Renewable energy can be used over and over again because it can replace itself quickly.  Renewable energy comes from the heat of our sun, or from heat inside our earth. It will always be available, no matter how much we use it. 

We have renewable energy on Martha’s Vineyard. Any day when the wind blows, or the sun shines, or we swim in the ocean, we can feel this energy. We can also capture this energy to make electricity from wind, sun, water, biomass and geothermal.

Long ago, more than a hundred years ago, Martha's Vineyard had no electricity and used 100% renewable energy. Wind energy was used by sailboats to carry people and supplies back and forth to the mainland. Windmills ground corn and wheat. Solar energy from the sun grew food, helped to warm houses and dried clothes. We burned wood to heat houses and cook food. We used waterwheels to grind corn. We used renewable energy for everything we did.

That all changed when steam and electricity were invented. We gradually began shipping nonrenewable energy to our Island, such as oil, coal, and gas. Now we use these fuels to heat our homes, dry our clothes, cook our food, and run our cars. More than 99.9% of the energy we use to make our Island work comes from the mainland. Today, we use much less than 1% renewable energy on Martha’s Vineyard.

What a change! We are learning to use renewable energy again with new technology to heat our homes, make hot water and to grow food in our gardens. We are beginning to make fuel for cars from vegetable oil. We are beginning to make electricity from solar panels and wind turbines.

We made posters and wrote about what Martha's Vineyard would look like, if we used more renewable energy to make electricity and fuel right here on our Island.

Take a virtual visit:
http://www.efieldtrips.org/Energy/index.htm

Energy From The Sun

Solar energy is all around us on Martha’s Vineyard, because it is energy that comes from the sun. Sol means sun. Solar energy is renewable, which means the sun will keep making energy for millions of years.

Solar energy travels through space from our sun to the earth in rays. Some are light rays that we can see. Some are rays that we can’t see, like x-rays. We can use solar energy to keep us warm. The light rays from the sun turn into heat when they touch us, or our clothes, or other objects. Without the sun we couldn’t live on earth, it would be too cold.

Plants use the light from the sun to grow. Plants take the energy in light and store it in their roots and leaves. That energy feeds every living thing on earth. When we burn plants and trees, we can use the solar energy stored in this biomass to cook, or warm our houses.

Solar energy creates the water cycle and the wind. We can capture that energy with dams and windmills to make electricity.

We can capture solar energy directly from our sun to make electricity with solar panels placed on buildings, signs, boats, calculators, spacecraft, satellites, and even model solar cars.

We have solar panels on Martha’s Vineyard; some are even on your school. Every time you take a ferry from Vineyard Haven, look for the solar panels on the lower roof of the Steamship Authority.

Electricity From The Sun

Solar Panels

It is difficult to capture the sun’s energy because it is all spread out – not much of the sun’s energy is concentrated in any one place. Some solar energy is collected when objects absorb and hold the heat from the sun, such as rocks, sand, and asphalt. But about fifty years ago, inventors learned how to capture the sun’s energy and convert it directly into electricity by using solar panels.

Photovoltaic cells inside the solar panel convert heat from the sun directly into electricity.

We have many buildings with solar electric panels on Martha’s Vineyard. Perhaps you’ve seen the solar electric panels on the ferry terminal in Vineyard Haven, or on your school, or near the beach in Aquinnah or Menemsha. Solar electric panels can be placed on the ground or on buildings to help make electricity.

Solar panels work when the sun shines. They slow down when it’s cloudy or rainy and they stop working when the sun goes down. They work best if the panels are facing south and get no shade.

The photovoltaic cells make a kind of electricity called direct current electricity. Yet we use alternating current electricity in our homes and schools. So we use a red box, called a Sunny Boy, to change the electricity into the kind we use. The Sunny Boy is attached to a wall inside the building and electric wires connect it to the solar panels. Once the Sunny Boy converts the electricity to the kind we use, it is sent through more electric wires to a solar meter. The meter measures the amount of electricity made in Kilowatt hours. Then the electricity is sent to the electrical panel in the building.

