Wind is an increasingly significant source of energy in Minnesota. The state's many wind farms take advantage of large areas of open prairie as a source of renewable energy. As a major producer of wind energy, Minnesota ranks in the top 10 in the nation for generating energy from wind. In 2014, wind energy supplied about 16% of electricity generated in Minnesota.
You can purchase a portion or all of your electricity from wind energy from your utility via a green pricing program. You may need to pay a little more than your existing energy rates. Some utility programs also provide added energy cost certainty with a credit for the cost of fossil fuels that would otherwise be used to generate electricity.
Subscribing to a utility green power program effectively increases the amount of renewable energy that a utility must procure above and beyond the minimum Renewable Energy Standard. The U.S. Department of Energy tracks current pricing for utility green power programs with links for more program information and to subscribe.
The Minnesota Department of Commerce reviews utility green pricing programs to verify that customer green pricing purchases are not double counted toward renewable energy standards or other programs.
Make your own wind energy system
Developing an on-site wind energy project on one’s property is a more tangible and visible option for sourcing renewable energy. This option also comes with more significant effort and long-term commitment. If you are considering a new wind energy system, "Guidelines and Resources for Distributed Wind Projects" is a good place to start.
The information and resources below will help in the planning and implementation of distributed wind energy projects (under 100 kW) at homes, farms, and businesses.
Guidelines and Resources for Distributed Wind Projects
The following is a list of guidelines and resources for anyone considering a wind energy system:
Call at least three dealers/installers for price quotes on comparable systems. Locate your latest electric bill to refer to, as the installer will likely ask you up-front how much energy you currently use on a monthly basis.
Questions to ask a renewable energy dealer or installer
What tools or methods does the dealer or installer use to assess the wind resource? [note: see wind resource assessment and additional siting considerations, below]
How long has the dealer/installer been doing wind turbine installations? What sort of training does the installer have on the proposed wind turbine model?
How many turbines have been installed (especially this model)? Are they still running? How much annual energy do the previously installed turbines produce?
Are existing customers satisfied with the wind turbine installation process? Are they happy with their wind turbines? Can the dealer/installer provide references?
What is the maintenance schedule? How often does the turbine require routine maintenance? Does the installer provide a maintenance service? What are typical maintenance costs for routine and unplanned maintenance? Is there a charge for travel time? Is there a minimum fee? How long does it usually take to get replacement parts? How long does it take to schedule a service visit?
What are the terms of the contract or warranty (get these in writing)? Does the warranty cover both parts and labor? Does the warranty cover the entire system or are there separate warranties for the turbine, tower, inverter/controller, etc.?
Wind resource assessment and additional siting considerations, see:
Solar, wind, and other renewables may not be the lowest cost way to reduce your energy bills. Optimize returns on your renewable energy system by investing in energy efficiency first. An energy audit is a good first step and is available through many utilities at a discounted price. After energy efficiency measures are taken, renewable energy may make sense for you as a clean energy source. The following questions may help you begin the conversation with a renewable energy professional. You will get the most out of the discussion if you do some initial homework.
Approximately how much energy will the system produce and what portion of energy use might I expect the system to offset annually? This is also known as the solar fraction or wind fraction.
Will the system measure and track energy production? How do I manage loads in order to achieve the predicted solar/wind fraction?
What is the current monetary value of the energy saved/generated?
Does your bid reflect the total cost of the system? Are structural engineering considerations included? Under what circumstances will I be charged extra for unanticipated costs? What incentives are available to offset the system cost? Who handles the paperwork for incentives?
Will you as be responsible for obtaining the appropriate permits? (For example, building, plumbing, electrical, zoning, as required by the local jurisdiction.)
Do you provide a maintenance or service warranty? How do you handle manufacturer warranties? What maintenance is recommended? How long can I expect the system to last?
How long have you been in business? How many installations have you done? Do you have references I can contact? Photos of previous installations?
