Before we go any further, we need to address the issue of renewable energy systems available through mail order or on the web. You will no doubt see some terrific prices on equipment at these Internet sites, but remember that things that are too good to be true often are. Few mail order dealers, with the exception of well-established companies such as Real Goods or Backwoods Solar, seldom can counsel you on system design or help you sort through and match the dizzying array of modules, inverters, charge controllers, meters, etc. available these days. We hav had countless people come into one of our stores in hopes we could help them fix broken, mismatched or improperly sized components. Another thing we hear quite a bit of is customer complaints about the old bait and switch where the bargain priced high quality products are always “out of stock” and people are pressured to accept inferior or malfunction products.

Comparing Solar, Wind and Micro-Hydro

Weighing various green energy systems will depend on your home site and what it supports. If you have reliable wind resources averaging nine mph or more, then perhaps wind power should be your first option. If you have great solar access, then photovoltaic might be your best choice. If you have a reliable, year-round source of running water, you are very fortunate and should give serious thought to this favored green energy resource. To gauge which system or combination of systems is right for you, read our previous chapters on the wide range of home energy options to judge what fits your conditions best and consult the Resources section for further in-depth reading and sources of information.

Hybrid Systems

What we have found over the years through experience, and most experts agree on this, is that hybrids sytems that can use combination of solar, wind, and/or running water are the most desirable, as one is often available when the other is not. For example, in summer when the winds are calmer, there is usually more sun. Likewise, in early spring there is often heavy water flow in streams and rivers when the skies are overcast, winds are spotty and PV typically underproduces. In reality, most renewable energy systems are hybrids in that they may use the electrical grid or a generator for backup power.

Professional Load Analysis and Site Surveys

A professional load analysis, like an energy audit, details your home power consumption and offers you the most effective ways to lower your costs. Site surveys on the other hand are meant to evaluate your potential renewable energy resources. After these steps are taken, you are ready to design a green energy system that not only fits your family’s unique energy requirements, but also gives you the greatest benefit for your investment. Taking the time to do this extra work will no doubt lead to a more trouble-free installation as well as fewer unwanted costs and headaches down the road.

After the load analysis or energy audit, we and most other renewable energy retailers are able to start calculating what your system might cost and what incentives and rebates for which you may qualify. A general estimate of system size and the components required can be put together, then you will get an approximation of the price. We and many other renewable energy dealers also insist on a site survey before going doing the estimate to avoid any misunderstandings. On more than one occasion, we have gone out to a property to begin planning a PV system, only to discover that the homeowner has absolutely no sun exposure and is unwilling to cut down a single tree to make it work.

If the homeowners decide not to go ahead with their green energy project, they will not have invested much at this point, only a few hundred dollars at most, and can walk away easily. However, a if the decision is made to move ahead with the system, the retailer will perform a site visit, if they have not already done so, to evaluate what green energy potential exists on your property. Site surveys cost anywhere from $50 to a few hundred dollars plus expenses, but this investment will spare you from making bad decisions and unnecessary spending. Particularly in regard to long-term investments such as these, careful planning and design has a huge impact on system performance and recouping your expense more quickly.

Another issue we sometimes face as retailers is the customer who approaches us with a set in stone idea of what he wants. It may be that they saw PV modules on a nice home and liked the way they look or that they have been captivated by windmills since childhood and simply must have one. It is often difficult to talk these people out of their choices when it become obvious that their site is not suited to their green energy dreams. Stay open to suggestions from your retailer, trust what he says, but be wary of ones that tell you everything you want to hear—such as “you don’t need to conserve or increase efficiency.” There are certainly dealers out there more than happy to sell you a $70,000 system on which you could have spent much less.

Insurance, Inspections and Permits

In the majority of states, you have a legal right to install a renewable energy system on your property. Nevertheless, you will need to obtain permits from your city or county building department or perhaps even approval from a local homeowners association. Almost certainly you will be require to obtain a building permit and an electrical permit before installing a solar or wind energy system. Normally, your renewable energy dealer is responsible for this as part of your overall system package. However, make sure you have it in writing from your retailer if this is included. Be prepared to work closely with your green energy provider though on these and other issues—especially in dealing with local governments with no experience in renewable energy installations.

