|
Wind Power click here
Solar Power Panels click here
Is Wind Right for Me?
You can find wind turbines used on everything from remote cabins to sailboats
and other applications including utility connected homes. According to the U.S.
Census, more than 17 million homes in America are located on land that is appropriate
for a small wind system. Could your home be one?
IS WIND RIGHT FOR ME? � There are four important factors to consider using
wind as an energy source for your house.
1. DO I HAVE A GOOD SITE? Siting a wind generator is extremely important
to the performance of the machine. It is the difference between a machine that
give you lots of energy and a garden sculpture. The ideal location for a wind
turbine is 20 feet above any surrounding object within a 250 foot radius. This
generally means your property should be at least one acre in size.
2. DO I HAVE THE RIGHT WIND RESOURCE? Wind is the �fuel� for your wind
generator. You should have at least a 9 MPH average wind speed at your location.
Wind maps are available for many countries and US states which will give you
an idea of the wind resource at your house. Check out these maps and see if
you have the right wind resource. You should live in a �Class One� or better
site.
If you cannot find your wind resource on the map, there are other ways.
A. Contact your the closest weather station, TV or radio station. Wind patterns
can change over short distances. We don�t recommend airports as they are generally
located in places with the lowest potential wind.
B. If you have trees in your area, use the Griggs-Putnam Energy Index This looks
at a tree and how the wind changes its shape.
3. WHAT ARE MY LOCAL LAWS: The next step is to determine if you have
any local laws from a Home Owner�s Association or City or County that prohibit
the use of towers.
You should research:
A. If you have a Home Owner�s Association read the guidelines relating
to towers or tall structures.
B. Contact your local County Planning and Zoning authority and ask about the
use of towers and tall structures. Remember, the tower must be 20 feet above
any surrounding object, if it is not, then performance will be lower.
4. WHAT INCENTIVES AND PROGRAMS DOES MY UTILITY OFFER?
By law, the local utility (company you pay your electrical bill to) must purchase
any excess electricity from you. There are both utilities that encourage the
use of wind systems and discourage it. Locate your electrical bill and then
find the number for customer service. Ask them for a copy of the policy relating
to �connecting a renewable energy system to the electrical grid�. Finally �
the best news of all. Many States in the union offer various types of tax incentives
and even rebates for your wind system.
United States Wind Maps
click here
Small Wind Basics
The use of wind energy has been around for well over a thousand years. Its
uses are only limited by the mind. However, there are certain physics that guide
us on what it can and cannot do. People have often dreamed of a small device
that can be installed on the roof of a house which can provide all the needed
energy. What is not understood by the non-technical are its limits. Like anything
in nature, there are limits to what is possible. Below we have put together
a number of interesting facts about wind.
What is a wind generator?
The proper name of a wind generator is actually �Wind Energy Converter� that
being a device that converts the potential energy in the wind to another form
of energy. This can either be mechanical or electrical.
How does the wind generator work?
When the wind blows, the rotor blade stops a percentage of the wind. That percentage
is what is converted into energy. According to physics, the maximum amount of
wind energy that can be converted is 59.3%. This is known as the Betz Limit.
I�ve seen lots of different looking designs, which is the best?
There are a number of types of wind generators. Research has been done on virtually
every possible concept with the objective of producing the maximum amount of
power for the lowest cost at the highest possible reliability. Conventional
experimentation has found that the horizontal axis upwind or down wind design
to be the best concept. The most common designs include:
A) Horizontal upwind: The generator shaft is positioned horizontally and the
wind hits the blade before the tower.
B) Horizontal downwind: The generator shaft is positioned horizontally and the
wind hits the tower first then the blade.
C) Vertical Axis: The generator shaft is positioned vertically with the blades
pointing up with the generator mounted on the ground or a short tower.
There are two basic types of airfoils (blades) a lifting and drag type.
