In the USA the Office of Energy Efficiency and Renewable Energy (EERE) is probable your best first port of call. EERE is engaged in many strategies to increase the use of renewable energy and improve the required technology.

In 2004 EERE awarded $506 Million in financial assistance. It is not involved in individual incentives but you can access a comprehensive US 

For direct grants to you, and for other incentives you should contact your local government authority first. The trail will lead to grants and rebates tailored to your solar water heating system, or other form of renewable energy appliance.

…or not. In which case you will immediately enroll in your local course “how to become an effective environmental lobbyist 101.” Also, there is good general information available on all kinds of solar energy grants.

In addition, you may also be interested also in this database of energy efficiency programs that can save you money.

Wind can be used to do work. The kinetic energy of the wind can be changed into other forms of energy, either mechanical energy or electrical energy. When a boat lifts a sail, it is using wind energy to push it through the water. This is one form of work. Farmers have been using wind energy for many years to pump water from wells using windmills like the one on the right. In Holland, windmills have been used for centuries to pump water from low-lying areas. Wind is also used to turn large grinding stones to grind wheat or corn, just like a water wheel is turned by water power. Today, the wind is also used to make electricity. Blowing wind spins the blades on a wind turbine — just like a large toy pinwheel. This device is called a wind turbine and not a windmill. A windmill grinds or mills grain, or is used to pump water. The blades of the turbine are attached to a hub that is mounted on a turning shaft. The shaft goes through a gear transmission box where the turning speed is increased. The transmission is attached to a high speed shaft which turns a generator that makes electricity. If the wind gets too high, the turbine has a brake that will keep the blades from turning too fast and being damaged. You can use a single smaller wind turbine to power a home or a school. The small turbine on the right makes enough energy for a house. In the picture on the left, the children at this Iowa school are playing beneath a wind turbine that makes enough electricity to power their entire school. We have many windy areas in California. And wind is blowing in many places all over the earth. The only problem with wind is that it is not windy all the time. In California, it is usually windier during the summer months when wind rushes inland from cooler areas, like the ocean to replace hot rising air in California’s warm central valleys and deserts. In order for a wind turbine to work efficiently, wind speeds usually must be above 12 to 14 miles per hour. Wind has to be this speed to turn the turbines fast enough to generate electricity. The turbines usually produce about 50 to 300 kilowatts of electricity each. A kilowatt is 1,000 watts (kilo means 1,000). You can light ten 100 watt light bulbs with 1,000 watts. So, a 300 kilowatt (300,000 watts) wind turbine could light up 3,000 light bulbs that use 100 watts! As of 1999, there were 11,368 wind turbines in California. These turbines are grouped together in what are called wind “farms,” like those in Palm Springs in the picture on the right. These wind farms are located mostly in the three windiest areas of the state: Altamont Pass, east of San Francisco San Gorgonio Pass, near Palm Springs Tehachapi, south of Bakersfield Together these three places in California make enough electricity to supply an entire city the size of San Francisco! About 11 percent of the entire world’s wind-generated electricity is found in California. Other countries that use a lot of wind energy are Denmark and Germany. Once electricity is made by the turbine, the electricity from the entire wind farm is collected together and sent through a transformer. There the voltage is increase to send it long distances over high power lines.

Summer time is coming; people will be doing some camping, hiking, and some people will be having picnics. You may be concerned about your ability to minimize the weight of packed goods while taking maximum storage space on such trips. When going camping with the family of course you will need to cook. Carrying a heavy stove can be a pain in the back.

There is a way that you can have a good healthy meal with your family outside of the house. If you are out hiking this is light enough so that you can take it with you- all you need to do is carry this on your back. You can build an inexpensive, easily constructed camp oven. This is sturdy, lightweight, and small. This can be used between meals to store food or other goods, and also is good to use as a washbasin or to wash plates and utensils after your meal.

