Hershey Middle School Science Class

In an effort to educate the communities we serve about the growing field of renewable energy, Wind and Solar LLC is proud to present the following material pertaining to Wind and Solar Energy technologies to the students of Hershey Middle School. We extend our thanks to the Science teachers and other staff members that worked to make this possible.

Contents:

1. Reasons to Switch to Renewable Energy

A) Pollution

B) Economics

C) Energy Independence and Sustainability

2. Wind Energy

A) How does Wind Energy Work

B) Finding Available Wind Resource

C) Problems and Solutions with Distribution

3. Solar Energy

A) Different Solar Technologies

B) Commercial vs. Residential

C) Net-Metering Law

1. Reasons to Switch to Renewable Energy

The reasons for switching to renewable energy are obvious when examined against today's most common forms of energy. Coal, Petroleum, and Natural Gas are all considered fossil fuels and combined currently make up about 80% of our Energy supply in the USA.

1-A) Pollution

Fossil fuels produce CO2, Methane and other greenhouse and harmful gases when burned to produce energy.

These gases are responsible for increasing the average temperature of our planet, which is devastating to important ecosystems such as the Great Barrier Reef and the Polar Ice Caps.

Fossil Fuels also produce gases that are harmful to people's health as well as other animals. For Example; Nitrogen oxides (NOx) emissions, a byproduct of all fossil fuel combustion, contribute to acid rain and ground-level ozone (smog), which can burn lung tissue and can make people more susceptible to asthma, bronchitis, and other chronic respiratory diseases.

Another form of pollution is created during the mining and extraction of fossil fuels. The chemicals used for extraction, and the erosion caused by mining, devastates the habitats of hundreds of species in ecosystems around the world.

Even more pollution is created when an accident related to fossil fuel mining and transportation happens.

Increasing the amount of energy from Clean and Renewable Energy Sources that we use in the world today will help to reduce the amount of pollution and damage to ecosystems that are essential to not just the health of our planet, but our own health.

1-B) Economics

Since the Wind and the Sun are free and can be found in abundance, it makes little economic sense to continue to pay for a continued supply of fossil fuels in the long run.

>Fossil Fuel Associated Costs:

Power Plant Construction + Operation and Maintenance + Fossil fuel mining and extraction + Disaster Relief + Health Associated Costs

>Renewable Energy Associated Costs:

Power Plant Construction + Operation and Maintenance

1-C) Energy Independence

One of the main benefits of Renewable energies like Wind and Solar, is that they get used close to where they get made. This means that the people using it don't have to rely on other people, companies, or governments to give them the energy they need. Not having to rely on others for your needs has obvious benefits.

2. Wind Energy

Wind energy is one of the cleanest and fastest growing forms of energy in the world thanks to the plentiful availability of the wind and the decreasing cost of Wind Energy Generating Equipment.

2-A) How does Wind Energy Work

2-B) Finding Available Wind Resource

In order to make a Wind Generator cost effective, the most important part of any project is determining whether there is enough Wind at the location of interest. Wind will depend on location and Height of the Tower supporting the wind generator. Here are two different maps showing the difference in Wind Resource Potential at 100 feet (30 meters) vs 260 feet (80 meters)

These maps only provide a rough idea of where to find a good Wind Resource when planning a wind farm. A detailed year/ multi-year Wind study must still be performed at the proposed site of installation to get an exact measurement on wind resource and determine whether it is a viable site. A wind study will typically consist of the installation of a temporary tower that holds wind measuring devices called anemometer (measures wind speed) and a wind vane (measures wind direction). The reading from these measurements will be analyzed with advanced computer modeling software to optimize the layout of the Wind Farm.

2-C) Problems and Solutions with Distribution

As can be seen in the wind map above, most good land-based wind resources are in remote areas such as the rocky mountains and great plains as well as other mountain tops scattered around the country. Since the majority of the population does not live near mountain tops, it makes it especially challenging to bring the electricity produced on a mountain to a city with a lot of electricity usage. This is one of the major expenses that needs to be considered when building a wind farm.

One of the latest advancements in Wind energy is the development of Off-shore Wind farms. As you can see in the wind maps above, there is a tremendous amount of resource potential out at sea. That is because there are no obstructions to slow down the wind such as mountains or buildings.

The development of offshore wind resource potential is solving the problem of long distance distribution. Countries such as Denmark and Holland have been pioneers in this technology for over 10 years, and it is just now arriving in the USA. Since nearly 2/3 of the US lives near a coast, it would be easy to deliver the electricity from the ocean to major cities such as NY, Philadelphia, Washington DC, etc.

The first offshore Wind farm in the USA started operating in December 2016. It is called "Block Island Wind farm" and is located off the coast of Rhode Island. Other projects are being considered up and down the east coast, with the most notable of these being the Atlantic Wind Connection, which would connect multiple off-shore wind farms through a large underwater transmission line connecting NY, NJ, DE and VA. This project would enable population centers to capture a large amount of Wind Energy without worrying about long transmission lines.

3. Solar Energy

3-A) Different Solar Technologies

There are different ways to capture the energy from the sun. The two most common forms of Solar Energy are Photovoltaics, and concentrated Solar.

When using photovoltaics, the energy coming out of the panels is Direct Current (DC), the same kind that is in batteries. However, the electric grid and most things that you plug into an outlet works with Alternating Current (AC). In order to make the electricity from solar panels usable, it needs to pass through an inverter. This will convert the electricity from DC to AC.

Concentrating Solar Power Towers have been emerging since the first one was put in service in 2007 in Spain. They consist of thousands of mirrors mounted on the ground which reflect the sunlight to a single point at the top of the tower. The light is so concentrated that it creates steam which then drives a turbine to produce electricity.

3-B) Commercial vs. Residential

Solar Photovoltaic Panels are so versatile that the same panels can be installed in large fields to create a solar power plants to power entire towns, or on the roof of a house to help people eliminate a family's electric bills. They can be mounted on the ground or on different kinds of roof.

Solar farms require a large amount of space to be installed, and this can lead to loss of habitat for many animals. Cutting down trees to install solar panels may seem counterproductive when it comes to saving the environment. The CO2 that trees absorb during photosynthesis is essential to the balance of our ecosystems. However, the truth is that producing solar energy will avoid more CO2 production from fossil fuels than those trees could ever absorb. Solar farms also help avoid all the associated pollution and environmental impacts associated with mining and extraction of fossil fuels.

3-C) Net-Metering Law

One of the main reasons that Solar PV (photovoltaic) is getting to be so popular is thanks to a law called Net-metering. This allows individual property owners to produce their own energy while remaining tied in to the grid, eliminating the need for expensive battery storage solutions to store the energy for use when the sun doesn't shine. Thanks to the net metering law, consumers of energy can produce more electricity credits than you need during the day, and use those same credits at night when the sun is not shining. This is also effective when it comes to higher summer production vs lower winter production, allowing you to produce credit in the summer which will then be used in the winter when days are not as long.