SOLAR FOUNTAINS
A solar water fountain is a convenient and inexpensive way to add a touch of
magic to any yard or garden. Because solar fountains do not require you to
run AC wiring from your house they can be put in any location on your
property and take very little time to install. Solar fountains are extremely
friendly to the environment. They don't require any external power source
so they don't increase the demand for electricity from polluting coal or
natural gas electric plants. You don't have to run long electric extension
cords or wiring from your house, just a short run between the solar panel and
the fountain, so there is less digging to do and less disruption of that garden
or yard you work so hard to maintain. Solar fountains are also inexpensive.
They use simple DC pumps and their costs are comparable to any other type
of conventional fountain, but they won't add to your electric bill.
Solar Fountains Components
Solar fountains are usually sold in kits which include the solar panels, the fountain housing and the pump
that moves the water. There are also some optional components you might want to get depending upon
your landscaping design. Let's take a look at each of these components:
Fountain Housing - There is almost no limit to the materials which can be used to create a fountain.
They can be made of stone, brick, tile, copper, iron, steel, wood, resin or plastic and may fit any design
an artist might come up with. There are basically two types of fountains: sprays (fountain jets) and
ornamental statuary. A fountain spray consists of a jet nozzle or ring attached to the outlet pipe of the
pump above the pond's water level. It produces an attractive ornamental spray. Geyser jets, which
produce a larger, more dramatic effect, are excellent for aerating the water since they introduce air
bubbles to the spray. Nozzles that produce delicate sprays or thin films (such as water-bell jets) need to
be installed in a virtually wind-free location or you are going to have to constantly replenish the water
supply. Statuary fountains run the gamut of designs from classical Greek figures and wall-mounted
gargoyles to modern art forms and whimsical spouting frogs or fish. Statuary fountain ornaments can be
bought separately to put in the pond or next to it. They can also be bought as complete, self-contained
units with pre-cast reservoir bowls and integrated pump and filter systems. In most cases the pump is
embedded somewhere in the housing though on some fountains the pump is remote and there is a pipe or
tubing that provides the water. For re-circulating types of fountains there is usually a catch basin that
holds the water before it is pumped back to the starting point of the fountain's cascade. For floating
types of fountains the entire housing may be underneath the water of a pond.
Solar Panel - The solar panels that are used for fountains are no different than the types that you might
put on your roof for generating electricity. Each panel contains a number of solar cells. The more solar
cells the more energy the panel can generate. For table fountains or smaller garden fountains a small
panel (like shown above) which contains 2-4 solar cells may be sufficient. For larger fountains,
particularly shooting fountains which require a bit more energy, you may need to use a full-sized solar
panel with up to 16 solar cells in it. We generally recommend that you buy your solar fountain as a kit
with the solar panels included. That way you will know that the size and output of the solar panel is
properly matched to the pump that goes with the fountain.
Solar Pump - Solar water pumps are designed to use the DC electric power generated by the photovoltaic
panels. They must work during low light conditions at reduced power, without stalling or overheating.
There are different types of pumps depending upon your application. Most small cascade style fountains
use a small delivery pump to move the water from the collecting basin at the bottom to the top of the
fountain. If you are putting your fountain in a pond or lake you would probably use a submersible type
pump. You can also purchase pumps separately should the current pump you are using fail and replace a
conventional pump with one designed to be powered by solar panels. You will need to get a pump that
matches the output (usually measured in gallons per minute) of the pump you are replacing. This is
usually not difficult and most solar or plumbing suppliers can help you find what you need.
Pump Controller - A pump controller is a device that is used to allow a solar pump to run more
effectively given the changes that will occur in power output from your solar cells during the day. In the
morning and late evening when the sun is low they will give your pump a boost so it can run a bit longer.
We recommend pump controllers on larger fountains because they make the fountain run longer and
reduce the strain on the pump itself.
Batteries - When it comes to fountains batteries are strictly an option. If you don't want to run your
fountain at night then you don't need them. The pump for the solar fountain will simply stop running
once the sun goes down. On the other hand if you like to see your fountain at night then you will need a
battery pack. These battery packs will charge during the day and then a built in light sensor will
automatically turn them on once the sun goes down.
Wiring - There may or may not be external wiring as part of the kit depending upon the type of fountain
you are getting. Some small fountains have a small solar panel or solar cell built into the housing of the
fountain so there are no external wires. However, for fountains that use a separate solar panel there is
wiring that goes from the solar panel to the pump in the fountain. The longer the wiring the more
flexibility you will have as to where to position the pump.
Nozzles - Many of the shooting type of fountain kits come with a variety of water nozzles so you can
experiment with different water effects. One thing to consider when using nozzle is the extent to which
they are going to be impacted by wind. If your fountain is in a windy area and the stream is too high the
wind may blow a lot of the water out of the fountain's catch basin. Beyond the fact this may occasionally
douse you or your guest, it will also mean you have to constantly replenish the water supply which can be
a bit of a headache.
