The motor you use is, without a doubt, the most critical component of your wind power generator. If you’re new to small wind turbine construction, you’ll find this to be one of the most perplexing (and contentious) components of the process. Oh, the motors, generators, and alternators! There are a number of words that appear to be referring to the same thing.
Many industrial motors create excellent wind generators at a low cost. The motor is used to generate power in a wind turbine. The “motor” would no longer be referred to as a “motor,” but rather as a “generator” or “alternator.” This article focuses on possible motors that can be found as surplus items on the internet and utilized to make your own custom wind generator.
Obviously, selecting the right motor for your generator is critical. If you pick the wrong one, you can find out that:
- Your wind generator will generate electricity, but not at a high enough voltage to generate usable electricity.
- Your wind generator will initially work, but it will overheat and quit working within a few days or weeks.
Don’t get discouraged, though. There are hundreds of motors that can create hundreds, if not thousands, of Watts of useful energy. Even better, we’ll give you some pointers on how to find one at a fair price.
Generators generate electricity in one of three ways: by induction, an exciter, or PERMANENT MAGNETS.
Magnets, Magnets, Magnets!
Permanent Magnet Motors are almost entirely used by do-it-yourselfers to make wind power generators since they are widely available, dependable due to their construction, and can generate electricity at virtually any RPM. Other sorts of motors, on the other hand, cannot be regarded to be in the same category.
A coiled copper coil is surrounded by permanent magnets within a permanent magnet motor. Electromagnetic induction drives these motors, which means power is fed into a coil of copper wire, which generates a magnetic field. The permanent magnets in the motor casing are at odds with the magnetic field formed by the energy flowing through the copper wire. As a result, the copper wire connecting to the motor’s shaft attempts to “push” away from the permanent magnets. As a result, your motor begins to spin!
When considering a permanent magnet motor as a generator, the same logic applies. The voltage difference between the two ends of the copper wire is created by spinning it with the wind’s energy in the presence of the magnets. Electric charges (electrons) flow in the copper wire as a result of the voltage differential, generating electric current.
Volts-to-RPM Ratio
One of the most significant criteria to check for when choosing a motor is the Volts-to-RPM Ratio. Because of their low cost and broad availability, most DIYers utilize their motor to charge a 12-Volt battery. To charge a 12-volt battery, the permanent magnet motor must produce at least 12 volts. If it doesn’t, it won’t be able to overcome the 12V battery’s impedance, and the motor will never charge the battery. How can you determine if your wind-powered motor is capable of producing more than 12 volts? Continue reading.
A permanent magnet motor’s volts-to-RPM ratio is defined as the number of volts necessary to spin the motor at a particular RPM (rotations per minute). Assume you have a permanent magnet motor with the following specifications on the label: “2500 RPM, 100 Volts.” Simply said, if you feed 100 volts to the motor, it will spin at 2500 rpm. It has a volts-to-RPM ratio of 0.040. (100 divide by 2500).
This figure gives an approximate idea of how many volts the motor will produce at a certain speed. Let’s pretend our 2500 rpm, 100 volt motor is rotating at 450 rpm. At what rpm will it create how much voltage? Here’s how to figure it out:
There’s one more thing to do now. 18 Volts must be multiplied by 80%. Why? Because the number 18 Volts only applies if the motor is being used as a motor. This motor isn’t being used to move anything. It’s being utilized as a generator, and it’s not 100% efficient. As a generator, it is approximately 80% to 85% efficient.
At 450 rpm, we know how many volts our motor will produce: 14.4 volts. The realistic RPMs of a wind generator must then be considered. Most likely, you’re constructing a “small” wind generator with a power output of 100-500 watts When the motor is under load (meaning the motor is attached to your battery bank), any well-constructed 50-to-60 inch diameter blades on that motor will easily produce 450 rpm in wind speeds of 8-10 mph. When a generator is under load, it has to work harder, which causes it to spin a little slower than when it is not. In wind speeds of 8-10 mph, this motor will start charging a 12V battery bank.
