Solar powered electric fence systems are becoming more and more common around the globe as a way of electrifying remote areas or where it is impractical to use mains power. Uses vary from small areas on a seasonal basis to full time large-scale fence systems.

The improved efficiency of our energizers has meant longer distances can now be reached for less cost (by efficiency we mean energy lost through internal circuitry.)

By combining premium Speedrite solar components or by choosing one of our Solar-Kits, you can easily tailor a system to your needs. So you can quickly have the fence up and running and be able to leave it to its job.

We have decades of experience using solar fencing, and we know when setting up solar systems it is all about reducing future maintenance. Investing a little more up front and installing it properly, will save a great deal of time and money for you in the future.

We have put together this Solar Selection Guide to make building your own solar system easy. If you require any further information please read our 'Electric Fence Manual' or contact one of our knowledgeable Speedrite dealers (see 'Dealer' link).

Please read below

The Selection Guide covers the following topics:

(Click on the following links to jump to the topics)

1. How does a solar system work?
2. Components of the solar system

• Choose your energizer
• Choose your battery
• Choose your solar panel
• Choose your earth system

3. Installation

• Choose your site
• Install your panel
• Install your earth system
• Connect the components

4. Maintenance
5. Battery Care Tips

A solar panel is made up of a number of photovoltaic cells connected in series. Electricity is generated between the front and back of each cell. Combined into a solar panel, these cells can produce enough voltage to charge a regular 12 volt battery.

The solar panel normally ensures that the battery remains charged at all times. The battery stores the energy generated by the panel, and powers the energizer 24 hours a day.

The solar panel will provide enough charge each day to maintain the battery’s charge within its operational range ( ideally over 50% charge). The solar panel selected should be able to replenish energy used by the energizer each day, so as to keep the battery in a healthy charge condition.

Any additional energy available above this daily requirement can be stored to improve the state of the battery, if not already fully charged. (The opposite also applies. If the energy generated does not meet the 24 hour energy requirement of the energizer, the total charge in the battery will decline.)

NOTE:
A solar panel will supply a reduced charge to the battery on a cloudy day. However, at night no electricity can be generated, therefore no charging will take place.

After a prolonged period of poor sunlight the energizer may discharge the battery such that the battery may be damaged or destroyed.

The point above illustrates the importance of choosing the correct combination of energizer, batteries and solar panel to suit the specific geographic location and the operating conditions the solar system will be used in.

There are four main components that make up a Speedrite solar system.

1. The Speedrite battery powered energizer
2. The battery (or battery bank)
3. The Speedrite solar panel
4. The Speedrite earth system

Each component requires careful consideration depending on your individual needs. Use the step-by-step guide to build your own customised solar system.

Step 1 Choose your Speedrite energizer

The Speedrite range of battery powered energizers includes models to suit virtually every electric fencing requirement. It is the energizer that provides the electricity to the fence, therefore the energizer is the first important consideration.

There are several factors that must be considered when selecting an energizer:
- The type of stock that will be fenced
- The size of the area to be fenced
- The total length of wire to be electrified and type of fence (single or multi-wire fence)
- The amount of vegetation that could grow onto the fence
- Future plans for extending the fence

As an approximate guide, 1 joule of output energy will power 10km (6.25 miles) of single wire fence, or approximately an area of 15 acres (6 ha). Table 1 shows the range of Speedrite energizers appropriate for a solar installation, with maximum output joules indicated.

For more information on selecting the correct Speedrite battery powered energizer for your requirements, ask your Speedrite distributor or refer to the Speedrite Electric Fence Manual.

Step 2 Choose your battery

The battery must suit the electrical current consumption (milliamps) of the energizer being used, and must have sufficient storage capacity to provide power to the energizer during periods of reduced sunlight (i.e. in winter or cloudy weather). The size of the battery chosen for the solar system will depend on the type of energizer you have selected. More than one battery may be required to supply enough charge and storage capacity for your energizer, this is often referred to as a “battery bank”.

Deep cycle batteries are recommended for use in solar systems, as they are more suited to the repetitive power draining and recharging that can occur in solar systems. The use of automotive batteries is not recommended, but may be suitable in some situations. Speedrite battery powered energizers will work with most brands of deep cycle battery. See your local Speedrite dealer or battery retailer for the suitable battery for your system.