This is simple to build (it takes less than five minutes to construct). You can find these items in your local hardware store. You start by finding a round or square can with a lid and handled that measures 9” wide and 12” tall using and awl or a sharp nail, pierce both the lids edge and the upper lip of the can to form two holes ½” apart in each piece to facilitate opening the cover fully (take the time to elongate these openings with your tool). Pass a loop of wire through the can and its cap and twist the free ends to form a loose ring, which will serve as a hinge for your oven’s lid. Take a section of heavy, galvanized hardware cloth, about 10-1/2 X 18”, and bend its flat surface so that it will fit inside the air tight stove snugly the long way as this will act as a shelf for a cooking tin or a piece of foil to rest upon. You can position the rack within the oven the way that you would like. Just remember you must leave enough room above it for the pan and victuals. For safety’s sake it’s best to build a “cleansing” fire to eliminate any fumes from the galvanization before cooking.

When you’re ready to use the tin oven, merely place the food of your choice (on foil or in a pan) on top of the wire shelf, add a small amount of water if you want your food steamed, press the containers cap on securely, and rest the stove on it’s side upon several rocks or a couple of logs placed within or around your campfire. To make cleanup chores easier, you may want to rub a layer of soap over the skin of the can so that soot will stick to the cleaner – which can be rubbed off – rather than to the metal itself.

In the 1890s solar water heaters were being used all over the United States. They proved to be a big improvement over wood and coal-burning stoves. Artificial gas made from coal was available too to heat water, but it cost 10 times the price we pay for natural gas today. And electricity was even more expensive if you even had any in your town! Many homes used solar water heaters. In 1897, 30 percent of the homes in Pasadena, just east of Los Angeles, were equipped with solar water heaters. As mechanical improvements were made, solar systems were used in Arizona, Florida and many other sunny parts of the United States. The picture shown here is a solar water heater installed on the front roof of a house in Pomona Valley, California, in 1911 (the panels are circled above the four windows).

By 1920, ten of thousands of solar water heaters had been sold. By then, however, large deposits of oil and natural gas were discovered in the western United States. As these low cost fuels became available, solar water systems began to be replaced with heaters burning fossil fuels.

Today, solar water heaters are making a comeback. There are more than half a million of them in California alone! They heat water for use inside homes and businesses. They also heat swimming pools like in the picture.

Panels on the roof of a building, like this one on the right, contain water pipes. When the sun hits the panels and the pipes, the sunlight warms them.

That warmed water can then be used in a swimming pool.

www.energyquest.ca.gov/story/chapter15.html

You’ve decided you want to make electricity with the wind.

You have your eye on a high-quality wind generator, and

you’ve chosen the balance of systems (BOS) components.

What’s left is the biggest and most important job—choosing

and installing the tower.

The mounting structure for a photovoltaic (PV) array

puts the solar energy collectors up in the fuel—sunshine.

Towers for wind generators do the same thing. Wind is the

fuel for a wind generator, and to collect it, you have to get

your machine above obstructions. Buildings, trees, and hills

block the wind, slowing it down and causing turbulence.

The standard guideline is to site a wind generator at least

30 feet (9 m) above anything within 500 feet (150 m). The

entire rotor needs to be well above obstructions, so start

your measurement from the tip of the lowest blade. Doing

less is shortchanging your investment in wind energy—it’s

like putting solar-electric panels in the shade.

Your tower needs to support the weight of your wind

turbine and handle the thrust loads put on it by the wind.

It’s easy to underestimate the severity of the environment

that wind generators work in. If you ever see a catastrophic

failure of a wind-electric system, you won’t forget it. And if

you make the tower too short, you won’t get much energy.

Purchase and install a tall, sturdy, permanent tower, so

your wind energy experience will be long lasting and as

productive as your wind site allows.

Tower Perspectives

It’s easy to get focused on the wind generator as the

primary component in a wind-electric system. After all,

it’s the collector—the machine that converts the energy

in the wind to electricity. It moves, which is exciting and

attracts attention. But it is quite often not the most expensive

component in the system. The BOS components can easily

cost more than the turbine, and the tower can cost two to

ten times as much as the turbine, depending on the site

and situation. Take a realistic view of your plans to tap

wind energy by looking at the total system cost, not just

the turbine cost. Costs for a typical off-grid installation are

shown in the table on page 66.

