Presentation on theme: "Solar Energy: An Overview"— Presentation transcript:
1 Solar Energy: An Overview Kenneth M. Klemow, Ph.D.Wilkes University
2 Points to be covered Energetics of sunlight at the earth’s surface Indirect uses of solar energyDirect uses of solar energyTypes of solar electrical generationCurrent levels of solar electrical generation capacity worldwideBenefits of solar power generationDisadvantages of solar
4 Solar energy vs. demand Total solar = 3850 zettajoules (ZJ) per year. Oceans absorb approximately 285 ZJ of solar energy per year.Winds can theoretically supply 6 ZJ of energy per year.Biomass captures approximately 1.8 ZJ of solar energy per year.Worldwide energy consumption was 0.50 ZJ in 2011.
17 Forms of solar thermal electrical generation Concentrating Solar Power Tower
18 Forms of solar thermal electrical generation Solar parabolic collectors
19 Solar powered transportation Zephyr - solar airplaneSolar powered car from Durham University
20 Solar Thermal vs PV Advantages for thermal Disadvantages for thermal No need to generate electricityHigher efficiency / energy densityCan last for decadesDisadvantages for thermalHigh weight associated with waterFreezing water expand, can burst pipesMinor failure can totally destroy system
29 Benefits of solar power Renewable and sustainableGenerally quiet to operateConserves fossil fuelsCan be implemented remotelyCan be scaled from tiny applications (solar calculators) to very large (solar powered communities)Can prevent pollution caused by fossil fuels
30 Comparative life-cycle CO2 emissions Energy sourceCO2 / kWeCoal1.4 – 3.6Natural gas0.6 – 2.0PV solar0.07 – 0.18Thermal solar0.08 – 0.20
31 Existing and potential solar energy development > 1 million Americans use solar water heaters> 200,000 homes use photovoltaic systems.Enough electrical power could be generated in 100 m2 area of desert southwest to supply US energy needs.
32 And according to this site: And according to this site:
33 Drawbacks to solar power Heavy investment.High-latitude areas receive relatively little sunshine.Solar unreliable at night, during winter, and during cloudy periods.Storage difficult; relies on batteries that may leak chemicals.Some PV cells use heavy metals - toxic and difficult to recycle.Solar farms require much land, currently between 5 and 10 acres / megawatt.
34 So, is solar the answer to our energy concerns? You tell me!