Ask an Expert


Have you ever wondered whether cars could run on cow manure? Or what kind of a difference it makes to use compact fluorescent bulbs? Now you can get answers to these and all your energy-related questions. Just Ask an Expert!

The Expert answers new questions regularly, so check back to see if YOUR
question is up!

Click here to ask a new question

Click on a question below to see the answer:

NEW! How much more energy efficient are triple-pane windows compared to dual-pane windows?

Answer: The energy efficiency of any building material is measured by how fast it transmits heat. This measurement is expressed as a “U-factor”—the lower the U-factor, the more energy-efficient the material. Modern double-pane windows have U-factors of about 0.30. Triple-pane windows can cut that by as much as half, for a U-factor as low as 0.15. [Reference:]

What is energy?

Answer: Energy is defined as the ability to change or move matter, or the ability to do work. Here are the different forms that energy can take:

  • Chemical energy is released by chemical reactions. These include the digestion of food or the burning of fuels such as natural gas.
  • Radiant energy can move through empty space. The heat and light given off by the sun are forms of radiant energy.
  • Mechanical energy moves objects from place to place. You use mechanical energy when you kick a ball or pedal your bicycle.
  • Electrical energy comes from the electrons within atoms. It can be created at a power plant or inside a battery. Lightning and static electricity are also forms of electrical energy.
  • Nuclear energy is contained in the nucleus at the center of an atom and can be released when nuclei are split apart or combined. Nuclear energy can be used to make electricity.

Why is energy created?

Answer: Humans have learned how to harness the energy in our environment and put it to use, but we don’t actually create energy, it’s just there! One of the basic laws of energy is that the total amount of it in the universe is constant, so energy cannot be created or destroyed. However, energy can be transformed, or changed, from one form to another. For example, we burn wood, coal, and natural gas to release their chemical energy as heat. We also generate electricity from various sources, including the movement of the wind, moving water, and sunlight. You can learn more about some of these sources by playing the Eco-Racer game on this website.

What kind of a difference does it really make to replace a regular light bulb with an energy-saving one?


  • LEDs use 75% less energy than standard incandescent light bulbs.
  • LEDs can save over $80 in energy costs over the lifetime of the bulb.
  • LEDs last up to 25 times longer than standard incandescent light bulbs.
  • On average, lighting accounts for 12% of a home's electricity use.

How much is the average heating and cooling bill for the state of Iowa? What is the average natural gas bill for the state of Iowa?

Answer: There are far too many variations in home size and heating and cooling patterns to provide a meaningful average heating and cooling bill or natural gas bill for the state of Iowa. But I can tell you that the average family in Iowa can spend over half of its annual household energy bills on heating and cooling! You can learn how to save energy on heating, cooling, water heating, lighting, and other home energy uses on this website. Start by playing the Stop the Guzzler game and doing the Home Energy Inspection with your family.

The appliances that use the most electricity are an electric space heater, electric air conditioner, electric water heater, electric clothes dryer, and possibly also your refrigerator.

Does leaving the lights on really use a lot of electricity? What appliance uses the most?

Answer: Compared to the bigger energy guzzlers like heating and cooling, water heating, and clothes drying, leaving lights on doesn’t technically use a lot of energy. Lighting represents only about 10% of home energy use. However, in the bigger picture, leaving lights on when they are not being used does waste electricity, and it’s important to try to save electricity in every way we can. So turning out lights is still a good habit to get into. And if you swap out your regular incandescent light bulbs with CFLs (compact fluorescent lights) or LEDs (light-emitting diodes), both of which use far less energy and last a lot longer than regular light bulbs, you will notice obvious savings in energy and cost. Replacing five incandescent bulbs with ENERGY STAR qualified light bulbs will save more than $150 in electricity costs over their lifetime. And, an LED bulb can last 25 times longer than a standard incandescent bulb.

The appliances that use the most electricity are an electric space heater, electric air conditioner, electric water heater, electric clothes dryer, and possibly also your refrigerator.

What are the five steps of basic transmission and distribution?

Answer: Visit our website to view virtual plant tours and see the phases of energy production from start to finish.

What organization in the world uses the most energy?

Answer: There is no worldwide, publicly available data on energy usage that would include all organizations. But according to the International Energy Association, among the four sectors of residential, commercial, industrial, and transportation, the industrial sector uses the greatest amount of energy, by a significant amount. The industrial sector consists of all facilities and equipment used for producing, processing, or assembling goods.

Does it use energy to leave a charger plugged into an outlet without a charging device connected to it?

Answer: Chargers are known as “energy vampires,” because they draw a lot of energy by being plugged in when items like cellphones or iPods are already charged or not even connected to them. In fact, only 5 percent of the power drawn by a cellphone charger is used to charge the device. The other 95 percent is wasted when it is left plugged into the wall! To stop this energy waste, get yourself (and your family) in the habit of unplugging all chargers when not in use.