 

A similar situation occurs when

it comes to installation. Students

attending wind system installation

workshops often expect that they will

spend a lot of time dealing with the

wind generator. In fact, most of the

installation time of a six-day wind

workshop is spent with the tower.

Assembling the wind generator and

attaching it to the tower takes only

a few hours, while assembling and

installing the tower can take two to

four days.

Tower Types

Three basic tower types are used for

almost all home-scale wind generator

installations. Tilt-up towers make

maintenance easy, with no climbing.

Fixed, guyed towers are very common,

climbable towers. Freestanding towers,

with no guy wires, are costly, but

attractive, and also climbable.

Tilt-up towers. My advice: If you have space for a tilt up

tower, use one! You will never have to climb your tower

(in fact, you won’t be able to). All maintenance will be done

with your feet on terra firma. If there’s any trouble with the

machine, you can have it down in less than an hour, and

back up in the same time once you’ve done the repair.

Tilt-up towers come in heights up to around 130 feet (40

m) for small-scale machines, with various sizes for different

machine weights and thrusts. The most common tilt-ups

are tubular steel, with sections of pipe coupled together,

and guy wires attached at each joint. All the guy wires on

one side of the pole (from each of the pipe joints) make up

a set of guy wires. For tilt-up towers, four sets of guy wires

are required, with three sets attached to one of the concrete

anchors placed at four separate points in a radius around a

concrete base at the center. The fourth set is attached to the

gin pole, which in turn gets attached to the fourth concrete

anchor when the tower is raised.

The major drawback of tilt-ups is the footprint needed.

You need a clear, open area for the tower, a diamond shaped

space (see diagram) that is as long as the tower

height plus the guy wire radius, and as wide as the guy

radiuses extending from the sides of the tower base. For a

100-foot (30 m) tilt-up tower, the guy radius will be about 50

feet (15 m); so a diamond-shaped area 150 by 100 feet will be

required. This area needs to be clear of trees and structures

so the guy wires can lie down cleanly. You’ll also need a

clear lane to drive a lifting vehicle, if you use one. Other

drawbacks: for minor repairs or service by people who are

comfortable climbing, a tilt-up can be less convenient than

a climbable tower. And you won’t enjoy the views from the

top of your tower!

 

Tilt-up towers consist of the tower pole and a “gin pole”

that is attached to it at 90 degrees. When the tower is down,

the gin pole sticks straight up in the air. When the tower is

up, the gin pole rests horizontally near the ground. The gin

pole is a big lever that allows you to easily lift the tower,

which pivots at its concrete base.

You can raise and lower the tower with a truck, tractor,

winch, come-along, or grip-hoist. The latter options allow

you to install towers in remote locations not accessible to

vehicles. The gin pole is generally 75 to 100 percent of the

guy radius in length. I prefer tower systems that use the full

guy radius for the gin pole length and permanently attach

the rear guys directly to the end of the gin pole.

Like all towers, tilt-ups have their hazards. Things can go

wrong. They can get dropped. Tow vehicles can slip. There

are real dangers if the anchors are not correctly positioned

and the guys get too tight while lowering or raising the

tower. You should do your homework before attempting to

install one, and always put the tower up without the turbine

on it the first time.

Fixed, guyed towers. Another type of guyed tower,

a fixed tower is lifted up once, and does not tilt down.

Guy wires hold it up, and any maintenance on the tower

or turbine is done by climbing the tower. These towers

come in various configurations, the most common being

triangular lattice sections, 10 or 20 feet (3 or 6 m) long, that

bolt together. You’ve probably seen this type of tower used

for commercial radio antennas and the like.

These towers must have a minimum of three sets of

guy wires, with an underground concrete anchor for each

set, and a concrete base under the tower itself. It’s possible

to install them one section at a time, using a different type

of gin pole, a vertical temporary crane that mounts on the

tower. The gin pole is moved up the tower one section at a

time, and is used to lift each succeeding section. This is a

slow, laborious process, and many people opt instead to lift

these towers with a crane.

