Iceland sits on top of two different ridges with earth surface plate aparting from each other at a rate of 2 centimeter a year. Iceland sits on top of many volcanoes because of that, and these volcanoes erupts once every 4 years. This causes Iceland consists of rupture land with different temperature, some provide warm water, and some are even hot enough to provide direct steam. The geothermal exchange is a consistent exchange of heat from ground water (cold) to underground water (hot).
Iceland harvests the steam to drive turbines, which generates electricity of the entire island. Harvesting geothermal energy has many advantages over traditional power plant options:
Emission free
Zero carbon
No fuel required (no input source needed)
More reliable than solar energy (only works in day time) and wind energy (subject to season changes)
Smallest land footprint
Almost limitless supply
Simple and reliable
Iceland’s geothermal energy plant produces 25% of its total electricity production. 40% of the geothermal energy is used for producing electricity, 43% is used for space heating, and the rest are used on various subjects that require direct heat. See chart down below:
The Peltier effect is the presence of heating or cooling at an electrified junction of two different conductors. A small Peltier device can usually be found in a hot & cold water dispenser. Peltier device works by transferring heat from one side to another, in which the action is reversible. The effect is one of the thermoelectric effect, when a current is flow through a junction between conductor A and conductor B, heat may be generated, or removed at the junction. The heat generated at junction per unit time is equal to:
Where () is the Peltier coefficient of both conductors, and I is the current flowing through.
The effect may only has 2% efficiency in practice (up to 5% in theory), so at this stage cooling or heating objects from electricity is still sub-optimal and can waste a lot of energy. See references down below.
The Stirling Heat Engine is a heat engine that functions when enough heat is supply as a source to the engine. Robert Stirling invented the engine in 1816. The source can be anything from solar energy, chemical energy, to nuclear energy. The Stirling Engine operates by cyclic compression and expansion of any gas particles (including Noble gas). It relies on the principle of thermal expansion, that gas particles expands (isothermal expansion) when heated and compresses (isothermal compression) when cooled.
Engine operates by cyclic compression and expansion of any gas particles (including Noble gas). It relies on the principle of thermal expansion, that gas particles expands (isothermal expansion) when heated and compresses (isothermal compression) when cooled.
The engine itself composes of a cylinder, a displacer piston (green), a power piston (orange), and a flywheel (rotating disc on the right). The displacer piston consists of about one third the volume of the cylinder. Working gas resides on both side of the displacer piston, and during the operation of the engine both sides always consist gases of different temperature. There is a slight gap between the displacer piston and the cylinder, so gases can exchange freely by pulling or pushing the power piston. When heat is supplied to the bottom part of the cylinder, the bottom portion of the cylinder heats up, causing the gas in that portion to expand, thus pushes the cylinder upwards. Cold air thus slips through the gap and enters the bottom portion of the cylinder; in exchange the hot air goes upwards and enters the rear portion of the cylinder. At this point the displacer piston moves down because cold air now resides at the bottom of the cylinder, this marks as a completion of one cycle. The next cycle begins when the bottom potion air heats up again and pushes the displacer piston upwards.
The Stirling Heat Engine in practice achieves the highest thermal efficiency among all heat engines. The engine does not require much maintenance; it is more reliable and quite when compared to internal combustion engines. Due to the nature of the engine the engine has a low power output, to increase the power output the engine needs to hold up more working fluid (gas), causing the increase to the size of the engine, as well as its production cost.
In modern world application, as the gas prices rises up quickly and people focus more and more about clean and green energy, more people are starting to pay attention to Sirling Engine. Although due to its high production cost and low power output it is not widely adopted by power plants, the engine has a wide use in submarines or space shuttles because of its reliability and quiet operation.
In this experiment, my partner and I was using a solar cell, voltage probe, NXT with light sensor, NXT adaptor, a flashlight to see the voltages and light intensity under our different colored filters. We tried 0 distance up to 4 inches, and with different colored filter. Each trial take thirty seconds and we averaged the numbers to get the voltage. After we collected the data on the computer, this is the graph that could possibly explain our results.
According to the graph, it’s obvious to realize that the lighter tones colored is easier to come through the filter and it’s more capable to receive more voltage in the solar cell. However, I couldn’t explain why does the 0 distance and 0 light could received that much voltage. It might because of the solar cell is not in a 100% dark space, the light in the classroom might received in the solar cell and caused voltage happened.
The purpose of the pulley lab is to find the relationship between force, mass, acceleration and time. We used a lego motor, a stand, string, some adjustable weight. This is the data we recorded during the process of the experiment.
According to the data we can tell that higher power level would cause higher acceleration, and of course with higher speed. And usually it takes shorter times compares to the lower power level with lower acceleration. The only thing I’m not fully understand was the relationship between acceleration and time. I realize the shorter the time spent pulling the weight the higher the acceleration was. I’m not entirely understand the connection between time and acceleration.
Coal-fired, natural gas and nuclear power plants are all electricity generators, they all have advantages and disadvantages.
Coal-fired: It has reliable supplier in certain regions, also have good efficiency to utilize it. During the time when coal-fired just been discovered to use for generate electricity, it is low cost, lower than nuclear. However, coal-fired isn’t perfect resource. It pollutes the environment by release exhaust gas, it also causes acid rains and global warming. And the transportation of coal cost a lot of money. Also the source can be dry up, and not always able to find new fields. Since it pollutes environment, and environment protection also requires expensive technologies and cost a lot.
Natural gas: It has nicely built infrastructure for fossil fuel supply, it also has the ability to make sure the quick changes of output upon grid requests. Again, it cost lower than nuclear. It pollute much more less than coal-fired and better for environment. But it’s expensive to produce electricity and heat.
Nuclear power plant: It is a relatively the best method to electricity out of these three. Nuclear power doesn’t pollute, and high efficiency to utilize it. The fuel can stock longer period than other sources, with low amount of produced waste. But same as above, it is very high investment costs during the construction.
It is highly controversial: its environmental impacts include the risk of polluting ground water, consuming fresh water, worse air quality, the potential triggering of earthquakes, noise pollution, surface pollution, and the finally risks to health and the environment.
Energy grid is an network for delivering electricity from suppliers to consumers. It have generating stations that produce power, and distribution to individual customers.
The infrastructure of energy grid in US were not very reliable since there are getting more and more accidents occurred that by grid energy storage. The grid needs to be updated and make it modern, we are experiencing the crisis of energy grid, and it needs to be updated soon. Since the technology is becoming more smart and automated, smart grid can help to reduce the accident happened from grid energy storage. Smart grid is performed in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity.
The following video is talk about how smart grid can improve the sufficiency, reliability and sustainability.
A brief intro that talk about America’s infrastructure.
Welcome to Blogs @ Suffolk University. This is your first post. Edit or delete it under Posts or make a new one under Posts>Add New, then start blogging! Be sure to visit the Appearance option to choose a new look for your blog!.
