mota.lopes.energy.water.spring.2010

ENERGIAS ALTERNAS E HIDROELECTRICA (ENERGIAS LIMPIAS)

We live in a warming world. Not the type of drastic temperature change that people may think of when they hear the term "Global Warming", but nevertheless, our world is warming. 2000-2009 has been the warmest decade since man was first able to measure temperature over 130 years ago. Scientists confirm that since about 1880 global warming has been an issue, and has been getting progressively worse. And although there has been much debate in local and national news, news papers, books, and online articles, there is no doubt that global warming is a result of human activities.

In the last century human kind has seen changes like never before, changes such as the industrial revolution, which set into motion the way that we live today. We have become, rightfully so, dependent on industry. But the amount of fossil fuels, such as coal or fuel oil, in our factories and power plants has increased exponentially over the las 100 years. The process in which we burn our fuel or coal involves the combination of carbon and oxygen in the, which forms



We depend on the sun to sustain life on earth. The suns rays enter our atmosphere and after about 1/3 of the nenergy is reflected back towards its source the earth absorbs the solar energy. The effect of the solar energy is a natural warming of the land, air (atmosphere), and sea. Most of the heat is radia ted back towards the sun, but some is trapped in our atmoshpere by a layer of gasses in our atmoaphere, this is known as the greenhouse effect.

It is clear that we cannot hope to continue burning fossil fuels forever, not because they will certainly run out, but because they are harmimg our envionrment, President Obama stated, "So we have a choice to make. We can remain one of the world's leading importers of foreign oil, or we can make the investments that would allow us to become the world's leading exporter of renewable energy. We can let climate change continue to go unchecked, or we can help stop it. We can let the jobs of tomorrow be created abroad, or we can create those jobs right here in America and lay the foundation for lasting prosperity."

The answer to our probelems are to find new, clean, and effective energy sources. Today scientists, chemists, engineers, and entreprenuers are all in a race to find the next best clean energy source. Two that these groups of people are trying to improve upon are wind turbines, like the one we can find on campus, and the hydroturbine, like those proposed to be used in the Cape Cod Canal. We will talk about both hydro and wind power. Two resources which are in abundance. The wind is always blowing, and the water is always moving, making them pefect sources for energy.


 * __Wind Power__**

Although wind energy currently accounts for less than 1% of the global energy consumption, it is becoming more popular each day. There are two types of wind turbines, the horizontal axis turbine, and the verticle aaxis turbine. The most common, and the one that we will focus on, is the one that can be found on Mass Maritime campus, the horizontal axi wind turbine. Wind turbines work by transforming the kinetic energy of win into the mechanical energy of the spinning rotor blades. As the rotor blades spin they turn a shaft which drives an elestric generator.



Although the structure may look very large, it only takes up little space on the ground. The towers can rise 260 feet above the ground, but only the base of the structure actually takes up surface space. Wind turbines take up a considerable amount less space than lets say...a nuclear power pland. And todays 50,000 commercial and residential wind turbines produce about 50 billion kilowatt-hours each year. These turbines are pumping out an equal amount of electricity to eight nuclear power plant. And with no by products, combustion gases, or waste, the electricity output from these glorified fans is a lot cleaner for our enviornment....and isn't that what our world is focused on these days, a cleaner enviornment. Not aesthetics, and how these wind turbines may not look pretty out there on the horizon. As long as were are not continually burning fossil fuels and speeding up the greenhouse effect, who cares is they're an eyesore, and in my opinion a menacing powerplant is more of an eyesore that a wind turbine.

It is no secret that nuclear powerplants can genreate electricity cheaper than wind turbines can. But wind turbines provide clean and renewable energy. And although the wind does not blow at a consistant rate all the time, making the turbine not 100% efficient, we do not plan on running out of wind any time soon, we do however, plan on running out of fossil fuels in the near future.

