Last friday in class, we continued our Robotics lab with a new solar cell activity! In this lab, we measured light from varying distances and recorded the changes in power. Next, we added color panels to see if we could get even more variables. In order to do this, my partner and I used our solar cell connected to our robot, a ruler, a flashlight, different colored panels, and of course, LabView. Below is a picture of our solar cell connected to our robot!

The solar cell is the little black box, which at first glance may look simple. However, after conducting the experiment I was able to see the way the cell actually worked and understand the complexity!

Our instructions were to hold the ruler up to the power cell and shine the light on the cell from varying distances above it. Then, with the help of LabView (thank god!), we were able to obtain the variances in data when we measured the light further away from the cell. We then did the same with the five different color panels we got from Professor Sonek. The panels looked like this:

When we started, we did not see much variance in the data. This was concerning as the whole point of the lab was to compare the data. However, after a few trial runs, I began to understand how to correctly obtain the data.  When we got a hang of the lab, we took data from shining the light at 8cm, 16cm, 21cm, and finally, 32cm. From these different distances, the effect of the distance of the  light on the power  cell was quite clear. When we began to add the colors, I guessed that they would not change much, however, I was sadly mistaken. The color panels actually did affect the data. I could not wrap my head around the fact that just because a panel was a different color, the power levels would be different! I would love to look more into this.

Anyways, our next task was to enter the data in excel and create graphs. This was perhaps the scariest part for me as I’m not an avid excel user and I really really really dislike graphs. After taking a deep breath and asking some questions, however, it all began to make sense to me. Maybe science isn’t so bad after all….

Our data appeared like this

Solar energy is the cleanest and most abundant energy source available in today’s day and age. Solar energy can be used for generating electricity, providing lighting, and heating water for domestic, commercial, and industrial use. What’s even more positive about solar energy is that it can be created in many different ways! According to seia.org, “there are several ways to harness solar energy: photovoltaics (also called solar electric), solar heating & cooling, concentrating solar power (typically built at utility-scale), and passive solar.” The first three of these, which are active solar systems, use electrical devices to convert the sun’s heat and light to usable sources of energy. The others are passive solar systems, which are made to collect energy from the sun’s heat and distribute it without the use of moving parts. This kind of energy is a flexible technology as “solar power plants can be built as distributed generation (located at or near the point of use) or as a central-station, utility-scale solar power plant (similar to traditional power plants).” The utility scale plants can even store the energy for use after the sun sets!!

http://www.seia.org/about/solar-energy

Due to the fact that solar energy is renewable and thus, will never run out, countries all of the world have been converting to using solar power. Below is a graph of the countries with the most installed solar energy.

Solar Energy Statistics

As you can see, Germany is the leading country in the Solar Energy industry, and its use is continuing to grow!  According to planetsave.com, “During 2009, Germany installed eight times more megawatts of photovoltaics solar energy capacity than America did that year.” While Germany has already converted much of its energy to solar, installing thousands of solar panels, the country plans to rely only on renewable energy by 2050. Recently, German solar farms produced a world record of 22 gigawatts of energy which is equivalent to the output of 20 nuclear plants. An image of the farms can be seen below:

Germany Smashes Solar Energy Records

Read more at http://planetsave.com/2012/03/06/top-6-countries-using-solar-energy/#Qyo0O8EJIEKwol5d.99

Just behind Germany is spain, which gets 10% of its energy from solar power. In fact, Spain was once the leader in solar power. Furthermore, the Vatican has the larger solar power plant in Europe! “Although it is the smallest country in the world, the Vatican has spent $660 million to build a massive 100MW photovoltaic installation. The output will be more than enough to provide enough power for the whole country.” This is an incredible step forward into solar energy. Below, is an image of the solar power device in the Vatican.

Over the next few years, it will certainly be exciting to watch countries convert to solar energy! Clearly, this is already happening and proving to be a success in creating more renewable energy in order to save our beloved planet earth. I will most definitely be looking more into this topic!

Today’s blog post will be focusing on the generation of electricity. While there are many different ways that electricity can be generated, the three I will explore today are electricity Generation from coal-fired, natural gas, and nuclear power plants. Through each individual process of generation, one can see the benefits and downfalls of each type of power plant.

