September 10, 2010
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Solar Water Pump

Technology Name:

Solar Water Pumping

Date Introduced in the market:

1980s

Maturity of the technology:

Mature

Status of development:

Established industry with continuous growth over 5+ years

Type of energy that can be produced (i.e. thermal, electrical):

Electric

Typical applications:

To pump water for delivery to livestock where the grid is not readily available and a reliable low maintenance system is required.
To pump large volumes of water or water from deep wells where mechanical pumps are not adequate.
To pump water from a dugout to a livestock waterer for livestock.
To pump water for crop irrigation
Pond management
As a portable water pumping system

Range of possible dimensions and sizing considerations for the system:

The main components of a solar water pumping system are the photovoltaic array, and the pump. Pump size and type will depend on the amount of water required (litres per day), total head required (amount of pressure pump must create). Pumps can be above the water or submersible, AC or DC. Size of the array will depend on the pump chosen, amount of water required, climate and solar exposure, whether or not the panels are placed on a tracker or a fixed mount.

Other considerations in designing a SDHW system include the cold water intake temperature, desired hot water temperature, pattern of hot water use.

Solar water pumping systems can be designed with or without storage. Batteries and or elevated water tanks/fenced in ponds are common storage.

PV panels:

The amount of PV power required will depend on the amount of water required daily. For example, assuming 10 percent losses of energy from wiring and the controller to the pump, 165 watts of PV could power an efficient 150 watt DC solar pump (see range of performance below) could pump over 1300 litres of water in 4 hours of direct sunlight.

Storage:

Deep cycle batteries are recommended for PV systems and batteries designed specifically to work with PV systems are available. Battery capacity is measured in amp hours. Most deep cycle batteries have efficiencies of about 80% depending on temperature.

Excess water can be pumped into an elevated storage tank or pond to ensure water is available via gravity on cloudy days.

Range of performance of the technology per unit installed:

Water pumping systems can be designed to meet a wide variety of water delivery needs. In most places in Canada, expect an average of between 3 and 4 kWh/day per installed kW of PV with a fixed mount PV array and a clear solar exposure. More is possible with a single or double axis tracking mounting system that tilts to follow the sun or a mounting system adjusted seasonally.
Solar water pumping systems are designed with slow pumps that are usually very efficient. The more efficient the pump, the less money will have to be spent on photovoltaics. A properly installed solar pump as small as 150 watts can lift water more than 65 meters at a flow rate of 5.7 litres per minute. For another example, a h.p. pump supplied by three 50-watt panels can deliver water at a rate of about 1½ gpm to a location 30 m higher than the source. As a comparison, a 3 h.p. low-lift irrigation pump powered by an array of 60 panels could deliver water at a rate of about 1,000 gpm.

Range of costs per unit of energy and per system (installed, and maintenance costs):

Photovoltaic panels

The cost of a solar water pumping system will vary depending on the capacity of the system. Generally, solar water pumping systems range in cost from $2000 - $6000.

Expected Pay-Back:

Solar water pumping is a economical and low maintenance alternative to a generator or bringing the grid to an unserviced area. Where the upfront costs of a grid extension are greater than the cost of the solar water pumping system (usually 0.5 km or further), the savings are immediate and ongoing with minimal maintenance costs. While the upfront costs are generally greater than a gas fuelled generator based water pumping system, savings are met over 5 - 10 years or sooner in maintenance and fuel costs.

Design, Installation, Maintenance & Operation of Solar Water Pumping System:
Design of a Solar Water Pumping System:

Expertise/knowledge required can include: sizing the Solar pumping system, plumbing, electrical, mechanical, general construction.

Installation of a Solar Water Pumping System:

Expertise/knowledge required can include: solar design basics, electrical, water pumping, plumbing, mechanical, general construction skills.

Maintenance of a Solar Water Pumping System:

Maintenance is minimal and will depend on the type of system. The simpler the system (no batteries, fixed PV mount), the less maintenance. Systems should be checked frequently to ensure proper functioning (every few days/number of days of storage capacity).
Expertise/knowledge required can include: solar basics, plumbing, electrical, mechanical.
Tasks to be done can include:
-Repair or replacement of pump after approx. 5-10 years.

Operation of a Solar Water Pumping System:

Can be monitored and operated by owner with instruction from contractor/installer.

Training for designers and installers:

Solar water pumping systems are fairly simple low voltage installations that can be completed by someone with training in electrical safety, clear instructions and good mechanical and construction skills. CanSIA is working with colleges to implement training programs for designers and installers of Photovoltaic systems, based on the North American Board of Certified Energy Professionals SDHW certification. A wide variety of training opportunities exist from online courses and free information to hands on workshops and college courses. See www.cansia.ca for more information.

Range of Operational & Maintenance requirements (ex: how much labour time per week for how many people):

Solar water pumping systems are very reliable and require limited maintenance. They should be checked regularly to ensure proper functioning.

Potential problems or challenges:
System performance:

Ensure the pump and PV array are chosen to meet your water pumping needs considering your climate and solar exposure.
Investigate maintenance contracts or warranties.
Ensure southern exposure clear of obstructions between the hours of 10 AM and 3 PM or longer.

Permitting:

Investigate possible permit requirements before beginning any project.

Range of warranties and life expectancy of the systems:

Warranties:
Panels are typically warrantied for 25-30 years and should continue to operate beyond 30 years with a slow decrease in efficiency.
Pumps come with warranties from 5 - 10 years and life expectancies of 7-12 years

Solar Resources Assessment:

Site specific solar resources can be measured by visual techniques and inspection or through commercially available solar site analysis tools. The U.S. National Renewable Energy Laboratory has extensive solar radiation resource information at http://rredc.nrel.gov/solar/. Links to Canadian solar radiation data can be found at http://www.canren.gc.ca/resou_asse/index.asp?CaId=55&PgId=452

Canadian Solar Resource maps are available at: http://atlas.nrcan.gc.ca/ and https://glfc.cfsnet.nfis.org/

Inputs and outputs for the technology:
Outputs:

Solar PV panels directly convert energy from the sun to Direct Current (DC) electricity. The DC electricity can be either used directly to power a DC pump, to charge batteries which then power a DC pump, or send power through an inverter that converts DC electricity to AC electricity to power an AC pump.

Inputs:
Sun:

A southern exposure unobstructed from the hours of 10 AM to 3 PM is preferred.

Pump parts:

Pumps may require some parts replaced after 3-5 years. Investigate warrantees. It is recommended to purchase potentially required spare parts with your system to avoid down time for ordering.

Potential combination with other energy systems (hybrids and combination systems):

Fossil fuel generators may be used as a back up energy supply.

Links to other sources of information:

 

Sources of supply (in Canada):

Check CanSIA's website for contact information for suppliers and installers in your area. www.cansia.ca
Énergie Solaire Québec sells for a small fee (free with membership) a list of renewable energy suppliers and businesses in Quebec. http://www.esq.qc.ca/

Recommendations on how to proceed with a project development:

Contact CanSIA: check their database for a local installer.
Finding a contractor: As when hiring any contractor, ask for references from other clients or examples of their work and past experience.
Contact your local municipal permitting office.
Ensure you have the necessary permits and the inspector is familiar with your plans before construction.
Check the links above for more information.
Investigate potential government incentives.


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Created: 02-14-2008
Modified: 03-31-2008