Solar CCTV for sites without power or network

A solar CCTV unit is a self-contained system: a photovoltaic panel, a battery, a 4G modem and a camera, all mounted as one assembly. Nothing runs to it. For the right site this is transformative, and for the wrong site it is an expensive way to get a worse camera.

When solar is the right answer

Solar earns its cost at distance. If getting mains power to the camera position means trenching a car park, cutting a road surface, or negotiating a supply from a neighbouring building, the solar unit is cheaper before you have priced the camera.

It is also the right answer for anything temporary. A construction hoarding, a worksite perimeter, an event boundary. The whole assembly demounts as easily as it went up and redeploys as the works progress.

When it is not

If there is a socket within thirty metres, run a cable. A wired camera on a cable run will be cheaper, more reliable and higher resolution than any solar unit, and it will not stop working during a monsoon week.

We would rather tell a customer to run a cable than sell them a solar unit they did not need. The units are excellent. They are not a substitute for infrastructure that already exists.

The battery is the engineering, not the panel

Singapore has good solar irradiance and genuinely dark afternoons. A system sized against average sunshine will drop out during a run of overcast days, and it will drop out at three in the morning at the end of the fourth grey day, which is precisely when you wanted it.

Size the battery for the worst realistic case rather than the average. This is the single specification that separates a solar deployment that runs for years from one that becomes a monthly complaint.

Panel angle is worth an hour of care

A panel angled wrong loses a substantial fraction of its daily yield, and near the equator the panel wants to sit close to horizontal with just enough tilt to shed rain. What matters more than the angle is shading. A branch that casts a shadow across the panel for forty minutes each afternoon is a real problem, not a cosmetic one, because partial shading on a panel disproportionately reduces its output.

Walk the position at the time of day when the sun is lowest, and look at what is between the panel and the sky.