1. Is wind energy a viable
resource to power my home? How do I get started?
The answer to this question requires some homework on your part. Here’s how
to proceed:
-
Household Consumption:
Check several of your household or facility electric utility bills (ideally,
the bills for a one year period) for the quantity of energy you use per
month. This energy consumption number will be expressed in kilowatt-hours
(kWh).
-
Average Wind Speed:
Get a general idea of the average wind speed in your local area. Here are
two ways to find this information:
·
Online wind
maps from the
U.S. Dept. of Energy's
"Wind & Hydropower Technologies Program":
www.eere.energy.gov/windandhydro/windpoweringamerica/wind_maps.asp
(click on your state's outline). Other online wind map links are available
here.
·
Local airports
often measure and record average wind speeds. Since the care that is taken to
properly site anemometers varies greatly from airport to airport, it is suggested to view the
location of the airport anemometer to be certain that it is mounted at least
30' in the air (and ideally 30' above any obstructions within a 500' radius).
If the anemometer is mounted lower than 30' above the ground or is obviously
blocked/shadowed by nearby buildings or structures, then the measurements
taken from the anemometer should not be trusted for gauging local average wind
speed.
-
Convert Units:
If the average wind speed you obtained from a wind map or airport is a
metric number (m/s or meters per second), convert the average wind speed to
mph [miles per hour] as follows: (wind speed in
m/s) x 2.24 = (wind speed in mph).
If you receive wind speed in “knots” (nautical miles),
use the following conversion: (wind speed in
knots) x 1.15 = (wind speed in mph).
-
Wind Generator Energy
Production Estimates: View our Energy
Estimates Graph. This chart shows how much energy (per month)
you can expect to produce with our each of our wind turbines – the
ARE110 (2.5 kW) and the
ARE442 (10 kW) – in four different wind regimes (listed along the bottom
of the graph as 8, 10, 12, & 14 mph average wind speeds).
-
Compare Consumption with
Production Estimates: Compare the amount of energy your household uses each month (from
your utility bills) against the amount you can expect to produce with either
of our wind generators. For example, if your household uses an average of
400 kWh per month, and you live in an area that receives an average wind
speed of approximately 12-mph, then the
ARE110 (2.5 kW) wind generator is a good match (the
ARE110 will produce approximately 410 kWh in a region with a 12-mph
average wind speed). If your household uses closer to 1800 kWh per month,
however, then the
ARE442 (10 kW) wind generator would likely be a more appropriate solution.
-
Wind Generator Prices:
You can find the retail prices for each of our wind generators on our
ARE Turbines
webpage. These prices include the wind turbine, control electronics, a
diversion load, and (for grid-connect systems) an inverter. The listed
prices do not include a tower, tower foundation materials (concrete &
rebar), or installation (mechanical and electrical). Because there are several variables with wind
generator installations (e.g. tower style & height, soil conditions,
concrete prices, local installation labor rates), it is difficult to
estimate project costs without a site assessment. Here are some
ballpark cost
ranges for complete, installed
ARE
wind energy systems:
ARE110
(2.5 kW): $20,000 - $35,000;
ARE442
(10 kW): $50,000 - $80,000.
-
Supplementing Wind with
Solar Energy:
There is a fairly large gap in production capacity between the
ARE110
and the
ARE442,
regardless of the local average wind speed. If your energy consumption
needs fall somewhere between the production capacities of our two wind
generators, you may find that supplementing your wind energy equipment with
an array of solar panels may provide a useful solution to help you more
closely match your energy consumption demands.
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2. What is my average wind speed? Is my wind resource good enough?
See Steps B through E of the response to
Question 1 for this answer.
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3. How large a turbine would I need in order to power my home or office?
See Steps A through E of the response to
Question 1 for this answer.
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4.
What is the difference between a grid-tie and an off-grid wind energy system?
Which type of system is best for my situation?
