Solar energy storage solutions

P Peter Lu Energy Storage Product Manager, GreenMore · Battery energy storage systems A Battery Energy Storage System (BESS) stores electricity in rechargeable batteries and releases it later when it is needed. Homes use it with solar to use more of their own generation and keep power on during outages; businesses and utilities use it to cut peak demand costs and support the grid. As solar and wind grow, battery energy storage systems have become a standard part of modern energy management rather than a niche option. What a BESS Does At its simplest, a BESS captures energy that is available now so it can be used later. Its main jobs are: Storing excess energy from solar panels or the grid during low-cost or off-peak periods. Releasing that energy during peak demand, at night or during a power outage. Balancing supply and demand to improve efficiency, power quality and reliability. How a BESS Works A battery stores direct current (DC), while most homes and businesses run on alternating current (AC), so power electronics handle the conversion in both directions: Charging — electricity from solar panels or the grid charges the battery, with the converter rectifying AC to DC where the source is the grid. Discharging — when energy is needed, an inverter converts the battery's DC back to AC for household or business use. Management — a Battery Management System (BMS) monitors cell voltage, temperature and state of charge, balances the cells and protects against overcharge, over-discharge and overheating. Main Components Component Role Battery cells and modules Store the energy; most GreenMore systems use lithium iron phosphate (LiFePO4) cells BMS Monitors and balances cells, enforces safety limits Inverter / PCS Converts DC to AC and back, manages grid connection EMS / controls Schedules charging and discharging and provides monitoring Enclosure Protects the system; wall-mounted, rack or outdoor cabinet depending on use Key Benefits Lower energy costs — store low-cost or surplus energy and use it instead of buying at peak prices. Less reliance on the grid — paired with solar, a battery increases self-consumption and reduces exposure to price changes. Backup power — keep essential loads running during outages or on unstable grids. Cleaner operation — support higher use of solar and wind instead of fossil-fired peaking generation. Power station-grade containerized batteries Where Battery Storage Is Used Residential. Home systems store rooftop solar for evening use and backup. GreenMore offers wall-mounted, stackable and all-in-one storage in common capacities around 5 kWh, 10 kWh, 15 kWh and 20 kWh, along with customized sizes, for households with solar. Commercial and industrial. Businesses use BESS for peak shaving, demand-charge management and reducing overall energy costs, as well as for backup at sites that cannot afford downtime. Microgrids and weak-grid areas. Combined with solar or wind, battery storage provides reliable power in remote locations and regions with an unstable grid, reducing dependence on diesel generation. GreenMore Storage Solutions GreenMore supplies a range of residential and commercial battery storage, from compact wall-mounted units to scalable cabinet and containerized systems for larger projects. Products use lithium iron phosphate chemistry with BMS protection and monitoring, and the team works with distributors, resellers and solar integrators to match capacity and configuration to each application. For help choosing a system, contact the GreenMore team or email export@gmsolarkit.com. Frequently Asked Questions What is the difference between a battery and a BESS? A single battery or cell only stores energy. A BESS is the complete system — battery modules, BMS, inverter or power-conversion equipment, controls and enclosure — that can be safely charged, discharged and connected to a home, business or grid. Does a BESS work without solar panels? Yes. A BESS can charge from the grid during low-cost periods and discharge during peak hours or outages. Pairing it with solar adds self-consumption and longer-term savings, but solar is not required for the system to operate. How long can a BESS power a home? It depends on the battery capacity and which loads are used. A typical home battery can run essential loads such as lights, communication and a refrigerator for several hours during an outage; pairing it with solar to recharge can extend that. Whole-home, high-demand use will shorten runtime considerably. What battery chemistry is most common in storage systems? Lithium iron phosphate (LiFePO4) is widely used for stationary storage because of its stable chemistry, long cycle life and tolerance of regular charging and discharging. The BMS and enclosure design remain important for overall safety regardless of chemistry. P Peter Lu Energy Storage Product Manager, GreenMore Peter works with distributors, installers and project owners to select battery storage for residential, commercial and microgrid applications. He helps customers match capacity, chemistry and power conversion to their loads and use patterns, and explains how a BESS operates day to day so purchasing and installation decisions are based on real requirements.

