Open Questions¶
Questions that need research but aren't urgent. Add questions here during research sessions and tackle them when priorities align.
Organization¶
Questions are grouped by topic. When a question is answered, move the findings to the relevant research document and remove it from this list.
Brine Processing & Byproducts¶
If the CaCO3 isn't precipitating in the MED system, how do we collect it?
- Context: MED thermal process may not automatically precipitate calcium carbonate. Need to investigate collection methods if it remains dissolved in brine.
- Related files: research/brine-byproducts-fractional-crystallization.md
- Priority: Medium
- Added: 2026-02-06
Are the pond sizes correct for the amount of evaporation that needs to happen in each? ✅ RESOLVED 2026-02-06
- Resolution: NO - original design (4 ponds @ 25 m² each = 106 m²) did NOT account for residence time requirements. Corrected configuration: 7 ponds totaling 204 m² (CaCO₃ 4m², four concentrators 144m² batch/rotating, two crystallizers 50m² batch/rotating). Batch operation with rotating cycles provides continuous brine processing. Concentrators need 33-day cycles (10 fill + 21 evap + 2 transfer), requiring 4 ponds offset by 8 days with 1-day overlaps for buffer.
- See: Updated calculations in research/homestead-scale-system.md and research/homestead-system-flowchart.md
Construction & Infrastructure¶
What's the deal with the greenhouse roof? ✅ RESOLVED 2026-02-06
- Resolution: Greenhouse roof must be transparent glazing (70-80%) + solar panels (20-30%). Green roofs with soil cover are appropriate for processing buildings (RO, BSF, mushrooms) and livestock shelters, but NOT for the greenhouse. See research/below-grade-construction-analysis.md for details.
- Related files: research/homestead-scale-system.md, research/below-grade-construction-analysis.md
Should salt evaporation ponds be moved to rooftops instead of ground level? ✅ RESOLVED 2026-02-07
- Resolution: YES - rooftop configuration finalized. Salt ponds now implemented on both roofs (194 m² total split across processing + livestock roofs). Each roof gets 97 m² (2 concentrators @ 36 m² each + 1 crystallizer @ 25 m²). Only CaCO₃ settling pond (10 m²) + bitterns tank on ground.
- Final configuration:
- Processing roof: Concentrators 2A, 2B (72 m²) + Crystallizer A (25 m²) = 97 m²
- Livestock roof: Concentrators 2C, 2D (72 m²) + Crystallizer B (25 m²) = 97 m²
- Ground: CaCO₃ settling pond (10 m²) + bitterns storage tank only
- Land footprint reduction: 204 m² → 10 m² ground (95% reduction)
- Key benefits achieved:
- Self-contained flow per roof (no cross-roof brine transfers)
- Evaporative cooling: 273 kWh/day time-averaged (7.8× facility cooling need)
- Eliminates green roof irrigation (60-100 L/day savings)
- Material handling: Weekly incremental harvest + gravity chute system (safe operation)
- Implementation details:
- Structural loading: 500 kg/m² (within roof capacity)
- Double-liner system with leak detection
- Fall protection and safety railings included in design
- Gravity chute salt harvest system ($800-2,000) eliminates heavy lifting
- Related files: research/rooftop-salt-pond-design.md (comprehensive analysis), research/homestead-scale-system.md (finalized configuration), research/salt-market-analysis.md (economics)
- Updated: 2026-02-07
Energy Systems¶
Can we use excess solar thermal capacity to process BSF outputs? ✅ ANSWERED 2026-02-06
- Resolution: YES - BSF larvae heat treatment (0.5-0.8 kWh/day) and frass pasteurization (2-3 kWh/day) documented in research files. Uses 19-27% of available capacity (17 kWh/day), leaving 12-14 kWh/day excess.
