The best building site CCTV system is the one whose power, data and recording are matched to your site before you look at camera specs. With no mains, that means three things working together: power that survives a UK winter, a 4G uplink sized to the footage you actually send, and local recording that keeps going when either of those fails. The main choices are a mobile tower or trailer, solar pole units, or a generator-fed cabin with a recorder. Tower hire and ownership tend to suit short jobs, while longer programmes and wider perimeters need a closer look at power and camera positions. Camera resolution matters, but it comes after those decisions.
What do building site CCTV systems need when there's no mains?
Choose the power and data architecture before the camera: a mobile tower, solar pole units, or a generator-fed cabin with a recorder. Camera choice comes second.
Mobile tower or trailer
Towers are commonly briefed as a self-contained unit needing no site power or broadband. Hire or ownership suits short jobs, one gate or a yard whose layout keeps changing. One mast gives one vantage point, so a big perimeter needs several.
Solar pole units
A pole-mounted camera with its own panel and battery, usually reporting over a mobile network. These suit long programmes where entrances and corners stay put. They are a poor fit for shaded plots, and short winter days leave less margin for 24/7 CCTV on construction sites.
Generator-fed cabin with a recorder
Cameras are cabled back to a recorder in the site cabin, which already has a temporary supply or generator. This suits a large perimeter on a long job where you want continuous local recording. An 8-channel unit such as the Hikvision DVR with 2TB drive takes HDTVI, AHD, CVI, CVBS or IP cameras up to 1080p lite. Your own electrician or installer fits it, working from the datasheet.
General guidance, not a specification:
|
Power source |
Uplink |
Redeployment effort |
Typical failure mode |
| Tower or trailer |
Own battery, generator or solar on the unit |
Usually mobile network |
Low: tow or lift to a new spot |
Fuel or battery runs out; one view only |
| Solar pole |
Panel plus battery |
Usually mobile network |
Medium: re-fixing and re-aiming |
Flat battery after dull spells or shading |
| Cabin and recorder |
Site generator or temporary supply |
Site broadband or a mobile router |
High: cable runs are re-laid |
Supply cut stops every camera at once |
A wireless CCTV system is only wireless for the data link. The cameras still need power, and the same applies to CCTV for a vacant building whose supply has been isolated.
Solar, generator or battery: how should you power site cameras?
Solar plus battery suits low-draw cameras on sites without mains, a generator suits heavier loads, and battery alone suits short-term cover. A wireless CCTV system removes the data cable, not the power cable, so every option needs the same sums.
Size the load first
Take each wattage from the product's own datasheet, then work through two lines:
- Daily watt-hours = (camera W + light W + router W + recorder W) × hours of operation per day
- Battery autonomy (days) = usable Wh ÷ daily Wh
Usable Wh is the battery's rated capacity multiplied by the depth of discharge its datasheet permits, so check that figure on the datasheet rather than assuming the full rating is available. For solar, the panel must also replace the daily Wh after charging losses.
Why December decides solar
As general engineering guidance, size solar for December, not June. UK winter days are short and the sun is low, so a panel that comfortably feeds a 24/7 construction site CCTV camera in summer can fall behind in winter and drain the battery over a few weeks. Use a winter yield figure from your panel supplier.
Generators
A generator gives dependable power but brings its own logistics:
- Someone must refuel it on a schedule.
- Noise limits where it can sit.
- Diesel is a theft target, so the tank needs securing.
- Recording must survive a restart, so put a UPS or battery between the generator and the recorder.
Battery-backed recording
Local recording protects footage if the 4G or internet uplink drops, but recording through a power outage needs backup power for both the recorder and the cameras. Set the recorder to shut down cleanly when the battery runs low, as an abrupt cut risks a corrupted disk.
Light also matters: a smart-light camera draws more than one running on infrared. Check the datasheet for the VIPER PRO 5MP 3K ColorVu camera before specifying it for a solar supply.
How much 4G data does a site camera need?
