 In this lesson we talked about alternative and renewable fuels. So exactly what are those? Main categories are wind, hydro, solar, geothermal, and biomass. This graphic shows the percentage of total energy consumption in the U.S. that renewable energy represents. You can see at this point in time, as of the latest information for 2010, renewable energy only represented 8% of total U.S. energy consumption. And within that group, you can see that the breakdown is solar, geothermal, wind, biomass, and hydroelectric power. This chart shows the total that the renewables represent in terms of consumption and major sources with a further breakdown into hydroelectric, wood, biofuels, and wind. You can see just in the last several years wind has started to increase as a percentage of total consumption. This pie chart shows the change in renewable energy consumption between 2006 and 2010. Most notably, biomass has increased as an overall percentage. Hydroelectric, in fact, has decreased. Solar has remained about the same as well as geothermal, but the increase has been in wind as one would expect. Wind power was once used for mechanical drives only, and it's gaining in popularity as a clean alternative source of electricity using turbine generators. Large wind farms are being built everywhere across the country where wind is considered to be a natural resource. I'm personally familiar and have seen massive wind farms in places such as West Texas, the Texas Panhandle, Western Oklahoma, and throughout Kansas. However, most of the wind farms started in California, and most of you, no doubt, have seen one of these in your travels. It will continue to increase in terms of the overall locations as well as the number of windmills themselves in these farms. Hydro power has been around for centuries. You're utilizing the water itself, the flow of the water as a source of energy. Centuries ago it was primarily used, the old water mill was used to grind grain, but in modern times a lot of the water is used to generate electricity using hydroelectric generators. There are thousands of hydroelectric dams throughout the world. One of the more modern and recent types of use of water currents themselves is the new generation of tidal power turbines. The current of water moving from, say for instance, the ocean into a port or a river's natural flow to the sea can be harnessed with underwater turbines that spin as the current moves through. The one pictured in the lower picture here is actually located in the North Sea off of Scotland. There is also an experimental tidal wave turbine being used in the East River in New York City, and currently it's powering a few small stores on the Brooklyn side of the East River. Solar energy industry, solar has been with us for several decades. The first real interest in the use of the sun's rays and sun's heat for energy purposes came with the first oil embargo and back in 1973 and 1974 there was a subsequent oil embargo in 1979. Of course at this point in time you had the organization of petroleum exporting countries that were controlling a vast majority of oil production and decisions they made caused major problems in the United States in terms of the supply of oil. So many looked to solar energy as a safe and clean alternative. The simple process is really just to collect the heat and energy from the sun. It can be used for space heating, heating of hot water, it can actually generate steam for electric turbines and then it can also be the light of the sun can be converted directly into electricity. Solar comes in two types, passive and active. In the passive use of solar energy we're basically taking the sun's heat via some type of solar collector and primarily it's being used for space heating and water heating and generation of steam. Active solar power is the conversion of the sunlight into electricity using photovoltaic cells that have semi-conductive materials in them. A large part of this is going to be dependent on atmospheric conditions. Several days of overcast skies may limit the amount of electricity that can actually be generated and of course the earth's position relative to the sun and some of the more northern parts of the United States in North America solar power may not be as easily accessible or a reliable source of energy as in other areas. Geothermal energy is basically taking the naturally occurring energy that exists below the surface of the earth for both heating and cooling purposes. Almost everyone is familiar with geysers and natural steam that emanates from the ground that can be harnessed used for industrial purposes, used for space heating purposes. The steam itself can actually drive electric turbines. What isn't as well known is the use of the cool air below the surface of the earth for space cooling. This application has been utilized in homes, large businesses and basically wells are drilled down anywhere from 40 to 50 feet and the cool air is brought up to the surface piped into buildings to cool them down which creates considerable savings on electricity for running air conditioning units. There are several types of biomass, several of these we're all familiar with. Of course there's wood, we're familiar with corn and other crops that are used to make ethanol which is a fuel source that's added to gasoline. Landfill gases, garbage itself can be burned and used into energy and then any type of fruit that can be fermented into alcohol basically represents a source of a type of fuel. Biomass, this is a landfill. Landfill gas is derived from decaying trash, if you think about it landfills are fairly large in their scope and all of that garbage, the organic matter eventually will decompose and methane is one of the byproducts of that decomposition. Literally there are wells as we do call them that are drilled down through the landfill itself to extract the methane gas and multiple wells can be drilled if the landfill itself is large enough and primarily the methane is used on site to generate electricity with a small natural gas fueled electricity generator. Another form of biomass is what we refer to as trash to energy. Solid waste itself can be used as a fuel source for combustion to create steam. That steam can be used in industrial processes or to generate electricity using a steam generator. Where I reside in Tulsa, Oklahoma we do have a trash to energy facility in the west part of town. The steam that's generated is sold to oil refineries and the electricity goes into the grid for the local utility. Another form of biomass is wood itself or wood waste. Obviously you can burn wood or wood pulp, wood chips. So it's a heat source for industrial steam and electrical generation. Warehouses are one of the largest paper product manufacturers in the country. It's a very large facility in the southeastern part of Oklahoma. They in essence recycle their own wood pulp and wood chips to create steam on site. They use that in the process of certain paper products. They also can use a steam to generate their own electricity. Form of biomass that's continuing to gain in popularity. These are the fuels that are made from crops, grasses and any type of biodegradable matter. Most of us are familiar with ethanol, primarily made from corn, certain sugars and certain types of grasses. When you go into a retail gasoline station and you see things like 90-10, that means that the gasoline that you're going to put in your car is comprised of 90% of unleaded and 10% of that has been an ethanol type of alcohol added to the gasoline itself. There's also biodiesel. These are engines, whether they're trucks, buses that can be currently used. Diesel can also use things such as vegetable oil, peanut oil, soybean oil or even recycled restaurant grease. Nuclear energy is considered to be a renewable energy source because of the very finite amount of uranium that's required to create steam and generate electricity. We don't believe we'd run out of uranium on this planet for thousands of years. I chose this picture in particular because I like the contrast in the background. You have the Simpsons-like cooling towers of a nuclear power plant in the foreground. You have a very large solar array of photovoltaic cells that generate electricity. So we have the nuclear energy with its questionable safety record versus the natural alternative and renewable energy source of the sun. Now going into too much of the physics here. This is a basic diagram of how we do in fact create nuclear energy through the process of nuclear fission. Last slide here is a generic diagram and illustration of electrical generation. The key process here is to create steam. The fuel source itself doesn't matter. It can be biomass, it can be coal, it can be natural gas, it can be diesel fuel. But the idea is we want to create steam so whatever the fuel is that is combustible we're going to create fire in a boiler. Tubes carrying cold water will circulate through that boiler which creates steam and in turn will drive a steam turbine. Steam turbine is nothing more than fan blades and attached to those fan blades you can see the turbine itself is in white and blue. There are magnets tied to a shaft. Those are housed in a copper wire containment. The spinning of those magnets creates the current that goes out to the grid. Anywhere between 90-90% of the steam then goes through a cooling tower and is recaptured, chilled and the process repeats itself.