The electricity that the solar panel makes is used immediately, or it's sent to a large electric power grid on the mainland through the electrical panel. If electricity is sent to the grid through the electrical panel, the solar meter spins backward! Electricity is sent from the electrical panel through wires and four large cables under the ocean to get to the mainland. 

When the power grid works, the solar electric panels work. When the grid has a power failure, the solar electric panels don’t work until the power failure is fixed.

Some solar panel systems store the electricity they make in large batteries until it is needed. These panels are not connected to the electric power grid, so they can operate during a power failure. The batteries are very large, expensive and hard to maintain. These systems are very useful in isolated areas on the Vineyard that don’t have power lines, such as some parts of Chappaquiddick.

Solar Hot Water

We can also make hot water with energy from the sun. A black, insulated box has a glass cover, with tubes of water winding around inside. This box is put on the roof of a house, or on the ground, and aimed at the sun. This is sometimes called a solar collector. It is heated by the sun all day. These tubes connect to a tank of water in the house and wrap around the tank to warm it. This can preheat the water, or provide all the hot water we need, depending on the day.

Fun Facts about Solar Panels

• There are no mechanical or moving parts to wear out.
• Photovoltaic cells were discovered at Bell Laboratories in the early 1950’s.
• Photovoltaic cells are used in space to power satellites.
• Photovoltaic cells are on space vehicles on Mars.
• Solar panels are regularly used for roadside emergency phones, calculators, space flights.
• More than 100,000 homes in the U.S. depend on solar panels as a primary power source.
• Solar panels don’t produce as much electricity when temperatures go above 80 degrees in full sun.
• Solar panels produce more electricity when temperatures are cooler!

Kid Solar Monitoring

Every day we go to the solar meter in our school to find out how much electricity is being made by solar panels on the roof of our school.

How does it work?

First, the sun’s rays are collected by solar panels on the roof of our school. The solar panels are made of photovoltaic cells. Photo means light and volt means measuring electricity. A photovoltaic cell turns light into electricity.

The electricity from the photovoltaic cell goes through electric wires that connect the solar panels on the roof to the Sunny Boy inside our school.

The Sunny Boy is a big red box that is on the wall in our school. It changes the kind of electricity we get from the photovoltaic cells (direct current) into the kind of electricity that we can use in our school (indirect current).

Then the Sunny Boy sends the electricity to the meter. The meter measures the electricity and tells us how much electricity is made each day. We collect data from the solar meter in kilowatt hours. A kilowatt is equal to the energy of ten 100-watt light bulbs.

Electricity then goes from the meter to our school’s electrical panel. We use electricity when we turn on lights and use our computers.

If there is more electricity than the school needs, then the left over electricity is sent to the power grid for our community. Our school is so big, it will probably never send electricity back to the grid – we will use it all.

How do we chart it?

Every day we chart how much electricity has been made by the solar panel. We put the data we gather into bar charts for each month.

Then we ask:
Which day made the most electricity? Which day made the least electricity? What was the weather like for each of the days? How much electricity was made in the whole month? Is there a connection between the weather and the amount of electricity made?

What about the length of day?

We have also been taking data of the length of days. We get the data from the computer and we chart it in two ways - as a bar graph and as a line graph.

When we compare our length of day charts with the solar charts, our prediction is that the length of day affects the solar panels. Because if the day is longer, then we will get more sun and the panels will make more electricity.

--By Harrison, Mikey, Stuart, Alex, Eric, Grade 3, West Tisbury School

Model Solar Cars: How Does the Solar Panel Work?

Photovoltaic cells inside the solar panel convert heat from the sun directly into electricity.

Each photovoltaic cell is made of two layers of silicon and millions of atoms. One layer of silicon has a small amount of boron added to it, which attracts electrons from the atoms, and creates a positive layer (the p-layer). The other layer of silicon has a small amount of phosphorous added to it, giving it extra free electrons, and creates a negative layer (the n-layer).

When the two layers of silicon are placed together, an interesting thing happens at the moment of contact: free electrons move between the two layers as the electrons become pulled from the bottom half to the top half. This contact point is called the p-n junction and it produces an electric field between the two layers.

Yet there’s a challenge.

The electrons are all attached to atoms, and the atoms won’t let go very easily.

This is where the sun’s energy turns heat into electricity.

