The Handy Chemistry Answer Book (2014)

ENERGY

QUANTIFYING POWER

What is a watt?

A watt is the standard SI unit of power, representing 1 Joule of energy per second. It is named after a Scottish engineer by the name of James Watt. To give an idea of how much energy this is, lightbulbs in your house typically use about 25 to 100 watts (new types of lightbulbs are doing a bit better than this, actually). For comparison, if you are doing manual labor over the course of a long day, your body will average somewhere in the range of 75 watts of power output.

What is a kilowatt hour?

A kilowatt hour (KWH) is a unit of energy representing the amount of work that is done by 1,000 watts of power operating for one hour. Notice that a watt represents a quantity of energy per unit time, also referred to as power, while a kilowatt hour simply represents a quantity of energy.

How many nuclear power plants are there in the United States?

There are currently sixty-five nuclear power plants in the U.S. and a total of 104 nuclear reactors. This is because thirty-six plants have more than one reactor.

How many nuclear power reactors are there in the world, and how many are currently under construction?

There are currently 436 nuclear power reactors around the world. The breakdown of the distribution by country is shown in the table below. Aside from the United States, a few other countries with large numbers of nuclear reactors are France, Russia, China, Japan, and Korea—each of these nations has at least twenty nuclear reactors currently in operation.

Number of Nuclear Power Reactors in Countries*

Country

Number of Active Reactors

Number under Construction

Argentina

2

1

Armenia

1

 

Belgium

7

 

Brazil

2

1

Bulgaria

2

 

Canada

19

 

China

19

29

Finland

4

1

France

58

1

Germany

9

 

Hungary

4

 

India

20

7

Iran

1

 

Japan

50

3

Mexico

2

 

Netherlands

1

 

Pakistan

3

2

Romania

2

 

Russian Federation

33

11

Slovakia

4

2

Slovenia

1

 

South Africa

2

 

South Korea

23

3

Spain

8

 

Sweden

10

 

Switzerland

5

 

Taiwan

6

2

Ukraine

15

2

United Arab Emirates

 

1

United Kingdom

16

 

United States of America

104

1

*As of January 2013.

How much energy is produced from a given amount of coal, oil, or gas?

One ton of coal can produce 6,182 kWh of energy

One barrel of oil can produce 1,699 kWh of energy

One cubic foot of gas can produce 0.3 kWh of energy

How much does it cost to produce energy from gas, coal, solar energy, etc.?

If one ton of coal costs $36, which gives an energy cost of $0.006 per kWh

And one barrel of oil costs $70, which gives an energy cost of $0.05 per kWh

And one cubic foot of gas costs $0.008, which gives an energy cost of $0.03 per kWh

Then a 4 kW solar panel system providing energy for an average ranch-style home and costing $25,000 and lasting about 20 years would provide about 120,000 kWh for the life of the system (depending on climate) and cost about $0.21 per kWh.

You can see that solar power is still more currently more expensive than other fuel sources.