10 Ways to Go

Green at White

Oak Middle

School

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1. Rain Garden

Why Plant a Rain Garden?

You know how precious freshwater is to life.You probably also know that freshwater is becoming increasingly scarce due to pollution, misuse, overuse and climate change.

So when someone asks you "why plant a rain garden?" you can tell them that you are doing it to help keep clean, fresh

rainwater out of the sewer system and you are doing your part to reduce pollution and preserve our water systems.

This sounds like a grand effort that only scientists, ecologists and politicians can do. But you can plant a rain garden and then spread the word and tell others that you plant native plants and rain gardens to improve the world you live in.

Explain to people who question you how rain and melting snow runs off roofs, driveways and even lawns and flows directly to the street, down the storm drain and right to our rivers and lakes. Tell them that this runoff is untreated and carries with it pollutants like oil, salt, fertilizer, pesticides, pet waste, transportation chemicals, sediment and all sorts of other things that shouldn't be in our freshwater.

Tell them that a rain garden can capture that runoff and hold not only thousands of gallons of rainwater that can be used in your own garden and yard but all of these pollutants that contaminate our waterways. Then explain after the capture of the water comes the soaking or infiltrating of the water deep into the ground so that it can be used by the nearby plants and trees. Tell them how the native plants planted in the rain garden also help to soak up the water and how the roots are deep and will break up hard soil and infiltrate water and nutrients deep into the soil.

Then finally, tell them how the plants, mulch and soil break up the pollutants and make them inert, not harmful. Explain how the moderate amounts of water and limited amounts of pollutants people shed from their personal property can easily be handled by the rain garden. And that these same pollutants will cause havoc if combined with pollution from your neighbors on your block and the next block and the neighborhood and the community. Imagine all the pollutants from a whole city moving, untreated into your rivers, lakes and streams that you might be drinking!!!!

Oh, ya, you can also explain that a rain garden is beautiful, creates habitat for birds and beneficial insects, reduces pest and harmful insects, makes a great statement in your yard and can be used seasonally to teach kids and adults about the nature of nature.

This is why we all should plant a rain garden ... or two ... or three ...

http://www.raingardennetwork.com/whyplantraingarden.htm 3/1/14

A Rain Garden is . . .

A rain garden is a shallow, constructed depression that is planted with deep-rooted native plants & grasses. It is located in your landscape to receive runoff from hard surfaces such as a roof, a sidewalk and a driveway. Rain gardens slow down the rush of water from these hard surfaces, holds the water for a short period of time and allows it to naturally infiltrate into the ground.

A rain garden can be thought of as a personal water quality system because it filters the runoff from your roof and lawn and recharges the groundwater.

A rain garden also conserves municipal water resources by reducing the need for irrigation.

Rain gardens are a beautiful and colorful way for homeowners, businesses and municipalities to help ease stormwater problems. There is a growing trend by municipalities and homeowners to incorporate natural processes to help relieve flooding and pollution.

2. Dual flush toilet

From Wikipedia, the free encyclopedia

Jump to: navigation, search

The examples and perspective in this article deal primarily with Australia and do not represent a

worldwide view of the subject.

Dual flush toilet

A dual-flush toilet is a variation of the flush toilet that uses two buttons or handles to flush different levels of

water. It was invented by Australian inventor Bruce Thompson in 1980 while working for Caroma,[1] and

although the first generation dual-flush toilet caught on, a redesign in 1993 cut water usage in half when used

properly.[1] It has been proven to save up to 67% of water usage in most homes.[2] Due to the more complex

mechanism, it is more expensive than many other types of low-flow toilets.[3]

Mechanism

The traditional Australian flush toilet, the dual-flush toilet differs from siphon-flush toilets in that it relies on

gravity to remove waste from the toilet. In addition to its dual flush feature, the lack of siphoning also results in

it requiring less water to operate.[3] The lack of siphoning also means that it is similar to an aeroplane toilet; the

water line is considerably lower than that of siphon-flush toilets. The main feature of the toilet is that it has two

buttons for releasing water. It outputs water in both 0.8-gallon (3 litre) and 1.6-gallon (6 litre) capacities.[4] The

smaller level is designed for liquid waste, and the larger is designed for solid waste. It also uses a larger 4-inch

(10 cm) trapway in the bowl, allowing for water to come out faster and clear the bowl efficiently. [4]

Advantages The dual flush toilet system, due to its ability to save up to 67% of water usage, has been promoted by the

Australian Government under its Target 155 campaign.[5] Dual flush toilet suites started out with a 9/4.5L flush,

however, innovations from Caroma, Australia's leading bathroom brand, have brought that down to 4.5/3L

flush, achieving a WELS rating of 4 and 5 stars in Australia.

