Updated March 12, 2016

Energy Efficiency -- Fact Sheet  

Here is a collection of facts that I have compiled.  They are based off of my own measurements and the findings of other groups like the EPA and the Department of Energy.  It is amazing how the little things really do add up. 

  • Over 10% of your electric bill is from phantom power. 
  • A 1 watt reduction in phantom power results in an energy savings of $1.00 per year (at 11.4 cents/KWH). A 100 watt reduction will net you $100/year. 
  • A typical mono-crystalline solar installation generates 12 watts per square foot. 
  • Calculate your solar electric needs by taking your average monthly electric usage / 30 days / 4.2 (full sun hours). For example, for 1000KW-hr/month of usage, you would need = 7.2 kW of solar panels to cover 100% of your electrical needs. 
  • Insulating and air sealing your house will reduce your energy bills by 20%-50%. 
  • All other things being equal, because of changes in air density, automotive fuel efficiency will reduce 10% for every 50°F drop in air temperature. 
  • PV-nRT  Where:

    • P = Pressure
    • V = Volume 
    • n = number of moles
    • R = Universal Gas Constant
    • T = absolute temperature. (0°F = 459.7°R)
If you get 30mpg when it is 70 degrees outside, you will get only 27mpg when it is 20 degrees outside. 



  • Low tire pressure will reduce your fuel efficiency by 40% or more. Increasing tire pressure to near the max sidewall rated pressure increases fuel efficiency by 40% or more. 
  • Lower freeway speed increases fuel efficiency. Driving 65 vs. 75 increases fuel efficiency by over 25%. Driving 55 vs. 65 increases efficiency by over 15%. 
  • A 1% reduction in vehicle weight increases fuel efficiency 1% (rough rule of thumb). 
  • A solar array the size of a parking space will collect enough solar energy in a year to power an electric car 12,000 miles. 

  • There is no single efficiency improvement that I know of that can cut your energy bills by 90%. But there are several that will reduce them by 2%, 5% or 10%. If you implement 18 improvements that each save 5%, you will cut your energy bill by 90%. 
  • It takes 6 - 7.5 kWh of electricity to refine 1 gallon of gasoline.   That's the same amount of energy an EV takes to drive 24-30 miles. If we stopped refining gasoline and all drove electric cars instead, our world would still use the same amount of electricity only without the oil and gas. 
  • Over 57% of all air pollution in the Salt Lake valley is from motor vehicles.
  • A typical computer magnetic, mechanical hard drive draws about 10-12 watts. The “green” variety draw about 5-7 watts. Solid state drives draw 0.6 watts to 2.5 watts. 
  • Replacing a standard ATX power supply (in a PC) with an 80+ Gold supply will save enough energy to pay for the upgrade in 1 year.  
  • It takes more energy to run the clock display and buttons on the microwave oven all day than to cook something in the microwave oven for 2 1/2 minutes. 
  • There is no such thing as a Golden Goose, except for Geothermal/Ground loop Heat Pumps, solar panels, nuclear reactions and successful financial investments. So long as you don't kill them, these will always return more back to you than what you give them. 
  • For those in the US, find your home's CO2 emissions here. Pick your state to get an even more accurate number for your local electric utility's CO2 emissions. 
  • A foundation bump-out on a home will add about $20,000 to the total cost of the home. If you skip the foundation bump-out and include a huge solar array instead, you can have a net-zero home for the same cost as a regular home.