· Does not require fuel. · The majority of the space taken up by a wind turbine is vertical. Resulting in little surface area being taken up on the ground. · Turbines are available in many sizes, meaning that they can be used by individuals looking to subsidize town electricity and save money in the long run, or by a city or town looking to send electricity to its residents. || · Compared to Coal, Nuclear and Natural Gas (all which are unclean for the environment) Wind Energy is on the expensive side. Costing an average of 4-10 cent per kwh. · Energy production is dependent on the speed of the wind, which is constantly fluctuating. · Many people view turbines as an eyesore. ||
 * Advantages || Disadvantages ||
 * · Wind Energy is clean: No greenhouse gasses or waste product are emitted.


 * __CO2 Emissions__**

In 2008, the average houshold consumption of electricity was estimated at 11,040 kwh. This worked out to be about 920 kwh per month. Lets take one household as an example. If this hoousehold was receiving its electricity from a wind turbine, there would be 0 CO2 emissions as a result. Barring the CO2 that was emitted in the production of the turbine. We only care about the emissions the turbine gives off while it is in use. Judging by this chart


 * Technology || Grams of C02 produced per kwh of electricity ||
 * Nuclear power plants || 90 - 140 ||
 * Gas buring plants || 330 - 360 ||
 * New coal burning plants || 1,000-1,100 ||

We can see that if the same about of kwh were produced by a Nuclear power plant then 993,600 grams-1,545,600grams of CO2 would be produced, If a gas burning plant were used to generate this electricity then 3,643,200grams-3,974,400grams of CO2 would be produced, if a Coal burning plant were used then 11,040,000grams-12,144,000grams would be produced. The numbers are staggering, keep in mind that these numbers are only taking into account a single household, imagine them on an even larger scale.

In the next part of the wiki I am goin g to discuss very briefly another form of renewable energy that I find very interesting. I will also introduce an idea of my own.
 * __Cape Wind__**

Cape Wind will be America's first offshore wind farm and it is right in our backyard. It will be in Horseshoe Shoal of Nantucket Sound. It is being planned to have 130 wind turbines built off of the coast of Cape Cod, Mass and production is estimated to take two years once the process is started. They are expecting the wind turbines to produce 420 megawatts of clean, renewable energy. They believe that this will produce cleaner air and bring down greenhouse gas emissions by 734,00 per year, they are also looking for it to create energy independence, cut energy costs, and create jobs which will in turn help the local economy. And the wind turbines are not going to create a problem for boats traveling in the waters close to shore because the wind turbines are planned to be spaced out 6-9 football fields from each other.

The benefits from having this wind farm produced is the high paying construction jobs that it will bring which will make the local economy on Cape Cod better. The jobs that will come of these wind turbines being put in Nantucket Sound will be year round and consist of monitoring, operating and maintaining the turbines so that they can be at their best efficiency for creating cleaner air. The turbines will be monitored 24/7 somewhere on Cape. They are expecting this to become a tourist attraction for local marinas and businesses.


 * __What Is Being Discussed__**

Many scientists welcome the idea of wind power and believe that it is a better way to produce energy for the world, and the Cape Winds communication director Mark Rodgers had this to say: "We are pleased the FAA has approved Cape Wind so that we can get to work on building America's first offshore wind farm that will create jobs, increase energy independence and contribute to a healthier environment. Cape Wind will provide the FAA with the funds they need to modernize and enhance their radar facility at Otis Air Force Base." Also in an interview once a Senator Hillary Clinton was quoted as being in favor of the idea for wind farms: "So I support comprehensive legislation that would overhaul our energy taxes; signal the market we're in this for the long run by extending for 10 years the production tax credit..." "We absolutely need the turbines." Even very prestigious scientifical research centers as WHOI (Woods Hole Oceanographic Institution) are discussing how they think that wind farms are a good idea: "We withheld judgment on the wind farm proposal until the release of the Draft Environmental Impact Statement, but now, having thoroughly reviewed the statement, the staff and trustees of The Woods Hole Research Center are strongly in favor of the proposed wind farm on Horseshoe Shoal in Nantucket Sound. While we do not generally take public positions on matter such as this, what the wind farm would signify and accomplish is so consistent with our mission, we could not BUT take an institutional position in favor of it." Some people however do see the wind farms as a bad idea and being frivilous in changing the world: "To us these windfarms are a disaster in the countryside, we know their effect on ‘global warming’ is pathetically tiny, but to the Government they are seen as ‘proof positive’ to a gullible populace that something really is being done to reduce CO2 emissions."-Edward Luscombe.