Australian governments are encouraging the replacement of old single flush toilets with more water efficient

toilets through toilet rebates.[6] For dual flush toilets, with a star rating of 4 or higher, owners may be able to

qualify to claim a rebate from the State Government in Victoria,[7] New South Wales or South Australia.

Sydney Water’s rebate program ended on 30th June 2011. [8]

Disadvantages

Despite the high water-savings quality the toilet has a few disadvantages. It may be slightly more expensive

than other low flow toilets.[3] Certain retrofitting systems have brought the price down significantly, costing

approx. $30 USD.[9]

"Dual flush units are a little more expensive than other low flow toilet designs. There is also the problem of

aesthetics. If you like a tidy toilet bowl that's half full of sparkling clear water, the dual flush concept will be a

bit of an adjustment. Typically, dual flush toilets only retain a little water in the bowl, and flushing won't always

get rid of all the waste. Even in full flush mode, there's some occasional streaking. With a dual flush toilet,

you'll probably use your toilet brush more often, but then you probably won't need to keep the plunger

nearby."[10]

http://en.wikipedia.org/wiki/Dual_flush_toilet 3/1/2014

3. Paper Towels Vs. Hand Dryers What is the argument about paper towels vs. hand dryers? How does it affect the environment and other factors?

Find out all about it, here.

Whether you prefer paper towels over hand dryers or vice versa, both of them have their own pros and cons.

Both of them affect personal hygiene, the environment, and even vary in costs. Before you develop a preset

notion about either, take a look at this old, yet raging debate regarding what is better and then decide what

would you prefer to use.

Effects on the Environment Scientific experts have proven that the carbon emissions and the emission of other greenhouse gases from the

use of paper towels are greater than those from the use of hand dryers. This is after taking into consideration the

entire production process, including discarding both. Also, the number of trees that go into producing paper

towels is extremely high. This has a negative impact on the environment. Moreover, they are used extremely

casually, one instead of two, for any and every purpose which leads to wastage. Though hand dryers run on

electricity, advanced ones are now being produced that don't take more than 10 - 15 seconds to dry hands

completely. This reduces the wastage of electricity considerably. They also last for over 7 - 10 years. Recycling

paper towels is not possible; however, they themselves may be made out of recycled material.

Personal Hygiene In terms of personal hygiene, neither of these two completely win the battle. You may follow the regular and

healthy procedure for washing hands. However, when you use hand dryers after washing your hands and do not

allow your hands to dry out completely, they are more susceptible to contracting and spreading harmful

bacteria. Studies show that wet hands carry over 500% more bacteria than hands that have been thoroughly

dried. With a paper towel, you can completely dry your hands. Experts have recommended against the use of

hand dryers in restaurant and cafeteria bathrooms due to this very reason.

Maintenance Common complaints regarding paper towels are made by facilities managers. It is natural for people to leave

behind a mess when using them in public restrooms. Cleaning up after them can be a tough task, and also

requires more cleaning material to be used. This again is an indirect way of harming the environment. On the

other hand, hand dryers do not require such extensive maintenance, unless they break down.

Cost There is also a difference in the cost between both. Firstly, a paper towel dispenser is definitely cheaper than a

hand dryer. However, one must take into account that a hand dryer lasts longer and that while the paper towel

dispenser is cheap, the cost of paper towels itself is definitely higher in the long run. As mentioned before, their

casual usage makes their overall cost much heavier. This is particularly the case in extremely crowded zones,

such as movie theaters, malls, restaurants, etc. People use them more than required, or they fall out of the

dispenser and are then deemed unfit to be used. In such a case, the wastage factor is much higher, which

increases the final cost. One must also consider the cost of paper towels in terms of transportation and storage.

With hand dryers, there is hardly any wastage. They are in fact timed, and thus use minimal electricity. So, the

costs there are not that heavy.

