Picea ensures reliable winter energy supply by storing surplus solar energy as hydrogen during summer. When sunlight is scarce, the stored hydrogen is fed into a fuel cell to generate electricity for heating (via heat pumps) and domestic use. The system’s waste heat recovery captures up to 90% of energy from fuel cell operation, directly heating water or space. In cold months, Picea can cover 100% of a home’s electricity and 50% of heating needs, reducing reliance on fossil fuels and mitigating winter energy price spikes. This aligns with Germany’s 2025 mandate requiring 65% renewable heating in new buildings.