There are currently clear national standards for connecting a home PV or wind system to the utility, and federal law requires the power company to provide you with an agreement to do so. These interconnection standards insure that your system components is safely connected to the utility grid, for your sake as well as that of the power crew. If you tie your system to the utility grid, an interconnection agreement is mandatory. These interconnection agreements lay out the minimum insurance requirements, but for most homeowners your existing homeowner’s insurance policy more often than not adequately covers these.

In addition to your interconnection agreement spelling out the stipulations for connecting to the utility grid, the power company should provide you with a purchase and sale agreement detailing your net metering provisions, the payment schedule for power you produce and other particulars.

Legal and Environmental Hurdles

Prior to investing lots time and money, research—or have your renewable energy retailer research—any possible legal and environmental issues of installing a system at your property. This is especially true with wind power. Some communities limit the height of the structures allowed in residential zones and local residents might object to wind systems blocking their view. No doubt you will encounter unfounded concerns about noise generated by your turbine or negative impacts on birds. These objections can often be overcome easily by providing the real facts about the low impact of renewable energy in a calm and courteous matter.

If your turbine will be grid-tied, investigate beforehand the requirements for interconnection to the utility and talk to other homeowners in your area with grid-connected renewable energy systems. Community zoning restrictions are available from local building inspectors and planning boards, which can inform you of the need for a building permit, as well as supply a list of other requirements.

Going the DIY Route

Deciding to install your own renewable energy system is a choice that many homeowners make, but it should be done only after careful consideration. DIY can indeed slash as much as 25 percent of the total purchase price, but properly designing and installing a safe an reliable system is not a weekend remodeling project for typical homeowner. Renewable energy installations (especially grid-tied ones) are very specialized, even if you are highly skilled at plumbing and wiring, and require lots of time and study of the system components and how they work together. That being said, there are a wealth of technical books and online resources available to educate you—many of them can be found in our Resources section at the end of this book. However, most grid-tied systems are installed by licensed contractors with years of experience in designing safe, efficient systems. In addition, many state rebate programs demand that the installation is done by a licensed professional—so the money you save with DIY is often less than that lost in rebates and incentives.

Even for renewable energy customers who can perform much of their own installation, we usually recommend that the homeowner hire an electrician to finish—or at least check—all the electrical connections. It also should be noted that some components often require calibrated or fine tune once they are installed to achieve maximum performance, and this can be tricky even with an owners manual and customer support.

Choosing an Installer

The company that sold you your system should ideally perform the installation, or at a minimum provide you with a list of reputable installers. Failing that, solar and wind turbine manufacturers, state energy office or even your power company can offer a installer contacts in your area if you purchased your components by mailorder or on the web. In many areas, renewable energy dealers and installers can also be found in the yellow pages. Your local Chamber of Commerce and the Better Business Bureau are also valuable sources of information. Last but not least, to find an installer in your area, ask your local American Solar Energy Society (ASES). The ASES has chapters in more than 30 states and can provide you with a comprehensive list of installers and dealers. Also check the ASES Find Solar web site at www.findsolar.com, which lists solar professionals in North America.

A Last Word

One of the best resources in finding reputable dealers and installers is through other green energy users. Ask other homeowners with renewable energy systems in your area who they used and if they were happy with the service they received. Above all, when you talk to prospective installers, find out what services they provide, get references and check those references carefully. Check with a mimimum of an installer’s three most recent customers. If you can, ask to visit some of the homes and speak with the homeowners. In some areas of the country, organizations such as the Northeast Sustainable Energy Association offers yearly “Solar Home Tours” where you can wander through some of America’s best green homes and pick the brains of people living with renewable energy on a daily basis. The infectious enthusiasm of these folks goes a long way in relieving any jitters about making such a bold choice in your own life. This level of effort may seem awfully time-consuming, but it is well worth it—and it is a great way to catch the green energy bug!

