Thermal Energy page1 - ElectroCity

1 Thermal . WHAT IS Thermal GENERATION? Geothermal Energy is the heat that flows What is Thermal generation? Thermal generation is the process of generating continuously from the hot interior of the Earth electricity Thermalfrom heat . heat generation is atoform refers the of Energy . process to the cooler ground surface. and use it to In most places directly drive ain the turbine heat Energy that is turned into electricity of generating electricity from heat . There can be world, there is not enough that spins a generator. of this heat to use made in many are four ways. Thermal It can fuels: Energy be produced by coal, natural for generating electricity.

2 New Zealand is one burning gas, woodfuelswaste such asandcoal, oil, gas or wood. geo- Thermal . StrictlyIt can of just a few countries in the world that have also be takennuclear speaking, from steam power from a geothermal is also Thermal geothermal fields where hot rocks are close field, or created by nuclear reactions. Energy fuel, but it is set aside in a class of enough to the surface to be useful. Wells are drilled deep into the ground and a mixture of its own because of it's unique traits. In this factsheet you will learn about the burning hot water and steam is taken out at high ofFossil fossil fuels, fuels (coal, such oil, gas),and as gas wood coal,(biomass).

3 Were and pressure. This steam is separated and piped to geothermal created millions of years ago from layers about Energy . For more information the power station, where it is used to drive a nuclear power, of animal andsee thematter. plant Nuclear Energy ' factsheet. turbine and generator in the same way as at other power stations. The water is usually put When Fossil coalsuch fuels, is burnt to produce as gas, heat ,were oil and coal, this heat back into the ground, so that the geothermal can bemillions created used toofcreate yearssteam. ago from Theanimal steamand reservoir isn't depleted. drives plant the steam matter that wasturbine, which isand compressed connected HUNTLY POWER STATION IN THE NORTH ISLAND SUPPLYS.

4 UP TO 20% OF NEW ZEALAND'S ELECTRICITY. compacted insideThe to a generator. layers of rock. Energy produced by the HOW. SOURCE:DO STEAM. GENESIS AND GAS TURBINES WORK? Energy . generator is passed through a transformer In New Zealand, three types of turbines are How is electricity generated from Thermal When coalNational into the is burnt Grid to produce heat Energy , transmission line whichthis used to drive the electrical generators of heat Energy can be used to create steam. The energystations: power fuels? delivers electricity throughout New Zealand. steam drives the steam turbine, which is In New Zealand, three types of turbines Natural gas to can provide Energy through the Conventional steam connected a generator.

5 The Energy produced generate heat fromturbine natural gas: byprocess of burning the generator it for heating is passed throughand cooking. a transformer The fuel is burnt in a boiler to heat water into It can into thealso be used National Grid totransmission fuel an electricity line. turbine. This is the Conventional steam under highSteam Turbine pressure. A conventional system that delivers electricity to all of steam turbine uses the pressure of the Wood waste (bio-mass) comes from wood Gas is burnt expanding in a boiler steam toaheat to turn water turbine. into The New Zealand. processing plants and other related industries.

6 Steam. A. turbine conventional drives steam a generator. Theturbine uses whole process Often the Biomass wood means waste a fuel is disposed that of, but is made from in living high pressure converts steam to heat Energy to turn a turbine. rotational The kinetic someThe things. situations it can be burned most common exampleinof order this to is turbinewhich Energy , drivesisa then generator whichinto converted converts electrical produce heat Energy . heat Energy wood waste, which comes from wood processing can make kinetic Energy . Energy into electrical Energy . steam. plants andSteam relateddrives a steam industries; forturbine to example, Open Cycle Gas Turbine pulp and paper generate mills.

7 Often the wood waste is power. Open-cycle gas turbine disposed of, but in some situations it can be An Anopen-cycle open cyclegas gasturbine turbineisisvery verysimilar similarto toa Three to burned types of power produce heatplants Energy ,arewhich used can to be jet engine onon anan aircraft and is the most basic a jet engine aircraft and is the most generate used powerways in different fromtogeo- Thermal Energy : generate electrical Thermal Energy turbine. Air is passed through basic Thermal Energy turbine. Air is passed dry steam, flash and binary. Dry steam Energy . athrough compressor and is then mixed with fuel gas a compressor and is then mixed plants take steam out of fractures in the in a combustion chamber.

8 It is then burnt and This work is copyright. The copying, adapting or issuing of this work to the public on a non-profit basis is welcome. No other use of this work is permitted without the prior consent of the copyright holder. From ElectroCity Genesis Energy 2010. the hot expanding gases create thrust that The processing of these trees into paper or withthe turns fuelgas gasturbine. in a combustion The shaft chamber. of the gasIt is can be milled usedresults timber to provide steam in a large and Energy amount of bark then burnt turbine and the hot is connected to agases create generator thrust which forwood and , This reduces which can transportation be burnt in acost.

9 Boiler that turnselectricity. generates the gas turbine shaft. The gas toNew create Zealand hasmanufacturing steam for vast forests of and/or exotic turbine shaft is connected to a generator electricity (non-native)generation. trees. The Thisprocessing is a good example of theseof Combined-cycle which generates gas turbine electricity. co-generation, and is discussed further trees into paper or milled timber, results in the in Combined-cycle gas turbines first combust the separate factsheet on co-generation. a large amount of bark and wood waste, Combined gas Cycle Gas in a gas turbine, Turbine which produces electricity which can be burnt in a boiler to create steam as above.

10 The exhaust heat is then passed Geothermal Combined cycle gas turbines combust the for manufacturing or electricity generation. through a boiler to create steam which turns a Geothermal Energy is the only renewable gas and then pass the exhaust heat through Thermal Energy available in the world. Using steam turbine. The steam turbine produces Geo- Thermal a boiler further to createand electricity, steam. The steamthe so improves turns overall geothermal Energy is a cleaner, greener way to a steam turbine, which efficiency of the operation. generates power. Geo- Thermal produce thermalenergy Energy , is the only renewable compared to using Both the gas turbine and the steam turbine fossil fuels, Energy Thermal and is not dependent available in the on the weather world.