1. Coal-fired power plants.

In coal-fired power plants,water is turned into steam, which then causes turbine generators to produce electricity. There are few steps to this process. First, heat must be created by reducing it to the fineness of talcum powder. After mixing it with hot water and air, it is put into the firebox which provides the maximum heat. Next, water is pumped through the pipes into the boiler, which in conjunction with the heat, creates steam that gets up to 1,000 fahrenheit. Then the steam creates a pressure that goes against a  series of giant turbine blades which turn the turbine shaft, which is connected to the shaft of the generator , where electricity is produced. Finally, the steam enters a condenser where millions of gallons of cool water from a nearby source  are pumped through a network of tubes running through the condenser. The cool water then turns the steam back into water so it can be used again to repeat the cycle.

Here is an image of the coal-fired power plant in its entirety:

Although low cost and versatile, coal-fired plants create high levels of pollution which causes health threats to society, and obvious destruction in nature. Furthermore, coal is not a renewable energy source. As you can see, there are many benefits and downfalls of coal-fired power plants.

http://www.duke-energy.com/about-energy/generating-electricity/coal-fired-how.asp

2. Natural Gas power plants

There are three types of natural gas power plants. They are steam generation, simple cycle, and combined cycle.  Similar to a coal-fired power plant, the steam generation plant uses natural gases to create steam that causes the turbines to spin and create electricity. The simple cycle plant burns natural gas to produce a high pressure gas that spins the turbine and convert electricity. These plants are used in times of high demand because of their short start-up times, however they are not very efficient in converting heat into electricity. Combined cycle plant use a heat recovery steam generator and simple cycle turbines to power itself.  In this plant, gas is burned to create high pressure gas and the excess heat from that process is captured and used to generate steam to spin a steam turbine. This plant is the most efficient of the natural gas plants, but due to its longer start up time, it is not used for the majority of the time.

Here is a picture of the three different kinds:

According to AEP.com, “The International Energy Administration (IEA) indicates that combined cycle gas plants have a higher average efficiency than coal plants. Simple cycle plants have efficiencies ranging from 35 – 42% and combined cycle plants have efficiencies of 52 – 60% compared to efficiencies of up to 46% for supercritical coal plants and 50% for ultra supercritical coal plants.”

Clearly, the natural gas plant is a better option than coal.

http://www.aep.com/about/IssuesAndPositions/Generation/Technologies/NaturalGas.aspx

3. Nuclear power plants

The nuclear power plant is a thermal power station heated by a nuclear reactor. The heat produced by the reactor produces steam to spin the steam turbine which is connected to a generator the produces electricity. The nuclear power plants produce around 20% of our nations power!  Although this system sounds simple, they are the most complex and sophisticated energy generators. According to ,Jan Willem Storm van Leeuwen  “A fundamental issue contributing to a nuclear power system’s complexity is its extremely long lifetime. The timeframe from the start of construction of a commercial nuclear power station through the safe disposal of its last radioactive waste, may be 100 to 150 years.” Furthermore, nuclear power plants also pose a threat to the health and safety of the public living near the plant. “The major hazards to people in the vicinity of the plume are radiation exposure to the body from the cloud and particles deposited on the ground, inhalation of radioactive materials and ingestion of radioactive materials.” A high exposure to radiation could cause death or serious illness. For this reason, the government has an emergency response plan in the event of a nuclear power plant incident.

Here is a picture of the Nuclear power plant:

www.tmaa.go.tz

http://www.ready.gov/nuclear-power-plants

Upon initial research on Germany’s green energy policy, I was very surprised to see that it was a policy that was not going well at all . This was shocking because one would think that any move towards green energy in today’s day and age would be positive and an improvement. After reading many articles, however, I found that this “improvement” in energy actually turned out to be a fluke.

The whole idea behind Germany’s green energy policy, or as they call it, Energiewende, which means energy transformation, is to transition from nuclear and fossil fuels to renewable energy sources in order to reduce green house gas emissions. This policy came into consideration in the 80s, was put into policy in 2000, and became increasingly more prominent after the Fukushima disaster in March 2011. As a result of the hurried pace of the policy, Chancellor Angel Merkel was forced to end nuclear power, closing seven reactors, which was initially set by the government to phase out by  2022. In The Economist’s article on Germany’s green energy policy, it states that “Germany reaffirmed its clean-energy goals—greenhouse-gas emissions are to be cut from 1990 levels by 40% by 2020 and by 80% by 2050—but it must now meet those targets without nuclear power.” Clearly, Germany’s ambitious goals of cutting greenhouse gas emissions are now going to be more difficult as their Energiewende poses many problems for the government’s plan. Even the chancellor herself admits that Germany may be in too deep, calling the policy a “Herculean task”.

Although this image from theenergyconnective.com, which was featured on the front page of The Washington Post, makes Germany’s policy appear attractive and functional, there are facts that state otherwise.

