Franklin Home Power Solution
For home batteries, AC-coupling allows solar energy to be stored in batteries by working with a standard grid-tied solar inverter. It serves as the building block for an AC-coupled home energy management and storage solution, particularly ideal for homes with an existing solar PV system, as it avoids the need for additional rewiring or replacing major components.
Solar panels produce direct current (DC) electricity, which is immediately converted into alternating current (AC) by the solar inverter to run home appliances. In an AC-coupled system, a solar inverter has already been installed. This AC power flows directly to home appliances or can be sent to the grid to earn credits. If there is excess solar energy, a battery inverter converts the AC power back into DC for battery storage. When the stored energy is needed, the battery inverter converts it back to AC for household use.
Key Components of an AC-Coupled Energy Management and Storage System
In an AC-coupled energy management and storage system, several key components work together to manage energy flow between solar panels, battery storage, and household loads.
Solar Inverter
The solar inverter converts the DC electricity generated by solar panels into AC electricity, which is suitable for powering household appliances and exporting to the grid.
Battery Inverter
The battery inverter/charger serves a dual purpose:
- Charging the Battery: It converts excess AC electricity from the solar inverter, grid or generator back into DC to store in the battery.
- Discharging the Battery: It converts stored DC electricity from the battery into AC for use in the home during periods of low solar production, time of use (TOU) power management, and utility outages.
Central Energy Controller
The central controller acts as the system's brain, coordinating the interaction between the power sources and household loads. It manages energy production, consumption, and storage levels to optimize efficiency.
During a grid outage, the central controller isolates the load panel and the PV inverter from the grid via an internal transfer switch, ensuring that home loads continue to receive power and avoid power back feed to the grid, which can otherwise pose a safety hazard for utility workers.
Devices such as the FranklinWH aGate perform these crucial functions, managing energy flow and maintaining high system performance.
Battery Storage Unit
The battery storage unit stores energy in DC form, allowing homeowners to utilize stored solar energy during nighttime or overcast days, to time shift utility energy in order to lower electricity bills, and to provide backup power during grid outages. The capacity and type of battery can vary based on the specific needs and design of the system.
For example, the FranklinWH aPower 2 features a 15 kWh storage capacity and 10 kW continuous output, powerful enough to provide whole-home backup for most homes.
Load Panel
The load panel contains circuits for the appliances and systems that need to remain powered during a grid outage. You can choose to have a whole-home backup (all house loads remain powered) or partial backup by setting up essential and non-essential load panels.
The essential load panel only contains circuits for critical loads that will be powered during a grid outage, such as refrigerators, lighting, computers, etc. The central controller ensures that, during an outage, these essential loads receive power from various power sources available, such as solar, battery, generator, or EV. The loads in the non-essential panel, on the other hand, will be disconnected during an outage.
Advantages of an AC Battery
The AC battery for a home energy management and storage system offers multiple advantages.
Ease of Retrofitting with Existing Solar Installations
One of the primary advantages of AC-coupling is its suitability for adding home battery storage to existing solar photovoltaic (PV) setups. An AC-coupled battery connects to the AC side of a home's power system. As it includes a dedicated inverter, it can be directly charged after the solar power has already been converted from DC to AC by the existing solar inverter, so it avoids significant modifications to the current infrastructure during system installation. This means saved labor and lower upfront costs.
Higher Flexibility and Compatibility
AC-coupled systems are compatible with a much wider range of solar inverters, providing greater flexibility in system design and component selection. This adaptability simplifies the process of upgrading or expanding energy systems, as components can be mixed and matched without compatibility concerns.
In addition, AC-coupled batteries can be installed at a considerable distance from solar panels in an electrical distribution grid, whereas DC-coupled batteries typically require proximity to the PV panels that charge them. This is because AC power experiences less voltage drop over distance compared to DC power.
FranklinWH aPower 2: The New AC Battery Marvel for Energy Management and Storage Solutions
The FranklinWH aPower 2 is the latest FranklinWH AC-coupled battery for homes, standing as a new standard for AC-coupled energy management and storage solution, with advanced features and innovations that lead the industry.
Leading-edge power and capacity: with 10 kW continuous power and 15 kWh capacity per unit, the aPower 2 is engineered to power your entire home.
15-year warranty: the aPower 2 offers a warranty that is 50% longer than the industry standard, ensuring extended longevity, reliability, and increased financial benefits.
Compatible with all solar inverter brands: the aPower 2 is designed to be agnostic to all solar inverter brands, allowing easy and streamlined system setup for both retrofit and new solar installations.
LFP cells for the highest safety: featuring LFP battery cells, the aPower 2 sets itself apart with unrivaled safety thanks to the exceptionally stable chemistry.
Unrivaled scalability: the aPower 2 can be stacked up to 15 units per aGate for a total of 225 kWh storage capacity.
Innovative thermal management technology: the fan-less natural cooling eliminates the risk of system failure by significantly and effectively improving heat dissipation. It also reduces noise and keeps it at merely 30 dBA. Internal heating also helps keep the batteries functioning in winter temperatures.
Integration with FranklinWH energy management controller: the intelligent aGate controller integrates aPower 2 with various other power sources and home loads, creating an energy ecosystem that revolutionizes the way homeowners generate, store, and manage their energy.
Backward compatibility: the aPower 2 is compatible with your previous aPower versions and allows easy expansion without overhauling your system.
Exceptional durability: with an operating temperature range of -4° F to 131° F and a weathering-proof rating of IP67, the aPower 2 is built to operate in harsh environments.
Engineered for energy-trade programs: homeowners with the aPower 2 can participate in energy-export programs such as net billing tariffs (NBT) and Virtual Power Plant (VPP) to earn extra credits that offset electricity costs.
Final Thoughts
An AC-coupled battery configuration is an exceptionally flexible method for integrating home energy storage with solar power systems, enabling a versatile home energy management and storage solution, particularly for those looking to add a home battery to an existing solar setup. The AC-coupled home energy management and storage system offered by FranklinWH takes a leap forward and is agnostic to all solar inverters, making it perfect not only for retrofits, but new installations.