This is in line with your goals, thus we can deduce that this permanent magnet motor would be suitable for use in a wind generator.
When looking for a permanent magnet motor, a voltage-to-RPM ratio of AT LEAST 0.035 is the minimum need. It’s perfect if the value is more than 0.035. If the value is less than 0.035, it will most likely be insufficient unless it is in a windy environment.
Amperage Rating
The motor’s amperage rating is the next item to consider. This tells you how much current the motor will generate when used as a generator. According to our experience, predicting the type of current your motor will generate as a generator is quite challenging. We’ve encountered motors that produce more amps than they’re rated for. One thing is certain: the higher the amperage rating, the better. A motor with a minimum amperage rating of at least 5 Amps is what you should be looking for. You’re good to go if the current is greater than 5 Amps.
The power generated by a wind generator is proportional to the amps and voltage:
Keep in mind that the more amps and volts the wind generator generates, the more electricity it generates!
Because we want to keep things simple and straightforward, we’ve skipped over some topics in this essay. This information, however, is all you’ll need to look for a wind generator motor with confidence.
Feel free to write us or submit a query on our User Forums if you have more specific inquiries regarding a motor or motors you’ve found. Our staff or a forum member will be pleased to address any particular queries you may have.
Also, please have a look at the quality WindyNation products we have available right here on our website. Compare them to the competition to see if they can match our 90-day Money Back Guarantee!
What is the best motor for a wind turbine?
Brushed DC motors are primarily used in home-made wind turbines. The power in a brushed DC motor comes from a commutator rotating the brushed motor’s electromagnets. A properly brushed DC motor can achieve high efficiency levels of up to 70%. An axle constructed of hardened stainless steel, a stack of laminations, wire, and brushes make up a high-quality brushed motor. One of the benefits of using a brushed DC motor is that it does not require any gearing while still charging a battery with voltages produced by light wind. Brushless DC motors are also easily accessible.
Is it possible to use a motor to generate electricity from wind?
We understand that choosing the correct motor for your home wind turbine may be difficult and stressful, so we’ve put up a guide to assist you in making the best decision possible.
Permanent Magnet or Permanent Coil?
When picking a DC motor for your wind turbine, there are two primary varieties to consider, but both work in essentially the same way. Both are made of copper wire twisted around magnets. Electricity is generated and diffused into the copper wire as the wind hits the turbine blades and begins to drive them, creating a magnetic field. This magnetic field then interacts with the magnets (pushing them back against them), turning the motor and converting the wind-generated electricity into AC or DC power (depending on the motor) and transmitting it to your battery/grid/appliances.
The interaction between the copper coil and the magnets is what distinguishes the two competing types of motors. The copper coil rotates freely in the center of permanent magnets in permanent magnet motors, and electricity is generated by the revolution of brushes created by the magnetic field created by the copper and magnets. Permanent coil motors have permanent copper coils with a rotating magnet in the center, thus they don’t need brushes to rotate and generate power.
Permanent magnet motors are the type we’ve covered here (owing to their price and accessibility for DIYers), but because they employ brushes, they degrade faster and require more regular maintenance than their brushless, permanent coil motor relatives. Instead, if you have the cash and know-how, we recommend looking for a brushless, permanent coil DC motor.
Wind Speed/Location
Before deciding on a wind turbine motor for your renewable energy project, you must evaluate some important factors (and take measurements). Wind speed is usually expressed in MPH (miles per hour), KPH (kilometers per hour), or M/S (miles per second) (metres per second). You’ll need to scout out the location where your wind turbine(s) will be built and installed, as well as determine the average wind speed (and direction) in that area.
Upwind wind turbines (depending on the blade design) face the wind, whereas downwind wind turbines face the other direction. You’ll need to make sure you have enough space to put a wind turbine that may face or face away from the direction the wind normally blows in your location.
However, the most crucial factor is wind speed. Permanent magnet DC motors (like the ones pictured above) are fantastic because they just need a small amount of torque to start turning and produce electricity; however, the amount of electricity created is entirely dependent on how your motor interacts with the environment.