To conclude this debate, only one point can be made. Though all arguments seem in favor of hand dryers, using

either is going to be a cause for several environmental issues in the long run. Even if paper towels are produced

from recycled materials and even if advanced hand dryers that dry hands in ten seconds are produced, it is

ultimately going to have a negative effect on the environment. Choosing one over the other is finally your

choice. Just remember that this choice is going to impact the environment over time.

Read more at Buzzle: http://www.buzzle.com/articles/paper-towels-vs-hand-dryers.html

4. Lighting Use lighting controls to automatically turn lights on and off as needed, and save energy. Of course you can save energy

by turning off lights when they're not needed, but sometimes we forget or don't notice that we've left them on.

The most common types of lighting controls include:

Dimmers

Motion, occupancy, and photosensors

Timers.

Before purchasing and using any lighting controls, it's a good idea to understand basic lighting terms and principles.

Also, it helps to explore your indoor and outdoor lighting design options if you haven't already. This will help narrow

your selection.

MOTION SENSOR CONTROLS

Motion sensors automatically turn outdoor lights on when they detect motion and turn them off a short while later. They

are very useful for outdoor security and utility lighting.

Because utility lights and some security lights are needed only when it is dark and people are present, the best way to

control might be a combination of a motion sensor and photosensor.

Incandescent flood lights with a photosensor and motion sensor may actually use less energy than pole-mounted high-

intensity discharge (HID) or low pressure sodium security lights controlled by a photosensor. Even though HID and

low pressure sodium lights are more efficient than incandescents, they are turned on for a much longer period of time than

incandescents using these dual controls.

HID and low-pressure sodium lightbulbs don't work well with just a motion sensor, as they can take up to ten minutes to

produce light.

OCCUPANCY SENSOR CONTROLS

Occupancy sensors detect indoor activity within a certain area. They provide convenience by turning lights on

automatically when someone enters a room, and save energy by turning lights off soon after the last occupant has left the

room. Occupancy sensors must be located where they will detect occupants or occupant activity in all parts of the room.

There are two types of occupancy sensors: ultrasonic and infrared. Ultrasonic sensors detect sound, while infrared

sensors detect heat and motion. In addition to controlling ambient lighting in a room, they are useful for task lighting

applications such as over kitchen counters. In such applications, task lights are turned on by the motion of a person

washing dishes, for instance, and automatically turn off a few minutes after the person leaves the area.

PHOTOSENSOR CONTROLS

You can use photosensors to prevent outdoor lights from operating during daylight hours. This can help save energy

because you don't have to remember to turn off your outdoor lights.

Photosensors sense ambient light conditions, making them useful for all types of outdoor lighting. These light-sensitive

controls are less effective inside the home because lighting needs vary with occupant activity rather than ambient lighting

levels. Many LED nightlights, however, have this feature built in which makes them effective and easy to use.

TIMER CONTROLS

Timers can be used to turn on and off outdoor and indoor lights at specific times. There are two types of timers: manual

timers, which plug into an electrical outlet for controlling objects such as lamps or light strings; and in-wall programmable

digital timers (which look like digital thermostats), which automate indoor or outdoor lighting.

Programmable timers are not often used alone for outdoor lighting because the timer may have to be reset often with the

seasonal variation in the length of night. However, they can be used effectively in combinations with other controls. For

example, the best combination for aesthetic lighting may be a photosensor that turns lights on in the evening and a timer

that turns the lights off at a certain hour of the night (such as 11 p.m.).

For indoor lighting, timers are useful to give an unoccupied house a lived-in look. However, they are ineffective for an

occupied home because they do not respond to changes in occupant behavior, like occupancy sensors.

http://energy.gov/energysaver/articles/lighting-controls 3/1/14

5. Ocean Tide Energy

The relatively constant flow of ocean currents carries large amounts of water across the earth’s oceans.

Technologies are being developed so that energy that can be extracted from ocean currents and converted to

usable power.

Ocean waters are constantly on the move. Ocean currents flow in complex patterns affected by wind, water

salinity, temperature, topography of the ocean floor, and the earth's rotation. Most ocean currents are driven by

wind and solar heating of surface waters near the equator, while some currents result from density and salinity

variations of the water column. Ocean currents are relatively constant and flow in one direction, in contrast to

tidal currents along the shore.