While fixed, guyed towers don’t require the open area

that a tilt-up tower needs, you still must have open lanes

for the guy wires. The guy radius will be 50 to 80 percent of

the tower height, and the guy wires will be visible. Costs for

fixed, guyed towers are in the same general range as tilt-ups,

but these towers can be installed on many sites that will not

accommodate a tilt-up tower, mostly because fixed towers

don’t need as much cleared space, or as level ground.

Freestanding towers. If your budget isn’t tight, a

freestanding tower might be your first choice. No guy wires,

no tilting, and it only needs a modest clear space for the

tower base. The drawback, of course, is cost. Freestanding

towers rely on steel and concrete to hold them up instead

of guy wires—lots of steel and concrete. This means higher

cost for these materials, as well as for excavation, concrete

forms, rebar, and labor.

Freestanding towers take two basic forms. Most common

is the three-legged Eiffel Tower style, with tubular legs

connected by angle iron braces. The other option is a

monopole tower—a large, single tube, similar to what is

used for utility-scale wind turbines. These are often quite

expensive, and out of the financial reach of most small scale

renewable energy (RE) users. Both types are usually

assembled on the ground and lifted with a crane.

A freestanding tower will cost at least a third to half

more than a tilt-up or fixed, guyed tower. But the end result

may be worth it. Aesthetically speaking, most people prefer

not to look at guy wires. Less land clearing is necessary, and

the tower is less vulnerable to damage than a guyed tower.

Homebrew towers. Many RE enthusiasts like to do

things for themselves. While I have a great deal of respect

for home brewers, I urge you to be careful when it comes

to towers. This is no place for lightweight construction or

engineering guesswork. If you’re going to try to build your

own tower, do careful research. Look at engineered towers

and get a sense of the designs, as well as the size and quality

of hardware used.

When in doubt, overbuild. Better yet, stick with

engineered towers that are professionally designed for the

job. To obtain permits, you may need an engineer’s stamp

on your plans, anyway. Most tower manufacturers have

engineers on staff who can provide you with specifications

and calculations that will make your local engineer’s job

easier, and less expensive for you.

Choosing Your Tower

So how do you choose your tower? First of all, look at the

function. Each turbine manufacturer will tell you what

tower size (pipe diameter or lattice tower size) is necessary

to hold your wind generator. Using the 30-foot/500-foot

rule, determine how tall your tower needs to be. Consider

mature tree height, and remember that trees grow, while

towers don’t. Then look at what tower

options you have.

Look at your site. Is there space

for a tilt-up tower? Do you have the

available footprint for guy wires? Then

ask yourself whether you or someone

you hire is going to be willing to climb

the tower to do the regular, twice-a year

maintenance. And ask yourself,

your family, and neighbors about the

aesthetics. Take the time to go and look

at installed wind-electric systems to

get a sense of what you’re getting into.

Look at your budget. Many people

would love to have a freestanding

tower, but the cost is prohibitive.

Whatever your tower choice, avoid

the most common mistake in wind

system design—don’t make your

tower too short! Taller towers will always give you more

energy for your investment, and you will not regret going

higher. Take the time to research your tower choices, and

make the best investment for the long-term. If you don’t

have experience installing wind generators and towers, seek

qualified help. Tower installation is not something to be

taken lightly, but if you do it right, you’ll have a solid base

for making some or all of your electricity with the wind!

 

 

 

Ian Woofenden

©2005 Ian Woofenden

 

Popular Science. Vol. 215. No. 2. 