Financing

As we have shown previously, renewable energy systems often require a sizable capital investment. Thankfully, if a homeowner does not wish to pay for their renewable home energy system out-of-pocket, there are now a host of financing alternatives for green energy that were not available just a few short years ago. Your renewable energy retailer can be an incredibly valuable resource in discovering financing options are available in your state and which are the most appropriate for you. By financing your renewable energy system, you can spread the cost over many years and the interest payments are often deductible. Typical financing options include: unsecured loans, home equity loans and home refinancing. Consult your financial institution about these options and see the Resources section at the end of this book for more information sources.

A Final Word on System Costs

Without a doubt, the question we get more than any other at USA Solar Store is, “What does a solar-electric system cost for an average home?” Justifiably, our potential customers want a ballpark price of our solar, wind, and micro-hydro systems so they can judge whether they feel it is worth it or simply whether they can afford it. Often, they will go away for a year or more and come back when they have made up their mind or saved up the money, and we respect that. Unfortunately, we are often unable to give simple answer to that question because there are so many factors involved.

As we have stated before, the average American home uses 800-1,000 kilowatt hours of electricity every month. However, estimating system costs solely on that figure alone might produce a misleading answer. Your power consumption often varies significantly, depending on the time of year, the age and type of appliances used most, as well and your lifestyle habits in general. At the risk of sounding too repetitive, follow the advice in Chapter Two on conservation and efficiency because this will greatly influence the amount you will end up spending on a renewable energy system. Again, every dollar spent on improving energy efficiency lowers the fourfold. Adding the the complexity of divining cost is the tremendous difference between the square footage of homes (and how much is actually used), and personal energy consumption throughout the different stages of life and among occupants.

Net Metering

According to the federal Public Utility Regulatory Policies Act, power companies have to allow you to connect your electrical energy system to the grid, and they are also obliged to purchase any surplus power you produce net of what you consume. In about three dozen states, renewable energy system owners profit from regulations governing “net” meter reading. In essence, the homeowner is charged for the electricity bought from the power company, minus the electricity generated by their renewable energy system. The meter spins forward as normal when energy flows from the grid into the home and backward when current flows from the building to the utility. With a net metering agreement, the homeowner is compensated at the retail electricity rate for kilowatt-hours of sustainable electricity transmitted to the utility. Net metering benefits are particularly important in regions with high electric rates. The local power company and the community in general benefit from reduced demand and the periods of peak demand, such as midday in summer, are when renewable energy systems are at their most productive. In addition, many utilities also sell or trade energy credits based on their customers production of power.

Net metering differs state-to-state and among utilities, but all net metering programs must detail their method of determining “net excess generation”—how the customer is compensated for electricity and the time period allowed to take the credit. If your net metering agreement measures net excess generation monthly, you may receive credit for the excess energy produced in that month only. A better deal is if your net metering regulations permit annual net excess generation in which the credit can be banked in your account for a year.

According to the Public Utility Regulatory Policies Act, power companies are required to let you to connect your solar electric system to the grid. Utilities are also obligated to purchase all excess electricity you produce but don’t use. When a local utility does not have net metering, it ususally requires the homeowner to install two meters: one to gauge the power you are taking from them, and another to calculate the electricity you are sending out to the grid. Under these circumstances, the power company pays only the wholesale rate for the electricity you provide to them. This less than ideal arrangement should be taken into account when designing your the system to avoid generating too much extra power or having to buy too much from the utility.

Rebates and State Tax Credits

There are many states and even some power companies offering credits that can offset much of the cost for your solar array and components. These rebates or tax credits can aid in reducing system cost, but don’t be tempted to buy a renewable energy system just to get these credits as many did in the 1970s—it is no longer worth it for those reasons alone. Most residential solar rebate programs are capped at a specific dollar amount, often equaling about 20-30 percent of per watt cost. Tax incentives often feature a sales tax exemption for renewable energy systems, property tax exemptions or state income-tax credits, providing homeowners with a greatly reduced upfront cost. The National Database of State Incentives for Renewable Energy listed in the Resources section features information on virtually every renewable energy incentives.

