There is no single renewable energy configuration that suits every commercial and industrial (C&I) site. Load profile, available space, budget and grid constraints all influence system design, but the starting point is more fundamental: how much independence does the business actually need?
The GoodWe article identifies five levels of energy independence, ranging from straightforward grid-tied solar to fully off-grid operation. Each brings different requirements for PV, battery energy storage systems (BESS), control and investment.
Five degrees of energy independence
At the simplest level, grid-tied solar generates electricity onsite when sunlight is available. Excess generation can be exported where permitted, while the grid supplies any deficit.
This can reduce exposure to electricity prices, but the installation remains dependent on the grid. During an outage, conventional grid-tied inverters also shut down.
Adding battery storage introduces further options:
- Limited backup: storage maintains selected critical loads during an outage
- Energy arbitrage: batteries charge when electricity is cheaper and discharge during higher-price periods
- Peak shaving: stored energy can reduce periods of high grid demand and associated demand charges
- Microgrid operation: solar, storage and other generation can maintain operations independently from the grid
- Off-grid operation: all electricity consumed onsite must be generated onsite
The appropriate level depends on the cost and operational consequences of losing grid power.
Using storage to manage energy costs
Flexible or dynamic tariffs create another role for batteries. Energy can be purchased and stored when prices are low, then used when grid electricity becomes more expensive.
For manufacturing businesses with high peak consumption, storage can also reduce demand charges.
GoodWe states that systems combining peak shaving and electricity arbitrage can potentially reach breakeven within five to 10 years, although it emphasises that amortisation depends heavily on the individual installation.
A smart energy management system (SEMS) becomes increasingly important as system complexity increases, coordinating PV generation, batteries and site loads.
When resilience requires a microgrid
Businesses requiring greater operational resilience need more than conventional backup.
A microgrid must maintain stable voltage and frequency as generation and demand fluctuate. This requires sufficient storage capacity and power output alongside grid-forming equipment such as appropriate power conversion systems (PCS).
Hospitals, campuses, industrial facilities and other critical operations may use this approach to maintain operation for hours or days. Backup generators can also be incorporated and managed alongside solar and storage.
True off-grid systems go further, removing the grid connection completely. Because solar generation alone cannot guarantee continuous supply, these systems generally require additional generation and redundancy.
Grid-forming control becomes critical
Independent operation requires further technical detail. When disconnected from the grid, the PCS must switch to voltage and frequency (V/F) control to maintain AC voltage amplitude and frequency.
Where multiple V/F-controlled inverters operate in parallel, communication between primary and secondary units helps maintain synchronisation, current sharing and system stability.
GoodWe offers C&I inverters between 30 kW and 125 kW alongside storage and PCS equipment. It also cites a 500 kVA on/off-grid switching cabinet for its ESA 125 kW / 261 kWh storage system.
These are company-specific product specifications.
Putting the concept into practice
GoodWe’s manufacturing site in Guangde, China provides an example of this integrated approach. The company says the site combines 4.7 MW of PV with 5.2 MWh of storage and an intelligent microgrid controlling generation, storage, EV charging and onsite consumption.
Nine C&I storage systems installed at the factory provide 1.125 MW of output and 2.35 MWh of storage capacity.
By mid-2025, GoodWe says renewable electricity accounted for 41 per cent of the facility’s total energy use.
For C&I operators, the wider lesson is that energy independence is not an all-or-nothing decision. The most appropriate system depends on how much grid exposure a business can accept, which operations must continue during outages and whether the investment is primarily intended to reduce costs, improve resilience or achieve both.
Explore the full insight from GoodWe on C&I solar, battery storage, microgrids and operational independence in PES Solar: https://pes.eu.com/exclusive-articles/commercial-resilience-and-operational-independence-in-ci-applications
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