Optimizing Electricity

Our Experience

My peak energy improvement was upgrading my furnace. I expected to see lower gas bills, but I was pleasantly surprised by the additional electricity savings as well. The chart below illustrates my electricity usage (vertical axis) against average temperatures (horizontal axis) after installing a 95% efficient furnace in 2011. Today, we have the option to eliminate gas bills entirely—along with the risks of methane leaks and their associated health hazards—by switching to a heat pump, which is much more efficient than even a 95% efficient furnace. Your Heating, Ventilation, and Air Conditioning (HVAC) system represents your largest energy expense and offers the greatest potential for savings. Upgrading to efficient appliances as needed can significantly reduce your costs over time.

This graph shows that our electricity unexpectedly dropped one half with a new furnace - in addition to a drop in gas.
Figure: Changing to an efficient furnace may improve not only gas bills, but electricity bills

We use 100% clean energy through our electricity provider in Wisconsin and have installed solar panels on our Chicago home. This effectively reduces the greenhouse gas emissions from electricity for both homes to near zero or even less.

Your Choices

Action Choices and LinksCostNotes
Address Your Entire Electricity Bill: Solar or
Clean Subscription		Solar: $$,$$$
Subscription: $ to $$
New Appliances are Much More Energy Efficient$$$ to $$$$There are additional pages (links) for HVAC, water heating and cooking

Address Your Entire Electricity Bill: Solar or Clean Subscription

A quicker way to cut greenhouse gas emissions from electricity is to make all your electricity clean. This can be achieved by installing solar panels on your roof or purchasing clean energy from your provider. When choosing a clean energy option, you can offset half, most, or all of your greenhouse gases depending on your plan or subscription. Check with your provider about how your rates may change annually. Fuel cost increases for avoiding fossil fuels may be small or significant, depending on the provider. The clean energy should come from renewable sources such as solar, wind, or geothermal.

New Appliances are Much More Energy Efficient

Engineers have made remarkable progress in lowering electricity consumption over the past decades. Many modern appliances use just a tenth (1/10) of the electricity compared to older models. Upgrading to new appliances can save you a significant or sometimes modest amount of money and reduce your greenhouse gas footprint, depending on which appliance you replace. This page highlights the approximate electrical loads of older versus newer appliances, demonstrating that you can invest in a greener lifestyle.

If you decide to invest in energy-efficient appliances, the table below compares the energy consumption of typical home appliances (second column) with that of new, state-of-the-art models (third column). The far-right column shows potential savings in kilowatt hours (kWh) and equivalent greenhouse gas reductions, listed in metric tons (tonnes). The ranges in column three reflect the lowest and highest greenhouse gas values.

