Wind Power Generator

JMI is venturing into Wind Energy for the home market doing business as JMI Wind Energy.  Our electricity-generating wind turbine is shown here.

JMI Wind Power Generator
2,000-watt three-phase generator (with super-strong magnets)
Direct Drive—no gears to wear out!
Rotor diameter is 8 feet
110-volt or 48-volt output (12- or 24-volt by special order)
Grid-tied or off-grid configuration
2-Year Warranty (does not include return shipping)
$3,495.00 plus tax and shipping (DIY version by special order)
Brochure (JPEG)
Note:  Spec's and prices are in flux and subject to change!

Links to Information on This Page
Equipment included
Equipment not included
Available options
Cost considerations
Description of equipment
Related electrical information
Estimated power consumption of household appliances

Equipment Included
6 blade (for low wind) or 3 blade (for high wind) turbine
2 kW generator
Kill switch
100 amp bridge rectifier
Dynamic braking system with dump load
Charge controller for 48-volt battery bank (off grid) or 110-volt grid-tie inverter

Equipment NOT Included
Wire (size will depend on voltage)
48-volt deep-cycle battery bank
12/24/48-volt DC to 110-volt AC power inverter

Available Options
Tower Kit
Includes anchor bolts, tower base and guy wire.  You must supply concrete pad(s) and 2" standard galvanized water pipe for 20 to 30  foot height.
USB wind generator power logger
Data recording of battery voltage, amps generated, wind turbine RPM and wind speed.

Cost Considerations
When looking at energy production costs and comparing solar versus wind energy, you should consider the cost per unit of energy output.  Having said that, getting real numbers for wind energy generation is much easier said than done.  Solar energy is pretty constant except for cloudy days which can be easily estimated.  Wind energy, however, depends on the specific characteristics of the generator and the duration and speed of wind activity, which is much harder to estimate.  Watch for more information that will be included here at a later date.  Complete cost recovery for the JMI Wind Power Generator will average three to four years based on our best estimates at this time using an average of 12 mph winds.

If you know the average wind speed for your area, the following formulas may be helpful for estimating annual energy output.  Jim Green at the National Renewable Energy Lab (NREL) developed a simple formula for annual energy output in Kilowatt-Hours (kWh).

kWh = 0.01328 x rotor diameter (in feet) squared x wind speed (in miles per hour) cubed or
kWh = 0.01328 x (diameter)² x (speed)³

If your average wind speed is 10 mph and you have a JMI Wind Power Generator, your estimated annual energy output would be 0.01328 x 8² x 10³ or 0.01328 x 64 x 1000 or approximately 850 kWh according to this formula.  As you can see from the formula, energy output increases exponentially with increased wind speed.  For more information, see the section titled Related Electrical Information below.

Wind energy is generally much cheaper than solar.  However, for Water Well Pumping, we strongly recommend a solar well system.  We recommend Robinson Solar Systems in Oklahoma (Toll Free at 866-519-7892).  The prices start at $1,650.00 and would allow you to use our JMI Wind Power Generator for other things such as lighting and household appliances.

One more thing to consider is tax breaks.  In Colorado, municipalities and counties are allowed to give property and sales tax rebates or credits to residential and commercial property owners who install renewable energy systems on their property.  Contact the city and county where your property is located.

Description of Equipment
Grid-Tied and Off-Grid Configurations
The "electrical grid" or "power grid" refers to the network for delivering electricity to your home.  It includes power generating plants, transmission lines and transformers.  The term "off grid" is becoming ever more popular as more people wish to be separate from, and not dependent on, the power grid.  Grid tied means that your equipment is tied into, or connected to, the power grid.  Our grid-tie inverter allows the JMI Wind Power Generator to simply be plugged into a household outlet to reduce your electrical bill.  If used off grid, the system charges a bank of batteries which are then used to power your equipment (cabin, boat, pump, lighting, communications equipment, etc.).

There are two basic configurations of the JMI Wind Power Generator system (or three with additional equipment) as shown in the following chart.

Kill Switch
An electric brake to stop the wind turbine from turning (shut down) by creating an electrical short.

Bridge Rectifier
Converts the "wild" variable alternating current (AC) output of the generator to variable direct current (DC) which is necessary for charging batteries or feeding a grid synchronous inverter.

Dynamic Braking System
Electrically regulates the speed of the generator by dumping excess energy into the dump load or other device.  The unit keeps the generator speed below 500 RPM during high winds for maximum low-voltage output.