As the sun shines on these materials, the sunlight has enough energy to knock the electrons off of the atoms. The sun’s rays energize the free electrons and they move - they are pulled to the top. When electrons move, they create electricity. The electrons keep moving in a closed loop, through a wire circuit, making direct current electricity as long as there is light from the sun. No other source of energy is needed. The moment the light from the sun stops, the photovoltaic cells stop producing electricity.

Wind

Wind energy is all around us on Martha’s Vineyard. If you look at a wind map of Massachusetts, you will see that it is very windy all around the Cape and Islands. We live where the average wind speed is between 14-19 miles per hour, depending on the day and area.

Do you know where wind comes from? Wind is moving air. The air is moved by the heat from the sun. The sun’s rays touch the earth, the earth absorbs the heat from the sun, and then the earth warms up the air that is very close to it. That warm air rises up into the sky. After the warm air rises, fresh cool air sinks down close to the earth and gets warmed up, and then it rises up into the sky. This makes wind. We couldn’t have wind without the sun warming the earth because solar energy creates the wind cycle .

We can use wind to do work for us. Wind energy is renewable, so the wind cycle will keep making energy for millions of years, as long as the sun shines.

It was wind that brought ships and people from Europe to the Vineyard long ago. Wind filled the sails of the ships, helping them to move through the ocean.

Windmills were built all over Martha’s Vineyard for hundreds of years. They turned moving air into energy to grind grain and pump water when electricity had not yet been invented. Once electricity was invented, we stopped using windmills here most of the time, because we brought electricity to the Vineyard from the mainland in cables under the sea.

Now a different kind of windmill, called a wind turbine, has been invented to create electricity from wind energy. We can capture wind energy with wind turbines to make electricity. There are many wind turbines all over the world and we have a wind turbine on Martha’s Vineyard.

When the wind spins the blades of the wind turbine, the rotor captures the wind’s energy. As the blades go around, the generator moves around to make electricity. What happens in high winds? Can the blades go too fast? Wind turbines work because they slow down the speed of the wind. They have an overspeed system to make sure it is kept under control during high winds.

Wind turbines can be connected to the electric power grid. This way electricity can always be available, whether the turbine makes more or less electricity than is needed each day.

Electricity moves from the wind turbine to the Inverter. The inverter changes the electricity into the kind we use at home or school. Then the electricity is sent to the meter, where it is measured as we use it. If the wind turbine is making more electricity than is needed, then the electricity is sent to the electric grid for anyone nearby to use and the electric meter spins backwards!

When the power goes out, the wind turbine must shut down when it is connected to the electric power grid, for safety reasons.

Wind turbines do not have to be connected to the electric power grid. When they are not connected, they are called a stand-alone system. Stand-alone turbines produce different amounts of electricity on different days, depending on the speed and strength of the wind on each day.

Water

Water energy is all around us on Martha’s Vineyard. We have the ocean surrounding us and we have many ponds and streams on our island. We are used to using water in many ways – for drinking, washing, gardening, playing, swimming, fishing, canoeing, sailing, and riding the ferry to get here!

Water is constantly moving. It moves from the clouds to the Earth and back again in a water cycle. The sun’s energy creates the water cycle because the sun heats and evaporates water all over the world, especially the oceans. Once it’s heated by the sun, water turns into water vapor and rises up to form clouds. When enough water vapor has gathered in the clouds, water falls from the clouds as rain or snow and then the cycle begins again.

Water energy is renewable. The water cycle has been making energy for millions of years, and will continue as long as the sun shines and the earth stays in balance.

We can use water to do work for us. When water flows, it creates energy and there are ways we can capture that energy. Long ago, we used water to move waterwheels on Martha’s Vineyard to grind corn and wheat and cut wood at our saw mills. We used waterwheels to change water energy into mechanical energy to do work for us.

On the mainland, a hydropower plant now captures water energy instead of a waterwheel. These hydroelectric plants on the mainland change water energy into electricity. When water flows down a dam, it builds up energy as it rushes through a turbine that turns a generator, which makes electricity. The water is sent back to the river. The electricity is sent to the electrical grid and used in homes and schools.

