WIND
FAQs
Q. Will
a small wind turbine save me money?
The wind turbine typically lowers
your electricity bill by 50 to 90 percent. It is
not uncommon for wind turbine owners with total-electric
homes to have monthly utility bills of only $8
to $15 for nine months of the year. In northern
parts of the country where less air conditioning
is used, the bills can be very low year-round.
The amount of money a small wind turbine saves
you in the long run will depend upon its cost,
the amount of electricity you use, the average
wind speed at your site, and other factors.
Q. What
size turbine would I need for my home?
Homes use approximately 10,000
kilowatt-hours (kWh) of electricity per year (about
840 kWh per month). Depending upon the average
wind speed in the area, a wind turbine rated in
the range of 5 to 15 kilowatts would be required
to make a significant contribution to meet this
demand.
Q. How do residential wind turbines
work?
A wind turbine, which is installed
on top of a tall tower, collects kinetic energy
from the wind and converts it to electricity that
is compatible with a home's electrical system. In
a normal residential application, a home is served
simultaneously by the wind turbine and a local
utility. If the wind speeds are below cut-in speed
(6 - 8 mph) there will be no output from the turbine
and all of the needed power is purchased from the
utility. As wind speeds increase, turbine output
increases and the amount of power purchased from
the utility is proportionately decreased. When
the turbine produces more power than the house
needs, the extra electricity is sold to the utility.
All of this is done automatically. There are no
batteries in a modern residential wind system.
Small wind systems for remote applications operate
somewhat differently.
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Q. How much power can I get from
a wind turbine?
The ability to generate electricity
is measured in watts. Watts are very small units,
so the terms kilowatt (kW, 1,000 watts), megawatt
(MW, 1 million watts), and gigawatt (pronounced "jig-a-watt," GW,
1 billion watts) are most commonly used to describe
the capacity of generating units like wind turbines
or other power plants.
Electricity production and consumption are most
commonly measured in kilowatt-hours (kWh). A kilowatt-hour
means one kilowatt (1,000 watts) of electricity
produced or consumed for one hour. One 50-watt
light bulb left on for 20 hours consumes one kilowatt-hour
of electricity (50 watts x 20 hours = 1,000 watt-hours
= 1 kilowatt-hour).
The output of a wind turbine depends on the turbine's
size and the wind's speed through the rotor.
Example: a 10-kW wind turbine
can generate about 10,000 kWh annually at a site
with wind speeds averaging 12 miles per hour, or
about enough to power a typical household.
Wind speed is a crucial element in projecting turbine
performance, and a site's wind
speed is measured through wind resource assessment
prior to a wind system's construction. Generally,
annual average wind speeds greater than four meters
per second (m/s) (9 mph) are required for small
wind electric turbines (less wind is required for
water-pumping operations). Utility-scale wind power
plants require minimum average wind speeds of 6
m/s (13 mph).
The power available in the wind
is proportional to the cube of its speed, which
means that doubling the wind speed increases the
available power by a factor of eight. The important
thing to understand is that what seems like a small
difference in wind
speed can mean a large difference in available
energy and in electricity produced, and therefore,
a large difference in the cost of the electricity
generated.
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Q. How
much land is needed for a small wind system?
The actual space required for a
small wind turbine tower is quite small. It can
be as small as one square yard.
Q. What is Net Metering?
Net Metering is the regulatory
ability to get credit for electricity you generate
with renewable energy and send backwards through
your utility meter. Exact provisions vary with
each Province, but the effect is to allow you to
generate excess power during the day, and use it
at night, without needing batteries.
Q. Don't I have to take wind measurements
for a year or more?
For most residential systems the
cost of taking wind measurements is not justified.
Q. Are wind turbines noisy?
Wind turbines are not noisy. The
evolution of wind farm technology over the past
decade has rendered mechanical noise from turbines
almost undetectable with the main sound being the
aerodynamic swoosh of the blades passing the tower.
There are strict guidelines on wind turbines and
noise emissions to ensure the protection of residential
amenity.
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Q. Do wind turbines frighten livestock?
Wind farming is popular with farmers,
because their land can continue to be used for
growing crops or grazing livestock. Sheep, cows
and horses are not disturbed by wind turbines.
Q. How strong does the wind have
to blow for the wind turbines to work?
Wind turbines start operating
at wind speeds of 4 to 5 metres per second (around
10 miles an hour) and reach maximum power output
at around 15 meters/second (around 33 miles per
hour). At very high wind speeds, i.e. gale force
winds, (25 metres/second, 50+ miles/hour) wind
turbines shut down.
Q. How long do wind turbines last?
A wind turbine typically lasts
around 20-25 years. During this time, as with a
car, some parts may need replacing.
Q. Will
I have to change any of the wiring in my house?
No. A wind turbine or solar panels are easily
retrofitted to virtually any home without the need
to change any wiring or appliances. In most cases,
the utility will install a bi-directional utility
meter to measure how much surplus electricity it
is purchasing from the homeowner.
Q. What
is "availability factor"?
Availability factor (or just "availability")
is a measurement of the reliability of a wind turbine.
Wind turbines have an availability of more than
98% -- higher than most other types of power generate.
After two decades of constant engineering refinement,
today's wind machines are highly reliable.
