small blades that do not interfere with such signals. Moreover, the blades of modern wind turbines are made out of materials that are “transparent” to telecommunications signals. As a result, small wind turbines are often installed to power remote telecommunications sites. Telecommunication equipment wouldn’t be installed in such locations if there were a problem with interference.
The Advantages of Wind Energy
Although residential wind turbines and their energy source, the wind, have a few downsides, wind energy is an abundant and renewable resource. We won’t run out of wind for the foreseeable future, unlike oil and natural gas.
Small-scale wind energy could also help decrease our reliance on declining and costly supplies of oil — if electricity generated by wind is used to power electric or plug-in electric hybrid cars and trucks, displacing gasoline, which is refined from oil.
Wind energy can also play a meaningful role in offsetting declining US natural gas supplies. In the United States, approximately 18 percent of all electricity is currently generated by natural gas, according to the US Department of Energy. As supplies decline, wind could help ease the crunch, supplying a growing percentage of our nation’s electricity.
Wind could even eventually reduce our dependence on nuclear power as well. In the United States, nuclear power plants generate about 20 percent of the nation’s electricity. Although wind energy does have its impacts, it is a relatively benign technology compared to conventional sources of electricity. It could help all countries create cleaner and safer energy at a fraction of the environmental cost of conventional electrical energy production. Wind energy can help nations reduce global warming and devastating changes in our climate. Wind can also help homeowners and businesses do their part in solving other costly environmental problems such as acid rain.
Another benefit of wind energy is that, unlike oil, coal and nuclear energy, the wind is not owned by major energy companies or controlled by foreign nations. An increasing reliance on wind energy could therefore ease international political tension. Reducing our reliance on Middle Eastern oil could reduce costly military operations aimed, in part, at stabilizing a region where the largest oil reserves reside.
Wind is also a free resource. The cost of wind is not subject to price increases. A wind- and solar-powered future might be one subject to less inflation. This is not to say that wind energy will be free of price increases. While the fuel itself (the wind) is free, the price of wind generators is likely to increase. That’s because it takes energy to extract and process minerals to make the steel and copper needed for wind turbines and towers. It also takes energy to make turbines and towers and ship and install them. As the price of conventional fuels and raw materials increases, the cost of wind energy also will go up.
Yet another advantage of wind-generated electricity is that it uses existing infrastructure, the electrical grid, and existing technologies. A transition to wind energy could occur fairly seamlessly.
Thanks to generous tax credits and other financial incentives, individuals in rural areas with good wind resources can meet all or part of their energy needs at rates that are often competitive with conventional sources. In remote locations, wind or wind and solar electric hybrid systems can be cheaper than conventional power, which requires the installation of costly electric lines that transport electricity from power plants to end users.
Fig. 1.5: Plug-In Hybrid. Electric cars and plug-in hybrids like the one shown here are the most promising automobile technologies on the horizon. They could be powered by electricity from the Sun and wind.
The Purpose of this Book
This book’s principal focus is on small wind-electric systems — those with rated output ranges from 1 kilowatt to 100 kilowatts. Most of the turbines we’ll be discussing fall in the 1- to 20-kilowatt (kW) range. The blades of small wind turbines (1 to 100 kW) range from 4 feet to 32 feet in length. Small-scale wind systems serve a variety of purposes. The smallest units are generally sufficient to power cabins and cottages; larger small wind turbines power homes and small businesses as well as schools, farms, ranches, small manufacturing plants, and public facilities.
This book is written for individuals who want a succinct introduction to small-scale wind systems that doesn’t require a degree in physics or engineering. My goal was to create a user-friendly book that teaches readers the basics of wind energy and wind energy systems. This book is not an installation manual, but it will help you learn about wind if you want to become a wind energy installer or install a wind turbine and tower on your property. It will also help you determine if wind energy is right for you, what your options are, and how much it is going to cost.
When you are done with this book, you should have a good knowledge of the key components of wind energy systems. This book will help you when shopping for a wind system or an installer. You’ll also learn about maintenance requirements.
If you choose to hire a professional wind energy expert to install a system — a route we highly recommend — you’ll be thankful you’ve read this book. The more you know, the more input you will have into your system design, components, siting and installation — and the more likely that you’ll be happy with your purchase.
This book should help readers develop realistic expectations. Wind energy systems, for instance, require annual inspection and maintenance — climbing or lowering a tower to access the wind turbine to check for loose fasteners and blade damage and, much less commonly, an occasional part replacement. If you are not up for it or don’t want to pay someone to climb or lower your tower once or twice a year to check things out, you may want to invest in a solar electric system instead.
Organization of this Book
After this brief introduction, we turn our attention to the wind itself, the driving force in a wind energy system. In Chapter 2, you will learn how winds are generated and explore the factors that influence wind flows in your area. We will also explore the factors that affect energy production by a residential wind turbine and why it is important to mount a wind machine on a tall tower.
In Chapter 3, we’ll explore small wind energy systems. You’ll learn the three types of residential wind energy systems: (1) off-grid, (2) batteryless grid-tie, and (3) grid-connected with battery backup. You’ll learn about the basic components of each one and hybrid wind systems.
In Chapter 4, you will learn how to assess your electrical energy needs and how to determine if your site has enough wind to make a wind system worthwhile. You’ll learn why energy conservation and energy efficiency will save you a lot of money on a wind energy system. You will also learn ways to evaluate the economics of a wind system answering the question: Does a wind system make sense from an economic perspective?
Chapter 5 will introduce you to wind turbines — what types are available and how they work. We’ll also give you shopping tips — what to look for when buying a wind turbine. We’ll spend a little time discussing building your own wind generator.
Chapter 6 describes basic tower options, the pros and cons of each one, and how they are installed.
In Chapter 7, we’ll study storage batteries and charge controllers, two key components of off-grid wind systems.
Chapter 8 addresses another key component of all wind energy systems, the inverter. You will learn how inverters work, what functions they perform, and what to look for
