Our experiment revolved around the effect of pH on the voltage produced by citrus batteries. The point of the experiment was to not only demonstrate how varying degrees of acidity can affect voltage production, but how electricity can be generated by a plain chemical reaction.
The process of conducting the experiment went rather smoothly and the overall process worked well. We were able to generate electricity from the beginning, albeit, it was a very small amount. Initially, we believed we would be unable to produce enough voltage to power anything, however, the use of batteries to supplement the circuit instead of using a dozen citrus fruits really helped the experiment take shape.
Our group reached a problem late into the experiment when we discovered that the orange, the fruit with the highest pH and therefore the lowest acidity, produced the highest voltage. The lemons and the limes produced a fraction of an amount less, but our group was baffled as to why the fruits with a higher concentration of acidity did not produce more voltage. It was only later that we realized that both acid concentration and the quantity of liquid affects how well the solution would help generate voltage. If we had the opportunity to do something different, we would use the juice of the fruits which contain the acid necessary for the experiment. By doing so, we would be able to control the quantity of juice and the fruits with less size would still have the same amount of liquid as an orange.
Our group also found it rather difficult to have the batteries connected in series with the electrician’s tape and copper wiring. If we could have redone the experiment, we would have found a better method than using electrician’s tape to hold the wire and battery in constant contact with each other.
Lastly, it would have been nice to have had more objects that required varying degrees of power to operate. It was difficult to find small, household objects that required small voltages and that were relatively easy to open. With the right objects, this would have further shed light on how little is necessary to generate power given the right materials to create a chemical reaction. In the end, our group and other groups were able to power a TI-30XA with over 6 volts and products with less required voltage to operate would have been a great addition.
The oil industry, with its history of booms and busts, is in its deepest downturn since the 1990s. Earnings are down for companies that made record profits in recent years, leading them to decommission more than two-thirds of their rigs and sharply cut investment in exploration and production. Scores of companies have gone bankrupt and an estimated 250,000 oil workers have lost their jobs.
The cause is the plunging price of a barrel of oil, which has fallen more than 70 percent since June 2014. The question on the minds of many people: why has the oil price been dropping?
Oil prices over the last several years from 2006-present
This a complicated question, but it boils down to the simple economics of supply and demand. Domestic production in the United States has nearly doubled over the last several years, pushing out oil imports that need to find another home. Saudi, Nigerian and Algerian oil that once was sold in the United States is suddenly competing for Asian markets, and the producers are forced to drop prices. Canadian and Iraqi oil production and exports are rising year after year. Even the Russians, with all their economic problems, manage to keep pumping.
On the demand side, the economies of Europe and developing countries are weak and vehicles are becoming more energy-efficient so demand for fuel is lagging a bit. Motorists and home owners that use oil to heat their houses end up benefitting from the plunge in oil prices. However, oil-producing countries and states such as Venezuela, Nigeria, Ecuador, Brazil and Russia are just a few petrostates that are suffering economic and perhaps even political turbulence. Needless to say, the overall oil industry has also suffered as many companies have gone bankrupt and others are struggling to keep their heads above water.
Hydraulic fracturing has helped boost the rate at which oil and gas can be extracted from wells, particularly in the United States. By increasing the current available supply, fracking helps to lower oil prices on a global scale. This is particularly true domestically, since oil does not have a historically strong local market in the U.S. Basic economics states that as the supply of any good increases, its relative cost decreases. The degree to which these decreases occur depend on many factors, including the elasticity of the good. Even though oil is a natural resource, it has no productive economic use unless it is extracted. This means that the real supply, in a productive sense, is limited to what engineers and well technicians can provide. Fracking lowers the cost of oil to the extent that it allows real supply to expand.
What exactly is hydraulic fracking? The term fracking refers to how the rock is fractured apart by the high pressure mixture. Fracking is the process of drilling down into the earth before a high-pressure water mixture is directed at the rock to release the gas inside. Water, sand and chemicals are injected into the rock at high pressure which allows the gas to flow out to the head of the well. The process can be carried out vertically or, more commonly, by drilling horizontally to the rock layer and can create new pathways to release gas or can be used to extend existing channels.
Example of how fracking is done
There are limits on the extent to which fracking can be used to increase supply. Oil is scarce, and hydraulic fracturing is more expensive and complicated than traditional oil extraction. If the global supply of oil increases and oil prices drop far enough, then the high expense of fracking is no longer justified. In other words, the success of fracking eventually imposes a limit on itself, unless technological changes make the technique less costly.
During our discussions, our group was able to come up with various possible experiments that we believe would meet the requirements for the final project. Though these experiments were different in set-up, they were similar because they involved generating energy and possibly how to produce energy in a more efficient way.
The first experiment we discussed involved the use of various fruits to charge or power different types of electrical devices. The purpose of this experiment would be to demonstrate how an electrical current can be generated using citrus fruits (such as lemons or limes) that is strong enough to power a small light bulb or charge a phone.
