Frequently Asked Questions

Frequently Asked Questions

Frequently Asked Questions—Energy Conservation

Q: Is it more energy efficient to keep turning fluorescent lighting on and off all day or to just leave it on? Our office uses the room at least every 20 minutes during an 8-hour work day but no one is ever in there all day.

A: By leaving fluorescent lamps on you save the lamp life, but not energy costs. It’s a trade off between buying new fluorescent lamps which are generally pretty cheap and the cost of electricity to run the lamps all day for 20 minutes of actual use. This depends on your cost of electricity. Basically, we’ve found it more energy efficient to turn lights off when not in use. (For that type of room it might be cost effective to install an Occupancy Sensor unless people actually turn the lights off when they leave.)

Q: Is it more energy-efficient to let a light bulb burn for a short period of time, or to turn it off and then on again? I read once that the surge in power when a bulb is turned on is equal to letting the bulb burn for a while?

A: It is more energy efficient to turn the light off than to leave it on. Energy is measured with respect to time. The unit used to measure electrical energy is the kilowatt-hour or thousand-watt-hour, the amount of power or watts that you use in one hour. The momentary or millisecond or less surge of electricity required to start your light bulb will not impact your energy cost, but leaving it on all the time will. With the rising cost of energy, it’s probably a good idea to turn the lights out when you are not using it. (Not to mention the pollution impact, less energy use, less emissions from power plants.) Turning the lights on and off a lot will impact your lamp life, however. If you compare the number of bulb(s) you need to buy versus the cost to let the light burn all the time, it will still probably be cheaper to turn the lights off.

Q: What is the most energy-efficient thing to do with your computer at the end of the day? Turn it all off or just turn off the screen or leave it all on? I don't have an Energy Star computer.

A: Just like fluorescent lighting, explained above, turn off your computer in order to use less energy, especially if it does not have an energy-saving mode.

Q: What does a power inverter do, and what can I use one for?

A power inverter changes DC power from a battery into conventional AC power that you can use to operate all kinds of devices ... electric lights, kitchen appliances, microwaves, power tools, TVs, radios, computers, to name just a few. You just connect the inverter to a battery, and plug your AC devices into the inverter ... and you've got portable power ... whenever and wherever you need it.

The inverter draws its power from a 12 Volt battery (preferably deep-cycle), or several batteries wired in parallel. The battery will need to be recharged as the power is drawn out of it by the inverter. The battery can be recharged by running the automobile motor, or a gas generator, solar panels, or wind. Or you can use a battery charger plugged into an AC outlet to recharge the battery.

Using an Inverter for Emergency Home Backup Power

A very simple way to use an inverter for emergency power (such as during a power outage), is to use a car battery (with the vehicle running), and an extension cord running into the house, where you can then plug in your inverter and electrical appliances.