Standard wind speed is 10-30 MPH, which affects roughly 400-600 RPMs in a household turbine; as a result, you should base your own windspeed-RPM calculation on the above, and make sure the motor you choose is near to the RPMs you estimate your area will deliver. You don’t want to put a 1500RPM engine in a 700RPM region since it will waste energy. Similarly, putting a 500RPM motor in a 700RPM region can cause it to overheat and destroy its internal systems quickly.
Simply put, you want a smaller, lower-powered motor if you live in a low-wind speed location, and a larger, higher-powered motor if you live in a high-wind speed area.
Motor Power
In order for a motor’s power output to attain its full potential, it must rotate at (or close to) its maximum RPM (revolutions per minute). However, your motor is unlikely to do so since (1) it is utilized as a generator in a wind turbine and so already performs at roughly 80% efficiency, and (2) wind speed varies and isn’t always powerful enough to push your motor to its limits. As a result, it’s critical that you select a motor that is appropriate for your needs and area.
When it comes to your needs, you’ll know what output voltage you require based on the specifications of the battery or appliance you’re charging. You’ll need at least 12 volts of output voltage from your turbine to charge a 12V battery (which is the most common among DIYers).
When it comes to wattage, your optimal output is determined by what you need the power for, but it’s important to know how many watts you want from your turbine before you start.
Basically, you’ll need a motor with at least the voltage output you need and roughly 130 percent of the wattage output you need (to cover any shortfalls in actual efficiency of the motor). For example, if you require 200 watts, you should purchase a motor with a nominal wattage of at least 250-300 watts, as the motor will rarely be running at its maximum RPM. Purchasing a motor that is less powerful than the demands of your battery/appliance(s) can cause the motor to break down rapidly.
Amperage Rating of the Motor
A motor’s amperage rating is a measurement of how much current it can produce. Simply put, the more amperage, the better. “No-load current = x amps” is a common way to promote amperage. It’s worth noting that ‘no-load’ just implies ‘not linked to a battery.’ The motor will function at a lower amperage than promised when connected to a battery. Finally, you want an amperage rating of at least 5 amps (if it isn’t specified, you may calculate amperage by dividing quoted wattage by voltage, as volts x amps Equals wattage).
AC/DC
Your wind turbine motor should provide either AC or DC electricity, depending on what you wish to charge. Normally, you’ll want DC power, but even with the permanent magnet DC motors we’ve showcased here, you may find that they output AC power. As a result, in order to project the correct type of electricity, you’d need a converter between the turbine and the battery. When looking for the best wind turbine motor, keep your AC/DC requirements in mind.
Material
Maintaining any renewable energy source in a world that still relies heavily on fossil fuels and non-renewables may be costly, so you want to buy a motor that will last and require as little maintenance as possible on its many components. Brushless permanent coil DC motors are the most durable types of wind turbine motors, as we’ve already described – however they’re pricey and not generally available. Brush-operated motors with permanent magnet components, on the other hand, can be quite durable. What you should look for is the sort of material used to construct your motor: is it corrosion-resistant, weatherproof, and built of high-quality metals that are resistant to acid, alkali, and salt corrosion? Anti-salt corrosion qualities are very important for wind turbine DIYers who live near the shore (salt from the sea will carry to your home turbine even if you’re kilometers inland).
Is there a DC motor in a wind turbine?
An electrical generator, as we learned in the previous wind turbine tutorial, is a rotating machine that converts mechanical energy produced by the rotor blades (the prime mover) into electrical energy or power. Faraday’s equations of electromagnetic induction, which dynamically induce an e.m.f. (electro-motive force) into the generator’s coils as it rotates, are used to convert energy. There are many various types of electrical generators, but one that we may employ in a wind power system is the Permanent Magnet DC Generator, also known as the PMDC Generator.