Dump-Load
Used by the dynamic braking system for receiving dumped extra energy.

1000-Watt Grid-Tie Inverter (included only in configuration 1)
Converts the DC output to 110vAC and matches the phase with your household current.  It allows the output from the JMI Wind Power Generator to be fed directly into your house wiring (via a standard wall outlet).  The inverter includes a bridge rectifier, dynamic braking system and dump load controller and is therefore, along with the dump load, the only equipment between the generator and grid.  (This configuration does not use any batteries.)  If the generator output overpowers the dump load controller, the system will disconnect from the generator.  Two grid-tie inverters can be used in parallel to give up to 2000 watts of output with the 2000 watt generator.  A 220vAC version is available.

If you are using less electricity than the generator is producing, it will feed into the electrical grid and run your electric meter backwards!*  Otherwise, it will slow down your electric meter.  The grid-tie inverter will automatically switch off if the grid is down (called "island protection").

* Installing the Grid-Tie Inverter may require a different electrical meter, a ground fault interrupter (GFI or GFCI) outlet, which can typically be identified by a red reset button, and installation by a certified electrician.  We recommend contacting your electrical utility before installation.  The Grid-Tie Inverter is currently not UL approved, therefore you must assume all liability when using the device.

1000-Watt 48-Volt Charge Controller (included only in configuration 2)
Prevents batteries from being overcharged and over discharged.  In includes a bridge rectifier, dynamic braking system and dump load controller.  The system shuts off output when the battery bank output is too low.  (NOTE:  12 or 24-volt Charge Controllers are available by special order.)

12, 24 or 48 Volt DC Output
The battery bank can be configured for 12, 24 or 48 volt output.  The generator will reach 12 volts before 24 volts which means that low-wind areas will work better with a 12-volt system.  Since RVs (recreational vehicles) are wired for 12 volts, that may determine your choice.  However, a 48-volt system (standard with the JMI Wind Power Generator configuration 2) is better because it uses smaller (higher gage) wire.  This will require 12-volt batteries to be connected in series (see below) to reach the higher voltage.

Deep-Cycle Batteries (not included)
The battery bank for the JMI Wind Power Generator should be built with deep-cycle batteries.  A deep-cycle battery is one designed to be regularly discharged using most of its capacity.  Compare that to a starter battery, such as found in any automobile, designed to deliver short, high bursts for cranking an engine, using only a small part of its capacity.  A marine battery is usually a hybrid between a starter and deep-cycle battery.  A deep-cycle battery is designed to be discharged between 50% and 80%.  It can be discharged to below 20% of capacity but the lifespan of the battery will be reduced by such deep discharges.

12/24/48-Volt DC to 120-Volt AC Power Inverters (not included)
Most DC to AC power inverters convert 12-volt or 24-volt direct current (DC) input to 120-volt alternating current† (AC) output.  They typically have two to four standard sockets for running household equipment.  These units are readily available from local auto, hardware or department stores and on the internet (see Inverter Basics below).  This type of equipment would be connected to the battery bank to deliver 110-volt household current and is not necessary when using the grid-tie inverter.

† The AC is alternating at 60 cycles per second or 60 Hertz, abbreviated 60Hz.  Standard household AC in the United States is typically written as 120vAC/60Hz.

Inverter Basics
In alternating current, the flow of electrons reverses periodically which is represented by a waveform.  There are two basic types of inverters, square wave (including modified square wave sometimes called modified sine wave) and pure sign wave.  Square wave inverters are cheaper to manufacture and are the type found in big box and auto parts stores.  A pure sign wave inverter produces a nearly perfect sign wave that is essentially the same as a utility companies output on the power grid.  (Our grid-tie inverter produces a pure sine wave.)

Square wave inverters will work fine for most appliances and electronic equipment except some sensitive equipment like laser printers, fluorescent lighting, audio equipment, medical equipment and electric shavers.  Any device that contains a motor with variable speed control will not work.  You may hear a buzzing sound in the audio of a TV or similar device.  Generally, electronic equipment using an AC adapter will work fine.

In summary, many appliances will run hotter and less efficiently and some can be damaged by square wave inverters.  Appliances can run at 30% greater efficiency, last longer and have less chance of damage on a pure sine wave inverter which, in the long run, makes them more economical.

