How much money do you spend on fuel for machinery? For many farmers, diesel costs are one of the biggest outgoings – anyone who has 400ha or so will be using roughly 30,000 litres of diesel annually and spending £20,000, so the last thing you want is some low-life helping themselves.

We’ve taken a look at some of the options to stop them.

1. Spike their plans

Planning a new tank? Let nature make life difficult for thieves, point out Lincolnshire Police, by siting the tank close to a prickly hedge. Also, the smallest trace of blood or shred of ripped clothing could help the police identify the offender.

2. Put them on camera

CCTV cameras are an effective way to check if anyone has been helping to themselves to your diesel and their presence is a good deterrent as well.

Cameras have been around for ages and used to be a pricey option because you needed to run cables around barns. Now it’s all done wirelessly and is a lot simpler.

There are lots of makes on the market and they are generally very effective. You can pick up a pack of four cameras and a screen that can show one big image or four smaller ones, and it works in the dead of night.

Screwfix, for instance, sells a four-set of cameras and a DVR (Digital Video Recorder) for £180.

Pay somewhat more (£400 to £450) and you can get a full high-definition 1080P wireless video recorder with 10.1in LCD monitor and 1TB of hard drive, audio recording and PIR sensor.

See also: Ultimate guide to farm security kit

3. Light up

Security lights make it less appealing for would-be thieves to sneakily help themselves. They don’t have to be on all the time – there are lots of units that use infra-red to bring on the lights.

Outdoor LED lights are getting cheaper to buy, too – a 30W LED with a super-bright 2700 lumens will cost about £26. There are lots of makes on the market, most of which can be found with a quick Google search.

4. Saunderson

If you’re wanting brute strength to keep the most determined thieves out, Saunderson Security’s Bulldog FTP10 fuel lock could be the answer.

It costs £77 and fits over a 25mm diameter parallel gate valve. It’s not super high-tech, but the bolt can’t be cropped once it’s in position and the keys can only be removed in the locked position.

5. Spinsecure

Designed for both farm diesel tanks and heating oil tanks alike, this 2in/50mm lockable filler cap spins freely when locked – making it impossible to remove – and it has no torque point for crow-bar entry. It comes with three keys, is weatherproof and has an O-ring sealed self-closing cover.

There is also a 2in/50mm female threaded pipe adapter available. Cost is £45.

6. Bund alarms

Bund alarms are a vital piece of kit for any farm and West Midlands company Centre Tank offers a variety of types. At their simplest, these alert you if diesel is leaking between the inner tank and the outer bund and cost about £75.

If it is activated, a red LED will flash and a 90dB alarm will sound to warn the user that the bund needs to be cleared and checked in case there is a leak.

It comes in a weatherproof enclosure and has a test button that will activate the sounder to check the battery and a mute button to silence the sounder. Prices start at £52.

7. Diesel leak?

Minehead, Somerset, company Fuel Tank Shop offers several models of the Watchman Alarm including the £75, 2in/50mm aluminium fuel tank vent cowl.

It uses ultrasonic measurement to continuously check the diesel level to prevent theft and a transmitter sets off an alarm when there is a sudden drop. One model fits all and is quick and easy to install. It is also suitable for steel and plastic tanks.

The receiver can also transmit the information on diesel level. It is suitable for tanks up to 3m in height and sets up a buzzing tone when diesel levels start to run low. Equally you can monitor it via an iPhone or Android app.

Top model is the Watchman Anywhere (£160), which can be sited anywhere. The first 12 months are free, then a modest optional installation is available.

8. Apollo Ultrasonic

Apollo Ultrasonic’s diesel level monitor/gauge theft alarm tells you how much useable fuel remains in the tank. The unit can be sited 200m away and is suitable for any tank up to 3m tall.

The top model costs £123 but there are cheaper versions for £68 available from Salisbury-based Tank Services.

Staffordshire company Fuel Theft Solutions offers a range of tank locks and alarm padlocks. If any attempt is made to cut through the short or long shackle, or force the lock, an ear-piecing 110dB alarm sounds.

The padlock comes with three anti-pick five-pin keys and two sets of batteries.