The recently released lithium battery units from LG Chem may position the company as the industry leader in lithium based energy storage systems (ESS) for both residential and large scale commercial installations.
The second generation residential energy storage unit (RESU) from LG Chem expands on the first successful RESU 6.4kWh battery which now includes five options; Starting from the compact RESU3.3 (3.3kWh) up to a much larger 19.6kWh battery system using 2 of the new RESU10 units combined. On the commercial side there will be multiple options from the medium sized 45-166kWh systems up to a massive 50 ton container packed with 4,800kWh of storage capacity. Yes that's 4.8MWh.
New RESU Battery Range
The new series (48V) RESU batteries are available in 3.3kWh, 6.5kWh and 9.8kWh sizes, while high voltage (400V) units are now available in 7kWh and 9.8kWh capacity. The direct replacement of the previous RESU6.4EX is the RESU6.5 which has 0.1kWh greater storage capacity but is 8kg lighter and 45mm narrower. More importantly it is now IP55 weather rated which means it can be installed in a semi-outdoor location such as a varandah or carport but not directly open to the elements.
Since the release of the Powerwall there has been an emerging trend to high voltage (HV) 400V battery systems which have several benifits including slightly higher efficiency and the ability to be DC coupled with the solar array which operates at a similar voltage. However all dedicated off-grid inverters operate at the more common 48V so the HV batteries will not work off-grid in many installations.
See full specification sheet here
Compatible with many popular battery inverters
LG chem have obviously been listening to solar installers and have been working with many inverter manufacturers to ensure there product is compatible and easily configured with almost all of the popular inverter brands.
Unlike the first Tesla Powerwall which was limited to two inverter types the range of compatible inverter brands (LV) now includes Selectronic, SMA, SolaX, Sungrow, Schneider, Ingeteam, GoodWe, Redback and Victron Energy and the higher voltage (HV) unit is compatible with SolarEdge and SMA, with more brands (using Canbus communication) expected to be added.
Warranty - careful in hot climates
The LG warranty is still 10 years however the cycle life and related warranty specifications, although more detailed, are now more conservative than the previous warranty. The new warranty states that...
"LGC warrants and represents that the Product retains at least 60% of Nominal Energy for the either 10 years after the date of the initial installation or for a minimum Energy Throughput as per the table below (whichever comes first) when the battery system is operated under a normal use followed by the specification and the manual provided by LGC"
The warranty also contains more detailed operating criteria which limits the operating temperature and energy throughput over the battery life. This could be a problem for installations in hotter climates such as regional Australian towns and remote locations. An exposed outdoor installation could easily reach 45 degC during the afternoon in many Australian towns so careful consideration will need taken when locating the battery, preferably inside a garage or a well insulated/ventilated area, as high ambient temperatures above 45 degC can quickly and permanently damage many battery types unless active cooling is employed.
See the full LG chem warranty document here
Commercial & Utility scale batteries
There are also 600V+ ‘Grid-scale’ units for large capacity commercial systems. (A higher voltage in-turn reduces the system current which improves efficiency and line losses in large high current systems)
In addition LG chem have publicised a range of ‘Power modules’ which are designed for high output short duration situations (less than 1 hour). These would be ideal for commercial installations where ‘peak lopping’ (also known as peak shaving) is required to maintain power draw from the mains below a preset level. This reduces strain on the electricity network and eliminates the extremely high usage charges associated with peak demand that cannot always be reliability sustained by the mains supply. The large scale storage systems can also be utilised by utility companies to help balance the electricity grid during peak times and of course help with the transition to a renewable energy power grid.
Comparison - LG chem vs Tesla Powerwall
See how the LG Chem RESU range compares to the Tesla Powerwall 2 and other leading battery technologies here - Complete Solar Battery Comparison & Review