While ocean currents move slowly relative to typical wind speeds, they carry a great deal of energy because of

the density of water. Water is more than 800 times denser than air. So for the same surface area, water moving

12 miles per hour exerts the same amount of force as a constant 110 mph wind. Because of this physical

property, ocean currents contain an enormous amount of energy that can be captured and converted to a usable

form. It has been estimated that taking just 1/1000th the available energy from the Gulf Stream would supply

Florida with 35% of its electrical needs.

Major Ocean Surface Currents (Source: NOAA)

Ocean Current Energy Technologies

The United States and other countries are pursuing ocean

current energy; however, marine current energy is at an

early stage of development. Relative to wind, wave, and

tidal resources, the energy resource potential for ocean

current power is the least understood, and its technology

is the least mature. There are no commercial grid-

connected turbines currently operating, and only a small

number of prototypes and demonstration units have been

tested. More advanced technologies have been developed

for use with tidal currents in near-shore environments.

There are a number of different current technology

concepts under development. Prototype horizontal axis turbines,

Artist rendering of ocean current turbines

similar to wind turbines, have been built and tested, and over the next 5 to 7 years would be the most likely

commercial development scenario.

Although ocean current technology is still in its early stages of development, several tidal and in-stream current

turbine applications are near commercialization. These devices take advantage of the daily tidal cycles in near-

shore ocean environments, or steady water flow from freshwater

rivers.

Seagen,the world's first commercial

tridal energy turbine.

Technical Challenges

For ocean current energy to be utilized successfully at a commercial scale, a number of engineering and

technical challenges need to be addressed, including:

avoidance of cavitations (bubble formation);

prevention of marine growth buildup;

reliability (since maintenance costs are potentially high); and

corrosion resistance.

Because the logistics of maintenance are likely to be complex and the costs potentially high, system reliability is

of particular importance. At present no open-ocean current turbines are deployed in U.S. waters—this

technology is truly in its infancy. However, there is interest in testing prototype turbines in U.S. waters in the

near future, particularly off the coast of Florida.

Environmental Considerations

OIn 2007, the Bureau published the Final Programmatic Environmental Impact Statement for Alternative Energy Development and Production and Alternate Use of Facilities on the Outer Continental Shelf. This document examines the potential environmental impacts related to renewable energy development on the OCS for each phase of development (technology testing, site characterization, construction, operation, and decommissioning). Actual proposals will be evaluated in project-specific analyses under the National Environmental Policy Act. Additional information regarding potential environmental impacts from current energy development can be found in the U.S. Department of Energy Report “ Report to Congress on the Potential Environmental Effects of Marine and Hydrokinetic

Energy Technologies” and at the Ocean Energy Systems Annex IV webpage.

http://www.boem.gov/Renewable-Energy-Program/Renewable-Energy-Guide/Ocean-Current-Energy.aspx

3/1/2014

Open Hydro system used for harnessing tidal

energy.

Wind Turbines in the Ocean Source: Stock photography (copyrighted)

6. Wind Energy

Energy from moving air

Wind is simply air in motion. It is caused by the uneven heating of

the Earth's surface by the sun. Because the Earth's surface is made

of very different types of land and water, it absorbs the sun's heat at

different rates. One example of this uneven heating can be found in

the daily wind cycle.

Electricity Generation from Wind

How Wind Turbines Work

Like old fashioned windmills, today’s wind machines (also called

wind turbines) use blades to collect the wind’s kinetic energy. The wind flows over the blades creating lift,

like the effect on airplane wings, which causes them to turn. The blades are connected to a drive shaft

that turns an electric generator to produce electricity. With the new wind machines, there is still the

problem of what to do when the wind isn't blowing. At those times, other types of power plants must be

used to make electricity.

Where Wind is Harnessed

Wind Power Plants Require Careful Planning

Operating a wind power plant is not as simple as just

building a windmill in a windy place. Wind plant owners must

carefully plan where to locate their machines. It is important to

consider how fast and how much the wind blows at the site.

As a rule, wind speed increases with altitude and over open

areas that have no windbreaks. Good sites for wind plants

are the tops of smooth, rounded hills, open plains or

shorelines, and mountain gaps that produce wind funneling.

Wind power plants produce electricity

Wind power plants, or wind farms, as they are sometimes called, are clusters of wind machines used to

produce electricity. A wind farm usually has dozens of wind machines scattered over a large area. The

world's largest wind farm, the Horse Hollow Wind Energy Center in Texas, has 421 wind turbines that

generate enough electricity to power 220,000 homes per year.

