The Complete Guide for Farmers, Smallholders, and Landowners
Introduction
If you keep livestock or want to protect land from predators, chances are you've considered electric fencing. It's affordable, effective, and surprisingly safe. But if you're new to it, it can feel overwhelming.
We hear the same questions time and time again: "What voltage do I need for sheep?", "Can I power my fence with solar?", or "Why isn't my fence giving a shock?"
In this guide, we've taken the 10 most common electric fencing questions and answered them in depth. Each section is written so that by the end, you'll not only understand how electric fencing works, but also how to build and maintain a system that works for your specific animals and land.
1. What Voltage Do I Need for Different Animals?
One of the first questions any farmer or landowner asks is: how strong does my fence need to be for my animals?
The answer depends on the type of livestock you're controlling. Each species has different hair, skin, and behavioural traits, which means the required voltage varies.
1. What Voltage Do I Need for Different Animals?
One of the first questions any farmer or landowner asks is: how strong does my fence need to be for my animals?
The answer depends on the type of livestock you're controlling. Each species has different hair, skin, and behavioural traits, which means the required voltage varies.
Recommended Voltage Guide
| Animal Type | Voltage Required | Notes |
|---|---|---|
| Cattle | 2,000–3,000 volts | Relatively thin hides and quick to learn respect for the fence. Once trained, even lower voltage can be enough. |
| Horses | 2,000–3,000 volts | Naturally sensitive animals. Wide electric tape is often used for visibility, reducing the risk of them running into it. |
| Sheep & Goats | 4,000–5,000 volts | Sheep's wool and goats' thick coats insulate them from mild shocks. Higher voltage is essential to penetrate. |
| Pigs | 3,000–4,000 volts | Intelligent but stubborn animals. A well-powered fence ensures they don't push through. |
| Poultry | 5,000+ volts | Feathers insulate even more than wool. Specialised electrified netting systems are normally used. |
| Predators & Wildlife | 4,000–7,000 volts | Foxes, badgers, and deer need higher deterrent levels, especially if they're persistent or already familiar with the land. |
Why It Matters
An electric fence doesn't rely on current (amps), which is what harms people. Instead, it delivers a short pulse of high voltage that startles the animal, teaching it to respect the boundary. Get the voltage wrong, and the fence is useless. Get it right, and animals learn quickly and safely.
2. How Far Can I Run an Electric Fence?
This question is really asking: how powerful does my energiser need to be?
The distance your fence can run depends on the joule rating of your energiser (its stored energy capacity) and how clean your fence line is.
Distance Guide by Energiser Size
- 1 joule energiser: 3–5 miles (ideal for small paddocks)
- 5 joules: 15–20 miles (suitable for small to medium farms)
- 15 joules+: 50+ miles (used in large-scale farming)
What Limits Distance?
- Vegetation touching wires: weeds and grass act as grounding points
- Poor grounding: inadequate earth rods reduce efficiency
- Loose joins or rusted connections: cause voltage drops
- Multiple fence lines: each extra strand adds resistance
Think of your energiser like a water pump. If the pump is weak or your pipes are leaky, you won't have enough pressure at the far end.
3. Do I Need Insulators If I'm Using Wooden Posts?
Many people assume wooden posts don't need insulators. After all, wood isn't a conductor — right? Not exactly.
Why You Need Insulators
Wood may not conduct well when bone-dry, but in the real world it's often damp. Wet wood conducts enough to drain power away from your fence. Over time, this can cut your voltage by thousands of volts.
Types of Insulators
- Screw-in insulators: for wires attached to wooden posts
- Tape or rope insulators: designed for wide tape, ideal for horse fencing
- Corner strain insulators: heavy-duty ceramic or reinforced plastic for areas under high tension
Investing in quality insulators ensures that the power you're paying for actually reaches the fence line.
4. Can I Electrify Barbed Wire?
This is a common question, especially where barbed wire is already installed. The short answer: you shouldn't.
The Risks
Animals can become tangled in barbed wire. Combine that with electricity and the shock can prevent them from escaping, leading to injury.
People (farm workers, ramblers, or children) can also get hurt.
