Dr. Brad Christensen Berea College Calculating the "Green" of Going Green

Purpose of this presentation To present mathematics as a tool Not to discourage or debate the value of “Green” technology

Usually Calculations involve Payback Cost per unit using traditional means Cost per unit using “green” technology How long before the savings equal the difference in purchase price

Southwest Windpower 900 Watt Whisper 100 Wind Generator Use wind to generate power and run your appliances and electronics. Perfect solution for cottages, 12 volt battery charging, back up power, remote power, and more. Unit has a cast aluminum frame and double sealed ball bearings. Maintenance Free only three moving parts. Max power up to 900 Watts or 60 Amps in ideal conditions. Made in USA Cast aluminum frame Double sealed ball Bearings Easy Installation Maintenance Free - Only 3 moving parts Carbon Fiber Composite Blades Ensure Low Wind Noise! Max Power up to 900 Watts or 60 Amps in Ideal Conditions Eco Options : Eco Options MFG Brand Name : Southwest Windpower MFG Model # : Whisper100 MFG Part # : $2,495.00/EA-Each Accessory/Part Type : Wind Generator Amperage : 40 A Assembled Depth (In Inches) : 51 in Assembled Height (In Inches) : 20 in Assembled Weight (In LBS) : 74 lb Assembled Width (In Inches) : 13 in Wattage : 900 W

Payback at max output

Reality 100 kWh per month with average 12 mph wind 100 kWh x.o844 = $8.44 month $2495 / $8.44 = months / 12 = 24.6 years

Whisper 500 Wind Generator 3000 watts max output at 24 mph wind 3 kw x 24 hrs = 72 kWh per day x.0844 = $6.07/ day $ / 6.07 = 1565 days / 365 = 4.28 years 500 kWh per month at 12 mph average wind speed 500 x.0844 = $42.20 month $ / 42.2 = 225 months 225 / 12 = years 30,000 watt turbine on Ebay for $50, times more power, 5 times more money

Average Wind in Charlotte- 7.4 mph

Sharp® 175 Watt Multi Purpose Solar Panel with Sharp® Module $997.97/EA-Each

Solar Panel Payback

Sunshine

Reality of Photo-voltaic Charlotte at 5 hrs of sunshine per day 175 watts / 1000 =.175 kw x 5 hrs. x.0844 =.o7 day $997 /.07 = 14, 242 days / 365 = 39 years

Why do we do it? Save the planet Reduce dependence on foreign oil Feel that it is the right thing to do Tax breaks Tax Credit Usually means you can subtract $______from the taxes you pay Tax Deduction Usually means you can reduce the amount of income you are taxed on by $________ Subsidies Government aid for production

North Carolina 0F&re=1&ee=1 Incentive Type: Personal Tax Credit Eligible Renewable/Other Technologies: Passive Solar Space Heat, Solar Water Heat, Solar Space Heat, Solar Thermal Electric, Solar Thermal Process Heat, Photovoltaics, Landfill Gas, Wind, Biomass, Hydroelectric, Geothermal Heat Pumps, Spent pulping liquor, Solar Pool Heating, Daylighting, Anaerobic Digestion, Ethanol, Methanol, Biodiesel Applicable Sectors: Commercial, Residential, Multi-Family Residential Amount: 35% Maximum Incentive: $1,400 - $10,500 (varies by technology); $2.5 million for commercial applications

Tax Credit for wind generators in NC “A maximum of $10,500 per installation for photovoltaic systems (also known as PV systems or solar-electric systems), wind-energy systems or certain other renewable-energy systems for residential use; “ Spend $10,000 on a Whisper 500 Wind Turbine Get $3500 off your State income taxes NC residents pay $ first 750 kWh used Wind generator cost $6500, produces about 100 kWh per month or $11.14, payback in 48 years

