Here are some common energy myths and the facts that debunk them. Click on a myth to learn the facts!
Myth: Turning fluorescent lights off when you leave a room does not save energy and shortens the life of the lamps.
Fact: Fluorescent lights use slightly more energy on start-up, but the light needs to be off for only about a second to make up for that surge. The only real issue is whether turning the light off and on frequently shortens the life of the lamp. Technically, turning the lamp off and on does shorten its life in terms of burning hours, but this will not likely cause you to replace the bulb more often than if the light was on 24/7.
A light that is left on 24/7 will have a longer burn time than one that is turned off when not needed. But, because the light is being turned off, the burn time is spread out over a longer period, which means that the replacement time is greatly extended. The actual break-even point depends on the cost of the lamp and labor to replace it (typically 5 to 15 minutes) and the local electricity costs.
A good guideline for fluorescent lighting is: Unless you're switching the lights on and off every few minutes, it is generally cost-effective to turn the lights off whenever you leave the room. In rooms where lights are on occupancy sensors or are being switched off frequently, install programmed-start ballasts to increase lamp life. Programmed-start, or "soft-start," ballasts cause less shock to the electrodes in the lamps than the standard instant-start ballasts and can double the number of starts a lamp can tolerate.
- Lights Out Q&A - Energy Experts
- Business Energy Use - Touchstone Energy
- Energy Myth Busters - Frederick Community College
Myth: Computer screen savers save energy.
Fact: Screen savers were not designed to save energy; they were designed to prevent "screen burn," a problem monitors used to have when fixed images were left on the screen for too long. Newer monitors don't have that problem, but screen savers are still widely used. Because the screen saver is actually a file your computer is running, it can use up more energy than it saves. Instead, set your computer to go into sleep mode after 10 or 15 minutes, and set your monitor to turn off in the same time period. Source
Myth: A computer on a network needs to be kept on 24/7 for backups and updates.
Fact: Newer network operating systems provide Wake on LAN (WoL) capability so computers can be "woken up" during the night for backups and updates, turned off again, then turned on in the morning to be ready for the user. Software is available to help facilitate this policy. Some programs also track energy use and energy saved by turning the equipment off.
Myth: I should run my HVAC 24/7 to avoid an increased demand charge from the "spike" that occurs when the equipment comes on.
Fact: Turning on HVAC equipment will cause a power spike that lasts only fractions of a second – not long enough to have a noticeable impact on demand charges. Utilities base demand charges on the average power used in a facility during some longer interval, usually 15 minutes. The spike from turning on HVAC equipment simply doesn't last long enough to significantly affect this average.
Not only are there no significant demand savings from running HVAC equipment continuously, but there are significant downsides. Energy use will be much greater and equipment life can be considerably shortened because the equipment will be running for longer periods.
Setting back the thermostat at night so it stays warmer inside in summer and cooler inside in winter – giving your HVAC equipment a little break – will reduce utility bills.
If you have heat pumps, the situation is a bit more complex. If the heat pump has its own thermostat, make sure to use a smart programmable thermostat designed to work with heat pumps, which will ramp up the temperature more slowly to avoid activating the electric resistance backup heaters, which are only about a third as efficient as the heat pump. The energy saved by reduced operation at night will more than make up for the extra energy used to bring it to temperature in the morning. In fact, bringing the building up to temperature too early can be wasteful.
Myth: Using soft-start equipment can cut demand charges
Fact: The use of soft-start equipment can lead to savings in equipment maintenance costs, but it won't reduce the demand charge on your electricity bill. When a motor starts up, it draws a lot of current. This "inrush current" is often five to six times the motor's full-load running current. All this current creates heat in the motor windings, and heat will kill a motor over time.
As their name implies, soft-starters ramp up the voltage applied to motor terminals over time, thereby limiting the inrush current and power, which significantly reduces heat buildup. By doing so, soft-starters can extend motor lifetimes – particularly for motors that are stopped and started frequently. In fact, with a soft-starter installed, you can turn a motor on and off much more frequently without worrying about damaging the windings.
If your motor application involves an intermittent load, you may be able to save money by installing a soft-starter and shutting the motor down in between loads rather than leaving it running continuously.
