Open Source Electrolyzer

https://chatgpt.com/share/69b78df5-6188-8010-8d76-08b5073da11a

No Exotic Materials Required

No exotic manufacturing is required - no exotic membranes outside of off-the-shelf Zirfon separator which appears to contribute 10% to the cost.

$10-20k for a 100kW stack. Payback of one year with 6 hour solar, quicker with wind.

Materials Breakdown and Sourcing

100 kW Open Source Alkaline Electrolyzer Stack – Bill of Materials

Component	Specification	Quantity	Typical Cost Range	Example Supplier / Source	Link
Nickel Foam (Cathode)	1–2 mm thick, 20–60 PPI, >99% Ni	~12 m²	$300–$1,500	MTI Corporation	https://mtixtl.com/products/0-5-mm-thick-nickel-foam-for-battery-cathode-substrate-or-solid-state-electrolyte-support-l-1000-x-w-200-mm-eq-bcnf-05m
Nickel Foam (Anode substrate)	same spec as cathode	~12 m²	$300–$1,500	Goodfellow	https://www.goodfellow.com/usa/nickel-sizes-foam-group
Separator (Zirfon-type diaphragm)	~0.3–0.5 mm polysulfone + zirconia composite	~12 m²	~$1,800	Agfa Zirfon PERL	https://www.agfa.com/zirfon/
Cell Frames / Spacers	HDPE / polypropylene plates	~100 pieces	$500–$1,500	McMaster-Carr plastic sheet	https://www.mcmaster.com/polypropylene-sheets/
End Plates	Carbon steel or stainless plate	2 pieces	$200–$600	Online Metals steel plate	https://www.onlinemetals.com/
Gaskets	EPDM or PTFE sheet 1–2 mm	~100 sets	$100–$400	McMaster-Carr gasket sheet	https://www.mcmaster.com/epdm-rubber/
Current Collectors	Nickel sheet or nickel mesh	~2–4 m²	$200–$800	Alfa Aesar nickel sheet	https://www.fishersci.com/shop/products/nickel-foil/AA43098
Busbars	Copper bar stock	~3–5 kg	$100–$300	McMaster copper bar	https://www.mcmaster.com/copper-bars/
Electrolyte	Potassium hydroxide (KOH), 25–30 wt%	~100–150 L solution	$200–$500	Lab Alley KOH	https://www.laballey.com/products/potassium-hydroxide-koh
Anode Catalyst Bath Chemical	Nickel sulfate (NiSO₄)	~1–2 kg	$50–$200	Sigma-Aldrich	https://www.sigmaaldrich.com/US/en/product/aldrich/656895
Anode Catalyst Bath Chemical	Ferrous sulfate (FeSO₄)	~1 kg	$20–$80	Fisher Scientific	https://www.fishersci.com/shop/products/ferrous-sulfate-heptahydrate
Anode Catalyst Bath Chemical	Boric acid (H₃BO₃)	~1 kg	$10–$40	Sigma-Aldrich	https://www.sigmaaldrich.com/US/en/product/sial/695092

Summary of Major Materials

100 kW Open Source Alkaline Electrolyzer Stack Summary

Material	Amount
Nickel foam	~24 m² total
Zirfon separator	~12 m²
Plastic frames	~100
Steel end plates	2
Gaskets	~100 sets
KOH electrolyte	~100–150 L

Corrected Stack Materials and Fabrication Budget (100 kW Alkaline Electrolyzer)

Detailed Stack Cost Breakdown (Prototype-Realistic)

Category	Description	Estimated Cost Range
Nickel Foam Electrodes	Cathode + anode substrate (~24 m² total)	$600–$3,000
Separator (Zirfon)	~12 m² diaphragm material	~$1,800
Electrolyte + Chemicals	KOH + NiSO₄ + FeSO₄ + boric acid	$200–$600
Gaskets	~100 cell gasket sets (EPDM/PTFE)	$150–$500
Plastic Frame Stock	HDPE/PP sheets for ~100 frames	$400–$1,200
Current Collectors + Busbars	Nickel sheets/mesh + copper busbars + terminals	$500–$2,000
End Plates + Compression Hardware	Steel plates, tie rods, bolts, springs	$500–$2,000
Fabrication + Machining	CNC cutting, drilling, finishing of frames and plates	$1,000–$3,000
Scrap, Yield Loss, Shipping, Contingency	Material losses, damaged parts, supplier overhead	$1,500–$4,000
Total Estimated Stack Cost (Corrected)	Prototype-scale, materials + fabrication	$6,650 – $19,100

Interpretation

Layer	Meaning	Cost Range
Raw materials only	Just purchased materials without fabrication overhead	~$3,600 – $8,400
Practical prototype build	Includes machining, scrap, and assembly realities	~$6,500 – $15,000 (typical target)
High-friction prototype case	Inefficient sourcing, mistakes, iteration cycles	Up to ~$19,000

Key Insight

The earlier mismatch came from mixing two different accounting layers:

• The visible table showed mostly **raw materials**
• The total implicitly included **fabrication, waste, and prototype inefficiencies**

A correct engineering budget must explicitly include:

• manufacturing steps (cutting, machining, assembly)
• process losses (scrap, rework)
• procurement overhead (shipping, minimum orders)
• structural components (compression system, busbars)

Without these, the estimate will systematically understate real build cost.

For planning purposes:

• **Use ~$7k–$15k as a realistic first prototype stack target**
• Expect cost reduction only after:

 * volume purchasing
 * simplified geometry
 * process standardization