2009 Toyota Camry Miles Per Gallon (city/highway) 22/32 Style: 4dr Sedan (2.4L 4cyl 5M) $18,186

2009 Toyota Camry Hybrid Miles Per Gallon (city/highway) 32/34 Style: 4dr Sedan (2.4L 4cyl gas/electric hybrid CVT) $ 24,213

Break even point

Calculations

2010 Ford Fusion S Sedan $19,270 Fuel Economy: 22 MPG city / 31 MPG highway

2010 Ford Fusion Hybrid Sedan Fuel Economy: 41 MPG city / 36 MPG highway $27,270

Break even point

2010 Toyota Highlander EPA Mileage Estimates (city/highway) 17/23 $29,200

2010 Toyota Highlander Hybrid Style: 4dr SUV AWD (3.3L 6cyl gas/electric hybrid CVT ) $34,900 EPA Mileage Estimates (city/highway) 27/25

Break even point

Notes on electricity 1 horsepower = 746 watts1 Kw = 1.3 hp 1 gallon of gasoline is about 10 kWh 10 kWh x.0844 = $.84 per gallon Energy Density- energy in a pound Gasoline5.75 kWh per pound Batteries1 kWh per 15 pounds Gasoline engines 25% to 33% efficient Electric motors 90% to 95% efficient

Nissan Electric nissans-electric-car-5991/ $20,000 to $33,000- so lets say……$28,500 Possible $7,500 tax credit for the first 200,000 buyers $0.90 to recharge at $0.14 kWh $.070 for NC residents 15,000 miles- $600 $0.04 per mile 15,000 for $466 in NC or $0.031 per mile

Tesla Roadster 55 kWh for full charge 244 mile range 55 x.0844 = $4.64 $4.64 / 244 = $0.019 per mile $100,000

Dodge Viper $91,000 Viper 0-60 in 4 seconds Tesla 0-60 in 3.9 seconds 22 mpg at $2.50 $0.11 per mile Tesla$0.019 per mile

Will we do it by choice? Cars of the 1950s 13 grams per mile hydrocarbons 3.6 grams per mile nitrogen oxides 87 grams per mile carbon monoxide Clean Air Act 1970….became reality in grams per mile hydrocarbons 1 grams per mile nitrogen oxides 3.4 grams per mile carbon monoxide

Results of Clean Air Act 1970 More expensive cars Pollution devices Catalytic converter Fuel injection Unleaded fuel more expensive than regular Eventually unleaded was regular Lower horsepower, reduced performance Lower compression ratio Less horsepower Smaller engines

Clean Air Act of 1970 Plus 40 years North Carolina has about 4 million cars Pre-Clean Air Act pollution rate 755,227,200,000 grams of hydrocarbons per year Post-Clean Air Act pollution rate 15,899,493,867 grams of hydrocarbons per year 1969 Pontiac GTO400 cid V-810 mpg 0-60 mph in 5.8 seconds 2008 Pontiac G83.6 liter (220 cid) 20 mpg 0-60 mph in 5.1 seconds

Ethanol howstuffworks.com 1 gallon of ethanol77,0000 BTU Requires 131,000 BTU to make and transport it David Pimental, Cornell University 1 BTU of fossil fuel to get 1.3 BTU of ethanol to market US National Renewable Energy Lab 11 acres of corn to power a car for 1 year 11 acres will feed 7 people $1.74 to produce a gallon of ethanol $0.95 to produce a gallon of gasoline $1 billion per year government subsidies

Bio-Diesel pounds of fuel from 1 acre of sunflowers 17,035 BTU per pound 7.6 pounds per gallon129,466 BTU per gallon Diesel fuel 19,494 BTU per pound 7.1 pounds per gallon138,407 BTU per gallon Make B100 Biodiesel for as Little as $1.00/gallon! (depending on crop) 100% Clean, 100% Renewable, 100% Affordable Fuel

Summary More often than not simple economics determines what we do and how we do it Alternatives are usually more expensive If forced, we come up with workable solutions Your students can use mathematics to analyze the feasibility of options

Dr. Brad Christensen Berea College Calculating the "Green" of Going Green