Safer Alternatives
- Run an electrified offset wire 6–8 inches inside the fence line to keep animals from leaning on the barbed wire
- Replace barbed strands with plain high-tensile wire where possible
Electrifying barbed wire might seem convenient, but it's a legal and welfare risk. Always go with safer options.
5. How Do I Keep Vegetation From Draining Fence Power?
This is one of the biggest day-to-day problems for electric fence users. Grass, weeds, and branches touching your fence act like tiny thieves, constantly stealing voltage.
Solutions
- Clear vegetation regularly: Mow, strim, or spray fence lines to keep them clear
- Use fewer contact points: High-tensile wire with larger spacing means fewer places for weeds to touch
- Choose a stronger energiser: Low-impedance models push through light vegetation
- Hot/ground wire systems: Alternate wires are live and earth, ensuring a shock even in weedy conditions
If you know your fence line will be in a heavily overgrown area, plan for it from the start with extra power.
6. Can I Power an Electric Fence With Solar?
Yes — and for many smallholders and remote farmers, it's the perfect solution.
Advantages of Solar-Powered Fencing
- Portable: can be moved with temporary paddocks
- Low running cost: no need for mains electricity
- Eco-friendly: renewable power source
Drawbacks
- Power limits: solar energisers typically power shorter fences
- Weather dependence: UK winters can be challenging — always choose an oversized panel and battery
- Battery maintenance: expect to replace the battery every 3–5 years
For small setups or mobile fencing, solar is excellent. For larger farms, a mains-powered energiser with a solar backup may be the best option.
7. How Do I Test If My Fence Is Working Properly?
Guessing isn't good enough. The only way to know your fence is working is to test it with a digital fence tester.
Testing Steps
- Start at the energiser: Check the output directly
- Move along the fence: Test every 100–200 metres
- Compare readings: If you see a large voltage drop, the problem is between the last two points
Signs of Trouble
- Cracked insulators: leakage into posts
- Loose joins: poor conductivity
- Weeds or branches: stealing voltage
- Grounding issues: poor earth rods or loose clamps
A healthy fence usually shows 5,000–8,000 volts at the farthest point. Anything less means troubleshooting is needed.
8. Is Electric Fencing Safe for Animals and People?
Yes — when installed correctly, electric fencing is one of the safest containment systems available.
- Shocks are short and pulsed, not continuous
- The system delivers high voltage but extremely low current, so it's unpleasant but not harmful
- Animals learn quickly and rarely test the fence after the first encounter
The main safety risks come from poor installation — like electrifying barbed wire, or allowing a live wire to hang loose.
9. How Many Ground Rods Do I Need?
Grounding is the single most overlooked part of electric fencing. In fact, experts estimate that 90–95% of fence problems are caused by poor earthing.
Grounding Guide
- Use at least 3 rods, 6–8 feet long
- Space them 10 feet apart
- Use proper clamps and avoid mixing metals (which can cause corrosion)
- Place rods in permanently moist soil if possible
If your fence isn't giving a shock, 9 times out of 10 it's the grounding system at fault.
10. Why Isn't My Fence Delivering a Shock?
Finally, the most common question of all: why won't my fence shock?
Common Causes
- Poor grounding: inadequate rods or dry soil
- Vegetation leakage: weeds, grass, or branches touching the fence
- Faulty components: cracked insulators, corroded joins, or damaged wires
- Weak energiser: underpowered for the fence length
- Poor connections: loose clamps or rusted terminals
Troubleshooting Checklist
- Test energiser output
- Check grounding system
- Walk the fence line with a tester
- Inspect insulators and joins
- Clear vegetation
Work through this methodically, and you'll nearly always find the fault.
Conclusion
Electric fencing may seem complicated at first, but once you understand the principles it's straightforward. The key is to design your system around your animals, install it properly, and maintain it regularly.
By answering these 10 most common questions, we've shown that voltage, grounding, vegetation control, and regular testing are the four pillars of a reliable electric fence.
Whether you're containing cattle, protecting sheep from predators, or simply managing a few horses in a paddock, the right fence will save time, money, and stress.