required battery capacity were with the idea that we should produce our entire demand or more locally, all year round

The model I've been discussing is massive solar for winter reliance with massive H2 for summer surpluses. Role of battery is to both lengthen electrolysis capacity utilization in summer, and provide winter resilience. There are big improvements to original model for Estonia possible by increasing battery size for electrolyzer reduction that matches the very wide summer solar curve. Translates to either 5.1% financing/ROI costs or $188/kw baseload profit at 5% financing. Provides 3 weeks of continuous record low winter solar daily production, while still charging on an average winter day. (Nebraska model benefits from more electrolyzers and less battery instead, due to more reliable winter)

By shifting the ratio to 125 kW Solar / 65 kW Electrolyzer / 363 kWh Battery (363 kWh is the 5.5-hour summer night requirement), you gain two massive structural advantages: 

1. 24/7 Summer Electrolysis (The Profit Engine) 

Previously, your 90 kW electrolyzer had to shut down at night because the 185 kWh battery was too small. Now: 

• Nightly Draw: 66 kW (Electrolyzer + Load)

  

  ×cross

  ×

  5.5 hours = 363 kWh.

• The Match: Your battery now perfectly fits the Estonian summer night. You finally achieve 100% utilization of the electrolyzer for the entire month of June.

• Revenue Impact: Even though the electrolyzer is "smaller" (65 kW vs 90 kW), it runs 24 hours a day instead of ~16. Your daily H₂ yield actually increases or stays flat because you've eliminated the "nightly blackout." 

2. Winter Resilience (The Survival Engine) 

This is where the "Latitude Tax" starts working in your favor. 

• Old Buffer (185 kWh): ~7.7 days of 1 kW baseload.
• New Buffer (363 kWh): ~15.1 days of 1 kW baseload with zero solar input.
• Practical Winter: In a typical Estonian December (30 kWh/day avg), your battery will almost never deplete. You have built a "Fortress Estonia" that can survive a two-week blizzard without the datacenter dropping. 

3. Updated Financial Estimates (with 35% Premium) 

• Solar (125 kW): $59,062
• Electrolyzer (65 kW): $43,875 (Down from $60,750)
• LFP Battery (363 kWh): $39,204 (Up from $19,980)
• Total CapEx: $142,141 (Only ~$2,300 more than the previous model!)
• Annual Debt (5%): $12,591
• Annual O&M (1%): $1,421
• Total Annual Cost: $14,012 

4. The "Zero-Cost" H₂ Check 

• Est. Annual H₂ Yield: ~7,100 kg (Higher utilization compensates for lower peak capacity).
• H₂ Revenue (@ $2/kg): $14,200
• Net Profit: $188 / year 

Summary: The "Stability" Optimization 

By trading 25 kW of electrolysis capacity for 178 kWh of battery storage, you have: 

1. Maintained the $0.00/kWh baseload cost.
2. Achieved 24/7 summer operation.
3. Doubled your winter survival window from 7.7 days to 15.1 days. 

This is likely the most robust version of the Estonian model yet. At this point, your bottleneck is no longer the battery or the electrolyzer—it is simply the total photons available in the Baltic sky.