * The controller will close the check valve that sits between the solar panel and the hot water storage tank. It also turns the auxiliary power on when the sun goes down.

Some solar water heaters have a shut-off valve that automatically closes when the sun goes down in order to save heated water. An auxiliary system will kick in when more hot water is needed. Auxiliary systems run on conventional energy, such as gas or electricity.

So this is how it works...

**Examples from around the world:** The solar heaters is widely introduced in many countries. Most of them are developed countries, but there is one exception, China. China is the biggest consumer on solar heaters. And because its so commonly used, you can see it almost everywhere. There's nothing special about it and I'm sure you have seen solar heaters once in your life. So I will just put some pictures of solar heaters: **The energy changes involved:** Heat energy to heat energy. Statistics and facts about solar heaters: (copied from wikipedia) |||||||||||||||| **Daily energy production (kW th .h) of five solar thermal systems. The evac tube systems used below both have 20 tubes** || //- Insolation 3.2 kW.h/m 2 /day ([|temperate] )// - //e.g. Zurich, Switzerland// || 5.3 || 3.9 || 3.3 || 4.8 || 4.0 || - //e.g. Phoenix, USA// || 11.2 || 8.8 || 7.1 || 9.9 || 8.4  ||
 * //Technology// || Flat plate || Flat plate || Flat plate || Evac tube || Evac tube ||
 * //Configuration// || Direct active [|[38]] || Thermosiphon [|[39]]  || Indirect active [|[40]]  || Indirect active [|[41]]  || Direct active [|[42]]  ||
 * //Overall size (m 2 )// || 2.49 || 1.98 || 1.87 || 2.85 || 2.97 ||
 * //Absorber size (m 2 )// || 2.21 || 1.98 || 1.72 || 2.85 || 2.96 ||
 * //Maximum efficiency// || 0.68 || 0.74 || 0.61 || 0.57 || 0.46 ||
 * //Energy production (kW.h/day)://
 * //- Insolation 6.5 kW.h/m 2 /day ([|tropical] )//

3Q