- See: research/dual-purpose-solar-thermal-pasteurization-med.md (Finding 7), research/chicken-seaweed-bsfl-livestock-manure.md (updated processing protocol)
What additional uses exist for excess solar thermal capacity? ✅ RESOLVED 2026-02-06
- Resolution: Expanded solar thermal system from 6 m² to 24 m² (4× scale-up) to support major thermal loads:
- 3 RV absorption fridges: 36 kWh/day (replaces propane/electrical, saves 7.8 kWh/day electrical capacity)
- Domestic hot water (DHW): 5.2 kWh/day (150 L/day at 50°C for 8-10 people)
- Mushroom + BSF processing: 3.3-4.6 kWh/day (existing loads)
- Total thermal demand: 49.0-50.3 kWh/day
- Summer surplus: 14-16 kWh/day excess feeds waste heat recovery cascade system
- Key benefit: Frees up 12.6 kWh/day (40%) of electrical capacity by shifting major loads to thermal storage
- Cost: $8,850-14,700 expansion
- Economics: Better than all-electric (similar cost, longer lifetime), saves $13,700-19,100 vs propane over 10 years
- See: research/solar-thermal-expansion-design.md (comprehensive design), research/rv-fridge-solar-thermal-retrofit.md (fridge retrofit), research/waste-heat-recovery-cascade-system.md (summer surplus uses)
- Updated: research/homestead-scale-system.md (capital costs, energy section)
What cooking methods does solar thermal support at 60-100°C?
- Context: With expanded solar thermal system, could solar thermal cooking reduce electrical load?
- Hot water at 60-100°C can likely do: boiling, simmering, stewing, steaming, slow-cooking, sous vide
- Probably CANNOT do: frying (needs 150-180°C oil), baking (needs 150-200°C dry heat), searing/browning (needs >150°C surface temp)
- Research needed: Practical solar thermal cooking systems, what % of daily cooking needs could be met, equipment design/cost
- Related files: research/solar-thermal-expansion-design.md
- Priority: Low (nice-to-have, not critical for system viability)
- Added: 2026-02-06
How much wind power is available in Baja California coastal areas and how could we leverage it? ✅ ANSWERED 2026-02-06
- Resolution: Baja California Pacific coast has good wind resources (>6 m/s average, 25% capacity factor). Mechanical windmills are superior to wind turbines for pumping applications. Best opportunity: Windmill aerator for aquaponics (proven commercial technology, eliminates 1.5-2.0 kWh/day load = 26-35% of electrical demand, $3,500-5,000 cost, 5-7 year payback). Seawater intake pump viable but weak economics (12-20 year payback). Direct wind-to-RO too complex for homestead scale. Hybrid wind-solar approach provides best 50-year lifecycle economics and resilience. Next step: 3-6 month on-site wind assessment before windmill investment.
- See: research/mechanical-wind-power-pumping-aeration.md for comprehensive analysis
- Related files: research/homestead-scale-system.md (energy budget), 00-development-roadmap.md (Phase 1 energy system)
Water Systems¶
(No open questions)
Agriculture & Livestock¶
What are the complete livestock feed requirements (including fish) and how much outside resource is necessary? ✅ RESOLVED 2026-02-06
- Resolution: Complete feed budget analysis shows 42% overall self-sufficiency from on-site sources (BSF, seaweed, browse). Breakdown: Fish 49% self-sufficient (BSF larvae), Chickens 30% self-sufficient (BSF larvae), Ruminants 90-95% self-sufficient (seaweed/browse). External feed costs: \(1,860-2,110/year (\)155-176/month). Optimization pathway to 60-80% self-sufficiency identified through Phase 2 fodder trees and Phase 3 Three Sisters grain production.
- See: research/feed-budget-self-sufficiency-analysis.md for complete analysis
Economics & Markets¶
(No open questions)
Site Selection & Geology¶
(No open questions)
Regulatory & Compliance¶
(No open questions)
Usage Notes¶
When adding a question: - Include context about why it matters - Link to related research documents - Assign a rough priority (Low/Medium/High/Critical) - Add date for tracking
When answering a question: - Document findings in the appropriate research file - Add a brief note here about where the answer lives - Remove the question or mark as resolved
Question priorities: - Critical: Blocks current design decisions - High: Needed for next phase of work - Medium: Important but work can proceed without it - Low: Nice to know, long-term consideration