A) The drag style airfoil is typically what you see with an old Dutch wind
mill or American water pumping wind mill. The blades are generally a flat plat
which the wind hits and causes to rotate. This type of design is great for very
low wind areas and will develop a lot of torque to perform an operation. However,
in medium to higher winds, their capabilities to produce energy are limited.
B) The lifting style airfoil is what you see in most modern wind turbines and
on airplanes. A properly designed airfoil is capable of converting significantly
more power in medium and higher winds. Actually, with this design, the fewer
number of blades the more efficient this design can be. Two European companies
actually produced one bladed machines however, dynamic balance issues prevented
them from becoming a commercial success.
Humans have used wind to grind corn, pump water or drive a ship for well over
a thousand years. It was not until the end of the 19th century did we begin
using wind energy to produce electricity. Today more than 50 companies around
the world produce an estimated 50,000 wind generators per year. Small wind is
now used to produce electricity for a variety of applications including utility-connected
homes and businesses, remote homes, water pumping, telecommunication systems,
off-shore platform lighting, and more.
Solar Panels
Are solar cells a new technology?
Modern solar cells with practical efficiency were invented in the early 1950s,
and have been used to power satellites since 1959. They became popular for terrestrial
applications in the mid-1970s, mostly for remote telecommunications, navigational
aids and other rugged, remote industrial uses including microwave, TV, radio
and cellular repeater stations. They have been powering urban applications such
as roadside emergency telephones and traffic sign boards since the mid-1980s.
With prices dropping steadily, they are now becoming affordable for urban homes
and businesses.
Do solar cells store energy?
No. Solar cells just convert sunlight into an electric current that must be
used immediately or stored in batteries to be used later.
How well do solar modules withstand, and work in, inclement weather?
In cloudy weather, solar modules work, although they produce less electricity
than on a sunny day. Under a light overcast, the modules might produce about
half as much as under full sun, ranging down to as little as five to ten percent
under a dark overcast day. If the modules become covered with snow, they stop
producing power, but snow generally melts quickly when the sun strikes the modules;
if you brush the snow off, they resume operation immediately. Our modules can
withstand one inch (2.5 cm) hailstones at 50 mph (80.5 kph).
What are the different types of solar technologies?
The four types of solar technologies are: Photovoltaics: Photovoltaic solar
cells, which directly convert sunlight into electricity, are made of semiconductor
materials. This can include very simple cells that power calculators and watches,
and complex systems that can light houses.
Passive solar heating: Buildings designed for passive solar and daylighting
combine building materials that absorb and slowly release the sun�s heat with
design features such as large south-facing windows. No mechanical means are
employed.
Concentrating solar power: This technology uses reflective materials such as
mirrors to concentrate the sun�s energy and convert it into electricity.
Solar hot water and space heating and cooling: Solar hot water heaters use
the sun to heat either water or a heat-transfer fluid in collectors.
What does photovoltaic (PV) mean?
The direct conversion of light into electricity. Photovoltaic cells convert
sunlight directly into electricity. When sunlight strikes a PV cell, electrons
are dislodged, creating an electrical current.
Photovoltaic cells power many of the small calculators and wrist watches in
use every day. More complex systems provide electricity to pump water, power
communications equipment light homes, and run appliances. Beyond the utility
power line, PV is often the lowest-cost means to provide electricity, and almost
always simplest and cleanest to operate.
Photovoltaic cells power many of the small calculators and wrist watches in
use every day. More complex systems provide electricity to pump water, power
communications equipment light homes, and run appliances. Beyond the utility
power line, PV is often the lowest-cost means to provide electricity, and almost
always simplest and cleanest to operate.
Photovoltaics are also making inroads as supplementary power for utility customers
already served by the grid. Currently costly compared to most conventional choices
for grid power, Photovoltaics is still a very small part of the energy make-up
of any country. However, more and more individuals, companies, and communities
choose PV for reasons other than cost: because of a desire to develop a clean,
sustainable energy source, interest in a clean back-up power source, a need
for placing power generation right at the source with no fuel, noise or moving
parts; and an attraction to a power technology that can be built right into
building roofs, facades, canopies and windows.