Wind Energy & the Environment

Wind: A clean source of energy

Wind is a clean source of energy, and overall, the use of wind for energy has fewer environmental impacts

than using many other energy sources. Wind turbines (often called windmills) do not release emissions

that pollute the air or water (with rare exceptions), and they do not require water for cooling. They may

also reduce the amount of electricity generated from fossil fuels and therefore reduce the amount of air

pollution, carbon dioxide emissions, and water use of fossil fuel power plants.

A wind turbine has a small physical footprint relative to the amount of electricity it can produce. Many wind

projects, sometimes called wind farms, are located on farm, grazing, and forest land. The extra income

from the turbines may allow farmers and ranchers to stay in business and keep their property from being

developed for other uses. For example, wind power projects have been proposed as alternatives to

mountain top removal coal mining projects in the Appalachian mountains of the United States. Offshore

wind turbines on lakes or the ocean may have smaller environmental impacts than turbines on land.

Drawbacks of wind turbines

Wind turbines do have negative impacts on the environment, but the negative impacts have to be

balanced with our need for electricity and the overall lower environmental impact of using wind for energy

relative to other sources of energy to make electricity.

Modern wind turbines are very large machines, and some people do not like their visual impact on the

landscape. A few wind turbines have caught on fire, and some have leaked lubricating fluids, though this

is relatively rare. Some people do not like the sound that wind turbine blades make. Some types of wind

turbines and wind projects cause bird and bat deaths. These deaths may contribute to declines in species

that are also being affected by other human-related impacts. Many birds are killed from collisions with

vehicles and buildings, by house cats and hunters, and by pesticides. Their natural habitats may be

altered or destroyed by human development and by the changes in the climate that most scientists

believe are caused by greenhouse gases emissions from human activities (which wind energy use can

help reduce). The wind energy industry and the U.S. government are researching ways to reduce the

impact of wind turbines on birds and bats.

Most wind power projects on land also require service roads that add to their physical impact on the

environment. Making the metals and other materials in wind turbines and the concrete for their

foundations requires the use of energy, which may be from fossil fuels. Some studies have shown that

wind turbines produce much more clean electricity over their operating life than the equivalent amount of

energy used to make and install them.

Source: http://www.eia.gov/kids/energy.cfm?page=wind_home-basics-k.cfm

Source: Adapted from a National Energy Education

Development Project graphic (Public Domain)

7. Geothermal Basics What Is Geothermal Energy?

The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal

energy is heat from within the Earth. We can recover this heat as steam or hot water and use it to

heat buildings or generate electricity.

Geothermal energy is a renewable energy source because the heat is continuously produced inside

the Earth.

Geothermal Energy Is Generated Deep Inside the Earth

Geothermal energy is generated in the Earth's core. Temperatures

hotter than the sun's surface are continuously produced inside the

Earth by the slow decay of radioactive particles, a process that

happens in all rocks. People around the world use geothermal energy

to heat their homes and to produce electricity by digging deep wells

and pumping the heated underground water or steam to the surface.

We can also make use of the stable temperatures near the surface of

the Earth to heat and cool buildings.

Use of Geothermal Energy

Some applications of geothermal energy use the Earth's temperatures near the surface, while others

require drilling miles into the Earth.

Geothermal Power Plants Geothermal power plants use hydrothermal resources that have two common ingredients: water (hydro) and heat (thermal). Geothermal plants require high temperature (300°F to 700°F) hydrothermal resources that may come from either dry steam wells or hot water wells. We can use these resources by drilling wells into the Earth and piping the steam or hot water to the surface. Geothermal wells are one to two miles deep.

Geothermal Heat Pumps Using the Earth's Constant Temperatures for Heating and Cooling

While temperatures above ground change a lot from day to day and season to season, temperatures

10 feet below the Earth's surface hold nearly constant between 50° and 60°F. For most areas, this

means that soil temperatures are usually warmer than the air in winter and cooler than the air in

summer. Geothermal heat pumps use the Earth's constant temperatures to heat and cool buildings.

A Geothermic Power Station

Source: Stock photography (copyrighted)

A Type of Geothermal Heat Pump System Source: U.S. Department of Energy, Energy

Efficiency & Renewable Energy (Public Domain)

They transfer heat from the ground (or water) into buildings in winter and reverse the process in the

summer.

