Who Saved Watt?!

The Economist (one of my favorite magazines) is running an article about AeroGrow, a company producing a simple household appliance that lets you almost effortlessly grown fresh produce in your own kitchen.  The technique is not new.  Using “aeroponics” to grow plants quickly without soil has been practiced for a long time by those growing their own marijuana.  But this company is the first to mass market an appliance that’s inexpensive, looks good, and can produce quality stuff for you and your family.

The article talks a lot about the business model and the founder of the company, but you would expect this from a magazine called “The Economist.”

Fascinating read.  You can read the full here.

Solar radiation is a general term for the electromagnetic radiation emitted by the sun. We can capture and convert solar radiation into useful forms of energy, such as heat and electricity, using a variety of technologies. The technical feasibility and economical operation of these technologies at a specific location depends on the available solar radiation or solar resource.

American Solar Map

Basic Principles

Every location on Earth receives sunlight at least part of the year. The amount of solar radiation that reaches any one “spot” on the Earth’s surface varies according to these factors:

• Geographic location
• Time of day
• Season
• Local landscape
• Local weather.

Because the Earth is round, the sun strikes the surface at different angles ranging from 0º (just above the horizon) to 90º (directly overhead). When the sun’s rays are vertical, the Earth’s surface gets all the energy possible. The more slanted the sun’s rays are, the longer they travel through the atmosphere, becoming more scattered and diffuse. Because the Earth is round, the frigid polar regions never get a high sun, and because of the tilted axis of rotation, these areas receive no sun at all during part of the year.

The Earth revolves around the sun in an elliptical orbit and is closer to the sun during part of the year. When the sun is nearer the Earth, the Earth’s surface receives a little more solar energy. The Earth is nearer the sun when it’s summer in the southern hemisphere and winter in the northern hemisphere. However the presence of vast oceans moderates the hotter summers and colder winters one would expect to see in the southern hemisphere as a result of this difference.

The 23.5º tilt in the Earth’s axis of rotation is a more significant factor in determining the amount of sunlight striking the Earth at a particular location. Tilting results in longer days in the northern hemisphere from the spring (vernal) equinox to the fall (autumnal) equinox and longer days in the southern hemisphere during the other six months. Days and nights are both exactly 12 hours long on the equinoxes, which occur each year on or around March 23 and September 22.

Countries like the United States, which lie in the middle latitudes, receive more solar energy in the summer not only because days are longer, but also because the sun is nearly overhead. The sun’s rays are far more slanted during the shorter days of the winter months. Cities like Denver, Colorado, (near 40º latitude) receive nearly three times more solar energy in June than they do in December.

The rotation of the Earth is responsible for hourly variations in sunlight. In the early morning and late afternoon, the sun is low in the sky. Its rays travel further through the atmosphere than at noon when the sun is at its highest point. On a clear day, the greatest amount of solar energy reaches a solar collector around solar noon.

Diffuse and Direct Solar Radiation

As sunlight passes through the atmosphere, some of it is absorbed, scattered, and reflected by the following:

• Air molecules
• Water vapor
• Clouds
• Dust
• Pollutants
• Forest fires
• Volcanoes.

This is called diffuse solar radiation. The solar radiation that reaches the Earth’s surface without being diffused is called direct beam solar radiation. The sum of the diffuse and direct solar radiation is called global solar radiation. Atmospheric conditions can reduce direct beam radiation by 10% on clear, dry days and by 100% during thick, cloudy days.

Measurement

Scientists measure the amount of sunlight falling on specific locations at different times of the year. They then estimate the amount of sunlight falling on regions at the same latitude with similar climates. Measurements of solar energy are typically expressed as total radiation on a horizontal surface, or as total radiation on a surface tracking the sun.

Radiation data for solar electric (photovoltaic) systems are often represented as kilowatt-hours per square meter (kWh/m²). Direct estimates of solar energy may also be expressed as watts per square meter (W/m²).

Radiation data for solar water heating and space heating systems are usually represented in British thermal units per square foot (Btu/ft²).

Learn More

Department of Energy Resources

• Solar Radiation Resource Information
  Renewable Resource Data Center

Reprinted from http://www.eere.energy.gov/consumer/renewable_energy/solar/index.cfm/mytopic=50012
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

South Carolina’s Port Authority willfully and knowingly seeks to dramatically increase the amount of diesel emissions in an already polluted area of Charleston. A proposal to develop a new port at the old North Charleston navy base is being pushed by the Port Authority, despite knowing the punishing environmental impact the port would have on the surrounding community. The local neighborhoods are poor and comprised mostly of minorities, which bears a striking resemblance to the poor and mostly minority community Hunts Point in New York.

