Lecture 5 AND 6 - Renewable Energy PDF

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Renewable Energy...

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Lecture’s 5 & 6 Renewable Energy

Sources of Energy

Blue: renewables (renewable in terms of human scale renewable, things able to be regenerated natural on their own.) Yellow: Non-renewables

How each works, their uses, advantages & disadvantages of: —Solar Kinds of Solar Energy (radiant energy emitted by the sun.)  Active Heating: mechanical means are used to store, collect, and distribute solar energy in buildings in order to provide hot water or space heating.

 Passive Heating: Using the sun's energy to heat a building; the windows, walls, and floors can be designed to collect, store, and distribute solar energy in the form of heat in the winter (and also to reject solar heat in the summer).

**More to do with how buildings are constructed.**  Solar energy with Photovoltaic Cells: we oftenest this panel on roofs etc, and they generate electricity. It is a specialized semiconductor diode that converts visible light into direct current (DC). Some PV cells can also convert infrared (IR) or ultraviolet (UV) radiation into DC electricity. ... Large sets of PV cells can be connected together to form solar modules, arrays, or panels.

**Sometimes there is a surplus of electrons, so the DC electricity is the kind of electricity formed (DC stands for direct Current). The type of electricity is converted from DC to AC (Alternating Current), almost everything that we have or use, uses AC electricity.*** **the closer the proximity of panels, the better, because if there is a long distance, the electrons will die in their way, so it is better for it to be closer**

**Distribution of Solar Energy around the US** Advantages to Solar •No CO2 emissions. •Easyto install, expand and move. •Cellslast to 20 years. •Lowland Use, (Not big amount of land space needed) •Net metering=(a system in which solar panels or other renewable energy generators are connected to a public-utility power grid and surplus power is transferred onto the grid, allowing customers to offset the cost of power drawn from the utility. One would get payed for sharing the electricity). This is done because one may be generating electricity but not using it. Disadvantages to Solar • 15% to 30% efficiency. •High Costs (however they arefluctuating a lot, now they are becoming more accessible.) •DC to AC conversion •Intermittent (occurring at irregular intervals; notcontinuous or steady.) Biggest difference of Solar Energy with other types There is no turbine, electricity is created directly. There is no generator. —WIND  Wind turbines may been land, or ocean. Denmark is the place with the highest amount of wind turbines in ocean.

** as generator spins, electrons are created, so electricity is created, so assuming that there is wind, electricity will be available** Advantages to Wind •25%-40% efficiency •No CO2 emissions •Low Cost, with economic benefits. (The cheapest renewables, wind is low cost since it is simple to install and opperate) •Easy to construct, expand

Disadvantages to Wind •Visual or noise pollution (not everyone likes the look of them) •Intermittent (there are places where there is not a big amount of wind) •High Land Use (however Land may be use for something else than just generating electricity. This is why it is mostly sold to farmers.) •Bird, bat kills –Hydropower  electricity produced from generators driven by turbines that convert the potential energy of falling or fast-flowing water into mechanical energy.

**it has been increasing over time**

**Putting a wall is the most difficult, costly and time consuming thing to do.** **many have multifunctions, they can keep water and use it for agriculture. Advantages to Hydro •Highly efficient (80-90% efficiency). Even though it is very costly, ones installed itis very efficient. •No CO2 emissions. (once in place, there is no co2 emission.) •Low-Costelectricity •Flood control. (damps •Irrigation.(agricultural irrigation, thesupply of water to land or crops to help growth, typically by means of channels.) •Recreation Disadvantagesto Hydro •High construction costs. •Alterslandscape, water quality, and flow. (because of sediment feeling up) •Dangerof collapse or dam break. •Displaces populations. –Geothermal  is thermal energy generated and stored in the Earth. relating to or produced by the internal heat of the earth.meaning hot. Earth's internal heat is thermal energy generated from radioactive decay and continual heat loss from Earth's formation. (Heat does not come from the sun) *almost 100% of Iceland has geothermal electricity. Also works as tourist traps*

** it is like the temperature of an oven, its is already coming out as steam, so one does not need to transform it** **places in the world that. Do this are normally more close to the crust.**

**There is a more common geothermal energy generator, and it is the geothermal heat pump (*we have one in Villanova.) it is not for maintaining electricity but for maintaining heat or cold temperature, helps to cool off or on the building** Advantages to Geothermal •Veryhigh efficiency – heat transfer •Lowland use and disturbance(just drilling some holes in ground etc..) •Constantgeneration (day or night does notaffect, or there is no seasonal effect, eventually it will ran out but nothing affects it) Disadvantages to Geothermal •GHG emissions for pumping •Scarcityof suitable sites(no puede ser instalado enmuchas partesdel mundo) •Oftennon-renewable – water replenishment •Costin most places is high •Fluidsmay contain GHGs(greenhouse gas) –Tidal Range

**There is basically a bulge of water following the moon, this is why moon affects tide.** Advantagesto Tidal Range •80-90%efficiency. (we don’t have to do anything with tides,basically they work on their own.) •NoCO2 emissions. Disadvantages to Tidal Range •Not feasible (possible to do easily orconveniently.) worldwide. •Highcost of power station. •Usuallyin estuaries

–Biomass Energy  is a renewable energy source from living or recently living plant and animal materials which can be used as fuel. An example of biomass is plant material that produces electricity with steam. An example of biomass is animal fossil fuel. Biofuels -ethanol= comes from corn.

(Whenever we see something with last two letters being OL, it has to do with alcohol. Ethanol is type of alcohol)

**very pure alcohol, cannot be drank by humans because it will destroy internal organs** **each step along the way, a kind of energy is required** -biodiesel= comes from combination of plant sources (not corn), basically any type of plant except corn. -biogas= can include animal waste, does not have to include only plant material. Gas, gained from this waste may be used later for cooking gas, lighting gas, or can be burned as heat source, basically it is a fertilizer. Advantages to Biomass •Cost effective when oil>$55/barrel. (only when oil is costly. •Makeuse of wastes. •Fuel production (only source of alternative fuel production)

Disadvantages to Biomass •Land Use (we need big field to growcrops etc) •CO2emissions is produced. •CH4emissions. •Ethicalissues (i.e, food for the poor, instead for gas forrich people in world) •Increasingfood costs. (supply goes down,demand goes up, so costs goes up) •Low efficiency. How should we choose renewable energy source??? (Five things to consider) 1. Production (how everything is made) 2. Transport (where its located vs where it is produced, the further away the less efficient it is, the less electricity may be used) 3. Point of use (residential, industrial or transportation) 4. Costs 5. Storage (having a good place to store energy is essential) Links to Sustainability  Longer lasting and. Avoid many of the negatives of fossil fuels and nuclear energy.  May be more adaptable to developing countries lacking fossil fuel-related infrastructure....