How Energy Has Hit the News
Can wind energy be developed in Florida?
What is the wind energy potential in Florida? There are fairly strong seabreezes along the coasts and for some period of the day, this energy might be harvested to augment conventional power and reduce pollution.
History of wind energy
Persians used wind energy in 644 A.D. to pump water, and in 1197, use of wind energy to grind grain was common. The electric light industry developed in the 1800s, while 1931 brought extensive electrical power generation. The Rural Electrification Agency brought cheap energy to distant farms, and wind-powered generators and pumps fell into disuse.
Solving global warming
The long-term effects of global warming will produce difficult times in some ten to fifty years if action is not taken now. So-called greenhouse gases like CO2 trap heat within the Earth's atmosphere. The surface temperature is now estimated to rise 10.4°F in 100 years. Much of the increase has occurred as the Industrial Age burned more fuel.
Renewable energy comparisons
Fossil fuels pollute the air as they burn, while wind and solar energy are nonpolluting. Many of these sources were widely used at the turn of the last century, and then abandoned as cheap coal and oil was found and electricity transmission lines were extended.
Wind energy basics
The power in the wind is proportional to the cube of the highly variable wind speed. Doubling the wind speed results in eight times as much energy. The power thus can range from insignificant to overwhelming, and its availability is statistical (Rayleigh distribution), requiring a means to store or immediately use the power.
Clearly the coastal regions are likely candidates to investigate, while inland areas are more suited to stand-alone power at remote sites. The energy is also proportional to the area intercepted, so larger turbines yield more energy. But as the size grows, the blade stresses are greater, increasing the possibility of failure.
Research and development
The Federal government DOE, NREL, NASA, became involved after the 1970's gas crisis. Large-scale government programs bounded the scope of designs, spent money, and yielded basic research but did not create reproducible wind turbines. They found that the vertical Darrieus rotor was subject to failures. Several 100-meter turbines were built, but many current ones are 120-150 ft diameter.
Well-documented engineering was performed in the 1940s. [Palmer] Independent companies pursued wind energy intensively in the 1970's. Largest world manufacturers of 1998 were NEG Micon (DK), ENRON Wind (USA), Vestas (DK), and Enercon (D).
Wind energy economics
The sun provides the energy for ocean currents, tides, waves, winds, and plant growth. Direct solar energy can heat homes, food, water, and dry materials. The best energy type for any given location varies greatly, and cost studies are necessary to find the best source. Wind turbines can now produce electricity at prices comparable to fossil fuel plants today, yet they have no pollution. Estimates are 4 to 8¢/kWh.
The Plains states are well suited for large-scale wind turbines. Only some 2% of that land would be needed to supply 20% of our needed electricity, and 95% of the land underneath would still be suitable for farming or ranching. [AWEA]
Tax incentives can compensate for existing direct subsidies to fossil and nuclear plants. The California wind farms were incentivized by subsidies passed by the California legislature. Distance to commercial power sources greatly affects the choice of independent power supply. The cost of extending commercial power lines (~$18,000/mile) far into a ranch may easily exceed the cost of a wind system.
Florida wind energy resources
Wind energy is limited in Florida to Class 1 (0 to 9.8 mph at 10 m, poor) inland and Class 2 (9.8 to 11.5 mph, marginal) levels offshore or in coastal areas.
[DoE, NREL, PNL]
The Florida interior has low speed winds that are unsuitable for significant power, although water pumping is possible. Newer systems use electric pumps driven by wind turbine generators. The background level winds from seabreezes are stronger within 20 miles of the coasts, but passing storm fronts bring higher energy levels every four days or so. There is potential for offshore wind farms, but an economic study would be needed to further assess this.
Where do we go from here?
Remote areas of the state can still use small-scale wind systems to some extent, and combination with solar PV cells creates a more efficient and reliable hybrid system. Offshore and near-shore systems may prove practical, but protection from hurricane force winds is still a key issue. Specific research for this application is needed to define the economics of the system. Distributed generation provides point-of-use generation for efficiency in avoided transmission losses and more reliable backup power. There are many uses for emergency power.
Conclusions
Florida wind energy has significant potential for special uses, but is unlikely to be a replacement for fossil fuel utilities. Like fossil fuel energy, wind energy can be financially imported to Florida via electrical transmission lines. In the grid systems, any type of energy may be purchased, but the electrical energy actually supplied may come from closer fossil fuel or nuclear plants though the windfarm is pushing energy into the grid farther away.
Wind energyin Florida?
Frank R. Leslie,
BSEE, M.S. Space Technology
November 12, 2002; Rev. 3