What is a PV cell?
The smallest semiconductor element that converts light into electrical energy
(DC voltage and current).
What is a PV array?
An interconnected system of PV modules that function as a single electricity-producing
unit. The modules are assembled as a discrete structure, with common support
or mounting. In smaller systems, an array can consist of a single module.
What is a solar cell and a solar module?
A solar cell, also called a photovoltaic (PV) cell, is the smallest element
that converts light into electrical energy. Each cell is made of silicon like
a computer chip. The silicon is treated so that it generates a flow of electricity
when light shines on it. Solar modules are series of solar cells wired together.
Are solar cells a new technology?
Modern solar cells with practical efficiency were invented in the early 1950s,
and have been used to power satellites since 1959. They became popular for terrestrial
applications in the mid-1970s, mostly for remote telecommunications, navigational
aids and other rugged, remote industrial uses including microwave, TV, radio
and cellular repeater stations. They have been powering urban applications such
as roadside emergency telephones and traffic sign boards since the mid-1980s.
With prices dropping steadily, they are now becoming affordable for urban homes
and businesses.
Do solar cells store energy?
No. Solar cells just convert sunlight into an electric current that must be
used immediately or stored in batteries to be used later.
How well do solar modules withstand, and work in, inclement weather?
In cloudy weather, solar modules work, although they produce less electricity
than on a sunny day. Under a light overcast, the modules might produce about
half as much as under full sun, ranging down to as little as five to ten percent
under a dark overcast day. If the modules become covered with snow, they stop
producing power, but snow generally melts quickly when the sun strikes the modules;
if you brush the snow off, they resume operation immediately. Our modules can
withstand one inch (2.5 cm) hailstones at 50 mph (80.5 kph).
What are the different types of solar technologies?
The four types of solar technologies are:
Photovoltaics: Photovoltaic solar cells, which directly convert sunlight into
electricity, are made of semiconductor materials. This can include very simple
cells that power calculators and watches, and complex systems that can light
houses. Passive solar heating: Buildings designed for passive solar and daylighting
combine building materials that absorb and slowly release the sun�s heat with
design features such as large south-facing windows. No mechanical means are
employed. Concentrating solar power: This technology uses reflective materials
such as mirrors to concentrate the sun�s energy and convert it into electricity.
Solar hot water and space heating and cooling: Solar hot water heaters use the
sun to heat either water or a heat-transfer fluid in collectors.
What does photovoltaic (PV) mean?
The direct conversion of light into electricity. Photovoltaic cells convert
sunlight directly into electricity. When sunlight strikes a PV cell, electrons
are dislodged, creating an electrical current. Photovoltaic cells power many
of the small calculators and wrist watches in use every day. More complex systems
provide electricity to pump water, power communications equipment light homes,
and run appliances. Beyond the utility power line, PV is often the lowest-cost
means to provide electricity, and almost always simplest and cleanest to operate.
The cost of PV has fallen by 90 percent since the early 1970s. Photovoltaics
are producing electricity for critical loads from the polar ice caps to the
tropics to satellites in outer space. There is a strong market today in developing
countries to provide rural electrification with solar panels, which replace
kerosene lamps, batteries, and wood fires at a far lower cost than the central
station power plants. Photovoltaics are also making inroads as supplementary
power for utility customers already served by the grid. Currently costly compared
to most conventional choices for grid power, Photovoltaics is still a very small
part of the energy make-up of any country. However, more and more individuals,
companies, and communities choose PV for reasons other than cost: because of
a desire to develop a clean, sustainable energy source, interest in a clean
back-up power source, a need for placing power generation right at the source
with no fuel, noise or moving parts; and an attraction to a power technology
that can be built right into building roofs, facades, canopies and windows.
What is a PV system?
A PV system is a complete set of components for converting sunlight into electricity
by the photovoltaic process, including the array and the balance of system components.
