Good day, sunshine!

1. Good day, sunshine! • Please get out your solar handout from last class!  • Please read the board!

2. Why fossil fuels?

3. Why NOT Fossil Fuels? • What are the drawbacks of using fossil fuels?

4. Sustainable energy sources

5. 4 types of Solar power • Photovoltaics • Concentrated tower systems • Passive and active heating systems

6. Photovoltaics

7. How does it work? • Photovoltaic cells contain a semiconductor material – creates a flow of electrons (electricity!) when hit by light. • Batteries store electricity for cloudy days or nights.

9. Discovery Green down town • Two arrays totaling 256 solar panels • how much is it generating RIGHT NOW????

10. Ikea on I-10 • 3,388 panels • Completed June 2012

11. Solar arc in Japan • 5,000 solar panels • 500,000kWh of electricity

13. Solar panels are great for remote locations – free standing systems • Customers don’t need to be connected to the grid

14. Our electric “grid” = power plants connected to consumers

15. Solar update! • US solar industry – record growth in 2012, 16,ooo,ooo panels installed in nation, record 76% growth • Texas is in the top 10 states for solar installation and has the “most untapped potential” for solar (still just .1%of electricity) • Module costs have dropped 60% last two years

16. Other kinds of solar power

17. Concentrated solar towers! 2007 near Seville • 624 mirror, 35-story tower • Heat turns water to steam for turbines • Power for 6,000 homes

19. Ivanpah Solar Electric Generating System – Mojave desert California • 5.5 square miles • Power for140,000 homes • Molten salt stores heat to be released on demand – even at night.

20. How it works • Light bounces off mirrors and is concentrated at top of tower. • Molten salt is pumped to top of tower where light heats it up • Molten salt is used to turn water to steam  turbine  generator  electricity! • Connected to existing electric grid.

21. Mirrors track sun’s movement

22. Passive solar – heats air or water; no electricity

23. In winter when sun is low in sky, light enters, bounces, turns into heat which is trapped by the super-insulated windows and walls. • In summer, wide roof overhang blocks sunlight, keeping house cool. • Windows face south and west.

24. Hudson Passive Project NY

25. Villa Nyberg, Sweden

26. Passivhaus, Germany

27. Fablab house, Madrid Spain

28. Crossways, UK

29. Vogel House, Switzerland

30. Active systems

31. Water piping on roof warms water. (New Hampshire)

32. Active systems • Can also be used to heat a house with radiators. Water pipes on roof heat up. Water brought down into heat exchanger in house which warms the shower water. Cooled water pumped back to roof to warm up.

33. Active system

35. 4th period homework • Tomorrow: building solar pizza box ovens!

36. 5th/6th period homework • Three questions for Mr. Morton of Texas Solar Outfitters. • Listen for the answers during tomorrow’s talk. Questions and answers turned in at the end of the period tomorrow for a grade.

38. Solar giants • Germany! - requires solar installation on new buildings; gave tax rebates for homes installing photovoltaics.

39. So what are the trade offs? • Benefits • Disadvantages