Week 5, July 9 2013, Trip to NRG Cheswick Power Plant

Summer Session, Week 5

Tuesday, July 9, 2013

The NRG Cheswick Power Plant is 1 of the NRG's 800 power plants nation-wide. It is coal-fired, like many of the power plants in Pennsylvania and the surrounding states. However, in states like Pennsylvania, which have deregulated energy industries, the consumer is free to choose which company provides their electricity. [If you are a PA resident interested in researching what this means for you, visit PAPowerSwitch.com]

Our guide, Kevin, explained that when it comes to coal-fired electricity generation, there is not a high rate of job growth, and that the Cheswick site only employs 103 people. However, because of certain laws and regulations placed on the energy industry, the company utilizes third-party consulting firms to prevent fines and penalties, and the market has been growing for these firms.

This particular plant supplies about 570 MW of electricity in a year. The coal used is delivered from the West Virginia pan handle via river barge on the Allegheny River, and the plant burns 5-6 of these barges daily. Those 5-6 barges produce 500-600 tons of ash a day. Burying it in a landfill owned by the company is a last resort. Instead, the ash is often given to concrete companies as additive.

To generate electricity, only a few materials are required: conductive wire, magnets, and relative motion between the two. With coal-fired electricity generation, coal is burned as a fuel to heat water into steam, then the steam is used to turn a turbine which creates a fast-spinning relative motion between the two. This causes electrons to move from + to - , one way, creating electricity.

All forms of fuel work in basically this same way, from coal, oil and natural gas to nuclear, wind and hydroelectric. All rely on the burning of a fuel to turn water into steam in order to turn a turbine. (The main exception is photovoltaic cells, which directly convert the sun's energy into the movement of electrons = electricity in a usable form.)

Back to our big focus in this summer's session: water. The Cheswick power plant purifies the water it uses to boil into steam beforehand. It was estimated that about 20,000 gallons of this water is lost in a day via leaks, cracks or otherwise. It takes 35 to 40 million gallons of this water to operate the power plant a day, but this includes steam that is reused by condensation before being boiled again.

The Cheswick power plant relies on the nearby Allegheny River to supply it with enough water to cool its machines, as well as to provide the temperature change necessary to convert its purified steam back into purified water. The purified and the river water never mix, but pass in parallel tubes by one another in order to provide cooling. It is estimated that the plant uses 249,000 gallons of river water for this purpose EVERY MINUTE.

In list form, the Cheswick Power Plant uses water for:

• Purified water for creating steam to turn a turbine
• River water to cool steam back into purified water for reuse
• River water to cool machines
• River water for firefighting
• Well water to replace steam water lost in turbine system

Pictures from our visit can be viewed here.

Week 4, June 27 2013, Exhibit Workshop

Summer Session, Week 4

Thursday, June 27, 2013

Exhibit Workshop with Kaleen

Today focused on how to present information to a typical museum audience, which is a mix of very young to older guests.

Our challenge for the day was to explore the museum and see how many different ways stories are being conveyed to the patrons at the Carnegie Museum of Natural History.

Some of the ones we found were:

• Through text - a plaque explaining a certain object through visual words.
• Through movement - the way that animal mounts or dinosaur bones are set up can tell a story of interaction between each other.
• Through video - spoken explanations with associated visuals
• Audio - Bird hall's "chirping" or audio recording
• Demonstration - typically at a teen docent carts

Week 4, June 25 2013, PWSA Field Trip

Summer Session, Week 4

Tuesday, June 25, 2013

Trip to Pittsburgh Water and Sewer Authority

The water that the PWSA (and all other water treatment plants in the Unites States) treats is used in Pittsburgh for everything from drinking water to flushing our toilets.

The process begins when the plant takes in large amounts of river water from the Allegheny, which is held in huge underground tanks before being pumped up to be treated. The first line of filtration captures large debris like leaves, sticks and even fish that were pumped up with the water by passing it through huge metal screens. Gravity is used to an advantage, as chemicals that cause impurities like bacteria and algae to coagulate and sink to the bottom of treatment tanks. These coagulates can then be removed from the water.

Due to Pittsburgh's limestone bedrock, water that is taken in from the Allegheny River has a slightly basic pH of ~7.2. In order to aid the coagulation process, the water is treated to adjust the pH to 6.9, as the reaction of the coagulant chemical with biological matter is sped up at a lower pH.

The water then sits for days in large open tanks that fill the space of an entire warehouse. These are called sedimentation basins. The plant introduces charcoal, which works in much the same way as a carbon filter such as a home-use Britta filter works. Finally, it is passed through microfilration filters that are only large enough to let a water molecule through. This then removes more unwanted compounds from the water that are too large to pass through the membrane of the filter. At last, it is pumped out for use.