But if inrush current and power are reduced, why can't soft-starters reduce demand charges? The answer has to do with how demand charge is typically calculated. The meter at your facility measures the average power you consume over each 15-minute period, and your demand charge is based on the maximum value of that average demand during your billing cycle. In contrast, a soft-starter affects a motor's power draw over the course of just a few seconds. The reduction of the motor's power draw over that short period is insignificant in comparison to the time over which the demand charge is calculated. So although the soft starter has a substantial effect on instantaneous power demand, it has no noticeable effect on your demand charge. Source
Myth: I need to turn the temperature up on the heating system very early in the morning in order to get the building up to temperature in time for the occupants.
Fact: Newer control systems may have "smart start-up" capability that learns the optimal time to come on so the building reaches setpoint temperature at the desired occupancy time. This takes into consideration the indoor and outdoor temperatures (for example, it needs to start ramping up earlier on a frosty morning). If your system has this capability, use it. If not, take the time to monitor your system and find out how early you really need to turn it back on to reach setpoint on time.
Most buildings take about two hours to reach setpoint. If you need to have it reach setpoint by 7 a.m., turn the heat or cooling on at 5 a.m. If you are not confident that will be adequate, consider programming in an interim period. For example, if you have the building temperature set back to 60° F at night and want it to reach 68° by 7 a.m. but you are not sure it will heat up in two hours, you could set it come on at 4 a.m. to bring the temperature up to 65°, then raise the setpoint to 68° at 6 a.m. As you try different scenarios, track the temperatures to see how the building actually performs.
In the summer, if the building is not cooling down to setpoint by morning startup, consider implementing a "night purge," which involves bringing in large amounts of cool outside air through an air-side economizer. For ideas on how to implement this, see the ASHRAE factsheet "GreenTip #1: Night Precooling"
Sometimes the start-up of multiple HVAC units is staggered to reduce the peak for the day. If the equipment is accurately sized so it runs at full load during peak conditions, then avoiding the start-up peak won't provide any benefit during peak months, but it may during the rest of the year. Source
Myth: Because of government intervention, we can no longer purchase incandescent and T12 fluorescent lamps.
Fact: It's true that because of the Energy Independence and Security Act of 2007 (EISA 2007), as of Jan. 1, 2012, companies were no longer allowed to manufacture or import the standard efficiency 100 watt incandescent light bulbs (or "lamps"). However, it is also true that:
- Many of these lamps are still available on shelves and in warehouses and can still be sold as long as supplies last.
- Colored lamps and specialty lamps such as rough service lamps, heat lamps, black lights, and shatter-resistant lamps will still be available.
- High-efficiency incandescent lamps made to replace the 100 watt lamps that use only 72 watts will continue to be available. Currently, they are much more expensive than the standard-efficiency incandescent lamps they replace – on the order of $2 to $5 per lamp. However, not only do they save energy, but they last two to three times as long as the traditional lamps, making them potentially more economical than the originals. EISA 2007 does not yet affect reflector lamps, such as flood or spot lights.
- Other wattages of incandescent lamps are still available. The plan is for 75 watt lamps to be phased out as of Jan. 1, 2013, replaced by 53 watt lamps. Production of the more common 60 watt lamps and 40 watt lamps will continue until Jan. 1, 2014. After this date, the 60 watt lamps will be replaced by 43 watt lamps, and the 40 watt lamps will be replaced by 29 watt lamps.
For those who still have incandescent lamps in service, it is time to start planning a conversion to compact fluorescent lamps (CFLs), LEDs, or the new high-efficiency incandescent lamps.
Changes in fluorescent lamp availability
The manufacture of magnetic ballasts for general-purpose lighting fixtures with "energysaving" T12s has already ended as per the Energy Policy Act of 2005. This act specifies that September 30, 2009 was the last date manufacturers could sell the ballasts to U.S. fixture manufacturers and as of June 30, 2010, manufacturing of replacement ballasts must cease. Keep in mind that the law pertains to efficiency standards rather than specific technologies, but the net effect is that the magnetic ballasts are too inefficient to meet the standards in most cases.
The good news is energy savings average 40 percent when converting from T12 to highperformance T8 lamps, and savings are even higher if controls are implemented that perform better than current operations. Lighting quality also improves. When changing from T12s to T8s, be sure to change the ballast to a compatible high-performance model at the same time.
Links to the EISA 2007 can be found on the EERE Appliances and Commercial Equipment Standards website
On July 14, 2012, most T12 and some of the non-high-performance models of T8 and T5 fluorescent lamps will no longer meet the lamp efficiency standards of the EISA 2007. You can learn more about this at this EERE website.
