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Too Hot to Handle, Too Cold to Hold. How to save up to 40% on your energy bill. Your Appliance IQ. Where do you use your other 27%? What rooms of the house? What activities?. http://www.a1arefrigeration.com/appliances_main.jpg. How Much Does it Use?. How Much Are You Paying?.
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Too Hot to Handle, Too Cold to Hold How to save up to 40% on your energy bill
Your Appliance IQ • Where do you use your other 27%? • What rooms of the house? • What activities? http://www.a1arefrigeration.com/appliances_main.jpg
Single biggest source of personal energy use Heating: The Big One • 40% of personal energy use (more in WI) http://slices-of-life.com/wp-content/uploads/2011/10/house_heating.jpg
Some Like it Hot: How We Get Heat • Gas Heating • Electric Heating • Wood Stove • Geothermal http://fela2fela.files.wordpress.com/2012/03/calcifer.jpg
Electric Burn fuel to produce heat Heat water to make steam Use steam to run turbine Use turbine to power generator Make electricity Use resistor to make heat Gas vs Electric What's Hot What's Not? • Gas • Burn fuel to produce heat http://www.cheyennelight.com/images/gas2.jpg
Electric heat uses 2-3 times as much gas from plant to house. • How much more does it cost to use an electric heater? • Which is better, gas or electric? http://thomaspmbarnett.com/storage/natural_gas_flame_money_z.jpg?__SQUARESPACE_CACHEVERSION=1331816254251
Other Hydro Wind Tide Solar PV Ways to Make Electricity • Heat Engines • Coal plants • Gas plants • Nuclear plants • Solar thermal • Biomass http://1.bp.blogspot.com/_mtCwxRRYyt4/TUBT187mkSI/AAAAAAAAAAU/p3-MLQDfmIY/s1600/renewable+energy+overview.gif http://upload.wikimedia.org/wikipedia/en/thumb/a/a2/Heat_engine.png/300px-Heat_engine.png
Other Electric No fuel burned to create electricity, free resources Electricity can be converted to heat at 100% efficiency Take up a lot of space (square feet per megawatt) Heat Engines vs Other Electric Revisited • Heat Engines • Maximum efficiency limited by thermodynamics (physics) • Power plants are 30-50% efficient • What happens to the other half? • Waste heat! • Can we use the waste heat to produce more work?
Waste Heat 100 GJ/yr = 3.17 kW…like every person in WI had 3 hair dryers running 24/7 the whole year. http://www.stwing.upenn.edu/~salexa/Research-WasteHeat.htm
Heat Pumps and Geothermal Heat http://t2.gstatic.com/images?q=tbn:ANd9GcRBitbxhT9R3EbwtjHmCfnO7HJ1_xL3X0cM8ACX3q8inJxIM9BVTw • What is a heat pump? • Heat engine in reverse (same idea as a refrigerator) • Put work in to get heat flow
So How Do They Work? You need a “working fluid” to transport the energy where you want it to go. This must be pumped around. The work needed is proportional to the difference between the outside and inside temperatures. http://www.envirowarm.co.uk/img/heatpump.png
The Nitty Gritty on Heat Pumps As the temperatures get nearer, you need less and less work to get heating/cooling. Geothermal cooling is 75% more efficient than the refrigerator in your kitchen. http://3.bp.blogspot.com/-Jv2Hk3xoLX4/TdOiOZsDRgI/AAAAAAAABko/UetT6_RmBf8/s400/im-in-your-fridge-cat.cats.kitten.kitty.pic.picture.funny.lolcat.cute.fun.lovely.photo.images.jpg
What Does This Mean?Three Ways to Eliminate Paying For Space and Water Heating • Option 1 • Harnessing waste heat from power plants would more than meet the space/water heating needs of all the US (residential). • Can we do it? • Option 2 • Integrated renewables (solar/wind) provide “free” energy resources that can be converted completely to heat. • Option 3 • Geothermal heat pumps achieve the desired heat transfer with minimal work input. http://t0.gstatic.com/images?q=tbn:ANd9GcRY6ldjvFdbNv1yzHxQODUdh2Bl-FXF_Qo2nA4r9X3Ix27PEeqd
A Caveat: Quality of Energy If we can convert energy into work, it’s more useful (ie higher quality). The quality of thermal energy (heat) is proportional to how much higher its temperature is than the surroundings. Mechanical energy and electricity are the highest quality (convert into any form 100%). Are electricity and high energy density fuels the best way to heat our houses and water? http://www.stwing.upenn.edu/~salexa/Research/WasteHeat/WasteHeatMatrix.png
A Re-envisioned Power Grid “Figure 4 - Results from this study highlight the benefits of a alternate energy consumption paradigm where power is generated in a distributed fashion, maximizing waste heat recovery opportunities and reducing primary energy consumption” http://www.stwing.upenn.edu/~salexa/Research-WasteHeat.htm
A Final Thought Use the right quality energy for the job! http://www.rallydev.com/agileblog/wp-content/uploads/2011/11/quality-control.jpg
In Summary When it comes to conserving energy and saving money, there are a few key ideas. For “high” temperature applications, gas saves 67% on energy and cost. (Hotter than you want to touch). For space/water heating, we have an excess of waste heat from power plants and an abundance of geothermal heat. To fill in gaps and further reduce costs, integrated renewables (wind/solar) are a cure-all.