Federal Solar Tax Credit

In 2005, the Energy Policy Act established a 30% federal tax credit of up to $2,000 for purchasing and installing residential PV and solar domestic hot water equipment. Nearly all expenses, including labor for site preparation, assembly, and original installation as well as for pipes and wires to connect the system to the home are allowable. The system only has to be sited

Contemporary home wind energy systems commonly consist of a rotor, a frame-mounted generator or alternator, a tail, a steel tower, electrical wiring and what we call the “balance of system”: its controllers, inverters and batteries. Through its spinning rotors, the wind turbine catches the power of the wind and turns it into motion. As in solar power systems, small turbines can be set up to feed the electrical grid, charge battery banks to provide energy to off-grid homes or both in grid-tied homes with battery backup.

Wind generators can be divided into two general categories based on the orientation of the turbine’s axis on which the blades rotate. Generators that rotate around a horizontal axis are the most common and what we normally think of when we think of wind power. Vertical-axis generators are less frequently seen but are growing quickly in popularity, particularly in Europe.

Horizontal-axis Wind Generators

Horizontal-axis wind generators are mounted at the top of a tower, and most are oriented into the wind by a simple tail-like fin, whereas large commercial turbines generally employ advanced wind sensors and motors to align themselves. Inside, gears convert the relatively slow movement of the blades into high rpm motion needed for generating usable sufficient levels of electricity.

Vertical-axis Wind Generators

As you might imagine, vertical-axis wind generators have their rotor shaft running vertically. The benefits of this system is that they are placed closer to the ground, so a large tower is not required to support it, and it need not be actively oriented into the wind. The downside is that they are habitually affected by a stressful torqueing action as well as by a drag effect created when the vertical blades rotate into the wind. It can also be difficult to mount vertical-axis turbines on towers to capture greater wind speeds, requiring that they function in the turbulent, weaker wind currents near the ground, which translates to lower energy production.

Swept Area and Wind Speed

Energy generation from wind turbines is infleunced by two primary factors, rotor diameter and wind speed. Simply put, the more area the rotor blades cover, the more energy you will capture. The speed and voulme of the wind you can capture at your site are the best gauges of your potential electrical output. Since wind power is relative to wind speed cubed, minute variances in average windspeed represent immense boosts in accessible wind power. Wind experts are quick to point out however that ground clutter and natural features at your site such as trees, your own home and hillsides all increase turbulence and decrease wind speed. This deprives a wind generator of potential energy and must be taken into account when installing a home-sized wind system.

Evaluating Wind Energy at Your Site

A wind generator big enough to supply a worthwhile part of the electricity considered necessary for a typical American home are estimated to need at least one acre of property. Fortunately, more than a quarter of homes in this country sit on sites appropriate to harvest small-scale wind energy. As with solar power, wind systems frequently have high initial costs but modest or no operating expense for the remainder of the system’s 20-30 year life. The practicality of a micro wind system depends on several factors, such as the existing wind at your location sufficient to cover your energy requirements; regulatory or zoning ordinances that bar setting up a wind turbine in your neighborhood; rebates and incentives available and whether your investment’s payback justifies the expense.

The good news is that wind power can be one of the financially sensible sustainable energy systems the homeowner can buy. Depending on the available wind at your home site, a micro wind power system can cut your utility expenses from 50 to 90 percent, eliminate the need to string power lines to new homes and remote sites, avert power outages, and cut your contribution to greenhouse gases.

If the wind blows regularly and at your location a small scale wind energy system is probably a good investment. First you need to research your annual wind speeds and prevailing direction of the wind where you live. If you live in varied terrain with lots of trees, hills or rocky outcroppings, you have to select the installation site carefully to avoid sheltered or highly turbulent areas. Ideally, the turbine should be situated upwind of houses and trees and a minimum of 30 feet above anything within one hundred yards of the tower.