When could the installation begin? From start to finish, including utility or permit approvals, how long might the installation take? (Permitting and incentive application processing vary by location.)
For wind and solar electric: Do you work with my electric utility to complete grid interconnection? Are there interconnection costs? (Utility interconnection costs and approval time vary.)
Will you provide an owner’s manual upon commissioning the system?
If there is a blackout, what options do I have for backup power and how much do they cost?
It is a good idea to speak to more than one contractor before making a final decision. As with any building improvement, it is important that you are comfortable with your contractor. Be sure that each bid specifies system type and size, expected energy production, maintenance requirements, and installed cost.
Disclaimer: The resources listed above are not an endorsement by the Minnesota Department of Commerce. Consumers are advised to perform due diligence in selecting a contractor such as seeking references, verifying licensing, etc.
Wind Speed Verification Tool
This interactive application identifies the wind speed for a specific Minnesota location at a 30 meter elevation above ground level, based on data used for the 2006 wind map. This data should be used as a general guideline for screening purposes only. Specific site conditions that affect wind speed should be evaluated by a trained wind site assessor before investing in a small wind turbine.
Troubleshooting and Tips on Finding Site Coordinates
Tips and resources to help locate site coordinates:
The Wind Speed Verification Tool should return a wind speed for any geographic coordinate within Minnesota. Enter latitude and longitude in decimal-degree format only (e.g. N 44.955, W 93.102). Do not use negative numbers.
For the state of Minnesota, latitude ranges from 43.57 to 49.38 degrees north. Longitude ranges from 89.57 to 97.20 degrees west.
A zip code is required to locate an address. The application may not be able to locate all addresses in the state.
If the wind speed verification tool can't locate the address of the property, but you know where the property is, try Google Maps. Right click on the location on the map and select "What's Here?" to get lat/long coordinates. Note: use the longitude number without the negative sign.
Minnesota Distributed Wind Webinars
These webinars cover a broad range of topics on market developments and best practices, including turbine selection, performance estimation, site assessment, U.S. Department of Agriculture (USDA) grant application process, the distributed wind energy supply chain, and market participants in Minnesota.
Search Renewable Energy Installers Directory
A directory called Clean Energy Builder is provided by Clean Energy Resource Teams (CERTS) to find companies in Minnesota that can help you plan, implement and manage clean energy projects.
Wind turbine towers can vary in height from 100 feet (30m) for small towers to 492 feet (150m) for industrial towers. Typically, wind turbine manufacturers recommend siting a tower on a minimum of a half to 1 acre of land without trees or buildings. Roof or building mounted turbines are an emerging technology and may require additional reinforcement and support to avoid structural damage from strong wind and vibration. Vibration from building mounted units can also result in loud noise.
Some jurisdictions restrict the height of the structures permitted in residentially zoned areas, although variances are sometimes obtainable. Most zoning ordinances have a height limit of 35 feet. You should speak with local representatives to determine any building permits, electrical permits, approvals, and certification that is needed prior to installing a wind system. This is a critical phase and it is vital that you have all approvals in place before beginning any installation or ordering your equipment. Your installer should have experience helping customers secure necessary permits.
A typical Minnesota home uses approximately 810 kWh of electricity per month. Depending on the average wind speed, a wind turbine rated from 5 to 15 kilowatts would be required to make a significant contribution to this demand. A 1.5- kW wind turbine will meet the needs of a home requiring 300 kWh per month in a location with a 14-mile-per-hour annual average wind speed.
Battery systems can be installed to store electricity for off-grid installations. Battery back-up for an off-grid site is an advantage when the cost to connect to the grid is significantly more than the cost of a wind energy system with battery backup. The cost of interconnection starts to become comparable at distances over a half-mile. Off-grid wind systems are typically combined with a solar electric system and/or a back-up propane, diesel or gas generator to provide more reliable power under a variety of seasonal weather conditions.