Electrical current is the flow of electrons (movement) of an electrical charge and is measured using an ammeter. Solid conductive metals contain large population of free electrons, which are bound to the metal lattice and move around randomly due to thermal energy. When two terminals of a voltage source (battery) are connected via a metal wire, the free electrons of the conductor drift toward the positive terminal, making them the electrical current carrier within the conductor. The active ingredient in the fruit are positively charged ions. A transfer of electrons takes place between a zinc nail and the acid from the fruit. The nails act as poles for the battery, one positive and one negative. Electrons travel from the positive pole to the negative pole via the light bulb wire (the conductor), generating enough electricity to light the bulb.
Our second experiment involved the construction of an AC electric generator which lights up a tiny incandescent light bulb. The generator is made from a hollow-ended cardboard box with a nail through the center. The box has many turns of varnished thin copper wire wound around, with four large magnets clamped around the nail. When the nail and magnets are spun fast by hand, the little light bulb lights up dimly.
This project would demonstrate how easy, yet difficult it can be to generate electricity, because it is not extremely complicated to build a generator to power up a bulb, but the steps and materials required are extremely precise and cannot be changed.
Lastly, the final experiment we discussed involved the use of coins, vinegar, paper, aluminum, and salt to create an electrical current to power a light bulb or electrical device. This experiment is very simple to complete, however, it would take a while to prepare. It would be a great way to test a variety of metals and also the number of coins used and how they affect the voltage produced during the experiment.
According to multiple sources, the Obama administration has proposed the most far-reaching climate change adaptation and mitigation measures ever put in place by a U.S. president. The plan includes everything from cutting power plant emissions to boosting the amount of wind and solar energy installations on public lands and buildings as the U.S looks to move into the future conscious of the effects of global warming.
The White House plan includes three main policy tracks. The first addresses emissions of greenhouse gases, chiefly carbon dioxide (CO2), from new and existing power plants. This version of the Climate Action plan would place limits on greenhouse gas emissions from more than 1,000 existing coal-fired power plants for the first time ever. The plan could also include natural gas power plants as well. Thanks largely to the global recession and the displacement of coal by natural gas in the power sector, the U.S. emissions of carbon dioxide (CO2) in 2012 may have been a lowest in a couple decades, but the first quarter of 2013 saw the percentage of electricity coming from coal start to go back up as natural gas prices increased, while U.S emissions rose by at least 4% during that time period.
Emission Rates and other factors 1997-2013
The White House has indicated that without additional measures to reduce carbon emissions from the electricity sector, continued emissions decreases are unlikely to be achieved by market forces alone (i.e., natural gas prices). Their proposal to limit emissions at existing power plants could help drive a continued drop in overall U.S. emissions.
CO2 levels assuming different rates of fossil fuel consumption
The White House has gone as far as recommitting the U.S. to meeting the greenhouse gas emissions reduction goals it established in the Copenhagen Accord in 2009, when the administration agreed to cut greenhouse gas emissions by 17 percent below 2005 levels by 2020. That would be approximately double the reduction the U.S. has seen due to the recession, increase the use of cleaner-burning natural gas, and increase energy efficiency since 2007.
The second track helps prepare the U.S. for the effects of climate change that are already occurring and are likely to occur in the next several decades due to the long-lived nature of CO2 in Earth’s atmosphere. The climate action plan calls for the Department of Energy to make up to $8 billion in loan guarantees “for a wide array of advanced fossil energy projects,” including carbon capture and storage, or CCS. Such technologies, which have not yet been proven to work at the commercial scale, could allow utility companies to continue burning coal for generating electricity, while capturing and burying the related carbon emissions, thus removing CO2 from the atmosphere.
Lastly, the policy proposals include provisions to work with the international community to address global warming, both from an emissions reduction and climate adaptation standpoint. The climate action plan commits the U.S. to working with international partners to reduce the emissions of not only carbon emissions, but also non-carbon based greenhouse gases such as HFCs. HFCs are used as a refrigerant and is a powerful short-lived climate warming agent. According to Durwood Zaelke, president of the Institute for Governance and Sustainable Development, a phasedown of HFC emissions in the U.S. can deliver a quarter of the administration’s 2020 climate goal. According to a study being published on Wednesday, a global phaseout of HFC use during the early part of this century can avoid a half a degree Celsius in future warming by the end of the century.
The Climate Action Plan also addresses other emissions such as methane emissions by ordering the EPA and other government agencies to develop “a comprehensive, interagency methane strategy” that includes addressing methane emissions from natural gas plants.” As a Climate Central research report found, how much methane emissions are coming from natural gas pipelines and power plants is key to determining how much climate benefits that electricity source provides.
The Obama administration has also looked to increase efficiency in vehicles by enacting the toughest passenger vehicle fuel efficiency standards in U.S. history. It requires hat passenger vehicles have an average performance equivalent of 34.1 miles per gallon by 2016 and 54.5 miles per gallon by 2025, which the White House claims will eliminate 6 billion metric tons of carbon pollution — more than the U.S. emits in an entire year.
Transportation emissions make up about 30 percent of U.S. greenhouse gas emissions, and heavy-duty trucks comprise more than 20 percent of that total. Currently, heavy-duty trucks, which are primarily transport trucks, have an average fuel economy of only 5 miles per gallon, so improving their fuel economy could help significantly lower emissions from the transportation sector. The administration has worked to enact post-2018 fuel economy standards for heavy-duty trucks, buses, and vans, by working with the auto industry.