It depends on whether you stream continuously or upload only on events. Event clips plus local recording on the recorder is the practical default for a site on 4G.
The arithmetic is simple: GB per day = bitrate (Mbps) × seconds streamed ÷ 8 ÷ 1000. Illustrative, set your own bitrate from the camera's web interface: assuming a steady 2 Mbps remote stream, one hour of viewing is 0.9 GB, while 24 hours nonstop is 21.6 GB. Real bitrates move with scene activity and night mode, so check a week of actual usage before choosing a plan size.
Levers that cut data
- Lower sub-stream for remote viewing. Keep the full-resolution main stream for local recording and view the sub-stream over 4G.
- Event-triggered upload. Send clips when motion or intrusion rules fire instead of streaming around the clock.
- H.265. The Hikvision DS-7208HGHI is listed as an 8-channel 1080p H.265 DVR, and H.265 generally needs less bitrate than H.264 for comparable quality.
- Lower frame rate on the remote stream. Fewer frames per second means a smaller stream, and it rarely matters for checking a gate.
SIM and signal
Pooled or business data plans suit multi-camera sites, because one allowance is shared and a quiet camera doesn't waste its own. Test signal at the camera position with a phone before anything is fixed. Where signal is marginal, an external antenna on a pole usually helps more than moving the router indoors.
Where should cameras point to stop plant theft and fly-tipping?
Cover the choke points first: the gate, the compound, plant parking and any gap in the fence line. Only then spend what is left on open ground.
Plant theft
A machine has to leave by a route, so aim one camera along that route to capture the vehicle and its number plate. Add a second, wider camera over the compound to show who entered and what they touched. Mount both high enough to be out of easy reach, but low enough that faces are still readable rather than the tops of heads.
Fly-tipping
Point a camera at the verge or hoarding line where vehicles pull in. Tipping happens in poor light, so give the camera a light source. Colour footage then records the vehicle's colour and the type of material dumped, which black-and-white infrared often can't.
This is a trade-off between deterrence and power draw. A smart-light camera such as the VIPER PRO 5MP 3K ColorVu records in colour at night and the visible light warns people off. Infrared is covert: it captures without announcing itself, and it generally draws less power, which counts on a temporary supply.
Put lit cameras on public-facing edges where you want to deter, and infrared where you would rather catch the offender.
PTZ on a tower
A PTZ on a tower covers a wide area, but it sees only one scene at a time. While it looks at the far corner, the gate is unwatched. Use it for the open ground and keep fixed cameras on the choke points.
Footage holds up when the recorder's clock is correct, the export plays with its own viewer, and retention outlasts the time it takes you to notice an incident. This is general guidance, not legal advice, and the police or your insurer may ask for something specific.
- Set time sync before the cameras go live, then check the clock against a trusted source after any power loss. A generator that cuts out overnight can leave a recorder showing the wrong time.
- Export the original file in the recorder's native format, bundled with its player. Don't film the screen during playback.
- Keep a record of who exported it, when, and which cameras and time window it covers.
- Don't edit, trim or re-encode. Store an untouched master and give out copies.
Retention maths
Days of footage equal usable drive capacity divided by the combined daily write rate of every camera. Work that sum through in your storage planning before you buy, and make sure the answer covers the longest gap between site checks, such as a bank holiday weekend.
For a generator-fed cabin, the 8-channel 2TB DVR is a sensible example to size against. It has 8 channels and a 2TB drive fitted, and it accepts HDTVI, AHD, CVI, CVBS or IP cameras up to 1080p lite.
UK GDPR and the ICO guidance
The ICO's CCTV guidance expects clear signage at the site entrances and a stated, documented purpose, such as deterring theft and vandalism. It also expects footage to be kept no longer than that purpose needs, and access to the recorder to be restricted to named people.
Have a process for handling subject access requests, since people recorded can ask for their images. Aim cameras to avoid neighbouring homes and public footpaths where you can. If coverage unavoidably takes in public space, a data protection impact assessment may be warranted.
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