What is PV conversion efficiency?
The ratio of the electric power produced by a PV device to the power of the
sunlight shining on the device.
Are solar electric systems safe?
Yes. Solar cells are mostly silicon, the primary component of sand. There is
no exhaust and no toxic materials to leak out of the system. The electricity
coming through the inverter is just like the electricity coming from household
wall sockets; you should use the same care you would with utility power. All
components are approved for utility interconnection and are installed according
to standard construction practices
Are solar power systems good for the environment?
Yes! Energy created through our solar electric system produces no pollutants.
Our smallest system typically cuts greenhouse gas emissions as effectively as
50 trees.
How do solar cells generate electricity?
Solar Panels, also known as Photovoltaics or PV for short can be thought of
as a direct current (DC) generator powered by the sun. When light photons of
sufficient energy strike a solar cell, they knock electrons free in the structure
forcing them through an external circuit (battery or direct DC load), and then
returning them to the other side of the solar cell to start the process all
over again.
Will solar work in my location?
Solar is universal and will work virtually anywhere, however some locations
are better than others are. Irradiance is a measure of the sun's power available
at the surface of the earth and it averages about 1000 watts per square meter.
Obviously different parts of the world receive more sunlight from others, so
they will have more "full sun hours" per day.
These panels are made of amorphous type solar cells. What is the difference
between amorphous cells and polycrystalline cells?
Amorphous solar panels contain no cells per say but are created rather through
a deposition process which actually forms the silicon material directly on the
glass substrate. To understand this a bit clearer, think of it as spraying the
silicon onto the glass in very thin layers. This film which gives amorphous
panels the "thin-film" nick name, is laser patterned which interconnects instead
of physical connecting tabs which eliminates a mechanical connection that can
break down and fail. The amount of silicon used in this process produces a film,
which is often up to 100 times thinner than that of a polycrystalline cell.
Furthermore, amorphous type solar cells are better at generating electricity
in all lighting conditions.
What types of batteries can I recharge?
You can recharge all types of 12 volt batteries including lead-acid automotive
batteries, deep cycle (traction type) batteries, gel-cell batteries, and heavy-duty
(stationary type) batteries. When using the Solar Module to run appliances on
a regular basis, we recommend the use of deep cycle marine batteries which are
designed to withstand frequent charge and discharge cycles.
Will the Solar Module drain my battery at night?
Once the solar charge controller is installed there is no danger of reverse
current, so you may leave your panel installed overnight
Can the Solar Module overcharge my battery?
Yes, but only if used without the charge controller. That is why it is important
to use a solar charge controller. Do not connect the panel directly to the battery
with wattages of 15W or higher. Always use in conjunction with a solar charge
controller.
Can I run my 110 volt appliances with my solar power system?
Yes. You can run your 110 volt appliances with an inverter, which will attach
to your battery to change the battery�s 12 volt (DC) energy into 110 volt (AC)
or 220 volt (AC).
Can my panel be left outdoors without a protective covering?
Yes. The Solar Module has been weatherproofed and can be mounted outdoors without
any additional protection.
Do I have to disconnect the panels from the battery when I drive my RV or
while I am recharging my battery by other means?
No, solar panels are designed to be permanently connected to the battery. There
is no need to disconnect them while driving a RV for example, or when charging
the batteries by other means such as AC chargers, or a vehicle�s generator or
alternator.
The LED on the panel does not light up. Should I be concerned?
The LED indicates that your unit is receiving daylight exposure. If it is not
lit, it may mean that you are not exposing the unit to enough daylight. Please
position the solar panel to maximize its exposure to the sun. If this does not
trigger the LED to work, it is possible that the LED is burnt out. The LED may
have a more limited life span than the panel. This in no way reflects on or
affects the performance of the solar panel. If the LED light is not blinking
and you feel you have sufficient daylight, test the solar module with a solar
voltage tester or a multimeter.
Do PV systems work better in hot or cold weather?
