*Wiring Diagram

Solar technology, perhaps in keeping with the rest of the technological world, is both rapidly progressing and changing. While this means exciting new innovations, it becomes difficult and oftentimes overwhelming to understand how to go about designing your system. This matter is further complicated with commercial and hybrid solar installations. Hybrid systems can prove particularly difficult as business and homeowners attempt to understand not only solar technology but battery technology as well. Trojan Battery’s recent solar battery line made matters somewhat easier, with specifications closer to reflecting energy technologies in solar. The added information and compatibility notwithstanding however, battery banks are expensive, often require a great deal of maintenance, and need to be replaced frequently (warranty periods range between 2-5 years on average).

For the reasons listed above and more, it is sometimes very difficult to size off-grid and hybrid battery systems with large, expensive battery banks. The development of lithium-ion technology for hybrid, (and sometimes off-grid), battery banks and exact matching to solar technology lowered the learning curve further, eliminated the need for time consuming maintenance, and increased average battery warranty periods, Enphase Energy and LG both have a 10-year warranty period. There are still a few noteworthy steps that homeowners need to take in sizing out their battery backup systems. For hybrid systems, we will be taking a look at Enphase Energy and LG Chem; we will conclude with a look at Discover Battery for off-grid applications.

LG Chem Battery with SolarEdge Inverters - Hybrid Systems

LG’s answer to the Tesla Powerwall, the LG Chem battery works to improve energy efficiency by enhancing your solar array’s performance. The result is not only useful energy storage, but stabilization of the power supply system. The LG Chem’s lightweight design can be easily be wall-mounted or floor-standing, indoor or outdoor, ultimately allowing ensuring that the system works for the installer, not the other way around. Simplified inverter connections make it easier to install, which saves both time and money in installation costs. The most current model, the RESU10H is 29.30 x 35.70 x 8.10 inches and offers up to 9.8kW of solar energy. Check out the LG Chem's specifications.

*SolarEdge Hybrid Battery Diagram of LG Chem Installation Materials and Functions

Sizing of the LG Chem battery will vary depending on your job specifications, however, for the RESU10H inverter you will need the  SolarEdge 7.6kW Hybrid Inverter, Auto Transformer, Electric Meter and current sensor. It is important to note that LG Chem batteries must be installed by a certified installer. A list of installers can be found in your area here.You can also look into getting certified to install LG Chem batteries for your DIY project, or as a professional installer, you can read more about becoming certified to install LG Chem batteries here. The LG Chem also has a warranty period of 10 years.

We hope to see more available batteries, compatible inverters and perhaps batteries that are set for off-grid. Currently the LG Chem RESU-H batteries will only work in a hybrid environment and cannot be used for off-grid systems. Off-grid batteries are available outside the H series with compatible inverters.

Enphase Energy Lithium-Ion Batteries with IQ Microinverters - Hybrid Systems

If you have been following trends in the solar energy for the last three years, you are sure to have heard of microinverters, if this is the case then you may also be familiar with the name Enphase Energy. The Enphase lithium-ion batteries work seamlessly with their microinverters and can currently be installed with the Enphase IQ series with the IQ6PLUS-B1200-LL-I-US00-RV1 batteries; the B280-1200-LL-I-US-00-RF0 batteries are compatible with the Enphase S series microinverters. Due to the fact that Enphase is no longer producing the S series microinverters, it is safe to assume at the moment that the S series battery will likely be a temporary battery. Home and business owners with S series microinverters may want to take advantage of the battery’s current availability. If you have the M series microinverters form Enphase (i.e., M215 or M250) neither battery will be compatible with your system. The microinverters, cables and monitoring unit would either need to be updated or a separate system installed with this particular battery. With this in mind, the following applies to the IQ battery only.

Home and business owners interested in this battery may already have an Enphase set up, however the compatible components are: Enphase IQ6, IQ6+, IQ7 or IQ7+ microinverters; IQ Envoy or IQ Envoy with combiner box; Enphase Q trunk cables, and the battery rack for wall mounting. The batteries are compact with a maximum output of 1.2kWh and are easily expandable, so you can expand the system overtime and not be concerned with oversizing your battery bank. Installation is quick and easy and can be accomplished with a single person. The batteries easily connect with household AC wiring and there is no high voltage DC in the system. Like the LG Chem battery, the batteries come with a 10-year  warranty. 

**Update: As of Nov 2018 the Enphase batteries are no longer available. Will post when there is other news.

Discover Battery (AES) Static and Mobile Lithium-Ion Batteries - Off-Grid Systems

Like the LG Chem and Enphase batteries,  Discover’s AES lithium-ion batteries require no maintenance and have dramatic improvements in cycle life and charge efficiency. This higher efficiency allows the batteries to operate up to 15% more effectively over competing lead acid batteries. In keeping with the trend set by its lithium-ion competitors, the AES battery is smaller and less weighty than traditional batteries, allowing easy installation and storage. At 192 lbs with a dimension of 18.50 x 13.30 x 14.70 inches, the batteries offer a possible solution to mobile battery requirements. Rather than use multiple batteries that need to be replaced frequently, fewer batteries will provide a better product with a greater return over time. Read Discover Battery's specs, installation guide, safety instructions and warranty statement.

In order to best understand your off-grid system needs, you need to first know the loads that you are trying to run the system on. There are a number of battery load calculators online, you may also want to consult a professional electrician prior to ordering an off-grid system. You can  contact Discover Battery here. Discover notes: “Extra considerations must be given to depths of discharge, operating voltages and currents when designing systems for use at maximum operating temperatures”. So, while the batteries are more attractive than their predecessors, sizing of complete off-grid systems is still difficult due to the number of environmental, and electrical considerations that come with it. That being said, Discover has a number of locations in the United states that can be contacted directly for custom off-grid designs.

Conclusion

In conclusion, lithium-ion batteries have quickly pulled renewable energy storage out of the stone age, however there are still a number of advances that still need to be made. Production is sometimes unreliable, waiting times are long, and confusing compatibility rules out some pre-existing systems, particularly when it comes to hybrid. We are confident that the industry will continue to dedicate research into development of renewable energy storage, and with the rapidness of technology being what it is, it may not be long before the next generation of lithium-ion batteries hits the market.