Tips on Buying and Using Solar Fountains
Here are some tips to help you out with your fountain:
Battery -- if you want your fountain to run at night, you will likely need to get a battery. Most do not
come with one, and therefore run only when the sun is out.
Solar panels -- if you find that your pump is not running at its full capacity, ensure that the solar panel is
aligned where it will receive the most sun throughout the day. If additional power is needed, add extra
solar panels.
Wiring -- if you know where you are going to put your fountain consider where you are going to put the
solar panel that powers it. If you are not sure go with a pump that has a pretty good length of wire
between the solar panel and the pump so you have maximum flexibility in positioning it. This is
important, not only for aesthetic reasons in landscaping but because in many cases repositioning the solar
panel may be essential if the fountain is in heavy shade.
Fluctuations -- know that your fountain will likely produce different water movement, depending on the
intensity of the sun.
Placement -- if the solar panel is separate from your fountain, you can place your fountain anywhere you
choose, as long as the panel can be placed in the sun. If the panels are integrated, on the other hand, the
entire fountain must be placed in the sun. And because solar fountains do not need to be "plugged in," you
can place them as far from a power source as you please.
A water feature in a garden can be very calming and relaxing. Many people like to sit outside near their
solar fountains or other garden features after a long day at work, and just listen to and watch it. Knowing
that your fountain is good for the environment makes it just that much better. Enjoy!
SOLAR WATER PUMPS
A solar water pump is simply any water pump that uses solar energy for its
power source. Solar water pumps are specially designed to utilize DC electric
power from photovoltaic panels. They must work during low light conditions at
reduced power, without stalling or overheating. Solar water pumps have one
significant advantage over other types of pumps, they do not require the
presence of an electric line in order to operate. This makes them extremely
useful in rural locations such as ranches and farms, or in the developing world
where electricity is often not available. In many parts of the world the cost of
running traditional water piping or an electric line for a pump is cost prohibitive. A solar water pump is a
perfect solution to this problem. Because of this they have been used extensively in places like India,
Africa and Asia both for pulling water from wells, providing water to livestock, and for irrigation.
Solar pumps have plenty of application in the U.S. as well. They have become extremely popular for rural
and agricultural well pumping and are starting to replace many pumps that were originally operated by
wind mills. Many homes in the U.S. rely on well water and solar pumps can be a convenient approach for
keeping their water tanks full. Solar pumps are also being used extensively in landscaping. Because they
do not require any type of wiring they allow landscapers tremendous freedom in where to place water
features such as fountains, streams and waterfalls.
Solar pumps are friendlier to the environment and cheaper to operate than conventional AC pumps. By
harnessing the energy of the sun they eliminate the need to use traditional fuel sources such as oil or coal
to generate the electricity they need to operate. This saves money as well, particularly in developing
countries where electricity is both scare and expensive. Also, because they eliminate the need for
digging ditches for electric lines or putting up power line poles, they are less disruptive to the natural
environment. Another advantage of solar water pumps is that they are not dependent upon the grid for
electricity. That means you can pump water even when the electricity goes out! For those homeowners
who rely on well water this can be a big advantage.
Types of Pumps
Solar panels generate DC current and so the vast majority of solar pumps use direct current rather than
alternating current so no current inverter is needed. Most of the pumps are packaged without batteries
so they really only run while the sun is shining. However, for most typical uses this is perfectly
acceptable and it has the advantage of being a very simple setup that requires little maintenance. There
are different kinds of pumps depending upon what you are trying to do:
Circulating Pumps : These types of pumps are often used in solar water
heatingapplications. They can be used to move either water or a thermal transfer
fluid such as antifreeze (glycol) through a home hot water heating system. These
same pumps can also be used for a pool heating system. They are also frequently
used in landscaping applications for waterfalls or fountains. Most circulating pumps
are relatively small and many have the option to run on AC or DC power.
Submersible Pumps: Submersible solar pumps are generally used for pumping from wells,
and are designed to fit inside the well casing in a drilled hole. The most common casing
size is 6", but 5" and 4" are also common. Some older wells drilled forwindmills are less
than 4", and most solar submersible pumps will not fit - for that the best thing is to
replace the windmill with an ERA jack pump. Submersible pumps can lift up to 650 feet
and are used when the water supply is more than 20 feet from the surface. The well may
be anywhere from a few feet to 1800 feet deep - but the deeper the well, the more
expensive the system. Depths over 400 feet will generally cost quite a bit more. Solar
powered well pumps are seldom suited for large amounts of water, such as irrigating larger fields if you
have AC power available. The largest pumps generally available are 1/4 to 2 HP.
