Who Saved Watt?!

When does it make sense to not turn off your lights?

The cost effectiveness of when to turn off lights depends on the type of lights and the price of electricity. The type of light is important for several reasons. All types of lights have a nominal or rated operating life, which is the total number of hours that they will provide a specified level or amount of light. However, the operating life of all types of light bulbs is affected by how many times they are turned on and off. The more often they are switched on and off, the lower their operating life. The exact number of hours that switching lights on and off reduces the total operating life depends on the type of light and how many times it is switched on and off.

Incandescent Lighting

Incandescent lights (or bulbs) should be turned off whenever they are not needed. Nearly all types of incandescent light bulbs are fairly inexpensive to produce and are relatively inefficient. Only about 10%–15% of the electricity that incandescent lights consume results in light—the rest is turned into heat. Turning the light(s) off will keep a room cooler, an extra benefit in the summer. Therefore, the value of the energy saved by not having the lights on will be far greater than the cost of having to replace the bulb.

Fluorescent Lighting

The cost effectiveness of turning fluorescent lights off to conserve energy is a bit more complicated. For most areas of the United States, a general rule-of-thumb for when to turn off a fluorescent light is if you leave a room for more than 15 minutes, it is probably more cost effective to turn the light off. Or in other words, if you leave the room for only up to 15 minutes, it will generally be more cost effective to leave the light(s) on. In areas where electric rates are high and/or during peak demand periods, this period may be as low as 5 minutes.

Fluorescent lights are more expensive to buy, and their operating life is more affected by the number of times they are switched on and off, relative to incandescent lights. Therefore, it is a cost trade-off between saving energy and money by turning a light off “frequently” and having to replace the bulbs “more” frequently. This is because the reduction in usable lamp life due to frequent on/off switching will probably be greater than the benefit of extending the useful life of the bulb from reduced use. By frequent we mean turning the light off and on many times during the day.

It is a popularly held belief that fluorescent lights use a “lot” of energy to get started, and thus it is better not to turn them off for “short” periods. There is an increase in power demand when a light is switched on, and the exact amount of this increase depends on the type of ballast and lamp. The ballast provides an initial high voltage for starting the lamp and regulates the lamp current during operation. There are three basic types of ballasts: magnetic (of which there are energy-efficient and not so energy-efficient types), cathode-disconnect, and electronic. All types can operate two or more lamps simultaneously. There are three main methods that are used in a lamp’s ballast to start the lamp: preheat, rapid-start, and instant-start.

In any case, the relatively higher “inrush” current required lasts for half a cycle, or 1/120th of a second. The amount of electricity consumed to supply the inrush current is equal to a few seconds or less of normal light operation. Turning off fluorescent lights for more than 5 seconds will save more energy than will be consumed in turning them back on again. Therefore, the real issue is the value of the electricity saved by turning the light off relative to the cost of relamping a fixture. This in turn determines the shortest cost-effective period for turning off a fluorescent light.

The value of the energy saved by turning a fluorescent light (or array of lights) off depends on several factors. The price an electric utility charges its customers depends on the customer “classes,” which are typically residential, commercial, and industrial. There can be different rate schedules within each class. Some utilities may charge different rates for electricity consumption during different times of the day. It generally costs more for utilities to generate power during certain periods of high demand or consumption, called peaks. Some utilities can charge commercial and industrial customers more per kilowatt-hour (kWh) during peak periods than for consumption off-peak. Some utilities may also charge a base rate for a certain level of consumption and higher rates for increasing blocks of consumption. Often a utility adds miscellaneous service charges, a base charge, and/or taxes per billing period that could be averaged per kWh consumed, if these are not already factored into the rate.

Energy Savings

To calculate the exact value of energy savings by turning a light off, you need to first determine how much energy the light(s) consume when on. Every bulb has a Watt rating printed on it. For example, if the rating is 40 watts, and the bulb is on for one hour, it will consume 0.04 kWh, or if it is off for one hour, you will be saving 0.04 kWh. (Note that many fluorescent fixtures have two or more bulbs. Also, one switch may control several fixtures—an “array.” Add the savings for each fixture to determine the total energy savings.)