A PV module's power output is reduced at high temperatures, but the lifetime
of the PV module (estimated to be at least 20, maybe 30 years) is not affected
by normal (outdoor) heat. The duration of sunlight and the intensity of the
sunlight has a major effect on the output of a PV module, and the increase in
temperature has a lesser effect on the output. Therefore, a PV module installed
in Arizona will put out much more energy over a year than an exact same module
installed in Boston, Massachusetts. The Boston module does not get as hot, and
would put out slightly more power when at peak (around noon time) conditions,
but the module in Arizona will get about 70 percent more sunlight energy in,
and will only lose about 20 to 30 percent due to the increase in operating temperature,
overall a gain of 40 to 50 percent. A general "rule of thumb" for crystalline
silicon PV module (the most common type to date) is that the efficiency (and,
therefore, the power output) is reduced about 0.5 percent for every degree C
increase in temperature. PV modules are usually rated at module temperatures
of 25�C (77�F) and seem to run about 20�C over the air temperature. So on your
hot day of 100�F, the module will be 120�F or 50�C, so it will have its power
reduced by 12.5 percent. The design of a PV system usually takes into consideration
the need to allow some "convective cooling" for the PV modules, that is, some
way to passively dissipate the heat generated from the module and minimize the
module temperature to increase the performance. The usual method is to leave
the back open and allow some air flow around the modules. --Steve Hester, Solar
Electric Power Association Technical Director
What types of materials are used in making a photovoltaic cell?
The most widely used material for PV cells is silicon, a semiconductor. The
silicon is "doped" (that is, it has a certain amount of impurities placed into
the silicon crystal) with either boron or phosphorus to give it the properties
needed to be a PV cell and give up electrons when exposed to light. The photons
of light (photons are actually small particles of light) "knock" the electrons
out of the outside band of the silicon atom and that is what creates the PV
effect. --Steve Hester, Solar Electric Power Association Technical Director
What are some of the possible substances that give off an electron when
exposed to light?
The most common is silicon (silicon solar cells start out as simple beach sand
and the sand is refined to be very, very pure). Other materials are selenium,
gallium-arsenide, copper and selenium, and cadmium telluride. --Steve Hester,
Solar Electric Power Association Technical Director
Would one of the substances in the solar cell give off an electron easier
if it were in the liquid state (because the molecules in a liquid have more
energy)?
All of the commonly used PV materials are solids at room or normal earth temperatures
and all work better if they are cold rather than hot (see question above). None
of the common PV materials are liquid at normal conditions and they would not
be as efficient at converting light to electricity when they were heated to
a liquid state due to the higher energy levels. The higher energy levels are
detrimental to PV efficiency because the molecules are moving around more and
the photons cannot "hit" the electrons as easily and they are recombined more
at higher energy levels. --Steve Hester, Solar Electric Power Association Technical
Director
What is the efficiency of current PV cells?
Current PV cells range from about eight percent (for a thin layer cell made
of amorphous silicon) to 18 percent (for a very good single crystal silicon
cell). Some very special cells have been produced for research purposes that
are in the high 20s. More typical single crystal silicon cells usually average
about 14 percent, thereby giving module efficiencies (sunlight to DC energy)
of 11 to 12 percent. Check out the Solar Electric Power Association performance
data on our Web page and look at the tables of data for the various sites. These
tables show the actual PV system conversion efficiency (sunlight to AC energy)
for the TEAM-UP PV system installations that are monitored. --Steve Hester,
Solar Electric Power Association Technical Director
If PV arrays get dirty, won't they deliver less power?
The impact of soiling on PV output is a frequently mentioned and widely misunderstood
issue. Designers commonly estimate that, in the absence of rigorous manual cleaning,
soiling will reduce annual generation by one to four percent. Bird droppings,
pollution, and dust from traffic or farming activities accumulate rapidly, however,
and can reduce output by as much as 20 percent over the course of a dry summer.