Geothermal Heat Pumps Are Energy Efficient and Cost Effective

According to the U.S. Environmental Protection Agency (EPA),

geothermal heat pumps are the most energy efficient,

environmentally clean, and cost effective systems for temperature

control. Although most homes still use traditional furnaces and air

conditioners, geothermal heat pumps are becoming more popular.

Geothermal Energy & the

Environment

The environmental impact of geothermal energy depends

on how it is being used. Direct use and heating applications

have almost no negative impact on the environment.

Geothermal Power Plants Have Low Emission Levels

Geothermal power plants do not burn fuel to generate electricity, so their emission levels are very

low. They release less than 1% of the carbon dioxide emissions of a fossil fuel plant. Geothermal

plants use scrubber systems to clean the air of hydrogen sulfide that is naturally found in the steam

and hot water.

Geothermal plants emit 97% less acid rain-causing sulfur compounds than are emitted by fossil fuel

plants. After the steam and water from a geothermal reservoir have been used, they are injected back

into the Earth.

Many Geothermal Features Are National Treasures

Geothermal features in national parks, such as geysers and fumaroles in Yellowstone National Park,

are protected by law, to prevent them from being disturbed.

http://www.eia.gov/kids/energy.cfm?page=geothermal_home-basics

8. Solar Basics Energy from the sun

The sun has produced energy for billions of years. Solar energy is the sun’s rays (solar radiation) that

reach the Earth. This energy can be converted into other forms of energy, such as heat and electricity.

Solar energy can be used for heat and electricity

When converted to thermal (or heat) energy, solar energy can be used to:

Heat water — for use in homes, buildings, or swimming pools

Heat spaces — inside homes, greenhouses, and other buildings

Heat fluids — to high temperatures to operate a turbine to generate electricity

The main benefits of solar energy are:

Solar energy systems do not produce air pollutants or carbon-dioxide

When located on buildings, they have minimal impact on the environment

Two limitations of solar energy are:

The amount of sunlight that arrives at the Earth's surface is not constant. It varies depending on location,

time of day, time of year, and weather conditions.

Because the sun doesn't deliver that much energy to any one place at any one time, a large surface area

is required to collect the energy at a useful rate.

Kinds of Solar Collecting Technology:

Solar thermal collectors

Low-temperature solar thermal collectors absorb the sun's heat energy to heat water or air for heating in

homes, offices, and other buildings.

Photovoltaic systems

Photovoltaic cells (PV) convert sunlight directly into electricity. Photovoltaic systems can range from those

that provide tiny amounts of power for watches and calculators up to those that provide the amount used

by hundreds of homes.

Hundreds of thousands of houses and buildings around the world have PV systems on their roofs. Many

multi-megawatt (MW) PV power plants have also been built. Covering 4% of the world's desert areas with

photovoltaics could supply the equivalent of all of the world's electricity. The Gobi Desert alone could

supply almost all of the world's total electricity demand.

Solar Photovoltaic

An array of solar photovoltaic panels supplies electricity

for use at Marine Corps Air Ground Combat Center in

Twentynine Palms, California. Source: U.S. Marine Corps

photo by Pfc. Jeremiah Handeland/Released (public domain)

Photovoltaic cells convert sunlight into electricity

A photovoltaic cell, commonly called a solar cell or PV, is the technology used to convert solar energy

directly into electrical power. A photovoltaic cell is a nonmechanical device usually made from silicon

alloys.

Some advantages of photovoltaic systems are:

1. Conversion from sunlight to electricity is direct, so bulky mechanical

generator systems are unnecessary.

2. PV arrays can be installed quickly and in any size.

3. The environmental impact is minimal, requiring no water for system

cooling and generating no by-products.

Solar Thermal Collectors Heating with the sun's energy

Solar thermal (heat) energy is often used for heating water used in homes and swimming pools and for

heating the insides of buildings ("space heating").

Solar Energy & the Environment Using solar energy produces no air or water pollution and no

greenhouse gases, but may have some indirect negative impacts on

the environment. For example, there are some toxic materials and

chemicals that are used in the manufacturing process of photovoltaic

cells (PV), which convert sunlight into electricity. Some solar

thermal systems use potentially hazardous fluids to transfer heat.

U.S. environmental laws regulate the use and disposal of these

types of materials.