 Action Choices and Links% Avg. Energy Use per Home Traditional kWh with Older DevicesState-of-the-Art: EnergyStar ‘Most Efficient’
Source: U.S. www.energystar.gov		Improvement in GHG with More Efficient Device
Heating, ventilation and air conditioning46 to 47% total
10,200 to 23,400 kWh/year
In northern states:
29% heat 17% cooling		Heat pumps can replace furnace and central air conditioning, very efficiently.  EnergyStar Furnaces rate to 98 to 99% efficient for natural gas, propane gas. 
Water Heating14 to 21% (U.S. govt: 20%)
4860 to 5400 kWh/year		Estimated to use 70% less energy and to save $550/year for family of 4.
Heat pump water heater averages  1213 kWh per year		4668 to 6912 lbs GHG OR
2117 to 3135 kg GHG
= 2 to 3 tons GHG
Lighting8-12%
Lumens   Incand   Halogen
375            25              20
800            60              45
1600          100             90
CFL             LED
                      4
13-15         6-8
23-28       16-20 		1 100W Incandescent = 72 kWh/year. For full electricity impact, multiply by number of light bulbs and hours.
Incandescents last 1,200 hours. CFLs last 8000 hours each.
LEDs last 50,000 hours each.
LEDs are 25% more efficient than discontinued fluorescents; replace with T8 (1 inch) or T12 (1.5 inch) LED according to fluorescent diameter.
Refrigeration4-5%  
1200 to 1944 kWh/year      		For Bottom Freezer:
12.8 ft3: 295 to 386 kWh/yr
16.1 ft3: 355 to 438 kWh/yr
28 ft3: 595 kWh/yr
Top Freezer:
17.5 ft3: 333 to 448 kWh/yr
20 to 21 ft3: 371 to 477 kWh/yr
Side-by-Side: one product rated “Most Efficient”
27.4 ft3: 546 kWh/yr		Assumes 300 to 500 kWh/yr:
1152 to 1848 lbs GHG
or 523 to 838 kg GHG
= 0.5 to 0.8 ton GHG
Cooking3 to 4%
680 to 1440* kWh/year
* assumes 1 hr/day each: oven, stove		Induction: 187-190, 195 kWh/yr
Radiant: 195 kWh/yr
Coil: 195 kWh/yr		Assumes
190 to 195 kWh/yr:
627 to 1594 lbs GHG OR
284 to 723 kg GHG
=0.3 to 0.7 ton GHG
Electronics – Entertainment3%
660 kWh/year (assumes 5h TV/day and 6h gaming/week)		  
Clothes Washing/ Drying3 to 13%
Washer: 900 kWh          
Dryer 845 kWh		Front Load Washer:
4.5 to 5 ft3: 74 to 120 kWh/yr;
452 to 4900 gallons/yr
No Top Load Washers rated Most Efficient
5 to 5.7 ft3: 110 to 150 kWh/yr;
4700-6087 gallons/yr
Dryer:
4 ft3: 125-154 kWh/yr;
4.5 ft3: 217-245 kWh/yr;
7.8 ft3: 266-460 kWh/yr;		Washer assumes
75-150 kWh/yr:
960-1056 lbs GHG OR
425-479 kg GHG
Dryer assumes
125 to 460 kWh/yr:
493 to 922 lbs GHG OR
224 or 418 kg  GHG

=.65 to .9 ton GHG (for washer & dryer)
Room Air Conditioner800 kWh
Varies by size, age.		12,000 Btu: 592 to 600 kWh
10,000 Btu: 470 to 500 kWh
9000 Btu: 415 to 422 kWh
8000 Btu: 375 to 414 kWh		 
Dishwasher2%
600 kWh/year		Max Place Settings = 12
   225 kWh/yr;
  2.36 gallons/cycle
Max Place Settings = 16
210 to 225 kWh/yr;
3.2 gallons/cycle		Assumes 225 kWh: 557 lbs GHG
OR 253 kg GHG
=1/4 ton GHG
Computers1%Battery-operated laptops are more efficient than desk-tops; both are low in power. 
Gaming equipment has higher electricity requirements.		 
Table: Improved Greenhouse Gas and KiloWatt Hour Efficiency with New Electronic Devices

Units and Abbreviations: lbs is an abbreviation for pounds, Kg is an abbreviation for kilograms, both are units of measurement of weight. 

  • kWh = Kilowatt hour, a unit of measurement used by electricity providers to measure electrical use.   
  • Ton refers to a metric ton, or tonne. 
  • GHG = Greenhouse Gas.

The Energy Star ratings shown qualify as EnergyStar “Most Efficient”, except where noted.

Sources for Column 2:

If you want to calculate your existing device’s actual kilowatt hours (kWh), find the current level:

  • estimated on an attached EnergyStar sticker; or
  • measured with a kill-a-watt (for lower voltage/amp appliances); or
  • listed (embedded) on the appliance.

To calculate greenhouse gas savings = (Column 3 – Column 2) * 1.28 lbs CO2/kWh => lbs CO2.

References

References for this section and links includes:

  • Harley, Bruce (2012) Insulate and Weatherize for Energy Efficiency at Home. The Taunton Press, Newtown CT.
  • Amann, Jennifer Thorne, Wilson, Alex, and Ackerly, Katie (2012) Consumer Guide to Home Energy Savings, 10th edition. New Society Publishers, Gabriola Island, BC Canada.
  • Presentation: How to Save the Planet and Save Money Too, 27 January, 2025.