Solartwin solar thermal controller Get rid of mains pumping for your solar water heater! Start Price GBP 120.00 Current Price GBP 120.00 Time Left - Bid Count 0 Buy It Now Price GBP 200.00 Reserve Price - Start Time Wednesday, September 03, 2008 End Time Wednesday, September 10, 2008 Location Chester, Cheshire See more about 'Solartwin solar thermal controller' Description What does the Solartwin solar controller comprise?Solartwin Zero Carbon Controller,  pictured above, suitable for the above pump and PV.  5 year Solartwin warranty.What is NOT included are a suitable photovoltaic panels and pump.  For these we recommend a 30W 12V nominal PV, and the Laing Eco-circ Brushless DC Impeller Pump D5solar-38/700 B or equivalent. Or you can buy alll three items from us as a package for £350.About the Zero Carbon Controller. This is a differential temperature controller which can be used for controlling a a variety of photovoltaic or low voltage DC solar heating systems including Solartwin. It makes your solar panel operate efficiently and safely, with very low or even zero operating carbon impact. As a user, it lets you see the water temperature near the top of your hot water cylinder. This temperature will be similar to what will come out of your taps. But behind the scenes it is doing a lot more. It controls whether the pump is on or off, using two special ways of working. These are called differential control and occasional heat export. Here is a brief explanation of each. Most of the time the controller is doing differential control. Here, it compares the temperature of the top of the solar panel with the bottom of the hot water cylinder and it switching the pump on or off accordingly. For example, when as the solar panel is a slightly hotter than the stored water in the cylinder, the controller switches the pump on. Provided there is enough solar electricity available, it then pumps send hot water from the panel into the top of the hot water cylinder so you can use it when you need to. Later, when the stored water is hotter than the solar panel, the pump normally turns, off since the panel would otherwise cool the stored water. However, when the top of the hot water cylinder does over a preset high temperature, such as 65 degrees C, heat export control takes over in order to  reduce the risk of scalding. Here, the pump keeps on pumping until the water at the top of the cylinder falls below the preset temperature. Then it reverts back to differential control. In a clever innovation the Solarwin Zero Carbon Controller does not require mains power, because its electricity comes from a solar electric (photovoltaic) panel. More info is on Youtube and the Solartwin.com website. Place a Bid!