Do Now:Baltimore Polytechnic Institute receives an average of 150 W/m2 every day during the month of January. How many kW of solar energy land on our football field per day in January?[ Explain your reasoning and show your work.]

23250 kW = 23.25 MW!!!

150 Wattsm2 * day

Area of football field in m2 1 day

Watts=x

150 Wattsm2 * day

100 meters * 50 meters1 1000 W

1 kWday

23250 kW=x x

Active Solar Energy

May 3, 2013 Objective: SWBAT understand how photovoltaic cells function and the difference between passive and active solar energy. The students will answer the question –How is solar energy converted for use in a typical home.

Essential Questions

What is active solar energy and how can it be used? How do solar cells work? How is electricity generated from solar energy

transformed for use in the home?

Active Solar Energy

The use of mechanical or electrical systems to convert solar energy into thermal or electrical energy. Heating Power Generation

Solar Water HeatingPhotovoltaics & Concentrating Solar PowerPV System Solar Tower Dish/Engine System

Active Solar Water Heating: Direct Circulation Systems

Pumps move water through solar collectors to warm and then back into a tank for home use; a controller monitors water temperature and turns the pump on/off

Indirect Circulation Systems Pumps move water through solar collectors to warm and then into a heat

exchanger to warm up the home’s water tank; a controller monitors water temperature and turns the pump on/off; there is an additional boiler in case more heat is required.

Active Solar Power Generation:

Photovoltaic Systems Light is turned directly into electricity

Concentrating Solar Power Systems Focused light from the sun either heats steam to run turbines or is

converted to thermal energy to run heat engines

Active Solar Power: Photovoltaics

Photovoltaics (PV) are materials that convert sunlight into electrical energy; Edmond Becquerel discovered the PV effect in 1839 and the first practical solar cells were created in Bell Labs in 1954.

Let’s watch a video on Photovoltaics!

And how engineers make..\Solar Innovator - Alta Devices.mp4 a difference

Active Solar Power: CSP

CSP technologies use mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat. This thermal energy can then be used to produce electricity via a steam turbine or heat engine that drives a generator.

Let’s watch a video on Concentrating Solar Power!

What’s Coming Up?

Next week we will do 4 solar activities in the next room. You will be in groups of three. Quiz on Solar next Friday