Wind Generator Power Logger (optional)
A USB hardware interface and software program for data recording.  It tracks battery voltage, amps generated, wind turbine RPM and wind speed.

Related Electrical Information
Watt
Power in Watts = volts x amperes (amps).

Example:  2.5 amps x 120 volts = 300 watts.  An electrical device rated at 2.5 amps running on normal household current (120vAC/60Hz) would take 300 watts of power.  Therefore, the device would take 30% of the grid-tie inverter's 1,000 watt power output or 15% of the 2,000 watt generator's maximum output.  And, of course, the capacity of any battery bank you have configured can be calculated using the information on this page.

Kilowatt-Hour
The Kilowatt-Hour (kWh) represents 1000 watt-hours and is the most common unit of energy used by utilities when billing for energy usage.  If the JMI Wind Power Generator is producing 1000 watts continuously (24/7) for 30 days, that would be 720 kWh (1000 watts x 24 hours/day x 30 days = 720 kWh) or 24,000 watt-hours (Wh) per day.  If you have a 10 amp device running on 120vAC/60Hz for 10 hours it would use half of the 24,000 Wh capacity (10 amps x 120 volts x 10 hours = 12,000 Wh).

Ampere-Hour
The Ampere (amp) is a unit of measure of electrical current (or flow).  Batteries are often measured in ampere-hours to show the total amount of electrical current capacity.  The easiest way to understand this rating is to remember that a device drawing 1 amp from a fully charged 200 amp-hr battery will run 200 hours (1 amp x 200 hours = 200 amp-hrs).  If the same battery was drained at 200 amps, it would last about 1 hour (200 amps x 1 hour = 200 amp-hrs).  Assuming a 12-volt battery bank, your energy capacity would be 2,400 watt-hours (12v x 200 amp-hrs = 2,400 Wh).

For this example, the following chart shows how long a particular electrical device (or combination of devices) could be run by this battery bank.

24,000 watt drain:  24,000 watts / 120 volts = 200 amps,  200 amp-hrs / 200 amps = 1 hour
12,000 watt drain:  12,000 watts / 120 volts = 100 amps,  200 amp-hrs / 100 amps = 2 hours
100 watt drain:  100 watts / 120 volts = 0.83 amps,  200 amp-hrs / 0.83 amps = 240 hours (10 days)
25 amp drain:  (25 amps x 120 volts = 3,000 watts)  200 amp-hrs / 25 amps = 8 hours

Serial vs Parallel
The battery bank can be created by connecting batteries in series or parallel (see illustration below).  When connected in series, the voltages of the batteries will be added.  When connected in parallel, the capacities (amp-hours) of the batteries will be added.  If the positive terminal of a each battery (except for the last one) is connected to the negative terminal of the next battery, they are connected in series.  If all negative terminals are connected and all positive terminals are connected the batteries are in parallel.  For example, if two 12-volt 200-amp-hour batteries are connected in series, the output voltage will be 24 volts and the capacity will be 200 amp-hours.  If two 12-volt 200-amp batteries are connected in parallel, the output voltage will be 12 volts and the capacity will be 400 amp-hours.  When building your battery bank, be sure to use batteries of the same type and rating.

Inconsistent Household Voltage Designations
You may be wondering why you see 110 volts in some places and 120 volts in another.  In the United States and Canada, voltage designations of 110, 115 and 120 (small appliances) as well as 220, 230 and 240 (large appliances) are used interchangeably to designate the same voltage ranges for standard household outlets.  The 110/220 volt designations are old and familiar.  The 115/230 volt designations are used with newer design standards where the equipment is designed to operate within plus or minus 10% of those voltages.  Electrical utilities typically use 120/240 volt standards with a plus or minus 5% variation.  So, not to worry...  In household voltage math, 110 = 115 = 120 and 220 = 230 = 240!

Estimated Power Consumption of Common Household Appliances
Power consumption will depend on many factors (brand, size, power levels, amount of time at each power level, features, cycles, modes, start-up load, etc.).  These are only estimates for comparison purposes.  Note that for microwave ovens, the cooking power is not the same thing as power consumption.  Check the back of the appliance or the owner's manual for power ratings.  Use these numbers to estimate the total watt-hours (Wh) (wattage rating x hours run) the wind generator needs to supply on an average day.

No federal or state taxpayer money was used in the development of this product.

Jim's Mobile, Inc.
d/b/a JMI Wind Energy