Energy
First Law: Energy cannot be created or destroyed.
Second Law: Energy can be changed from one form to another, but at each change there is a significant loss of energy. All energy becomes heat radiated into the environment.
Net Energy = Gross Energy - Energy Costs. Energy costs include extracting, refining, transporting, converting and using. Other costs include environmental, social and "embedded."
Consumption
Americans use about 25% of the world's energy but represent less than five percent of the world's population.
Fossil Fuels
Petroleum accounts for half of the energy consumed in Florida. Natural gas supplies 11% of our energy. Coal supplies about 21% of Florida's energy. Floridians and visitors used about 6.14 billion gallons of gasoline per year (16.8 million gallons per day).
Electricity
Electric-generating plants take three units of fuel and produce two units of heat and one unit of electricity.
Utilities consume 50% of Florida's energy.
Electricity is usually measured in watts and time. (Kilowatt = 1000 watts.)
Kilowatt/hour = 100-watt bulb burning for 10 hours. The average Florida household uses 1000 kWh each month. Since it takes about one pound of coal to produce one kWh of electricity, it requires about 1000 pounds of coal to produce the electricity for each Florida household each month (six tons per year).
Florida's 57 electric utilities generate over 111 billion kWh each year, an additional 11 billion kWh is imported.
Electrical Power
A typical waste to energy plant is 10 mW (million watts). It produces enough electricity for 30,000 people.
A 1000-mW plant produces enough electricity for a city of 350,000 people. This is a common size for a nuclear plant.
It would take the primary productivity of 912 square miles of southern pine forest to provide the fuel for a 1000 mW electrical plant operating at 80 percent load and 33 percent efficiency each year.
Renewables
The solar radiation that falls on one-half of one percent of land area in the United States is equal to our total projected energy demand in the year 2000. Unfortunately, land plants collect this energy at less than one percent efficiency. Total U.S. biomass fixation is about five million tons per year and (at 7,500 Btu per pound) is equal to 75 quads.
Florida receives a maximum of 300 Btu per square foot at solar noon on a cloudless day; 1,600 Btu per square foot (5,045 watt hour/m2) is a good average for the entire day. Renewables provided about 5% of the 1990 energy budget.
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