Installation and maintenance of battery systems adds significant up-front and maintenance costs to a wind energy system, so they are not generally recommended for sites that are already connected to the utility power-grid. Costs vary widely depending on the back-up power needs, but typically add 25% to the up-front cost of the system. Battery life is typically 4-10 years depending on battery type. Most electricity storage systems use lead-acid batteries. Once spent, the batteries must be properly disposed of. Where a grid connection is already available, connecting to the grid without batteries is the most cost-effective and environmentally friendly way to go.
Wind turbines operate thousands of hours per year, often under harsh conditions. The wear and tear on a small wind turbine has been compared to putting 100,000 miles a year on a car. As a result, periodic maintenance is required to maintain bearings and lubricants. The maintenance costs of a wind turbine depend both on the quality of the turbine and the local climatic conditions such as the amount of turbulence at the site. For basic maintenance, not including major overhaul or repair costs, the average annual repair costs are approximately 1% of the original turbine cost. With proper maintenance, a wind turbine should last 20 years or longer
A general rule of thumb for estimating the installed cost of a residential turbine is $5,000 to $10,000 per kilowatt, depending on size, application, and service agreements with the manufacturer. 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. For a wind tower that is tall enough to take advantage of available wind (100-120 feet for small wind systems) the tower itself is often just as expensive as the turbine equipment – a fact that is frequently overlooked in reports of wind system pricing.
Depending on your wind resource, and the size of the turbine, a small wind energy system can lower your electricity bill by 50-90%. If you generate 400 kWh/month (4800 kWh/yr) and you pay $0.08/kWh, you can save $384 per year in offset electricity costs. In Minnesota, if you generate more electricity than you use in a month, the utility must pay you the average retail rate for the excess electricity. If your excess electricity is 100 kWh/month and you pay $0.08/kWh, then the utility will pay you $8.00/month.
It can take anywhere from ten to forty years to recapture costs of equipment and installation, depending on the size and complexity of your installation, the wind resource, price of electricity (or distance from the grid), electricity usage, finance rate, and available rebates or incentives.
The Office of Energy Security does not endorse any particular manufacturer or installer, however, the OES can provide a list of renewable energy dealers and installers. You can also call or go to the manufacturer’s website to see who distributes their equipment in Minnesota. When shopping for a wind turbine system, you should compare warranties, predicted lifetimes, and the manufacturer’s and turbine model’s reputation for quality and service.
Even if building a wind turbine on your property is not an option, there are a number of options to invest in wind power. Green Pricing programs are available from your utility so that you can offset your electricity usage by investing in new wind energy development. You can also purchase Renewable Energy Certificates from the Chicago Climate Exchange through a variety of brokers. See the Department of Energy’s website for more information. Communities can take advantage of Minnesota’s Community-Based Energy Development (C-BED) tariffs that provide higher payments from utilities for community based projects.
Green pricing is an optional utility service that allows customers an opportunity to support a greater level of utility investment in renewable energy technologies. Participating customers pay a premium on their electric bills to cover the incremental cost of developing new renewable energy generation facilities. In Minnesota, utilities cannot use green pricing energy generation to satisfy renewable energy mandates, so the green pricing program is a way for customers and utilities to go above and beyond the minimum standard.
Wind turbine noise levels from small wind turbines are comparable to the noise level that a refrigerator or air conditioner would be from an adjacent room. Noise level issues from industrial size wind turbines are mitigated by setback requirements that specify an acceptable decibel level, comparable to natural background noise levels. Bird deaths due to wind development will never be more than a very small fraction of those caused by other commonly accepted human activities. The modern wind turbine is far less harmful to birds than are tall buildings & windows, domestic cats, vehicles, pesticides, radio towers, and airplanes. Summaries of available wind studies can be found at www.currykerlinger.com and at www.nationalwind.org. Wind power does not create any carbon dioxide or toxic byproducts, so compared to the noise levels and environmental effects of conventional fossil fuel energy sources, wind is an optimum environmental option.