The Basics of Building a Simple Greenhouse 

                Combining a geodesic (the geometry of curved surfaces) dome and a solar greenhouse makes the perfect project for anyone looking to better the environment and grow organic vegetables and beautiful flowers.  Designing an elliptical dome allows the east and west axis to run lengthwise through the structure.  Because of the dome structure, it allows a sufficient south face.  However, if a circular shape was used, it would be insufficient as there is no direct south face for proper sun exposure.                Simply designed with 2×4’s, this dome structure contains a vinyl inside with approx one-inch air space.  On the south-facing end, segments are double-glazed with a fiberglass outside.  Access to the inside is provided by a short extension which can be placed on either the east or west end.                  Thermal storage is very sufficient with greenhouses.  Approx. thirteen 55-gallon drums painted in black, filled with water, and directly exposed to sunlight will allow record storing temperatures!  Even on cloudy days, these drums will hold a sufficient amount of heat that protects the greenhouse from freezing temperatures in the evening and night time hours.                Inside a simple garden of vegetables and house plaints in the winter months can be grown.  When spring comes a vegetable garden can continue its growing.  With having vegetables and flowers, water will be needed.  Why not use a solar pump?  Harmless to the environment, harmless to your wallet, and a simple beautiful garden of healthy vegetables and flowers are grown.

Solar Lighting Basics

Solar hybrid lighting system.

Research under way at Oak Ridge National Laboratory (ORNL) could lead to entirely new, highly energy-efficient ways of lighting buildings using the power of sunlight. This new technology, called Hybrid Solar Lighting, (HSL) would use sunlight to simultaneously light interior spaces and generate electricity.

Hybrid solar lighting makes better use of sunlight in its natural form and specifically targets the energy consumed by electric lights—the largest consumer of electricity in commercial buildings. Electric lighting accounts for more than a third of all electricity consumed for commercial use in the United States.

HSL, currently in the research and development phase, would use a specially designed collector to focus natural, full-spectrum sunlight into optical cables while simultaneously converting otherwise wasted infrared energy into electricity. The optical cables would then deliver the full-spectrum sunlight to light fixtures throughout a building. Additionally, HSL would convert sunlight to electricity much more efficiently than conventional solar technologies.

In a solar lighting and power system, the roof-mounted concentrators collect sunlight and distribute it through the optical fibers (enlargement) to hybrid lighting fixtures in the building’s interior. The system also produces electricity for supplemental lighting or other uses

Richard A. Lovett
for National Geographic News

November 29, 2006

Part of the Digital Places Special News Series
More Digital Places Stories>>

A buildup of carbon dioxide in Earth’s atmosphere could require changes in the way satellites are launched and might impact the function of global positioning systems (GPS), an international team of atmospheric scientists suggests.

Networks of orbiting GPS satellites send signals back to Earth that allow everything from jetfighters to cell phones to pinpoint their exact locations.

The same carbon dioxide that is a prime culprit for global warming in Earth’s lower atmosphere is also causing the upper atmosphere to cool and contract, the team reported in last week’s issue of the journal Science.

This change will be both good and bad for the orbiters, Jan Lastovicka, lead study author and researcher at the Institute of Atmospheric Physics in Prague, Czech Republic, said in an email.

As the upper atmosphere pulls in closer to Earth, the air at altitudes where low-orbit satellites reside will be less dense, meaning the craft can more easily maintain orbit and therefore last longer, Lastovicka said.

But spacecraft—including those that deliver new satellites into orbit—currently jettison booster rockets and other debris at about the same altitude.

The craft drop debris at just the right height to ensure that it will fall back to Earth relatively quickly and burn up in the atmosphere.

“If the atmosphere contracts, there will be less atmosphere up there to get rid of all the junk,” said study co-author John Emmert of the U.S. Naval Research Laboratory’s E. O. Hulburt Center for Space Research in Washington, D.C.

As conditions continue to change, space agencies will need to reevaluate their launch procedures to avoid increased risk, he said.

Rapid Changes

Changes in the upper atmosphere could also affect radio signals being sent from GPS satellites.

Inside the highest layer of the atmosphere is a region called the ionosphere, where charged particles help reflect radio waves back to Earth.

Changes in the ionosphere caused by solar storms or other cosmic radiation have been known to affect the way radio signals travel through the atmosphere (related news: “Stronger Solar Storms Predicted; Blackouts May Result” [March 7, 2006]).

But there are ways to take such fluctuations into account when calculating GPS relays, said study co-author Rashid Akmaev of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado.

