How does renewable technology work?
SOLAR WATER HEATING - How it works:The joy of this is that we don't need the persistently sunny heat of the equator to obtain the benefits of solar energy. There are two types of solar water heating systems - active: which requires circulating pumps and controls, and passive: which do not.
The Components: Most systems consist of a control unit, a well insulated storage tank, a collector, and collector kit. There are three types of collectors but the most common types used in Ireland are the flat plate and collector tubes.
Operation The sun shines on the collector - in this example we will use an evacuated tube collector. This heats the heating fluid, which passes directly over the condenser or in the case of a direct flow collector, the heating fluid is passed through the tube within a co-axial heat exchanger. This fluid then passes through a heat exchanger into the storage tank, transfering the heat to the water. A pump transfers the heated water through the domestic system. The control unit uses temperature sensors to monitor heat differences between the collector and the tank and switches the pump on and off accordingly. There is also an expansion vessel in the system to contain increased water volume, due to the rise in temperature, and thus increased pressure of water.
WOOD PELLET STOVE - How it works:
A wood pellet stove looks like a solid fuel stove or wood burner on the outside but inside it is very different. Firstly, it requires electricity to function. Secondly, the fuel that it uses, wood pellets, by their nature require continuous feeding into the burnpot, so that requires an auger. These wood pellets are stored in a fuel hopper of varying sizes, depending on the output of the stove may be 12kg - 40kg, which is filled from the top of the stove.
Operation The stove is turned on, there is an ignition device within the stove which heats up, a few pellets are fed into the burnpot, and they catch fire. As the pellets burn, more pellets are fed into the burnpot. Combustion are fan blows hot air around the fire to maintain a high temperature and enable the pellets to burn efficiently and evenly. A flue gas fan blows the exhaust gases from the stove, into the flue. (As the outlet from a pellet stove is much smaller than a traditional chimney, typically a flue is installed either through the rear of the wall behind the stove, or maybe into an existing chimney.) There is very little ash from the burning of woodpellets, but any ash falls through the gate to a collector under the burn pot. This can be regularly cleaned out with a hoover. Due to the construction of the stove and the way it works, the stove itself does not radiate as much heat as a solid fuel stove, but instead blows the hot air into the room by a convection air fan.(Although the front glass is very hot to touch.!)
All of this is controlled by a control unit, usually located at the top of the stove. This allows you to set a temperature for the stove, and once this temperature is reached, the stove will reduce the feed to the auger motor, to just enough pellets to keep the stove 'ticking over'. Some stoves on the control unit have a timer function, which can set the stove to come on and off on a daily or weekly basis.
WOOD GASIFICATION - How it works:
The Principle: Gasification is a method of extracting energy from organic materials such as wood. The process converts the wood into carbon monoxide and hydrogen by reacting the raw material at high temperatures with a controlled amount of oxygen and/or steam. The resulting gas mixture synthesis gas or syngas is then more efficient than direct combustion of the original fuel because it can be combusted at higher temperatures. Gasification itself and subsequent processing neither directly emits nor traps greenhouse gasses such as carbon dioxide.
Components of a boiler 1.Control unit 2.Fuel chamber door 3.Forced draught fan 4.Bottom door 5.Fuel chamber 6.Primary air duct 7.Ceramic nozzle with secondary air duct 8.Combustion chamber 9.Ash chamber 10.Exhaust gas heat exchanger with turbulators 11.Damper 12.Safety heat exchanger 13.Supply line 14.Return line 15.Chimney neck
Operation of a SOLARBAYER Boiler: For heating up, the boiler is equipped with a heating damper which is operated with a connecting rod at the front side of the boiler. The interior of the boiler consists of a fuel chamber where the fuel is dried out and turned to gas. The wood-gas produced will then be lead into the combustion chamber via a nozzle. There it starts burning by adding secondary air. The hot waste gases are cooled down in the heat exchanger.
Please bear in mind that this is not an exhaustive description of how each technology works, but rather a general description. It may not apply to every product.