Off-Grid Without Solar: HHO + Wind

For cloudy climates, HHO pairs with wind power. Generate hydrogen when wind blows, use it anytime. This post details our design for a solar-free off-grid system in the Pacific Northwest.

◉ The Problem with Solar Here

Seattle area gets 150+ rainy/cloudy days per year. Solar panels produce maybe 20% of rated capacity during the grey months. You'd need massive battery banks to bridge multi-day cloudy stretches.

But wind? Wind blows year-round, often stronger during storms when solar fails. A 3kW wind turbine in our area produces more annual energy than a 6kW solar array.

◉ Energy Storage via Hydrogen

HHO acts as energy storage without lithium batteries:

1. Wind blows: Turbine generates excess electricity
2. Electrolysis: Excess power splits water into H₂ and O₂
3. Storage: Hydrogen stored in low-pressure tanks (5-10 bar)
4. On demand: Fuel cell or modified generator burns H₂ for power

The key insight: hydrogen stores indefinitely. No self-discharge like batteries. Generate all winter, use all summer if needed.

◉ System Architecture

Wind Turbine (3kW)
        │
        ├──► Charge Controller
        │           │
        │    ┌──────┴──────┐
        │    │             │
        ▼    ▼             ▼
    DC Bus (48V)    Electrolyzer
        │              │
   House Loads    H₂ Storage
        │              │
   ▼ Inverter         │
        │              │
    AC Loads    Fuel Cell/Genset
                       │
                   DC Bus ◄─┘

The DC bus is the heart. Everything connects to 48V DC — turbine, loads, electrolyzer, fuel cell. The system software (written in Lateralus, of course) decides where power flows.

◉ Component Selection

Wind Turbine

We're using a Primus AIR 40 with custom controller. 400W at 12.5 m/s wind, rated to 40 mph storms. The stock controller is replaced with our own MPPT unit.

Electrolyzer

DIY PEM electrolyzer using Nafion membrane and titanium plates. Currently 500W capacity, produces ~150 L/hr H₂ at full power. Efficiency around 65%.

Storage

Three 100L tanks at 10 bar pressure = 3,000 liters H₂ stored. That's roughly 9 kWh of recoverable energy via fuel cell, or 30 hours of baseline loads.

Fuel Cell

Horizon H-1000 PEM fuel cell, 1kW output. Clean, silent, 50% efficient. For higher loads, we fall back to a propane generator that can also burn H₂.

◉ Control System

The brain is a Lateralus program on a Raspberry Pi 4:

import sensors
import control

fn energy_dispatch_loop() {
    loop {
        let wind_power = sensors.read_wind_power()
        let load_demand = sensors.read_load_demand()
        let h2_pressure = sensors.read_h2_pressure()
        let battery_soc = sensors.read_battery_soc()

        // Decision pipeline
        let action = (wind_power, load_demand, h2_pressure, battery_soc)
            |> calculate_surplus()
            |> match {
                Surplus(watts) if h2_pressure < 10 =>
                    Action::Electrolyze(watts),
                Surplus(watts) =>
                    Action::DumpLoad(watts),  // Heat water
                Deficit(watts) if battery_soc > 20 =>
                    Action::UseBattery,
                Deficit(watts) if h2_pressure > 2 =>
                    Action::StartFuelCell,
                Deficit(_) =>
                    Action::AlertLowEnergy,
            }

        control.execute(action)
        sleep(1000)  // 1 Hz control loop
    }
}

◉ Real Performance Data

From December 2025 (our worst solar month):

Metric	Value
Wind generation	187 kWh
House consumption	142 kWh
H₂ produced	8,400 L
H₂ consumed	6,200 L
Grid backup used	0 kWh

Zero grid usage in December. The system actually built up hydrogen reserves.

◉ Economics

Total system cost: ~$8,500 (turbine $2k, electrolyzer $2k, fuel cell $1.5k, storage/plumbing $2k, control system $1k).

At $0.12/kWh grid rates, payback is ~6 years. But the real value is resilience — we've run through three multi-day power outages without noticing.

◉ Safety Notes

Hydrogen requires respect:

• All storage is outdoors in a ventilated shed
• Pressure relief valves on every tank
• H₂ detector in shed triggers automatic vent fans
• All electrical connections are explosion-proof rated
• Fuel cell exhaust is just water vapor — safe indoors

◉ Lessons Learned

1. Electrolyzer efficiency matters. Going from 50% to 65% efficiency cut our storage needs by 30%.
2. Low-pressure storage is safer. 10 bar is nothing compared to industrial 350+ bar tanks. Standard propane fittings work.
3. Wind is underrated. A good site (exposed hilltop, coastal, plains) makes wind viable even in "solar country."
4. Lateralus pipelines map perfectly to energy flows. The control code basically wrote itself.

See the HHO page for more details and build documentation.