Integrated Residential PV & Energy Storage
In 2025, with continuously rising global electricity prices and the phasing out of net metering, integrated storage has become the most cost-effective energy investment. GRAMUU helps users upgrade "rooftop PV" to "24-hour green electricity self-circulation."
Core Advantages
Modular Expansion
5kWh per cabinet, scalable up to 100kWh. Supports stacking of 10 cabinets, suitable for everything from one-bedroom apartments to 15kW villas.
Grade A LiFePO₄ Cells
>8000 cycles @ 80% DOD, wide operating temp (-20℃ to 55℃), fully certified by UL1973, IEC62619, CE, and UN38.3.
UPS-Level Switching
≤10ms seamless off-grid switching. Ensures continuous power during outages, California PSPS, and Grid Instability.
Smart App + TOU
AI algorithm automates charging based on local time-of-use prices, saving an additional 15-30% on annual electricity bills.
Plug-and-Play EV
7kW/11kW Type2 optional. V2H/V2G firmware reserved for future vehicle-to-grid connectivity upgrades.
Typical Application Scenarios
Self-consumption
Store excess solar power during the day in batteries, discharge during peak evening hours to offset high TOU prices.
Peak shaving & valley filling
Capitalize on price differences (e.g. Texas > $0.3/kWh). Payback period in 2 years. Energy storage + inverter = 24/7 electricity freedom.
Emergency backup power
Critical for hurricane seasons or ice storms. 10ms switching ensures uninterrupted power for fridges, internet, and ventilators.
Green electricity arbitrage
UK Octopus Agile dynamic pricing: charge when price < 0, discharge when > 0.35 £/kWh. Annual return 7%+.
Technical Specifications
| Model | GRAMUU PowerWall 5 | PowerWall 10 | PowerWall 15 |
|---|---|---|---|
| Available energy | 5.12kWh | 10.24kWh | 15.36kWh |
| Rated power | 2.5kW | 5kW | 7.5kW |
| Peak power | 5kW (10s) | 7kW (10s) | 10kW (10s) |
| Voltage range | 44.8-58.4V | 44.8-58.4V | 44.8-58.4V |
| Cycle life | >8000 cycles | >8000 cycles | >8000 cycles |
| Protection level | IP65 | IP65 | IP65 |
| Operating temperature | -20℃~55℃ | -20℃~55℃ | -20℃~55℃ |
| Certification | CE/UL1973/IEC62619/UN38.3 | Same | Same |
Frequently Asked Questions
Using a California TOU-4 price difference of $0.32/kWh and 30% federal ITC, a 10kWh system breaks even in ~5.8 years; or 4.2 years with SGIP rebates.
Compared to NCM, LiFePO₄ has a thermal runaway temperature >270℃, is cobalt/nickel-free, passes UL9540A combustion tests, and is safe for indoor wall-mounting.
Yes, supports both AC-Coupled and DC-Coupled access. Compatible with Enphase, SMA, SolarEdge, Huawei, and more.
Hardware has reserved V2H/V2G interfaces. OTA update expected Q2 2026. Ready for UK National Grid DFS and California CAISO VPP programs.
10-year whole unit warranty, 24/7 online service. Local warehouses in US/EU/South Africa + certified engineers. On-site arrival in as little as 48 hours.
Take Action Now
Get the 2025 residential PV energy storage solution + local subsidy list. OEM branding, white label APP, and API secondary development supported.