Here’s a
basic overview of the three basic types of residential wind energy systems:
-
Grid-Connect
(a.k.a. Grid-Tie or Grid Intertie)
Systems without Batteries: Grid-connect systems interface
directly with the electric utility grid via an inverter (provided with
grid-connect
ARE
wind generators). An
ARE
Voltage Clamp (a.k.a. grid-connect controller) rectifies the wind
generator’s “wild” (variable voltage & frequency) alternating current (AC)
to direct current (DC) and limits the maximum output voltage in order to
maintain the health of the inverter. The inverter changes the DC outputted
from the Voltage Clamp into AC at the required frequency (60 Hz or 50 Hz,
depending upon the country) and synchronizes with the utility power grid,
prior to sending energy produced by the renewable energy system to household
appliances and/or to the grid.
Advantages:
Grid-connect systems avoid
the inherent inefficiency and vigilant maintenance requirements of batteries.
Sizing a wind energy system for grid-connection is also simpler than with its
battery-charging counterpart, because the utility grid can make up for
mismatches between the electrical loads and the wind generator’s production
capability. Additionally in many states, there are production incentives for
renewable energy sent to the utility grid (while relatively few states provide
renewable energy incentives for off-grid production).
Disadvantages:
If the utility grid shuts
down, so do grid-connected renewable energy systems without battery back-up.
In situations where continuous power is critical or where power outages are
frequent, battery back-up equipment (see letter C below) may be
advisable.
-
Battery-Charging Off-Grid
Systems:
Battery-charging systems feed through a charge controller and into a battery
bank. This type of system is primarily used in remote locations where grid
power is not available. When storing renewable energy exclusively in
batteries, the renewable energy equipment and battery bank must be sized
appropriately to maintain sufficient energy to match consumption and
maintain battery health.
Advantages:
Battery-charging systems
provide their owners with energy independence. Thus, off-grid systems are
unaffected by electric utility grid outages.
Disadvantages:
When insufficient energy is
captured by a battery-charging system, the homeowners must curb their usage to
match (since there is no infinite power source, such as the utility grid, to
draw upon). Conversely, when the battery bank is full and renewable energy is
being produced at a rate faster than loads are being fed, the excess energy is
usually “wasted” by heat dissipation (this excess energy can optionally be put
to use with water-heating elements in a hot water tank). Batteries require
vigilant care and maintenance to keep water and charge levels adequate.
Renewable energy batteries are expensive, and failure to properly maintain
them can be a very costly mistake.
-
Grid-Connect Systems with
Battery Back-up:
Grid-connect systems with battery back-up can be configured in several ways
– with batteries filled from the utility grid or from the renewable energy
system. This system functions similarly to the system described in letter
A (Grid-Connect Systems without Batteries) above but continues
to function via a back-up battery bank when the local utility grid
experiences a power outage.
Advantages:
This system combines the best
traits of the other two system types. The utility grid can be utilized to
fill in energy consumption gaps or over-production surpluses, and they
continue to operate (on batteries) if the utility power grid experiences an
outage.
Disadvantages:
Since this type of system
uses batteries, careful maintenance and attention to battery water and charge
levels are required in order to maintain healthy batteries. Also, this is
generally the most expensive of the three system types, because a more complex
configuration comprised of both grid-connect and off-grid equipment is
required.
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5. What types of towers are available for mounting wind turbines?
-
Guyed Tilt-up Towers:
Guyed tilt-up towers utilize tubular sections (e.g. pipe, tubing) joined by
couplers and suspended on four sides by guy wires. In addition to the
vertical portion and guy wires, each tower includes a “gin pole”, which is
mounted at a right angle to the vertical tower sections. The gin pole
serves as a lever arm for tilting the tower up and down by rotating along a
pivot point at the tower base. See a photo of an
ARE
tilt-up tower here.
Advantages:
Guyed tilt-up towers are
usually the least expensive tower type, because they are comprised of less
steel than other towers. No climbing is required (or allowed) with guyed
tilt-up towers, as they tilt up and down for access to the wind turbine.