Another way to judge the wind resource is to obtain average wind speed information from a local airport. However, be aware that local terrain differences and other factors might cause the wind speed supplied by your airport to be different from your particular location and bear in mind that airport wind speed is generally measured at only 20-30 feet above the ground. Since average wind speed increases with height, your wind speed atop a 100 foot tower could be more than 25% greater. The National Climatic Data Center gathers this data from airports across the country and offers wind information for sale, but your renewable energy retailer or installer should give you a wind resource report based on geological and satellite data as part of your system design and installation plan.

Wind resource maps online also can be utilized for estimating the wind resource in your location. Usually, the highest average annual wind speeds in this country are found near the seashore, on ridgelines and in the Midwest. However, countless areas have winds powerful enough to power a micro wind generator. More detailed wind resource information, including the summaries of wind data from approximately 1,000 airports are included in the Wind Energy Resource Atlas of the United States published by the U.S. Department of Energy, and can be found at the National Wind Technology Center web site (www.nrel.gov/wind/) and the Department of Energy’s Wind Powering America web site (www.windpoweringamerica.gov).

Whether your system is grid-tied or stand-alone, you must also factor in the distance between the wind generator and your house (the wire run) since a considerable amount of electricity may be lost in transit if the distance is too great. Installing greater lengths of wire or larger gauge wire also raise your system price. Because wire run losses are smaller with AC current as compared to DC current, if you have a lengthy wire run it is prudent to invert DC to AC.

Local Regulations

When considering potential sites for your wind turbine, be certain to verify land use laws, zoning regulations and building codes for ordinances that might affect installation of a wind turbine on your property. Many locales restrict tower height or require a clear zone around your tower in case it falls over (this rarely happens). Despite the fact that wind turbines are vastly more visually pleasing than power lines, generally unfounded complaints about noise, wildlife impact and aesthetics are raised regarding wind turbines by communities than any other renewable energy system, so be prepared. Nevertheless, wind power is gaining acceptance rapidly as we enter what promises to be a golden age of green power so it is getting easier for the renewable enrgy pioneers every day.

Turbine Sizing

The size of the wind turbine your home requires depends on how you plan to use it. A typical home uses approximately 10,000-12,000 kilowatt-hours of electricity annually. Depending on the wind resource at your site, you would need an expensive five to fifteen kilowatt-hour turbine to meet to this demand. Conversely, more economical one kilowatt-hour wind turbine might be sufficient to cover the requirements of a houshold needing 250-300 kWh per month at a site with an annual average wind speed of 14 mph or better. Manufacturers and installers will give you the expected annual energy output of the turbines they sell according to your annual average wind speed.

Towers

Wind energy experts will always tell you that the higher you go, the better the wind. Because wind speeds increase with height over level ground, wind turbines are erected atop a tower. In essence the greater the height of your tower, the more power your wind turbine can generate. The tower also lifts the turbine above air turbulence at ground level. A common maxim is to mount the wind turbine on a tower so that the tip of the rotor blades are a minimum of 30 feet above any obstacle that is within 300 feet.

Experiments have demonstrated that fairly small increases in tower height can give higher rates of power production more than enough to justify the added cost. For instance, to raise a 10 kilowatt-hour turbine from a 60-foot tower to a 100-foot tower prduces a 10% increase in system cost, but will produce about 25% more energy. Mounting turbines on rooftops is not recommended because wind turbines vibrate and therefore transmit that vibration down to the structure on which they are mounted. This can lead not only to annoying noise levels and structural damage to the building, but roofs can also create excessive turbulence that can shorten the life of the turbine and limits its effectiveness.

The three basic tower types are tilt-up towers, fixed towers and freestanding towers.

Tilt-up towers— Although tilt-up towers are more costly, these give the homeowner an painless way to perform repairs on micro turbines of five kilowatts or smaller. Moreover, you or your installer will never have to climb the tower and if there are mechanical issues with the turnine, and you can generally lower it in less than an hour and raised it up again just as quickly once repairs are complete. The major downside of tilt-up towers is the footprint required since you need an open area for the tower to lie down.