The Water Works PWSA supplies water to Reserve township, Fox Chapel, Aspinwall, the city of Pittsburgh, South Side, Millvale, etc. The facility typically serves 300,000 residents of the city, and up to 500,000 people on a workday, as people drive into the city for work. The Water Works on average puts out 65 million gallons of clean drinking water a day.

The amount of energy it takes to do this, from running the machines to just turning the lights on is ~$5 million.

Clean, treated water is used in many different industries, even fracking. Alternatively, the water can be drawn directly from the water source that supplies drinking water to people.

Pictures from our tour can be viewed here.

Week 3, June 20 2013, Exhibit Design Day

Summer Session, Week 3

Thursday, June 20, 2013

Today was an exhibit design day with Kaleen.

We focused on how to present information in an exhibit in ways that are both informational and engaging, rather than the usual block of text next to an object behind glass, which is typical in museums.

Every teen was given a concept, design, or prototype to report on, but the report could not just be lecture like text at a museum would be.

Energy tie-ins for many of the inventions/designs/etc were:

• How do we get technologies like these to areas of the world most in need of them? (i.e. the Aquaduct bicycle prototype)
• There is a cost to manufacture, ship
• Often they are expensive, but are needed in the poorest parts of the world

Pictures from today's session can be viewed here

Week 3, June 18 2013, Panther Hollow Watershed Walk

Summer Session, Week 3

Tuesday, June 18, 2013

Today, we explored an urban watershed near the Carnegie Museum of Natural History.

Our guide for the watershed tour was Krissy Hopkins, a Pitt PhD student who studies green infrastructure, hydrologic function, and holistic accounting of green infrastructure costs and benefits. Before we departed for the watershed walk, she gave us a brief overview of her work at Pitt, as well as explaining how to take certain measurements, and why they are important.

Our equipment included water testing bottles, a meter stick a stop watch, and a Garmin GPSmap 62s, as well as trash bags and gloves in anticipation of picking up trash we would find along the way.

Weather conditions were rainy, which was actually a stroke of luck, as the rainwater-fed streams that empty into Panther Hollow Lake were flowing, and all streams had increased water flow. As we made our way off the paved roads and sidewalks of Oakland and into Panther Hollow valley, we experienced first-hand how trees mitigate the urban heat island effect; as we progressed further into the foliage, the cooler and less humid it seemed to get.

We took two water samples at the following locations:

1. Phipps Run stream at GPS location N 40°26'16.1" W 079°56'45.6"
2. Panther Hollow stream at GPS location N 40°26'11.6" W 079°56'43.4"

(Position formats for both sites are hddd°mm'ss.s" , Map Datum WGS 84, Map Spheroid WGS 84)

We were able to measure average flow rate by floating a piece of leaf down the stream and calculating the time it took the leaf to travel one meter. The meter stick was also used to determine stream depth at time of sampling.

Water sample testing will be done in a future Energy-Net session, as we did not have the materials available to us this day.

Week 2, June 13 2013, Pollutant Lists

Summer Session, Week 2
Thursday, June 13, 2013

Today, we had to switch our original plans around because of inclement weather. Instead of taking a walk and exploring the Panther Hollow watershed near the museum, we stayed inside and explored what pollutants exist in water, as well as their sources, specific impacts on water, if they're regulated, whether the regulations are for surface or drinking water, etc.

We first attempted to guess the answers by hypothesizing what sources each pollutant could come from as well as their effects on water quality by using any previous knowledge we had. Each of these educated guesses was assigned a color-coded sticker for confidence. Then, we began research online to confirm or refute each.

This was a chance to sharpen first our critical thinking skills, and then our Internet research skills.

The finished product was a poster-sized grid of information about each pollutant in water that we will be testing this summer. We then copied it into our field notebooks for future reference. It will come in handy later when we begin to form hypotheses about the water we will study.

Week 2, June 11, 2013, Allegheny vs. Monongahela Rivers

Summer Session, Week 2
Tuesday, June 11, 2013

Today, we focused on how to read topography maps of our area. Our first exercise was to draw our local watershed by locating our house on topo maps of Pittsburgh and its suburbs and predicting where and how water would flow, given the geography shown on the maps.

Some pointers for reading topo maps are:

• Elevation = increase in the amount or level of something (100 feet, 100 meters, etc; scales may change for each map)
• Waterways "point" upstream
• Close lines = steep slopes
• Far lines = gradual slope

Our next activity involved finding and reporting differences between the Allegheny River and the Monongahela River, which meet at The Point in downtown Pittsburgh and form the Ohio River. We used our Internet research skills to find facts about the rivers, including:

• Length
• Area
• Number of Electrical Generating Units (EGU's) there are
• Locations of their headwaters
• How many locks and dams there are
• How many people live in their watersheds
• What industrial plants there are in their watersheds
• Which river's water would you prefer to drink, given the above information?