Disadvantages:
Guyed towers require
significantly more real estate than self-supporting towers, due to the span of
guy wires. Tilt-up towers require horizontal clearance for the full tower
height in one direction from the tower base. Tilt-up guyed towers are not
climbable for minor inspections, troubleshooting, or repairs.
-
Guy-less Tilt-up Towers:
Guy-less tilt-up towers utilize tubular sections (e.g. pipe, tubing) in a
self-supporting design (without guy wires). These towers typically utilize
a gin pole which is removable.
Advantages:
Guy-less tilt-up towers
combine the sleek aesthetics and smaller footprint of a monopole tower with
the convenience of a tilt-down tower.
Disadvantages:
Guy-less tilt-up towers
are the most expensive tower type for wind turbines.
-
Guyed Lattice (a.k.a.
Guyed Truss) Towers: Guyed lattice towers usually utilize a narrow, 3-legged lattice
structure suspended on all three sides by guy wires.
See a photo of a guyed
tower here.
Advantages:
Guyed lattice towers are
generally the second (to guyed tilt-up towers) least expensive tower type.
They are climbable – an advantage for individuals who enjoy climbing.
Disadvantages:
Guyed towers require
significantly more real estate than self-supporting towers, due to the span of
guy wires. Guyed lattice towers also require a crane for tower and turbine installation;
likewise, a crane is required for removing the wind turbine, in the
event that this becomes necessary.
-
Self-Supporting Lattice
(a.k.a.
Free-Standing Truss) Towers: Self-supporting lattice towers utilize 3- or 4-legged
lattice structures without guy wires. See a photo of a self-supporting
tower
here.
Advantages:
Self-supporting lattice
towers have relatively small footprint, as there are no guy wires. They are
climbable – an advantage for individuals who enjoy climbing.
Disadvantages:
Self-supporting lattice
towers are generally more expensive than guyed towers but less expensive than
monopole or guy-less tilt-up towers. They require a crane for tower and
turbine installation; likewise, a crane is required for removing the
wind turbine, in the event that this becomes necessary.
-
Self-Supporting Monopole
Towers:
Self-supporting monopole towers utilize a tapered cylindrical structure.
They do not utilize guy wires. Climbing pegs may be provided optionally.
Advantages:
Self-supporting monopole
towers provide the smallest footprint of all wind turbine towers and sleek,
attractive aesthetics. They are may be made climbable – an advantage for
individuals who enjoy climbing.
Disadvantages:
Self-supporting monopole
towers are the second (to guy-less tilt-up towers) most expensive tower type
for wind turbines.
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9. How does my R.E. company go
about becoming an
ARE
dealer ?
ARE
looks to its dealers to provide site assessments and local answers to
customers' questions. In many cases, dealers will also be called upon to
provide installation assistance (or complete turnkey installation) of our wind
generators and towers for customers. Dealers are expected to be
experienced with and knowledgeable of residential renewable energy, in
general, and about wind energy, specifically. Hands-on experience
installing a residential wind generator is invaluable experience and is a
pre-requisite to becoming an
ARE
dealer. We encourage renewable energy companies with the following
qualifications to apply to become
ARE
dealers:
-
Experienced Wind Installers/Dealers:
If you or someone else from your renewable energy company already has
significant hands-on experience or expertise in the wind energy industry,
then
ARE
would be happy to welcome you into our dealer network.
-
Graduates of 3 - 5 Day
Hands-on Wind Energy Workshops:
If your none of your
company's personnel has significant wind energy experience, then a company
representative will need to gain hands-on wind installation experience
through a reputable renewable energy training organization, such as Solar
Energy International or the Midwest Renewable Energy Association. See
links for R.E. training
here.
Fill out an
ARE
dealer application
here.
NOTE TO INTERNATIONAL COMPANIES:
ARE
does not yet export its wind generators outside of North America. We
hope to expand the distribution of our wind generators to other continents in
the latter part of 2007. If you are interested in distributing
ARE
products in countries/regions outside North America, you are welcome to send
an email introducing your company and stating your desire to distribute
ARE
products. We will retain these requests until we begin international
distribution.
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Abundant
Renewable
Energy
