the green leaf inn is a net zero hotel thatrelies on and demonstrates 7 different energy systems. the cogeneration system or combined heat and power system will generate two useful forms of energy by burning a single fuel.this chp or cogen system will burn natural gas- while producing electricity and hot waterfor use on the property. electric power plants generate electricity, but discard all of theheat by-product that is created as waste. this valuable thermal energy is usually discharged into the surrounding environment through cooling towers and flue gas giving the power plantan overall energy efficiency rating of only 35%. a cogeneration system on the other handgenerates electricity but captures most of this thermal energy to use as steam or hotwater elsewhere. the overall fuel efficiency
rating of a cogen system can be up to 92%while sparing the environment and reducing energy expenses. the cogeneration unit at the green leaf innis a marathon ecopower microchp. the engine was built and assembled locally at marathonengine systems in east troy, wisconsin. the engine has the ability to run 5,000 continuoushours between scheduled maintenance visits. "this an eight and a half horse power pistondriven engine it's purpose is for making thermal energy and for making electrical energy in the ecopower microchip unit. the engine- can be used in hotels, multi-family apartment buildings, car washes, residences, swimming pools- anything thatwould need thermal energy. the unit is 93%
efficient. 68% percent of the unit is thermaland 25% of the energy is electric." how does the chp system work? natural gas fuel enters the ecopower chp unit and is used in an internal combustion engine just likean automobile. the engine turns an electric generator in order to make electricity whichis used to power the hotel for lighting, hvac and pumps. the waste heat given off by theengine block is captured by circulating water around it -- like your car's engine. anotherheat exchanger system captures the waste heat from the gas exhaust created by burning thenatural gas. all of the waste heat is then used for theradiant floor heating or can be delivered through pipes to the thermal storage tank. for use at a later time.
"mike, now that we have the system here that will generate thermal energy and electrical energy. how do we actually integrate this in to thebuilding system so we can use that thermal energy?" "when the unit is running we are doing bothobviously at the same time. we are look at the vessel that we are putting all thethermal energy in to. so the unit is running. we have a pump and a mixing valve that iscontrolled by the computer system of the unit. that energy is now taken out of the unit.it' sent over to the thermal buffer tank where we store that energy here. wehave three sensors that are in to the tank. so we start to heat the tank up, and as weheat the tank up that stratification line will change and the sensors will determinehow much heat is in the tank. if the chp is
not making enough heat, then we will havethe complimentary boiler come on to give us a boost on the top of the tank and as we fillthat up- we'll shut that boiler off and then continue to operate off the chp." "mike, is this the potable or non-potable water in here?" "this is a non-potable water in this tank.this would be the boiler water and the water would come out of this tank and be sent tothe indirect hot water heater or whatever type heating system we are going in to." cogeneration plays a vital role in creatingonsite hot water and electricity for the green leaf inn. due to green technology like this,the green leaf inn will be the first net-zero
hotel in north america. net zero because itwill produce more energy onsite then the inn consumes on annual basis. for more information, log on to www.greenbuildtv.com and click on the projects tab to follow the green leafinn and all our other green projects. interested in learning more about marathon ecopower microchp or any of the green products appearing on greenbuild tv? go to gbtv.com. click the green directorylink on the top of the page. the green directory is the place to learn about all our greenproducts.