Then you need to find out what you are paying for electricity per kWh (in general and during peak periods). You will need to look over your electricity bills and see what the utility charges per kWh. Multiply the rate per kWh by the amount of electricity saved, and this will give you the value of the savings. Continuing with the example above, let us say that your electric rate is 10 cents per kWh. The value of the energy savings would then be 0.4 cents ($ 0.004). The value of the savings will increase the higher the watt rating of the bulb, the greater the number of bulbs controlled by a single switch, and the higher the rate per kWh.

The most cost-effective length of time that a light (or array of lights) can be turned off before the value of the savings exceeds the cost of having to replace bulbs (due to their shortened operating life) will depend on the type and model of bulb and ballast. The cost of replacing a bulb (or ballast) depends on the cost of the bulb and the cost of labor to do it.

Lighting manufacturers should be able to supply information on the duty cycle of their products. In general, the more energy-efficient a bulb/light is, the longer you can keep a light on before it is cost effective to turn it off.

Reprinted from http://www.eere.energy.gov/consumer/your_home/lighting_daylighting/index.cfm/mytopic=12280
EERE copyright: “Materials on the EERE Web site are in the public domain. EERE requests that it be acknowledged as the source in any subsequent use of its information.”
See http://www1.eere.energy.gov/webpolicies/ for more information on copyright

So, you want to get 100 miles per gallon of gasoline?  Just buy one of these bad boys…

Sleek, futuristic looking, highly efficient, and insanely expensive:

http://www.aptera.com/

Alternatively, you can look to the Japanese who were pursuing efficient engines before it was vogue.  As a result, they’ve got years of a headstart on American automakers who wrongly believed that bigger SUVs were better.  The Japanese “minicars” get 47 miles per gallon!

http://www.msnbc.msn.com/id/20000407/

Not to be outdone, General Motors is looking to introduce mini cars to the American market.  These get up to 50 mpg:

http://www.msnbc.msn.com/id/17878603/

Last but certainly not least on our mini car parade is the official “Mini”, as in, that’s the brand name, the Mini Cooper.  These little cars get up to 35 mpg on the highway:

http://www.automotive.com/2007/12/mini/cooper/specifications/index.html

That’s what this article in the Wall Street Journal suggests.

For a long time, it has been widely believed that daylight-savings time would reduce energy use.  More sunlight, less lighting costs, or so the theory goes.  Up until two years ago, a minority of Indiana’s counties participated in daylight-savings time.  But in 2006 the state legislature mandated the entire state would follow daylight-savings time.  This scenario provides the kind of data any Freakonomics-type economist dreams of.

What are the findings?

Indiana households spent $8.6 million extra in electricity bills.  The researchers concluded that the reduced cost of lighting in afternoons during daylight-savings time is more than offset by higher cooling costs on hot afternoons and heating costs on cool mornings.

According to the WSJ article, a 1975 study by the Department of Transportation showed that daylight-savings time reduced demand for electricity by 1% in March and April.  But a 1976 report by the National Bureau of Standards found no significant energy savings.

I find this data interesting, so I thought I’d check the data provided the Energy Information Administration.  The EIA data shows 2,769 kWh (central air conditioners) or 950 kWh (room air conditioners) by 57.5 and 23.3 million households, respectively.  That’s 80 million households with AC.  By contrast, the average household consumed approximately 940 kWh of electricity for lighting.

So, 107 million households burning 940 kWh for lighting equals roughly 100 billion kWh.  80 million households with AC, on the other hand, consume 183 billion kWh of electricity!  Indiana’s $8.6 million in additional electricity usage equates to about 78 million kWh or enough to power 7,300 more homes.

I don’t think this is the economy of candles Ben Franklin envisioned when he suggested waking Parisians earlier in the day to enjoy more natural sunlight.

Here are step-by-step instructions for installing an insulation blanket on an electric storage water heater. If the insulation blanket you’ve purchased comes with instructions, read and follow those.