P Peter Lu Energy Storage Product Manager, GreenMore Adding battery storage to a solar system is possible in most cases, but the path depends on what inverter you have today. Some systems are battery-ready and accept a DC-coupled battery directly; others need a second inverter for an AC-coupled retrofit. The first job is to identify which situation you are in, then choose the battery type, capacity and operating mode that match your goals. Why add a battery in the first place A battery changes what you can do with the solar energy you generate. The typical reasons are: Higher solar self-consumption. Store excess daytime generation instead of exporting it, and use it in the evening. Time-of-use savings. Shift stored energy into peak tariff periods to reduce grid imports. Backup power. Keep essential loads running during an outage — but only if the inverter and battery are configured for backup. A standard grid-tied battery system shuts down during an outage unless it has backup capability and an islanding relay. Be clear about which of these is your main goal. Backup, in particular, has specific hardware requirements and cannot be assumed from "solar plus battery" alone. The key question: what inverter do you have? Your existing inverter determines how the battery connects. There are three common situations. Existing setup How a battery is added Hybrid or battery-ready inverter (has a DC battery port or battery terminals) DC-coupled battery connects directly to the inverter. This is the cleanest retrofit if the battery is on the inverter's compatibility list. Standard grid-tied string inverter (no battery port) AC-coupled retrofit: keep the existing inverter and add a battery storage inverter (often called a battery inverter or storage system) on the AC side. Alternatively, replace the inverter with a hybrid unit and fit a DC-coupled battery. Microinverter or optimizer system AC-coupled only. Each panel already converts DC to AC at the module level, so the battery connects through a separate AC battery system. DC-coupled vs AC-coupled The two coupling methods describe where the battery sits relative to the inverter. Both work, but they have different efficiency, cost and retrofit implications. Attribute DC-coupled AC-coupled Connection Battery connects on the DC side, sharing one hybrid inverter with the solar array Battery has its own inverter and connects on the AC side alongside the existing solar inverter Efficiency One DC-to-AC conversion for stored solar; slightly higher round-trip efficiency Solar is converted to AC, then back to DC for storage, then to AC again; more conversion steps Retrofit suitability Best for new builds or when replacing the inverter Best for retrofits where the existing inverter is young and working well Cost Single inverter; often lower total cost if you are starting fresh Two inverters; but avoids replacing a working unit If your existing inverter is near the end of its warranty or you already planned to replace it, moving to a hybrid inverter with DC-coupled storage is usually the tidier solution. If the inverter is relatively new and efficient, AC coupling preserves that investment. Off-grid/grid-connected solar energy storage architecture principles Choosing the battery form factor Stationary home batteries come in three common forms. The choice depends on available space, future expansion plans and how much of the system you want integrated. Form factor Best for Wall-mounted battery Limited floor space; garage or utility-room walls; fixed capacity Stacked (modular) battery Starting small and adding modules later; capacity growth without extra footprint All-in-one system (battery + hybrid inverter integrated) Simplest installation and commissioning; single supplier responsibility Sizing the battery Capacity should follow your load profile and goal, not the largest unit available. For self-consumption: size usable capacity around the evening load that is not covered by solar — commonly 5 kWh to 15 kWh for a single-family home. For backup: list critical loads and multiply wattage by required hours of autonomy, then divide by DoD and inverter efficiency. Check power, not just energy. The battery and inverter must deliver enough continuous kW for simultaneous loads and enough peak kW for motor starting. A large kWh battery with a small inverter still cannot run the whole house at once. LFP (LiFePO4) is the standard chemistry for stationary storage because of its cycle life and thermal stability. The exact cycle count depends on DoD and operating conditions, so compare cycle curves on the datasheet rather than relying on a single headline number. Installation steps Audit the existing system. Record inverter model, PV array size, system voltage, and confirm whether the inverter is battery-compatible. Gather interval electricity use if possible. Confirm compatibility and permits. Verify the battery is on the inverter's approved list (for DC coupling) or that the two inverters are configured for AC coupling. Check local permits and grid interconnection rules. Install and commission. Mount the battery, run DC or AC cabling with proper protection, and configure charge/discharge settings and backup transfer if applicable. Set the operating mode and schedule. Self-consumption, time-of-use or backup priority — and review performance after the first few weeks against the expected savings. Battery work involves high-voltage DC and grid-connected wiring; it should be carried out by a qualified installer who can also certify the installation for warranty and insurance purposes. To explore options, start with the all-in-one energy storage system, the off-grid solar storage system, and the full lineup on the home energy storage category page. For help deciding between DC and AC coupling, use the contact page. FAQ Can I add a battery to any existing solar system? Almost always, but not always in the same way. Hybrid inverters accept a DC-coupled battery; standard string inverters and microinverter systems need an AC-coupled battery system. In rare cases an inverter is so old or proprietary that replacing it with a hybrid unit is the most practical route. Will my battery power the house during an outage? Only if the system is designed for it. A grid-tied battery without backup certification and an islanding relay must shut down during an outage for safety. If backup is important, specify backup-capable hardware and decide which circuits are protected. Is it better to replace my inverter or add an AC-coupled battery? If the inverter is within its warranty and working well, AC coupling usually makes sense and avoids waste. If it is aging, inefficient, or out of warranty, replacing it with a hybrid inverter and a DC-coupled battery gives a cleaner, single-system solution. How long can a battery run my home without solar or grid? It depends on the battery capacity and which loads you keep on. A 10 kWh battery might run essential loads (fridge, lights, internet, communications) for roughly 8 to 12 hours; a 20 kWh battery roughly double that. These are rough estimates — the real number comes from your actual load wattage and the battery's DoD. P Written by Peter Lu — Energy Storage Product Manager, GreenMore Peter works with distributors, installers and system integrators to size residential and commercial storage around real load profiles. He focuses on LiFePO4 systems that match the inverter, grid rules and backup needs of each destination market.