Which are the factors to be considered while buying energy storage systems?
Basics 101 : Understanding Specifications of Storage Tower (also known as AC Coupled or Retrofit Inverter)
Home Owner if you use Path to Green Homes, you will be able to choose the right equipment and get a quote from your nearest installer. We don’t stop at recommending brand names e.g. How is LG? PathToGreenHomes helps you drill down to matching series and model e.g. 1Φ (4-5kW) RESU Series with 5kW AC Power.
Below is the specification of storage tower which you will find commonly in data sheet, installation and warranty manuals.
Storage Towers may have inbuilt or approved 3rd party battery makes. The battery capacity maybe expandable later by Paralleling “No of Parallel Battery w/o addn devices” or series “See Battery Voltage”
A 5KW inverter should work >5KW for a small “time period (secs)” to accommodate surge loads like aircons, motor, pump etc. If Overload ( secs) is ZERO (0), it means that Backup overload load is not possible.
Round Trip efficiency in AC Coupled / Tower is the final efficiency after all losses including battery charging and battery discharging loss. Path to Green Energy has observed that many manufacturers are instead mentioning only the electronics efficiency not comparable to Round Trip Efficiency. Many AC Coupled inverters do not have in built battery but require 3rd party compatible battery. So to arrive at Round Trip efficiency deduct battery charging and discharging loss ( 8%-12%).
Inverter colour is personal choice. However the quality of paint, C5 corrosion level are imp for longevity. In future plastic housing of inverters (to save cost) will make an arrival which need compliance to mechanical, electrical and tough EMI compliance
“Damaged SPD” can be part of an expensive board & need for replacement for both SPD and the expensive board. It may cost $100 for such replacement. Not very common but Path to Green Energy prefers equipment where only SPD replacement is possible.
Each time battery is discharged that’s one battery cycle. There are 365 days in a year and 10 years means 3650 cycles (100% charge and discharge each day). Please ask supplier if can battery be fully discharged Or weather maximum 90% / 80% of discharge is recommended since it has price implication
High Battery voltage reduces losses. As the household load increases (EV, Heat Pump), storage capacity maybe increased (not all inverters allow it) by adding more batteries in Series. Note : However not all brands will allow battery capacity addition, by mixing an existing (Old battery) with a new one. For them such mismatch is unacceptable
Storage capacity may later be increased, by adding batteries in PARALLEL instead of Series. No of units in parallel is an inverter feature to parallel batteries, without purchasing an additional data logger.
Intergrate 3rd party reliable weather data from MetroControl / Skytron/ SolarLog useful for PV Energy prediction. In a EV scenario regional meteorological data can create a generation forecast, which it compares against your own consumption behaviour.
Communication between devices through the local area network will reduce the complexity of system wiring. Wireless connection is more beautiful, but the complexity of the initial configuration increases.
In General EV Charger can integrate in any PV grid. However this requirement is “Yes” when an Electric vehicle can be charged quickly, in a PV-optimized or forecast-based manner. The solar power should fully feed the car and not the grid.