Other variables -- such as surface material and orientation -- are also believed
to influence soiling. To get a better idea of how soiling affects PV, PVUSA
is conducting a simple side-by-side test of two identical modules installed
on a fixed-tilt rooftop. One module is cleaned three times a week while the
other is left to the forces of nature. The short-circuit current of the two
modules has been monitored for nearly two years now. The difference in appearance
is remarkable [with one heavily covered with dirt]. PVUSA has determined that
annualized soiling losses can be expected to exceed seven percent during a normal
rainfall year such as 1999, but only four percent during a wet year such as
1998, when El Ni�o weather resulted in twice the normal amount of rainfall in
the Sacramento [California, U.S.A.] area [where the test is being held]. PVUSA
estimates that, during drought years, the annual soiling losses may exceed 10
percent. Certainly, PVUSA s Davis [California] site represents a harsh soiling
environment. They receive little or no rain from April to November and local
agricultural activities can create quite a bit of dust. However, these results
suggest that PV systems in the area -- and likely others -- would benefit from
array cleaning. Now that PVUSA has quantified the effect of soiling and the
proportional energy losses, a metric will be developed to determine when to
clean the array. They also will investigate different ways of cleaning modules
in search of the safest, most beneficial, and most cost-effective method. Excerpted
from "How Clean is My Array? The Real Dirt on Soiling," PVUSA Project Update,
Third Quarter 1999. For further information, contact pvusa@endecon.com.
What types of batteries does this solar panel maintain?
Any 12 V battery used in cars, boats, RVs, motorcycles, etc.
How long does it take to charge a dead battery?
This solar panel is ideal for trickle charging all types of vehicle batteries
and power packs. If the battery or power pack is completely drained, use a larger
Solar Power Panel (11-1881-0 or 11-1882-8).
Can I use this solar panel outdoors?
No, this solar panel is not weatherproofed. If this solar panel is weathered,
the warranty will become void.
Do I need a Motomaster� Eliminator Battery Charge Controller (11-1890-0)?
No, a Battery Charge Controller is only need for panels 15 W or greater.
Can I start/drive my vehicle while the unit is connected to the battery
or cigarette lighter?
No, please make sure that this panel is not in use while you are using your
vehicle.
Can I extend the wire?
Without loss of power or voltage, the 12� wire can be extended up to a maximum
of 25� with a 16-gauge wire. Ensure proper connections.
What types of batteries can this solar panel charge?
Any 12 V battery used in cars, boats, RV�s,motorcycles, etc.
Can I use this solar panel outdoors?
Yes, this solar panel has been weatherproofed. The weatherproofing includes
UV protection and protects from weather effects of -35�F to 175�F.
How long does it take to charge a battery?
This solar panel generates 5 W of power per hour,which is equal to 350 mA
of current under ideal conditions. For example, under ideal conditions,the panel
will generate 5 W x 7 hours per day x 7 days per week for a total of 245 W of
power.
How long does it take to charge a depleted battery?
In direct sunlight, this solar panel produces 1 A/hr. By adding up to 10 solar
panels, the time needed for charging would decrease. For example, under ideal
conditions, one panel will generate 15 W x 7 hours per day x 7 days per week
for a total of 735 W of power.
How can I run 120 V AC appliances with my Solar Power Panel (11-1882-8)?
Connect the battery to a power inverter that converts DC power to AC power.
Can I overcharge my battery?
Yes, it is strongly recommended that a Battery Charge Controller (11-1890-0;
sold separately) be used to prevent overcharging.
How many panels can I connect to my 7 Amp Solar Charge Controller?
You can connect up to 105 Watts of Solar Power to the 7 Amp Solar Charge Controller.
Panels should be connected in parallel � positive to positive, negative to negative.
When will the Charging Indication light (green) light up?
The charging controller indication green light will light up when the battery
voltage reaches 14.2 Volts and the SCC will prevent the solar panels from overcharging
the battery. It is normal for the SCC LED to light on and off as the battery
voltage cuts in and out.
|