Q. Does solar work for commercial buildings?
Solar can be installed on office buildings, warehouses,
retail buildings, schools, and government facilities.
Anywhere electricity is used, solar electricity
can be used.
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SOLAR FAQs
Q. What are solar concentrators?
Solar concentrators use lenses,
mirrors, parabolic dishes or other optics to concentrate
energy from the sun. Very often, they have a mechanism
so that these devices track the path of the sun
during the day. In solar thermal applications,
troughs or large mirrors amplify sunlight to
create heat, which heats a liquid or gas that
turns turbines to make electricity.
Q. How much space does the system
need?
A typical system requires about
7 to 8 square feet for each dollar of your electric
bill. This figure varies depending upon your electric
rates.
Q. Do the panels need to be mounted
on my roof?
Panels are often mounted on the
roof, but can also be mounted on the ground. Ground
mounts are great if the house is shaded, or if
dormers or other obstructions limit available space
on the roof.
Q. Do the panels need to face south?
South is best, but panels installed
facing east or west still generate a very high
percentage of possible power. It is usually more
effective (and more attractive) to install the
panels in the same plane as the roof direction,
rather than build an awkward mount to angle them.
Q. How long will the system last?
The solar panels have a 25 year
power warranty from the manufacturer. This is longer
than almost anything else you can buy. The rest
of the system has a 5 year warranty in most areas.
Inverters can have warranties up to 10 years.
Q. What happens when the utility
has a power outage?
Most systems are “clean power” systems,
without batteries. These systems do not generate
power when the utility is out, even if it is sunny.
If backup power is desired, a battery system can
be added. This increases the complexity and cost.
Most people find that what they want is clean power,
and find that the very occasional outage does not
bother them, so they do not purchase the battery
option.
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Q. Do I need batteries with the system?
Batteries are only required if
you want backup power when the utility is out of
service. Without batteries, the system has no way
to store power, and for safety reasons cannot produce
power without the utility in operation.
Q. What is Net Metering?
Net Metering is the regulatory
ability to get credit for electricity you generate
with renewable energy and send backwards through
your utility meter. Exact provisions vary with
each Province, but the effect is to allow you to
generate excess power during the day, and use it
at night, without needing batteries.
Q. What happens if the panels get
covered by snow?
Solar panels need sunshine to
generate power. While some sun does make it through
several inches of snow, little electricity is generated
when the panels are covered with anything. Most
power is made during clear sunny days.
Q. Do I need to install a new roof
before the solar panels are installed?
Solar panels will last many years
(over 25), and because of this, we want the roof
to be in decent condition, as it does not make
sense to remove and reinstall the panels after
only a few years. However, after the panels are
in place, they will greatly reduce the wear on
the roof by blocking ultraviolet rays, keeping
most snow and ice off the roof, and keeping anything
from hitting the roof. Most installations do not
require a new roof prior to PV installation.
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Q. What happens if the panels are
shaded?
Solar panels should be installed
in areas where they get significant shade-free
sun every day. Even small amounts of shade can
significantly reduce the output.
Q. Do I need to clean the panels
periodically?
Most of our customers do not clean
their panels. In most areas of the country, there
is sufficient rain to clean the panels. However,
if you are in a dusty area (very near a busy dirt
road, very urban area, etc.) you may see a performance
gain from cleaning the panels monthly. If necessary,
a hose stream is usually sufficient for cleaning.
Do not use metal, hard, or abrasive methods for
cleaning. Do not spray water on the panels when
they are very hot.
Q. If I sell my property, what effect
does Solar panels have on the sale price?
Energy conservation and renewable
generation adds value to a home. Surveys have shown
that for every $1,000.00 saved per year, $20,000.00
is added to a home's value. Solar energy can be
one of the best home improvement investments you
make.
Q. How long does it take to install
a PV system?
Typical residential systems take
from 2 to 5 days to install. Systems mounted on
the ground and systems with batteries are more
complex, and may take longer. Most of this time
is spent outside your house, so there is little
disturbance to you. Commercial systems take several
weeks to over a month to install, depending upon
size and type of installation.
Q. Will
I have to change any of the wiring in my house?
No. A wind turbine or solar panels
are easily retrofitted to virtually any home without
the need to change any wiring or appliances. In
most cases, the utility will install a bi-directional
utility meter to measure how much surplus electricity
it is purchasing from the homeowner.
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ENERGY CONSUMPTION FAQs
Q. What would be a typical energy usage amount?
The average Canadian home uses
between 700-1500 kWh per month. About 30% of our
total energy consumption is used to heat water.
Q. What is the consumption of typical
household appliances?
Appliance/Equipment Power (watts)
- 4 x 24 watt lamps 96 W
- 42” plasma TV 330
W
- portable phone 6 W
- clock 3 W
- iron 1,100 W
- water pump (automatic) 350 W
- high efficiency refrigerator 150 W
From the data above: If you have the television
set on for two hours a day, every day of the year,
that’s (365 days x 2 hours) 730 hours. The
TV draws 330 watts of power for 730 hours for a
total annual energy consumption of (330 watts x
730 hours) 240,900 watt hours. In the standard
measurement of kilowatt hours, this is 240.9 kWh.
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