This factsheet, "Impact of Amended Energy Conservation Standards on General Service Fluorescent Lamps," should be helpful.
Myth: Since space heaters are 100 percent efficient, the most efficient way to keep occupants comfortable is to let each of them use their own space heaters.
Fact: One of the sayings in the energy business is "A watt is a watt is a watt." Electric heaters are essentially 100 percent efficient, meaning that the electricity supplied to the heater is totally converted to heat. What is hidden in that statement is that producing electricity from fossil fuels at a power plant and delivering it to your building is typically only about 35 percent efficient.
The heat in your building is probably provided by natural gas or by a heat pump. Natural gas heating is typically 80 to 90 percent efficient so, overall, it is much more efficient than electricity. More to the point, natural gas heat is usually much cheaper per delivered unit of heat (in British thermal units) than is electric heat. Likewise, heat pumps are two to three times as efficient as an electric heater, or effectively 200 to 300 percent efficient, because they do not actually produce heat, but move heat from outside to inside the building using the miracle of refrigeration technology.
To make sure your building occupants are comfortable, you need to set the temperature so few personal heaters are needed. If many of your occupants are using space heaters, evaluate the building to make sure that temperatures are constant and evenly distributed. If you can adjust setpoints or air distribution to make more occupants comfortable without using space heaters, you will most likely also be using less energy. In some cases, it may be worthwhile to rebalance the air distribution in the building.
The nice thing about space heaters is that even though they are more expensive to operate per Btu, they only need to heat a small area to provide extra heat to one person. So one person who prefers to have their space at 72 degrees can heat just their space without having to raise the building temperature to 72 degrees. Space heaters also make a lot of sense for occupants working during evenings or weekends. They can just heat their space, rather than turning on the HVAC system for the entire building.
The most effective space heaters are radiant heaters. Radiant heaters heat people and objects, not the air, so they can make you feel warmer with less heat output. However, they're not effective in all applications because it is necessary for the person who desires heat to be in the "line of sight" of the heater. In an office situation, however, most occupants will feel warm enough by heating their legs or feet with a space heater under their desk. Several models of leg or feet warmers are available, some of which operate as radiant heaters, and most are designed to be very safe. Some use as little as 100 watts of electricity. Consider these for your occupants who desire a bit more heat than their office mates.
Myth: Energy efficiency and energy conservation are the same thing.
Fact: It's true that the terms "energy efficiency" and "energy conservation" are often used interchangeably, but they do have slightly different meanings.
Energy conservation is the term we used in the 1970s during and after the 1973-74 oil crisis when saving energy became a national priority. Many of us turned down our thermostats and turned off our lights when asked to do so by President Carter. Those changes did save energy, but when the crisis was over and energy seemed abundant again, the term became unpopular and was associated with visions of shivering in the cold and dark.
But energy savings can also be accomplished by providing the same service more efficiently, which is what we mean by "energy efficiency." Advances in technology have increased the efficiency of appliances, light bulbs, car engines and electronics so you can use less energy to light your house, keep food cool or heat your house. Saving energy through enhanced energy efficiency often means not having to sacrifice anything. In fact, many energy-efficient solutions actually provide better service than the more wasteful alternatives. For instance, occupants are provided with better comfort and indoor air quality with higher performance HVAC systems.
Myth: I should not use compact fluorescent lamps (CFLs) because they can be dangerous and expensive to clean up if they break because of the mercury they contain.
Fact: One of the concerns that people who do not like CFLs like to focus on is that they contain mercury, which makes them hazardous. The phrase "contains mercury" sounds alarming, but there is actually very little risk posed by the tiny amount of mercury in CFLs, and the benefit to the environment of using them is huge. This also pertains to standard linear fluorescent lamps.
First off, the amount of mercury in the newer fluorescent lamps is much lower than it was in the past. A CFL contains 1.4 to 5 milligrams of mercury, or about 1/1000th of what is contained in a mercury thermometer. The most harmful and most difficult-to-control mercury pollution is what's in the air. The most common source of air-borne mercury is coal-burning power plants. Therefore, the BEST way to reduce mercury pollution is by saving electricity. Using a CFL saves MANY TIMES more mercury from going into the air than is contained in the lamp. Even if fluorescent lamps broke frequently, they would emit much less mercury into the air than they save in their lifetime because less coal is burned to produce the electricity needed to keeps the lights on.
