This guide is aimed at installers who plan and install battery storage in commercial projects. It explains economics, sizing and selection — manufacturer-independent and from a PV wholesaler's perspective.
When is battery storage worthwhile in commercial projects?
Battery storage pays off in commercial projects mainly through three levers: higher self-consumption of PV power, capping expensive load peaks (peak shaving) and backup-power capability. Because commercial electricity tariffs usually include a demand charge (€/kW peak load) on top of the energy price, capping peaks alone noticeably reduces grid costs.
What is peak shaving — and how does it cut electricity costs?
Peak shaving is the targeted capping of short-term load peaks using the storage system. Because the demand charge is calculated from the highest measured quarter-hour load, intercepting even individual peaks significantly reduces grid charges — the storage supplies power from the battery instead of the grid in those moments.
How do installers size a commercial storage system?
Sizing a commercial storage system is based on the load profile (quarter-hour values), the PV output and the project goal. Unlike residential, it is the load profile — not annual consumption — that is decisive.
- Load profile & peaks of the business (for peak shaving)
- PV output and generation profile
- Goal: self-consumption, peak shaving or backup power
- planned charging infrastructure or process loads
- available grid connection
DC- or AC-coupled commercial storage?
A DC-coupled storage system is connected directly to the PV array via a hybrid inverter and is more efficient for pure PV self-consumption. An AC-coupled storage system charges on the grid side and can be flexibly retrofitted, including to existing systems or for pure load management.
| Criterion | DC-coupled | AC-coupled |
|---|---|---|
| Efficiency (PV self-consumption) | higher (one conversion) | lower (two conversions) |
| Retrofit to existing system | limited | flexible |
| Load management without PV | less suitable | well suited |
Which storage solutions does PVSelected carry for commercial projects?
PVSelected carries scalable storage solutions for the commercial power range. The Sigenergy system covers commercial projects with the SigenStor Energy Controller (three-phase up to 30 kW) and the C&I / SigenStack solutions; the SigenStor BAT modules can be cascaded for higher capacities.
What should installers consider when selecting?
- Scalability — modular expansion with the project
- Cycle stability & warranty — designed for commercial load cycles
- Backup power — if required
- Monitoring / energy management (EMS) — for peak shaving and reporting
- System compatibility — inverter, storage and charging from one system
Frequently asked questions about commercial storage
Does PVSelected supply commercial storage to end customers?
No — PVSelected is a pure B2B wholesaler and supplies installers and trade partners only.
Does PVSelected help with sizing commercial projects?
Yes, through technical support and the configurator for project-specific system sizing.