Solar vs Mains Traffic Signal: 10-Year TCO Comparison
Choosing between solar and mains power for a traffic signal affects the total cost of ownership (TCO) for 10-20 years. This guide shows the real cost comparison including installation, operation, battery replacement, and maintenance.
Quick Cost Comparison
| Item | Solar (10-yr TCO) | Mains (10-yr TCO) |
|---|---|---|
| Initial install | $5,000-7,000 | $7,000-30,000 |
| Battery replacement | $1,200 (2x AGM) | $0 |
| Electricity | $0 | $1,310 ($0.15/kWh × 8,737 kWh) |
| Maintenance | $2,000 (annual visit) | $1,500 (annual visit) |
| Battery disposal | $100 | $0 |
| Total 10-yr TCO | $8,300-10,300 | $9,810-32,810 |
For most remote sites, solar is 50-70% cheaper over 10 years. For sites adjacent to the grid, mains can be cheaper.
Installation Cost Breakdown
Solar Installation
- Solar panel + mount: $800-1,500
- Battery bank (AGM): $600-1,200
- MPPT charge controller: $200-400
- Pole and foundation: $2,000-3,000
- Signal heads: $1,400-1,800 (300mm set)
- Total: $5,000-7,900
Mains Installation
- Signal heads: $1,400-1,800
- Pole and foundation: $2,000-3,000
- Mains connection (within 100m): $1,000-3,000
- Mains connection (over 500m): $10,000-25,000
- Total adjacent to grid: $5,400-7,800
- Total remote site: $15,000-30,000
Operating Cost Comparison
Solar Operating Cost
- No electricity cost
- Battery replacement every 3-5 years (AGM) or 8-12 years (LiFePO4)
- Annual maintenance visit: $200
- Panel cleaning (annual): $0 (rain typically sufficient)
- 10-year operating: $2,000 + $1,200 (batteries) = $3,200
Mains Operating Cost
- Electricity: 80W × 24h × 365 = 700 kWh/year × $0.15 = $105/year
- Surge protection replacement: $200 every 10 years
- Annual maintenance visit: $150
- 10-year operating: $1,500
When Solar Wins (TCO)
Solar is more cost-effective when:
- Distance to grid exceeds 200m
- Trenching costs exceed $5,000
- Electricity is expensive ($0.20+/kWh)
- Site has good solar exposure (PSH > 3.5)
- Battery access for replacement is feasible
- 3+ days of autonomy is acceptable
GAOQIAO has supplied solar signals to sites where mains connection would have cost $25,000+ for trenching alone. In these cases, solar pays for itself in year 1.
When Mains Wins (TCO)
Mains is more cost-effective when:
- Grid is within 100m
- High reliability is critical (no battery risk)
- Traffic signal must operate 24/7 regardless of weather
- Site is in an area with poor solar exposure
- Long-term electricity costs are low (subsidized)
GAOQIAO specifies mains for hospital access roads, fire stations, and other critical infrastructure where signal reliability is paramount.
Battery Chemistry Comparison
| Chemistry | Cycle Life | Cost | TCO Impact (10-yr) |
|---|---|---|---|
| AGM Lead-Acid | 500-800 | $400-600 | $1,200 (2 replacements) |
| Gel Lead-Acid | 800-1200 | $500-800 | $1,000 (1 replacement) |
| LiFePO4 | 3000-5000 | $1,200-2,000 | $0 (no replacement) |
For 10-year TCO, LiFePO4 is often the lowest cost despite higher upfront cost.
Reliability Trade-offs
| Aspect | Solar | Mains |
|---|---|---|
| Uptime | 95-98% | 99.9% |
| Outage cause | Battery, weather | Grid failure, equipment |
| Recovery | Replace battery | Wait for grid |
| Maintenance | Battery-focused | Equipment-focused |
GAOQIAO solar signals with proper sizing achieve 98% uptime. For mission-critical applications, dual-source (solar + mains backup) provides best of both.
Conclusion
For most urban sites, the break-even is around 200m of grid distance. For remote sites, solar is 50-70% cheaper over 10 years. For critical infrastructure, mains provides better reliability.
GAOQIAO can help you decide based on your specific site. Send us your distance to grid, electricity rate, and reliability requirements.
Get a Quote
Send us your site details and we will return a 10-year TCO comparison and quotation.
Email: sky-sale@njgq.net
WhatsApp/Phone: +86-18805173545
Tel: +86-25-84471080
Frequently Asked Questions
How long do solar traffic signals last?
The signal heads last 15-20 years. The battery needs replacement every 3-5 years (AGM) or 8-12 years (LiFePO4). Solar panels last 25+ years.
Can I add mains backup later?
Yes. GAOQIAO controllers support dual-source input with automatic failover. Adding mains backup later is a simple electrical addition.
What is the actual battery cost over 10 years?
AGM: about $1,200 total (2 replacements at $600 each). LiFePO4: about $1,800 once (no replacements). Despite higher upfront, LiFePO4 is often cheaper over 10 years.
Does solar work in winter?
Yes, with proper sizing. GAOQIAO sizes systems for the worst-case winter month, not the annual average. This ensures reliable operation year-round.
Related GAOQIAO Products
These public GAOQIAO catalogue pages are related to this article.
- Traffic signal controllersWired and solar controllers with 6-56 outputs.
- LED signal heads200mm, 300mm, 400mm with EN12368 certification.
- Signal polesVertical, signal arm and double-arm configurations.
- Spare partsLED modules, lenses, visors and accessories.