Best Victron system configuration for an off-grid lighthouse with generator backup and redundancy

Q&A and troubleshooting
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1

Hello,

I’m designing an off-grid solar power system for a maritime lighthouse (El Hierro, Canary Islands).
The site has no grid connection, but there is a diesel generator available for backup.

The proposed setup so far:

  • Battery bank: 24 × 2 V – 3750 Ah (lead-acid stationary), connected in series → 48 V / 180 kWh gross

  • PV array: 12 × 480 W panels → 5.76 kWp total

  • Expected loads: mainly lighting, communications, and control systems (moderate continuous power, critical uptime)

I initially considered using a Victron RS 48/6000 Smart Solar inverter, but I’d like expert opinions on whether this is the best choice — or if another configuration (for example, Quattro 48/5000 or 10000 VA, with external MPPTs) would provide better redundancy, generator integration, and long-term reliability in a harsh maritime environment.

Could you please advise on:

  1. The optimal inverter/charger + MPPT combination for this system size (48 V, 5.76 kWp, 180 kWh batteries)?

  2. Recommendations for redundancy — e.g., two smaller inverters in parallel vs. one larger unit?

  3. Best practices for generator integration and automatic start/stop using Victron components?

  4. Any specific considerations for marine or corrosive environments?

Thanks in advance for your guidance.

2

Please DON’T use Lead Acid batteries in this situation. Either use Sodium ion or Lithium Ion batteries instead. Both are as cheap as Lead Acid, and will last far longer without the environmental Hazard, corrosive and explosive gas problems. This will also help with corrosion protection, as the battery room won’t require so much ventilation.

Redundancy: 100% on battery and inverter systems, 150% on charging - Make sure that there are at least 3 different charging options.

Both inverters should be capable of carrying the full load. I would use external mppt’s as it will be easier to include diversity, and easier for replacements

If the Generator is 3 phase, then a 3 phase arrangement of inverters will cover the charging and inverting requirement, The light and communications systems should be run directly from DC using DC/Dc converters if voltage matching is needed.

3

Who much power did the diesel generator have?