1. Cut the tank top insulation to fit around the piping in the top of the tank. Tape the cut section
   closed after the top has been installed.
2. Fold the corners of the tank top insulation down and tape to the sides of the tank.
3. Position the insulating blanket around the circumference of the tank. For ease of installation,
   position the blanket so that the ends do not come together over the access panels in the side of the
   tank. Some tanks have only one access panel.
4. Secure the blanket in place with the belts provided. Position the belts so they do not go over
   the access panels. Belts should fit snugly over the blanket but not compress it more
   than 15%–20% of its thickness. The installation is easier with two people. If working alone, use
   tape to hold the blanket to the top until you get the belts into position.
5. If your water heater has the temperature/pressure relief valve and the overflow pipe on the side
   of the tank instead of on the top, install the blanket so these items are outside of the blanket.
   Depending on the piping arrangement and location, you may need to compress (or even cut) the
   blanket.
6. Locate the four corners of the access panel(s). Make an x-shaped cut in the insulating blanket
   from corner to corner of each access panel.
7. Fold the triangular flaps produced by the cuts underneath the insulating blanket.
   Repeat steps 6 and 7 for the rating/instruction plate.

Note: The blanket must not be installed on a leaking tank. If your tank leaks, you need a new water heater.

Don’t set the thermostat above 130ºF. The wiring may overheat.

Reprinted from http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=13080
EERE copyright: “Materials on the EERE Web site are in the public domain. EERE requests that it be acknowledged as the source in any subsequent use of its information.”
See http://www1.eere.energy.gov/webpolicies/ for more information on copyright

I drive a 13 mile (one-way) trip to work 5 days a week. Most of those are on a looong stretch of road without traffic lights and a 55mph speed limit. My little Toyota hums along, getting ~34 miles per gallon. In this day of $3+ for a gallon of gas, I’m glad I chose efficiency when I bought my car years ago. SUVs were all the rage.

I cannot understand why people want to buy ridiculously huge trucks that get 8 mpg. Fashion? Please. Fashion is more fickle than Paris Hilton. Still, where I live, there are people who want trucks just to have a truck.

I’d think the image above was a joke if I didn’t live in South Carolina:

This is a stereotype that certainly does not reflect the masses, but there’s still a kernel of truth in there. And the parking lot of the local supermarket is crowded with rows and rows of SUVs that aren’t really needed, they were just fashionable.

I think the pendulum is swinging in the other direction now. With gas prices continuing to rise, I believe people are going to change their buying patterns towards one that values efficiency and conservation. It’s smart. Buying cars or light bulbs or any other product for efficiency and conservation is better for your wallet and your environment.

What do you do when you’ve got millions of dollars in the bank and you really believe in being green? You buy a rainforest, naturally!

Johan Eliasch, 43, an English businessman, bought over 400,000 acres in the heart of the Amazon jungle. He bought the land from a timber company to proctect the plants and wildlife, and he’s invited scientists to come do research in his bit of the Amazon.

What I find interesting is his role as Deputy Treasurer of Britain’s Conservative party. Imagine that, a political conservative who actually wants to conserve things! This is not, on the face of things, the state of affairs in the U.S., unfortunately.

To be fair, there are some political conservatives who are also conservation minded. Governor Mark Sanford of South Carolina, for example, is a Republican with a sound environmental record. I’m certain there are others like him, but the vocal minority of political conservatives in the U.S. drown out their moderate brethren. What we hear is “guns, God, and gays” as being important to the conservative base, but this is not a fair representation of the entire political landscape. It just happens to be the loudest.

One is stodgy and ancient technology. The other is sleek and efficient. One is yesterday’s news. The other is at the center of a revolution solving many of the challenges we face. Climbing energy consumption, rising gasoline costs and electric bills, greenhouse gases, and dependence on foreign oil.

The compact flourescent light bulb (CFL for short) uses just 25% of the energy of the old incandescent light bulb. In America alone, we consume over 100 billion kilowatt hours (kWh) on lighting! At an average cost of $0.11 per kWh, that’s over $11 billion!

Consider this: If all of America’s 107 million households swapped just one 60 watt incandescent bulb that runs for 4 hours a day for a CFL, we would save 19.26 billion watts of electricity. How can that be? A 60 watt equivalent CFL only uses 15 watts of electricity. Do the math. It adds up fast, and it’s all money in your pocket. Compact flourescent light bulbs will save you money on your electricty bill and reduce your average energy consumption.  It’s good for your environment, too.

The new thing	Yesterday’s has-been