 * __Wind Farms Onshore Vs. Offshore__**

Stan Calvert, chief engineer for the Energy Department's Office of Wind and Hydropower Technologies, believes that offshore wind farms can be better than onshore because the wind out at sea has more energy production potential due to the water being so calm and flat. Also, the wind offshore is of higher quality and the wind onshore is very turbulent in places. Mark Rodgers discusses how the Cape Winds (offshore wind farm) has a 38 percent expected energy output per year which is much better than the expected energy output for onshore wind farms. Offshore wind farms are easier to install there is nothing to get in the way of the process because there are no bridges, no roads and no communities living around. An advantage to onshore wind farms is that most of the farms are not built near major cities and the cost is about fifty percent less for installing them on land compared to at sea. It can cost sometimes double as much to install a offshore farm. Calvert discusses in an interview how much less an offshore wind farm produces compared to a onshore wind farm. The numbers were 600 megawatts offshore and 50,000 megawatts onshore. Personally, I like the idea of both farms onshore and offshore because I think that they both help out in equal ways, but seeing how the economy is bad right now it would probably be better to produce onshore wind farms due to prices.

**Onshore**

**Offshore**


 * __Hydro Power__**

Hydro power brings us back to the days of old when factories were built on rivers so that they could use the rivers flow to turn their watermill to perform various activities. Today, hydro power is is the cheapest form of renewable energy. Since there are numerous prototypes and ideas out there on how to harness energy from river flow, canal flor, tidal movements, and wave activity we will just focus on one that we find interesting.

Portugal became the first country to build a wave farm. The wave farm has three wave energy converters, that in 2008 were producing 2.5 MW of electricty, and feeding nearly 1,500 homes. And once again, waves will never be in short supply. You can ask any Maritime Cadet about waves and they'll give you a funny story or two about something that happened on Sea Term. The wave energy converters in Portugal were manufactured by Pelamis Wave Power, who plan to add another 25 units to the farm, increasing its generation to 21 MW, and saving 60,000 tons of CO2 emissions per year.



Each unit consosts of four sections. As the waves move up and down, so do the sections as the sections move up and down hydraulic arms drive generators that are located inside each section. Power is hten fed via underwater cable to Portugals shores and fed by a substation into their national power grid.


 * __My Own Idea__**

Without any reasearch I am going to propose a solution of my own. A solution that combines both wind and hydro energy. Another form of hydro energy that has been implemented are under water turbines, much like regular wind turbines.



Now we all know what a ocean wind farm is, and if we do not, we will know very soon with the construction of one on Cape Cod. Ajn ocean wind farm is much like a regular wind farm on land, the only difference being its location. So, since an underwater turbine needs a flow of water to be able to generate any electricity, I propose that we find a suitable location that can facililitate an oceanic wind farm, but also has even a slight current, and combine these two technologies. In one unit we would have, above the surface of the water, a standard wind turbune, and beneatht he surface of the water, a standard underwater current turbine. This would generate more electricity, with less of the ocean bottom space teaken up. Like I said, this is just a proposal without any research, so I am unsure of how feasible this idea would fair in real life, but I plan on researching it further.




 * __Websites Used__**
 * 1) []
 * 2) []
 * 3) []
 * 4) []
 * 5) []
 * 6) []
 * 7) []
 * 8) []
 * 9) []
 * 10) []