Table 1 provides recommended battery sizes for given Speedrite battery powered energizers. This table is based on providing continuous operation for periods of up to seven days with little or no sunlight and shows requirements running the energizer at both full power and half power. The correct battery must be chosen as a battery that is too small for the system may be damaged or destroyed over time.

Table 1 Battery and solar panel selection

Step 3 Choose your solar panel

All modular Speedrite solar panels utilise premium multicrystalline cells. These cells provide up to 100% greater energy-generation efficiency and over double the life of standard amorphous type panels. With a toughened glass panel and heavy-duty alloy frames, Speedrite solar panels are designed for rugged agricultural conditions. (Speedrite solar panels have a rated 10-year warranty from the date of purchase for power output, whereby the solar panel is guaranteed to deliver at least 90% of its minimum rated power output.)

All Speedrite panels 50 watts and higher are regulated, which prevents the panel from over-charging the batteries in your system. As the battery approaches a full state of charge, the current into the battery is reduced to a trickle or switched off to maintain the battery at full charge, preventing any damage to the battery.

All Speedrite solar panels are compatible with the specially designed universal mounting bracket system. The easy to assemble mounting bracket enables you to correctly position the panel for optimum energy generation. The bracket also accommodates all sizes of energizer, keeping your system compact and secure.

The selection of the correct size panel is determined by a number of factors:
1 Current draw of the energizer
Larger energizers draw more current, and will require a larger battery or battery banks, and therefore a larger solar panel or multiple panels, to maintain the charge level of the batteries.
2 Pulse speed or power setting of the energizer
The faster the pulse speed or the higher the power setting, the more current the energizer will draw, and the larger the panel will need to be. The values in Table 1 are based on the maximum current draw of the model (the fastest setting) and at a lower current comsumption setting.
3 Daily solar radiation conditions
The amount of useful sunlight may vary considerably depending on the geographic location of the solar panel and the time of the year. A larger solar panel will be required in an area with less useful sunlight hours.(measured in peak equivalent sun hours per day 100w/m²/day)
4 Required period of operation
If the energizer is required to operate during winter, the battery and solar panels selected must be able to maintain the desired output at these lower daily sunlight levels.

Table 1 provides recommended solar panel sizes based on the current drawn by your chosen energizer, and the number of ‘ equivalent peak sun hours per day’ at the location of your system. Make your selection using the lowest equivalent peak sun hours per day your solar system will be required to operate under. (e.g. in winter if in use year round)

Contact your local weather bureau for accurate local equivalent peak sun hours per day.

Step 4 Choose your earth system

As with all electric fence systems, a solar system requires appropriate earthing. If the location of the solar system is isolated it is even more important to set up your earth system correctly to ensure reliability and low maintenance.

Larger energizers exerting more power on extensive fence systems require a larger Earth system capable of capturing electrons (current) returning to the energizer via the soil. Soil types, mineral content, and ground moisture and also fence load are all determining factors that determine how many earth rods will be required. Refer to the Speedrite Fencing Manual for more detailed information on effective earthing.

Table 2 shows the recommended minimum number of 2 m (6 ft) earth rods for given energizers in moist soil conditions. If the system is subject to dry soil conditions, add more earth rods, or for extremely dry conditions, a bentonite salt earth system may be required(available in kit form).

Table 2 Recommended minimum number of earth rods

Now that you have chosen the components for your Speedrite solar system, it is important to set up your system correctly to ensure trouble free operation.

Once again, use the step-by-step process outlined below.

Step 1 Select your site

When selecting a suitable location for your solar system it is important to consider the following factors.

1 Access
Consider the frequency of inspections and the ease of access for maintenance.
2 Protection
Consider protection of the components from the environment and animals.
3 Safekeeping
Consider the security of the system from human intervention.
4 Proximity to fence
Try to position the energizer at the hub of radiating fences. This will reduce sections from the energizer and minimise the resistance of current flow over the length of the fence.
5 Earth
Consider the proximity of the energizer, panel and battery to an appropriate earth site.

