Chapter 1
Introducing the World of Home Wind Electricity
In This Chapter
Determining whether wind energy will work for you
Breaking down the components of a wind-electric system
Understanding electricity and wind-energy principles
Getting a handle on your energy situation
Designing, installing, and operating your system
Have you ever watched a wind generator spinning in the breeze and wanted one for your home? Youâre not alone. Wind generators â big and small â are captivating. Something about capturing the elusive, invisible force of wind excites people. Iâm here to help you take that excitement and succeed in making meaningful amounts of electricity from the wind for years to come. Think of this chapter as your introduction to the wide world of wind energy.
Figuring Out Whether Wind Energy Is Right for You
People chase after wind energy for a variety of very different reasons. Yours may include reducing your impact on the environment, saving money, increasing the reliability of your homeâs electricity, boosting your social status, or adopting a fascinating hobby. Being clear about your motivation can help you make sure you reach your goals. For example, if wind energy is a hobby, youâll be less concerned about payback; if itâs an environmental passion, youâll want to make sure youâre actually cleaning up the Earth, not burdening it with more stuff.
To be successful, you obviously need wind, and you need a good site where you can install a tall tower to get up into the good wind. But you also need to please your local bureaucrats, as well as your family and neighbors. Educating yourself about the common objections to wind energy can help you educate others about the reality of a wind-energy system and get them on your side.
If you have the right site and situation, you still need to have or hire the skills to design, install, and maintain a system. Someone â either you or someone you hire â has to be hands-on. Someone needs to be ready to take on a system that isnât easy and may well give you headaches at times. Finding mentors, experienced wind-energy users, and professionals can help. Chapter 2 explores these issues and more in detail.
Understanding the Components of Wind-Energy Systems
If your goal is to make wind electricity, you need more than a wind generator. A wind-electric system, even at its most basic, includes the following parts:
Wind generator: The spinning device that captures wind energy and converts it to electricity
Tower: The steel structure that holds your wind generator up in the wind
Transmission: Wire and associated equipment
Controls: The charge controller, inverter, and so on
Batteries and/or grid interface: Equipment for energy storage and grid interconnection
Metering, disconnects, overcurrent protection, grounding, and more: Gear to keep track of your systemâs performance and keep the system safe
Chapter 3 details these system components so you can understand their functions and be ready to think about how to put them together in your system.
Focusing on Electricity Fundamentals
You canât do a good job of designing, installing, and operating an electrical system without understanding electricity. If you donât know a watt from a volt, Chapter 4 helps you with plain-language explanations of electrical terms, including the following:
Wattage: The rate of energy generation, transfer, or use
Watt-hour: The unit of electrical energy
Voltage: Electrical pressure
Amperage: The flow rate (often called current) of electrons (charges)
Direct current (DC): One-way flow of electrons
Alternating current (AC): Two-way flow of electrons
Amp-hour: Battery storage capacity
Ohm: Resistance to the flow of charges
Hertz: The frequency of AC alternation
Perusing Wind-Energy Principles
In addition to having a clear understanding of electrical principles, you want to understand wind-energy principles. Wind is invisible and a bit mysterious. Its power increases with the wind speed cubed (V3), which is a particularly important concept to understand; it means that a small change in wind speed can have a big effect on how much electricity youâre generating.
Capturing wind energy requires a large enough collector on your generator, and air density (and therefore elevation) also has an effect on power. (One wind power formula says that the power in the wind equals 1/2 times air density times the collector area times the wind speed cubed, or P = 1/2DAV3.)
Although this formula helps you understand the comparative power available in the wind, energy (measured in watt-hours) is the prize you seek, so focusing on instantaneous or maximum power (measured in watts) is a distraction at best. And you donât want watt-hours for a day, week, or a year but for years if not decades, so you should seek reliable equipment that churns out the watt-hours for the long haul. Chapter 5 explores these topics and more.
Getting a Grip on Your Energy Situation
Because your goal is undoubtedly to make some or all of the electrical energy for your home, understanding how much energy you use is crucial. The next step is to work on energy efficiency â making the best use of your energy. Your siteâs wind-energy potential needs careful consideration, too. All these steps improve your chances of generating the amount of energy you need.
Before designing a system, you need to decide how your system will or will not relate to the utility grid. The grid allows you more leeway in how much energy you can use or need to produce, but hooking up does involve getting through some red tape.
After you calculate how much energy your chosen turbine is likely to produce on your site, you can get an idea of the value of your investment. If you decide not to go after wind energy, you have some other options. Read on â this section covers all these energy issues.
Conducting an assessment and increasing your homeâs efficiency
An energy assessment can give you a big-picture view of the energy use of your family, including specifics about each energy user in your home (by energy user, I mean your air conditioner or stereo, not, say, your spouse and kids). The simplest way to get the overall view of your electricity usage is from your utility bill, but getting more specific can help you ferret out the biggest culprits.
Chapter 6 gets down to the nitty-gritty for you. Ideally, youâll end up with a detailed list of all your homeâs energy users, with an accurate number of kil...