As with any type of power plant, large solar power plants can affect

the environment where they are located. Clearing land for construction of the power plant may have long

term impacts on plant and animal life. They may require water for cleaning solar collectors or

concentrators and for cooling turbine-generators. Using ground water from wells may affect the

ecosystem in some arid locations. Birds and insects can be killed if they fly into a concentrated beam of

sunlight created by a "solar power tower."

http://www.eia.gov/kids/energy.cfm?page=solar_home-basics#solar_thermal_collectors-basics

9. Composting

How Does Composting Work /Conserving Valuable Resources

Composting, often described as nature’s way of recycling, is the biological process of breaking up of

organic waste such as food waste, manure, leaves, grass trimmings, paper, worms, and coffee

grounds, etc., into an extremely useful humus-like substance by various micro-organisms including

bacteria, fungi and actinomycetes in the presence of oxygen.

Actinomycetes are similar to fungus in the way they grow and spread, but its distinguishing elements

are that the types of materials they are efficient at decomposing. The active nature in this microscopic

bacteria and the sheer number present (about 10 million per 1 gram of soil), make them highly

effective at breaking down materials like tree bark, newspaper, and other hard organic material.

Today, the use of composting to turn organic wastes into a valuable resource is expanding rapidly in

many countries, as landfill space becomes scarce and expensive, and as people become more aware

of the impact they have on the environment.

How Does Composting Work / Composting Bins

A compost bin is an efficient way of making rich compost and results in fewer yard-trash and garbage

bags. Many varieties of compost bins are available commercially. It allows for control of the four

factors that affect the speed of decay: oxygen, water, food and temperature.

A healthy compost contains a balance of one-quarter green stuff such as: vegetable scraps, coffee

grounds, grass clippings or manure—to three-quarters brown stuff such as: leaves, straw, grass

clippings, shredded paper, coir fiber, wood pellets, or sawdust. In other words, ¼ green matter to ¾

brown matter.

How Does Composting Work / Nature’s Best Fertilizer

During composting micro-organisms from the soil eat the organic (carbon-containing) waste and

break it down into its simplest parts. This produces fiber-rich, carbon-containing humus with inorganic

nutrients like nitrogen, phosphorus and potassium. The micro-organisms break the material down

through aerobic respiration.

Through the respiration process, the micro-organisms give off carbon dioxide and heat. The more

heat generated, the faster the decomposition occurs. During the composting cycle, the contents need

to be mixed approximately weekly.

Compost is a soil conditioner, mulch and fertilizer all wrapped into one. It benefits the environment as

a natural fertilizer for gardening and farming.

Why Composting?

Composting is a topic of growing interest in schools throughout the country. Why composting? There are a

number of reasons.

Composting provides a partial solution to an issue of great concern in many communities. All around the

country, landfills are filling up, garbage incineration is becoming increasingly unpopular, and other

waste disposal options are becoming ever harder to find.

Composting provides a way not only of reducing the amount of waste that needs to be disposed of,

but also of converting it into a product that is useful for gardening, landscaping, or house plants.

In outdoor compost systems, there is a complex food web at work. Some of the more familiar

soil invertebrates, such as millipedes, sow bugs, snails, and slugs help to shred the organic matter into smaller

sized pieces, creating greater surface area for action by microorganisms, which are in turn eaten by invertebrates

such as mites and springtails.

A common assumption is that composting makes sense only out in the country or in suburban areas where

people have large yards. Some of the most avid composters, however, live in the heart of inner cities, where the

compost they make helps to restore or replace worn-out or contaminated soils for school or community gardens.

These gardens and accompanying compost systems appear in former vacant lots, and even on roof tops and

balconies of schools and community buildings.

Composting can successfully be carried out at a wide range of scales, from multi-acre commercial or

municipal windrows to simple backyard heaps.

To sum it all up, composting is a topic that addresses a real-world issue and helps to instill a sense of

environmental stewardship in youth. It can be carried out at a wide range of scales, indoors or out, in

any geographic location. Because it is a process that relies on biology, chemistry, and physics, it can be

used for a wide range of scientific projects or experiments and can help students to see the

interconnections between various scientific fields.

Sources:

http://www.benefits-of-recycling.com/howdoescompostingwork/

http://compost.css.cornell.edu/why.html

Source: http://www.asla.org/greenroofeducation/pdfs/StudentWorkbook.pdf

10. Green Roofs