Geothermal

Geothermal energy is heat underneath the ground, inside the earth. In some places in the world, it’s right near the surface, bubbling up in hot springs, or volcanoes. We can see it and feel it. It’s very hot. In other places, like Martha’s Vineyard, geothermal energy is deep underground, so we don’t feel it and we are less aware of it. Because it’s underground, this energy is not affected by the sun. Yet geothermal heat flows outward from the core of the earth all the time. Some scientists think that without the heat from the core, our earth would become cold, even with the sun shining.

If you ever look at the cliffs in Aquinnah, you can see that the earth is made of layers. The cliffs have different layers of colored clay, sand, and soil on the crust of our earth. These layers then continue deep underground. There are many, many layers inside our earth. There is a layer of magma and rock that’s called a mantle. Then there is a layer of magma that is so hot it’s really liquid rock. There is an iron core in the middle of the earth.

Geothermal energy is renewable energy, because it is always available deep inside our earth. Heat is made each day in our earth’s core.

We can use geothermal energy to work for us. In some countries, like Iceland, people can swim outside in the middle of winter in hot springs, or they can take showers with water from the hot springs, and their homes are heated with water from the hot springs. Magma is near the surface in Iceland. They use geothermal wells to pipe the hot water into their homes.

In certain parts of the U.S., mostly California and Nevada, geothermal power plants can also use steam from geothermal wells to make electricity. These power plants are built where the magma is much closer to the earth’s crust, so the well doesn’t have to be so deep.

• The steam comes up the well from the mantle, deep inside the earth.
• The steam is sent to the power plant through pipes.
• The steam spins turbines in the power plant and electricity is generated.
• The steam turns back into water and is returned to the ground.
• The electricity goes through wires to homes.

We don’t always need a power plant to generate geothermal energy to heat homes and buildings in the U.S. Out West, many ranches and farms near geothermal springs are capturing steam to make electricity themselves. Over 200 resorts in the West also use geothermal energy to heat hot water for everyone to use and for swimming pools.

Biomass

Everywhere you look, biomass is all around us on Martha’s Vineyard. Biomass is anything that is alive, like trees, bushes, grass, animals, or food that we’re growing. It is also our garbage, any food that we throw away, because it was once alive. We use biomass every day. Everything we eat comes from plants. Everything animals eat comes from plants. And plants use the sun’s energy to grow. Plants absorb the sun’s energy and store it in their roots and leaves. When we eat the plants, we get energy from them. When we eat animals, we get energy from them and from the plants that fed them.

Long ago on Martha’s Vineyard, the Wampanoag used biomass to take care of themselves. The Wampanoag used biomass to both make and heat their homes. They used biomass to make canoes. They used biomass for fuel for cooking. The trees and bushes grew again. Then they could use them again. Biomass was an important part of their lives. The Wampanoag used 100% renewable energy.

Biomass is still an important part of our lives. We use biomass for food on-island and we ship food from the mainland. We use trees to build our houses and for fuel. Trees grow in our State Forest, and we can get a permit to cut trees there to provide fuel for our homes. Some people burn wood in their fireplace or wood stove to make heat and keep warm.

Since we can regrow plants and trees for food, shelter and heat, biomass energy is renewable energy. We can always grow more, if we take care of the earth. Biomass has been making energy for millions of years by using the sun, wind and water to regrow plants and trees.

Biomass can be used as a fuel to heat buildings. Some people think that an Island school could have a furnace that burned wood from the State Forest to keep the school heated, instead of using nonrenewable energy like oil.

Biomass can be used as a fuel to make electricity. Some towns on the mainland take garbage and burn it to make electricity.

Biomass can also be converted to a fuel to run our cars and school buses! This fuel is called biodiesel and it is made from vegetable oils. It can also be made from used oil from restaurants and then it often smells like French Fries. Biodiesel fuel is sold on Martha’s Vineyard. See if you can smell the cars that use biodiesel fuel! In some places, biodiesel is used as fuel for school buses. It does not produce as much air pollution.

Nonrenewable energy
Oil, coal, propane, natural gas and uranium are called nonrenewable energy because they take millions of years to form. Once we use them, we cannot replace them quickly.