Deck 3: Solar Radiation and Earths Climate, Solar Thermal, Photovoltaics & Energy Conservation and Efficiency

Question 1

What is the average available solar radiant power available to the entire USA? (Hint: Average insolation for USA is 177/m²; and, total area 3.615 x 10⁶ square miles.) About how much solar energy is available every year? What is the equivalent number of BTUs?

Answer 1

1.66 x 10¹⁵ W; 5.23 x 10²² J; 50,000 QBtu

Question 2

Assume we were to convert 1/500^th of the available solar radiant energy of the total USA area to usable form assuming 100% efficiency. What state would be closest in area to be required to be covered completely with solar panels? What state area would be required if you had only 15% efficiency?

Answer 2

New Jersey; Pennsylvania

Question 3

Calculate the total power output of the Sun at the distance of the Earth. Assume a power density at Earth of 1400 W/m² and a distance of Earth from the Sun as 1.5 x 10⁸ km.

Answer 3

4 x 10²⁶ W

Question 4

Using the above calculation for the total power output of the Sun; calculate how much solar energy is emitted in one year.

Question 5

Assume we were to convert 1/500^th of the available solar radiant energy of the total USA area to usable form assuming 100% efficiency (Hint: see question, and your answer in Chapter 9.) What state would be closest in area to be required to be covered completely with solar panels? What state area would be required if you had only 15% efficiency?

Question 6

What is the current available from a typical single solar photovoltaic panel (130 W) if the electric potential developed is 17.5 Volts?

Question 7

Consider a region where it costs an average of $8.00/W of solar panels installed. What is the cost to install a 3 kW solar photovoltaic system for a residence?

Question 8

A heat pump maintains a home's temperature at 20^o C. If the air temperature outdoors is - 5^o C, what is the maximum coefficient of performance (COP)?

Question 9

A home freezer maintains -5^o C. If the home is maintained at 20^o C; what is the maximum efficiency in terms of the energy efficiency ratio (EER)?