Hunts Point, at the southern tip of the Bronx, just above Manhattan, has one of the highest asthma rates in the nation. Approximately one out of every three children has asthma in Hunts Point.

Given the connection between diesel exhaust and respiratory disease, it is not surprising that Hunts Point is also a hotspot of diesel pollution. The Hunts Point Cooperative Market includes one of the largest meat markets in the world, as well as the Hunts Point Produce Market, through which 80% of fresh produce in the New York area moves. The market draws hundreds of diesel trucks each day, which are a major source of the 20,000 diesel truck trips through the neighborhood each week. On average, a long-haul truck operator can have an 8–12 hour layover at the Hunts Point market while waiting to load or unload, or to comply with the federal rest period requirements. When trucks idle through this layover, the resulting diesel emissions place a serious burden on the people who live and work in Hunts Point.

Considering the connection between diesel exhaust and asthma, why would otherwise rational people choose to pursue a new port in North Charleston that would produce 250% more vehicular trips per day than Hunts Point? Does South Carolina’s Port Authority want to win the title “highest asthma rates in the nation” from New York? And this is using the port’s very low traffic estimate. The reality is more like 500% more trips/day.

You can help prevent this.

1. Contact your state legislators and express your disapproval! You can lookup your legislators here:

http://capwiz.com/scccl/state/main/?state=SC&view=myofficials#0

2. Consider this article a petition. Write your name and disapproval in a comment on this article. We will aggregate them into a formal complaint to local officials.

Help keep our air clean! Speak up now!

You can easily conduct a home energy audit yourself. With a simple but diligent walk-through, you can spot many problems in any type of house. When auditing your home, keep a checklist of areas you have inspected and problems you found. This list will help you prioritize your energy efficiency upgrades.

Locating Air Leaks

First, make a list of obvious air leaks (drafts). The potential energy savings from reducing drafts in a home may range from 5% to 30% per year, and the home is generally much more comfortable afterward. Check for indoor air leaks, such as gaps along the baseboard or edge of the flooring and at junctures of the walls and ceiling. Check to see if air can flow through these places:

• Electrical outlets
• Switch plates
• Window frames
• Baseboards
• Weather stripping around doors
• Fireplace dampers
• Attic hatches
• Wall- or window-mounted air conditioners.

Also look for gaps around pipes and wires, electrical outlets, foundation seals, and mail slots. Check to see if the caulking and weather stripping are applied properly, leaving no gaps or cracks, and are in good condition.

Inspect windows and doors for air leaks. See if you can rattle them, since movement means possible air leaks. If you can see daylight around a door or window frame, then the door or window leaks. You can usually seal these leaks by caulking or weather stripping them. Check the storm windows to see if they fit and are not broken. You may also wish to consider replacing your old windows and doors with newer, high-performance ones. If new factory-made doors or windows are too costly, you can install low-cost plastic sheets over the windows.

If you are having difficulty locating leaks, you may want to conduct a basic building pressurization test:

1. First, close all exterior doors, windows, and fireplace flues.
2. Turn off all combustion appliances such as gas burning furnaces and water heaters.
3. Then turn on all exhaust fans (generally located in the kitchen and bathrooms) or use a large window fan to suck the air out of the rooms.

This test increases infiltration through cracks and leaks, making them easier to detect. You can use incense sticks or your damp hand to locate these leaks. If you use incense sticks, moving air will cause the smoke to waver, and if you use your damp hand, any drafts will feel cool to your hand.

On the outside of your house, inspect all areas where two different building materials meet, including:

• All exterior corners
• Where siding and chimneys meet
• Areas where the foundation and the bottom of exterior brick or siding meet.

You should plug and caulk holes or penetrations for faucets, pipes, electric outlets, and wiring. Look for cracks and holes in the mortar, foundation, and siding, and seal them with the appropriate material. Check the exterior caulking around doors and windows, and see whether exterior storm doors and primary doors seal tightly.

When sealing any home, you must always be aware of the danger of indoor air pollution and combustion appliance “backdrafts.” Backdrafting is when the various combustion appliances and exhaust fans in the home compete for air. An exhaust fan may pull the combustion gases back into the living space. This can obviously create a very dangerous and unhealthy situation in the home.