First, let’s consider that Germany produced more energy by coal than it has in a quarter century! While the government’s policy claims to be seeking new renewable energy sources, it is evident that Germany has spent much of its’ time and resources mining for coal instead of looking for sources of green energy.

This comic, featured in dissentmagazinge, shows the irony of how Germany’s plans to help the country have blown up in their faces (quite literally). The smoke is representative of all of the excess coal it has been burning in the process of looking for new energy sources, which has lead to a rise in CO2 levels.

Next, there’s the fact that as a result of this coal burning, carbon dioxide levels have grown increasingly larger. According to the-american-interest.com, “Germany’s carbon dioxide emissions, which rose from 917m tonnes in 2011 to 931m tonnes in 2012, are estimated to show an increase of 20m tonnes when figures are tallied for last year.” This is a huge increase that seems to be going in the opposite direction of the ultimate goal of the Energiewende!

Furthermore, the costs are rising very fast, which may pose yet another problem to the policy. Germany’s minister of public economics that the country’s energy intensive industry may begin to look for cheaper prices as prices are estimated to climb to $32 billion in 2014 alone and will continue to climb upward.

Ultimately, Germany’s green energy policy is a big controversy throughout the world-it is even under investigation by the European Union for said policy. The Economist writes that, “it is hard to think of a messier and more wasteful way of shifting from fossil and nuclear fuel to renewable energy than the one Germany has blundered into. ”  This is due to the fact that the prices are high and will continue to grow, there are many risks involved, and some effects are already doing the exact opposite of what was intended. In fact, there may be a larger number of greenhouse gas emissions than was initially intended as well. However, some say that Germany can turn this around and become a leader in green energy. Perhaps there will be a transformation, or perhaps the Energiewende will, in fact, be a failure. While most evidence seems to push for a more negative outcome, one must always keep the positive in mind and have hope. Perhaps we will see Germany transform before our eyes-Only time will tell!

http://www.economist.com/node/21559667

http://hotair.com/archives/2013/12/19/germany-under-investigation-for-their-green-energy-policies/

http://www.the-american-interest.com/blog/2014/01/09/end-result-of-germanys-green-energy-policy-more-coal/

On Friday, January 31st, our class completed the second task with our Lego Robots. For this task, we had to measure the distance of our Robot’s travel and compare it to the LabView statistics, thus calculating our percentage error. Although we had to do less work in LabView, and focus more on our actual Robot and measuring the distance it traveled with a ruler.

When I initially saw what we had to do, I panicked. As I have mentioned before, anything that involves numbers or calculations is utterly terrifying to me. I hadn’t even used a ruler since middle school. Luckily, I got over my fear and jumped head on into the assignment. After Professor Sonek explained in detail the steps we would have to take in order to complete this activity, I felt more assured. The program on LabView was already set up for us, so we just had to type in the time and power of the robot. The Program looked something like this:

As you can see, the area where we had to enter the power and time made the whole thing much less complicated as it was already set up for us.

We also had to use a ruler to measure it’s distance. That part was a bit hard at first as it was a difficult process that you had to really pay attention to in order to get the correct measurements. We had to redo our measurements many times due to inexact measurements. That process, which we did by hand in front of our computers, looked something like this:

Our group did not use paper or a marker to get a more accurate reading, which would have been very helpful. We used only our fingers, a ruler, and our own perception. Perhaps next time we can implement this method to prevent any inaccuracies. It looks like it would save a lot of time and frustration.

Then, we had to compare our measured to distance to the distance calculated by LabView. My partner and I recorded our own measurements next to those of LabView in our notebooks. LabView measured the number of wheel turns, distance, velocity while we measured merely the Robots distance in centimeters, which we had to convert to meters. My recordings, which were a bit unorganized looked like this:

We had to do the experiment three different times, each time using a different level of power and testing that level three times as well. The Formula we were given to calculate our percentage errors was:

[Distance(m)-Distance(LV)/(Dis(m)+Dis(LV)/2)]

In this equation (m) stands for the distanced we measured with the ruler and (LV) stands for LabViews measurements. I tried doing the equation out by hand a few times but kept getting it wrong. Like I said, I’m not good with numbers. Luckily, my partner knew how to use excel and put our calculations and the formula in to be calculated by excel. Our end result looked like this:

The last column represents our error percentages, which after comparing with other groups seemed off. We tried a few different things to get more accurate results, but ran out of class time. We are hoping to fix this next class.

Overall, I am proud of my completion of this activity, even if the numbers were off. I understood what we needed to do, and most of what we were doing while we were doing it. I even sharpened up on my math skills and learned how to better use excel.

Until next class, folks!