Surface Pumps: These types of pumps use a suctioning approach and are good for
applications with shallow wells, ponds, streams or storage tanks. They work best
if the water supply is 20 feet or less from the surface. Whenever you should try to
minimize the suction lift to just a few feet. The maximum possible suction for any
pump is about 20 feet but if you push them to lift more than a few feet they will
become noisy and come under more strain. As with other solar pumps the solar
panels for the pump can be remote from the pump itself which allows a great deal
of flexibility in placement. In some landscaping systems designed for pools and
ponds the whole system floats with the solar panels lying just below the surface of the water.
Delivery pumps: These pumps are used to move water from one place to another.
Some are capable of high pressure while others are intended mainly for moving
large volumes at low pressure (such as moving water from a cistern to a stock
watering tank). Flows can be small (1/2 gallon per minute) up to 30-40 g/m.
One disadvantage of DC solar pumps which do not use batteries is that the energy they generate varies
throughout the day based upon the available sunshine to the solar panels. Therefore most DC solar pump
kits include a device called a linear current booster (LCB), also called a pump controller, which acts like
an automatic transmission, helping the pump to start and not to stall in weak sunlight. An LCB also allows
the pump motor to run longer during the day by translating additional voltage to necessary current during
periods of low sun.
Solar Panels for Pumps
Solar pumps get their power from solar panels. The type of solar panels you would use is no different than
the kind that might be put on a roof in a residential solar electric system. Solar panels come in many
different sizes. Generally the larger they are the more watts of electricity they can generate. The
number of watts you will need to generate, and therefore the number of solar panels you will need for
your pump, depends upon the size of the pump and what you are going to use it for. For example, when
using solar panels with submersible well pumps the number of panels you will need depends greatly upon
the depth of the well -- the deeper the well, the more power needed, and therefore the more solar
panels needed. When using delivery pumps the number of panels you will need is a function of the volume
of water you need to move (usually measured in gallons per minute) and the water pressure you must
generate.
Most DC pumps are fairly small and only require a single solar panel. The solar pump kit manufacturer will
have properly matched the solar panels output to the power requirements of the pump. However, if you
find your pump requires more energy you can usually add on another panel since most panels are designed
to be connected in strings or modules. The main thing is to be sure that you don't exceed the maximum
voltage the pump can handle. If you are not sure check with an electrician or the contractor that
provided you the pump.
Low volume pumps use positive displacement (volumetric) mechanisms which seal water in cavities and
force it upward. Lift capacity is maintained even while pumping slowly. These mechanisms include
diaphragm, vane and piston pumps. These differ from a conventional centrifugal pump that needs to spin
fast to work efficiently. Centrifugal pumps are used where higher volumes are required.
Most solar pumping systems use water storage rather than batteries, for simplicity and economy. A float
switch can turn the pump off when the water tank fills, to prevent overflow. Compared with windmills,
solar pumps are less expensive, and much easier to install and maintain. They provide a more consistent
supply of water. They can be installed in valleys and wooded areas where wind exposure is poor. A PV
array may be placed some distance away from the pump itself, even several hundred feet (100 m) away.
The smallest solar pumps require less than 150 watts, and can lift water from depths exceeding 200 Feet
(65 m) at 1.5 gallons (5.7 liters) per minute. You may be surprised by the performance of such a small
system. In a 10-hour sunny day a solar pump can lift 900 gallons (3400 liters). That's enough to supply
several families, or 30 head of cattle, or 40 fruit trees! Slow solar pumping lets us utilize low-yield water
sources. It also reduces the cost of long pipelines, since small-sized pipe may be used.
Determining the Type of Pump You Need
One of the first things you will need to do in most water pumping scenarios is determine whether a
submersible pump or a surface pump is best. This is based on the nature of the water source. Submersible
pumps are suited both to deep well and to surface water sources. Surface pumps can only draw water
from about 20 feet (6m) below ground level, but they can push it far uphill. Where a surface pump is
feasible, it is less expensive than a submersible, and a greater variety is available.
Once you have decided the type of pump you will need you will need to determine the flow rate required.
Here is the equation, in the simplest terms: Gallons (Cubic Meters) per Hour = Gallons (Cubic Meters) Per
Day / Available Peak Sun Hours per Day Peak Sun Hours refers to the average equivalent hours of full-sun
energy received per day. It varies with the location and the season. For example, the arid central-western
USA averages 7 peak hours in summer, and dips to 4.5 peak hours in mid-winter. In most cases, to be safe,
you will want to talk to your well contractor or a local pump provider to ensure that you have correctly
estimated your requirements but inevitably whoever you talk to is likely to ask one or more of the
following questions, so be prepared:
1.
2.
3.
4.
5.
6.
7.
8.
How deep is your well or alternative water source?
What is the static water level in the well (the static level is that height in the well to which the
water rises under it’s own pressure)?
How many gallons per minute does your well produce?
How many gallons per day do you need?
Will you pump to a non-pressurized holding tank or to a pressure tank?
How many feet above the well head is the tank located?
If a pressure tank is used, how many pounds of pressure will you ask the pump to create?
How many feet from the solar array to the well head?