In homes where a fuel is burned (i.e., natural gas, fuel oil, propane, or wood) for heating, be certain the appliance has an adequate air supply. Generally, one square inch of vent opening is required for each 1,000 Btu of appliance input heat. When in doubt, contact your local utility company, energy professional, or ventilation contractor.

Insulation

Heat loss through the ceiling and walls in your home could be very large if the insulation levels are less than the recommended minimum. When your house was built, the builder likely installed the amount of insulation recommended at that time. Given today’s energy prices (and future prices that will probably be higher), the level of insulation might be inadequate, especially if you have an older home.

If the attic hatch is located above a conditioned space, check to see if it is at least as heavily insulated as the attic, is weather stripped, and closes tightly. In the attic, determine whether openings for items such as pipes, ductwork, and chimneys are sealed. Seal any gaps with an expanding foam caulk or some other permanent sealant.

While you are inspecting the attic, check to see if there is a vapor barrier under the attic insulation. The vapor barrier might be tarpaper, Kraft paper attached to fiberglass batts, or a plastic sheet. If there does not appear to be a vapor barrier, you might consider painting the interior ceilings with vapor barrier paint. This reduces the amount of water vapor that can pass through the ceiling. Large amounts of moisture can reduce the effectiveness of insulation and promote structural damage.

Make sure that the attic vents are not blocked by insulation. You also should seal any electrical boxes in the ceiling with flexible caulk (from the living room side or attic side) and cover the entire attic floor with at least the current recommended amount of insulation.

Checking a wall’s insulation level is more difficult. Select an exterior wall and turn off the circuit breaker or unscrew the fuse for any outlets in the wall. Be sure to test the outlets to make certain that they are not “hot.” Check the outlet by plugging in a functioning lamp or portable radio. Once you are sure your outlets are not getting any electricity, remove the cover plate from one of the outlets and gently probe into the wall with a thin, long stick or screwdriver. If you encounter a slight resistance, you have some insulation there. You could also make a small hole in a closet, behind a couch, or in some other unobtrusive place to see what, if anything, the wall cavity is filled with. Ideally, the wall cavity should be totally filled with some form of insulation material. Unfortunately, this method cannot tell you if the entire wall is insulated, or if the insulation has settled. Only a thermographic inspection can do this.

If your basement is unheated, determine whether there is insulation under the living area flooring. In most areas of the country, an R-value of 25 is the recommended minimum level of insulation. The insulation at the top of the foundation wall and first floor perimeter should have an R-value of 19 or greater. If the basement is heated, the foundation walls should be insulated to at least R-19. Your water heater, hot water pipes, and furnace ducts should all be insulated.
For more information, see our insulation section.

Heating/Cooling Equipment

Inspect heating and cooling equipment annually, or as recommended by the manufacturer. If you have a forced-air furnace, check your filters and replace them as needed. Generally, you should change them about once every month or two, especially during periods of high usage. Have a professional check and clean your equipment once a year.

If the unit is more than 15 years old, you should consider replacing your system with one of the newer, energy-efficient units. A new unit would greatly reduce your energy consumption, especially if the existing equipment is in poor condition. Check your ductwork for dirt streaks, especially near seams. These indicate air leaks, and they should be sealed with a duct mastic. Insulate any ducts or pipes that travel through unheated spaces. An insulation R-Value of 6 is the recommended minimum.

Lighting

Energy for lighting accounts for about 10% of your electric bill. Examine the wattage size of the light bulbs in your house. You may have 100-watt (or larger) bulbs where 60 or 75 watts would do. You should also consider compact fluorescent lamps for areas where lights are on for hours at a time. Your electric utility may offer rebates or other incentives for purchasing energy-efficient lamps.

Learn More

Evaluation Tools

• Home Energy SaverLawrence Berkeley National Laboratory
• Home Energy CheckupAlliance to Save Energy

Financing & Incentives

• DOE Weatherization Assistance ProgramOffice of Energy Efficiency and Renewable Energy

Reading List

• Krigger, J.; Dorsi, C. (2004). Residential Energy: Cost Savings and Comfort for Existing Buildings. Helena, MT: Saturn Resource Management.

Reprinted from http://www.eere.energy.gov/consumer/your_home/energy_audits/index.cfm/mytopic=11170
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

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.