Solar and Battery Runtime on a Mobile Security Trailer — The Real Numbers

A monitored trailer's daily load: 4 PTZ cameras at 8W each (32W), NVR + edge processor (~45W), cellular modem + failover (~15W), talkdown amplifier idle (~5W, spikes to 60W during broadcast), interior + perimeter lighting (LED, ~20W).

Total baseline: ~120W continuous or ~2.9 kWh/day.

• Cameras (4 PTZ): 32W
• NVR + edge AI: 45W
• Cellular: 15W
• Talkdown idle: 5W (spikes 60W)
• Lighting: 20W
• Total: ~120W / 2.9 kWh per day

Guardtress trailers ship with ~1,200W solar array (four 300W panels on the fold-out array) and ~15 kWh lithium battery bank.

Under Houston average conditions (5.2 peak sun hours/day), solar produces ~6.2 kWh/day — more than 2x load. Battery bank alone runs the trailer for ~5 days at full load with zero solar input.

A stretch of 5+ overcast days is rare in Houston but happens 2–3 times per year. Solar production drops to ~20–30% of nameplate, or roughly 1.2–1.8 kWh/day — below load.

Battery covers the shortfall for the first 4–7 days depending on charge state entering the overcast window. Beyond that, the on-board fuel generator (48-hour tank) activates automatically.

• Overcast week solar output: ~20–30% nameplate
• Battery-only runtime: 4–7 days
• Generator backup: 48 hr per tank
• Refuel logistics: automated for extended deployments

Ask any prospective vendor for: (1) solar array nameplate wattage, (2) battery bank capacity in kWh, (3) load profile in W continuous, (4) battery-only runtime, (5) generator backup runtime, (6) automated refuel logistics.

Anything vague is a red flag. Reputable vendors publish these numbers.

Standard Guardtress deployments across the Houston metro land in 24–72 hours from signed quote to live monitoring. A single solar-powered mobile security trailer covers roughly 1.5–2 acres of open ground, carries 5–7 days of no-sun autonomy, and runs on bonded cellular so it needs no site power, no trenching, and no permanent mounting. Units relocate with a standard pintle hitch as the work front moves — a real advantage on phased Houston builds where the exposure point changes every few weeks.

Every unit ships with license plate recognition (LPR), analytic tripwires tuned to human and vehicle shapes, and two-way talkdown from a live U.S.-based monitoring center. Verified events escalate to the Houston Police Department or the Harris County Sheriff's Office as a confirmed crime in progress, which moves the call up the priority queue instead of into the false-alarm pile. Site plans, camera angles, and escalation contacts are set during a 30-minute assessment before the trailer leaves the yard.

• Assessment to live monitoring: 24–72 hours
• Coverage per unit: 1.5–2 acres, 360° with LPR at entry
• Power: solar with 5–7 days no-sun autonomy, no site power required
• Escalation: verified talkdown, then HPD / Harris County Sheriff dispatch
• Service area: Houston, Sugar Land, The Woodlands, Pasadena, Baytown, Conroe, Katy, Galveston, League City, Pearland

Houston contract guards run roughly $28–$42 per hour loaded, so a single unarmed guard on a 12-hour night shift costs about $10,000–$15,000 per month — for one set of eyes that can only be in one place, takes breaks, and turns over often. A monitored Guardtress trailer covers the same perimeter continuously at a fraction of that, and the spend moves from a headcount line to a predictable OPEX line you can hold to the schedule.

The math usually turns on two numbers: what a single loss event costs you in materials plus schedule slip, and whether your carrier offers any credit for a written 24/7 monitoring plan — a question worth asking your broker directly. Full site-by-site pricing is in our construction site security cost guide, and the head-to-head breakdown is at Guardtress vs. security guards.

• Houston guard rate: $28–$42/hour loaded
• One 12-hour guard shift: $10,000–$15,000/month
• Monitored trailer: fixed monthly OPEX, no overtime or turnover
• Builder's risk documentation: written monitoring plan formatted for broker review