“You would presumably be able to do the same thing in the future if the ionosphere changes” due to cooling temperatures, he said.

Emmert agreed, noting that “GPS is most sensitive to rapid small-scale fluctuations in the ionosphere.

“So I suspect that long-term, it probably would be something that would easily be adapted to. But who knows; there might be unforeseen consequences.”

Hot and Cold

Atmospheric cooling seems contrary to prevailing news about global warming.

But what many people might not know is that the upper and lower atmospheres react differently to carbon dioxide emissions, Akmaev said.

In the Earth’s lower atmosphere, carbon dioxide traps solar energy, causing the air to heat.

But in the upper atmosphere the greenhouse gas causes the thin upper air to radiate energy more rapidly back into space, becoming cooler.

Overall, Akmaev said, the upper atmosphere is cooling at a rate of 9 to 18°F (5 to 10°C) a decade—and perhaps even up to 30°F (17°C) a decade—according to one observational study.

As the cooler gases hug more closely to Earth, the density at any given altitude is dropping by about 2 to 3 percent a decade, he added.

For Akmaev, the study’s take-home message is simply that human activities are affecting the atmosphere at all altitudes from surface to space.

“If we continue monitoring it,” he said, “we will learn more about how the whole atmosphere changes, not just at the surface.”

Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun’s energy and make it useable. Today, the technology produces less than one tenth of one percent of global energy demand.

Many people are familiar with so-called photovoltaic cells, or solar panels, found on things like spacecraft, rooftops, and handheld calculators. The cells are made of semiconductor materials like those found in computer chips. When sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity.

On a much larger scale, solar thermal power plants employ various techniques to concentrate the sun’s energy as a heat source. The heat is then used to boil water to drive a steam turbine that generates electricity in much the same fashion as coal and nuclear power plants, supplying electricity for thousands of people.

In one technique, long troughs of U-shaped mirrors focus sunlight on a pipe of oil that runs through the middle. The hot oil then boils water for electricity generation. Another technique uses moveable mirrors to focus the sun’s rays on a collector tower, where a receiver sits. Molten salt flowing through the receiver is heated to run a generator.

Other solar technologies are passive. For example, big windows placed on the sunny side of a building allow sunlight to heat-absorbent materials on the floor and walls. These surfaces then release the heat at night to keep the building warm. Similarly, absorbent plates on a roof can heat liquid in tubes that supply a house with hot water.

Solar energy is lauded as an inexhaustible fuel source that is pollution and often noise free. The technology is also versatile. For example, solar cells generate energy for far-out places like satellites in Earth orbit and cabins deep in the Rocky Mountains as easily as they can power downtown buildings and futuristic cars.

But solar energy doesn’t work at night without a storage device such as batteries, and cloudy weather can make the technology unreliable during the day. Solar technologies are also very expensive and require a lot of land area to collect the sun’s energy at rates useful to lots of people.

Despite the drawbacks, solar energy use has surged at about 20 percent a year over the past 15 years, thanks to rapidly falling prices and gains in efficiency. Japan, Germany, and the United States are major markets for solar cells. With tax incentives, solar electricity can often pay for itself in five to ten years.

Night-time travel is a necessary part of the busy world in which we live, but due to decreased visibility, traveling in the dark can be dangerous. The British have shed some light on night driving with the invention of the Astucia SolarLite flush road stud. The stud emits LED light, which is powered by small solar panels. The new stud tech is present on 120 British roads, and night-time accidents are down a dramatic 70% since the devices were installed. Amazingly, the SolarLite road stud gives drivers 900 meters of visibility, which increases reaction times to over 30 seconds. Reaction time with standard reflector studs is just 3.2 seconds.

With thousands of Americans dying on night roads every year, any incremental price vs. reflector studs would likely be a drop in the bucket when compared to the incredible savings in insurance claims alone. The government mandates billions of dollars in safety equipment on our cars and trucks, and both the automakers and customers foot the bill in the name of safety. If the SolarLite road stud is nearly as effective as it claims, the governments incorporating them could effectively reduce the likelihood that many automotive safety features would never need to be deployed.