Because there is no structural difference between conventional motors and DC wind turbine generators, permanent magnet direct current (DC) machines can be employed as both. In reality, the same PMDC machine can be driven mechanically as a basic generator to generate an output voltage or electrically as a motor to move a mechanical load. As a result, the permanent magnet DC generator (PMDC generator) is an excellent candidate for use as a simple wind turbine generator.
When a DC machine is connected to a direct current source, the armature rotates at a constant speed specified by the associated supply voltage and magnetic field strength, operating as a “motor” that produces torque. However, if we use rotor blades to mechanically rotate the armature at a higher speed than its designed motor speed, we may effectively turn this DC motor into a DC generator, creating a generated emf output proportionate to its rotational speed and magnetic field strength.
The field winding is usually on the stator and the armature winding is on the rotor in traditional DC machines. They have output coils that rotate with a stationary magnetic field to provide the appropriate magnetic flux. The magnetic field, which controls the power, is supplied by either permanent magnets or an electromagnet and is obtained directly from the armature via carbon brushes.
The stationary or static magnetic field passes through the rotating armature coils, generating an electrical current in the coils. The armature rotates in a permanent magnet DC generator, therefore the entire generated current must travel through a commutator or slip-rings and carbon brushes arrangement to provide electrical power at the output terminals, as depicted.
Is it possible to utilize a DC motor as a generator?
Both brushed DC and brushless DC (BLDC) motors can be used as generators, which may surprise design engineers. Brushed DC motors are used in generator applications that require a DC voltage output, whereas brushless DC motors are used in AC voltage applications.
A modest wind turbine generates how many volts?
Small wind turbines, also known as micro wind turbines, are utilized for micro-electricity generation rather than big commercial wind turbines like those found in wind farms. Passive yaw systems are more common in small wind turbines than active yaw systems. Larger turbines have geared powertrains that are actively aimed into the wind, whilst smaller turbines employ a direct drive generator and a tail fin to point into the wind.
Small wind turbines normally produce 500 W to 10 kW of power, but they can be as small as a 50 Watt auxiliary power generator for a boat, caravan, or micro refrigeration unit, and the Canadian Wind Energy Association (CanWEA) classifies “small wind” as high as 300 kW. Small wind turbines are defined by the IEC 61400 Standard as wind turbines having a rotor swept area of less than 200 m2 that generate at a voltage less than 1000 V.c. or 1500 Vd.c.
Is it possible for me to construct my own wind turbine?
Perhaps you live on a boat, vacation in a secluded lodge, or, like me, live off the grid. Maybe you just want to save money on your electricity bill. In any case, you can create a homemade wind generator using a few low-cost, easy-to-find items, giving you access to electricity for as long as the wind blows. You’ll be able to light up that storeroom, power your barn, and keep all of your vehicle batteries charged with a generator.
Solar and wind power are used to power my off-grid cottage, which is powered by a bank of four 6-volt golf cart batteries wired for a 12-volt system. My system is protected from under- or overcharging by a charge controller and a battery minder. I spent less than $1,000 on the entire setup, which includes lights, fans, a television and audio, refrigeration, and a disco ball that rises for special occasions.
To power a home, how big of a wind turbine do you need?
Small wind turbines for home usage typically range in size from 400 watts to 20 kilowatts, depending on how much electricity you need to create.
Each year, a typical home consumes roughly 10,649 kilowatt-hours of electricity (about 877 kilowatt-hours per month). A wind turbine rated in the range of 515 kilowatts would be necessary to make a meaningful contribution to this demand, depending on the typical wind speed in the area. In a location with a yearly average wind speed of 14 miles per hour (6.26 meters per second), a 1.5-kilowatt wind turbine will cover the needs of a home consuming 300 kilowatt-hours per month.
A competent installation can assist you in determining the amount of turbine you’ll require.
Create an energy budget first. Because energy efficiency is typically less expensive than energy production, reducing your home’s electricity consumption will likely be more cost effective and reduce the size of the wind turbine you require.
The amount of power generated by a wind turbine is also affected by its tower height. A skilled installation should be able to assist you in determining the tower height required.