Step 2 Install your solar panel

Use the Speedrite universal mounting bracket to mount the solar panel on a suitable post. Comprehensive instructions are included with the mounting bracket.

TIP
It is recommended that solar systems with multiple panel set-ups be mounted on a pole extending between two strainer posts for maximum stability.

Once the mounting bracket is assembled the panel must be positioned to obtain maximum daily sunlight exposure. Ensure that shadows will not fall on the panel at any time during the year.

The panel should always face toward the equator (facing north in the Southern Hemisphere and south in the Northern Hemisphere).

Panel tilt angle (see figure 1) will be determined by the latitudinal location of the solar system. As a general rule, solar panels should be set with a tilt angle equal to the geographic latitude, plus 10° to 15° . Table 3 provides tilt angles for example locations. For maximum efficiency it may be necessary to adjust the tilt angle of the panel at different times of the year (down in winter and up in summer).

Figure 1 Tilt angle

Table 3 Tilt angle

Step 3 Install your earth system

Moist soil is the key to a good earth. If there is no moist soil in the area close to the energizer it is possible to position the rods some distance away and still be effective. Ensure that the earth site is at least 10 m from the earth site of any other electrical system and never connect two or more energizers to the same earth system.

- Hammer the earth rods into the ground, leaving approximately 15 cm (6 inches) above ground. The distance between each earth rod should be at least 3 metres (10 ft).
- Use a suitable wire/ insulated cable and securely connect appropriate earth clamps to join the earth rods in series, and connect to the earth terminal of your energizer.
For maximum earthing effectiveness in dry conditions, use an earth wire return fence configuration. (see Speedrite Fencing Manual for details).

Step 4 Connect the components

Where your solar system requires more than 50 watts of solar power, multiple panels will be supplied (See figure 3 – multiple panels). The panels are connected in parallel to provide the greater wattage that you require.

If your solar system requires more than one battery, a ‘battery bank will need to be created. This is simply two or more 12-volt batteries connected in parallel (see Figure 3 – multiple panels).

Gases given off by lead acid batteries during charging are potentially hazardous, and may cause explosion or corrosion. Batteries must be well ventilated and positioned away from the energizer and the solar panel. Battery boxes are especially practical when the batteries are to be exposed to the elements. Insulation is recommended where ground temperatures often freeze as this can damage batteries.

The panel and connecting leads should be protected from damage by livestock. It is recommended that a small fence be constructed around the solar assembly.

Figure 2 Solar Kit	Figure 3 Multiple panel setup

While minimal maintenance will be required, regular checks of your solar system will ensure reliable performance (every 6 to 8 weeks). Here are some pointers to maximise the life and performance of your solar system:

- Clean the solar panel with a soft, damp cloth to remove any residue or dust film.
- Check the mounting bracket is secure and the tilt angle is correct (if necessary, change the angle to accommodate the change in seasons).
- Check all leads and connections are secure and undamaged by animals or vegetation.
- Check electrolyte level in batteries.
- Check the fence line for any faults using a Speedrite Fault Finder. Clear any debris or vegetation that may be causing a short on the fence.
- Check all exposed terminals and wires for evidence of corrosion from environmental conditions such as salt or chemicals. Tend to any connections that show early signs of corrosion.

Refer to the battery manufacturers instruction regarding safety and care of the battery. Some guidlines are:
Optimising the life of your battery:
- Choose the correct size battery for your system.
- House the battery in a suitable battery box if the battery is likely to be exposed to the weather.
- Inspect the battery regularly to ensure that the battery electrolyte level does not fall below 12 mm (½”) above the surface of the battery plates.
- The use of de-ionised, distilled or rain water is recommended to top up the battery electrolyte level.
- Recharge a discharged battery as soon as possible.
- Store spare batteries completely charged and recharge at regular intervals (every 8 weeks).
- Avoid subjecting batteries to temperature extremes < -10° C (14° F) or >50° C (120° F).
Safety:
- Do not short out the terminals of the battery
- Ensure that the battery is well ventilated during charging.
- Ensure that the battery is not exposed to naked flames or sparks.

Should you require any further assistance please see you local Speedrite dealer