As long as the lamps remain intact, there is no risk of contamination. The chance of breaking a lamp in an office setting is very small. But what if you do break one? Despite alarming stories you may have heard, cleaning up is a broken CFL lamp is straightforward. First, increase the ventilation in the room where the bulb broke by opening windows and doors. Then use index cards or other stiff paper to pick up the broken pieces of glass. Don't use your bare hands, and don't use a vacuum cleaner because this can disperse the mercury more widely. Once you've picked up the big pieces, use something sticky like duct tape to pick up smaller pieces. To be extra safe, stay out of the area for a few hours to let any remaining mercury disperse. Source
For more information about fluorescent lamps and cleanup, see "Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury"
Myth: Because of budget cuts, I cannot afford to make the capital improvements I need to make to save real energy.
Fact: If you have an energy efficiency project in mind that you think would save your agency money, but have assumed that you would probably not be able to get the project approved because of budget cuts that, think again. If your project can save enough energy to pay for the cost of the project in a reasonable amount of time, you can probably find a way to finance it. If you work with a state agency, local government, or school district, the Washington State Department of Enterprise Services (DES) Energy Program is ready to help. They have contracted with several Energy Services Companies (ESCOs) around the state to provide energy services and can help you with contracting, managing and financing energy efficiency projects. In some cases, a budget-neutral project can be put together within the operating budget that is currently used for paying the utility bills.
Even if you do not have a project in mind, the ESCO can perform an audit at your facility for no charge to help identify energy efficiency projects in your facility that can be financed in this way.
Advantages of the DES Energy Savings Performance Contracting (ESPC) Program:
- Performance contracting is authorized in the Revised Code of Washington under Chapters 39.35A&C.
- DES maintains a list of pre-qualified ESCOs for you to select from.
- DES will assign an experienced energy engineer to help manage your project.
- You select the energy service company you wish to work with.
- Owners participate in equipment and subcontractor selection.
- DES can provide information on low-interest state treasurer financing.
- Verification of savings is documented in measurement and verification reports provided by the ESCO and reviewed by DES.
For more information, see the DES website or call Roger Wigfield at 360-407-9371.
For local governments and school districts, contact the Washington State Treasurer's office for information about the Local Option Capital Asset Lending (LOCAL) program.
Myth: Correcting power factor saves a significant amount of energy.
Fact: Power-factor correction can reduce energy use by a tiny amount, but unless your utility charges a penalty for lower power factor, improving it won't have a big impact on your electricity bill. The actual energy saved by correcting power factor is usually less than two percent of your total electric bill – seldom enough to justify installing capacitors to improve your power factor.
Utilities generally only charge power factor penalties to large commercial and industrial customers. How they charge for this varies from utility to utility. It may not be a line item on your bill, so understanding what you are being charged for low power factor will often require a thorough understanding of utility billing. In most cases, if you do not have a separate demand charge, you probably are not being charged for low power factor.
To find out the power factor charge, look for a demand charge in kVA, a separate charge for kVARh (which will require a separate kVARh meter at your facility), or an adjustment or surcharge added to your demand charge. For more information on how utilities charge for low power factor and how to calculate how much you are paying for it, contact your local utility and see Chapter 2 of Energy Management for Motor Driven Systems.
If you are being charged a power factor penalty and your power factor is below 85 percent, it may be worth correcting your power factor. More information on how power factor works and how to correct it
Besides saving on power factor penalties, correcting power factor can, in some cases, increase the carrying capacity of a circuit because it will reduce the current on the line, and line sizes, transformers, and breakers are sized according to current. This "released capacity" may be particularly valuable if it allows a customer to delay or avoid the purchase of additional circuit capacity.
Beware of "power factor correction devices." Power factor is generally corrected by installing power capacitors, which can be supplied by reputable companies and installed by a qualified electrician.
- Beware of anyone trying to sell you a device that you can simply install on your system and claims to save 5 to 30 percent of your total energy use. They often have a demonstration kit that involves a circuit with a small unloaded motor, a switch and their device. When they flip the switch, you can see that the current is reduced. This does not mean it is saving energy.
- Beware of any device that is supposed to save you energy by any mechanism that seems mysterious. These are most commonly referred to as power conditioning devices or something similar. If the advertisements say that the devices are "recycling energy" or "cleaning up your power," ask your utility or other experienced professionals you trust before investing in these devices. They may provide valuable services such as harmonic filtering or surge suppression, but only get these if you need them.
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