Fixed, guyed towers—A fixed, guyed tower is erected once, then does not tilt down again. Guy wires hold it in place, and any maintenance is done by climbing the tower. Fixed, guyed towers do not need the open drop zone that a tilt-up tower needs, but you still must have open space for the guy wires. Costs for these are comparable to tilt-ups towers, but can be installed on many sites that will not accommodate a tilt-up tower, because they don’t need as much cleared level space.

Freestanding towers—If aesthetics, not cost, is a primary concern, a freestanding tower might be your first choice. There are no guy wires, no tilting involved and freestanding towers only need a modest space for the tower base. Freestanding towers take two basic forms. Both types are usually assembled on the ground and lifted with a crane. The most common version is the three-legged style, with tubular legs connected by angle iron braces. The other option is a monopole tower—a single tube similar to what is used for utility-scale wind turbines only smaller. These are often quite expensive, and out reach financially for most small-scale renewable energy users. A freestanding tower will cost at least one-third to one-half more than a tilt-up or fixed, guyed tower.

Balance of System

The balance of system parts that you need in addition to the turbine and the tower depend on your application. Most manufacturers and dealers will provide you with a system package that includes all the components you need for your application. The balance of system required will also depend on whether the system is grid-connected, stand-alone or part of a hybrid system. For a residential grid-connected application, the balance of system parts may include a controller, storage batteries, inverter and wiring.

Cost

Installation costs vary greatly depending on local zoning, permitting, and utility interconnection costs. A small turbine can cost anywhere from less than $1,000 for small “camp” sizes, and for large home systems from $3,000 to $50,000 installed, depending on size, application, and service agreements with the manufacturer. The American Wind Energy Association (AWEA) estimnates that a 10 kilowatt home wind system costs approximately $32,000 compared to a similar photovoltaic solar energy system which would cost over $80,000. Wind energy becomes more cost effective as the size of the turbine’s rotor increases. Although small turbines cost less in initial outlay, they are proportionally more expensive.

The cost of an installed residential wind energy system with an 80-foot tower, batteries, and inverter typically ranges from $15,000 to $50,000 for a 3- to 10-kW wind turbine. Although wind energy systems involve a significant initial investment, they can be competitive with conventional energy sources when you account for a lifetime of reduced or avoided utility costs. The length of the payback period—the time before the savings resulting from your system equal the cost of the system itself—depends on the system you choose, the wind resource on your site, electricity costs in your area, and how you use your wind system. For example, if you live in California and have received the 50% buydown of your small wind system, have net metering and an average annual wind speed of 15 mph, your simple payback would be approximately 6 years.

The Bottom Line

The Wind Energy Payback Period Workbook found at www.nrel.gov/wind/docs/ is a spreadsheet tool that can help you analyze the economics of a small wind electric system and decide whether wind energy will work for you. It asks you to provide information about how you are going to finance the system, the characteristics of your location and the properties of the system you are considering. It then provides you with a payback estimate measured in years. If it takes too long to recoup your investment, i.e., the number of years for payback exceeds the life of the system, wind energy may not be desirable for you.

Innovation and Design–Integrating understanding of all the construction trades in the design process, planning to make the most long-lasting house possible, and orienting the house for solar design. 11 points

Locations and Linkages–Selecting a socially and environmentally responsible site. 10 points

Sustainable Sites–Minimizing the impact of construction and the home on the site. 22 points

Water Efficiency–Conserving indoors and outdoor water. 15 points

Energy and Atmosphere–Constructing a tight, well-insulated building envelope with efficient heating and cooling systems. 38 points

Materials and Resources–Reducing product waste during construction while using green materials. 16 points

Indoor Environmental Quality–Using appliances, installation methods, and ventilation procedures for improving indoor air quality. 21 points

Awareness and Education–Compiling a homeowner’s manual for covering the ongoing operation and maintenance of the home. 3 points

• Effective Insulation

• High-Performance Windows

• Tight Construction and Ducts

• Efficient Heating and Cooling Equipment

• Efficient Products and

• Third-Party Inspection to verify the energy efficiency measures, as well as insulation, air tightness, and duct sealing details.