2024 Solar Industry Trends: Inverters, Batteries & Modules

The Solar Coaster Continues

After 20 years in the industry, I would expect things to be a bit calmer or more sedate, but no, the solar coaster continues its wild ride. The chaos in the inverter industry due to the recently introduced module-level shutdown codes appears to have subsided somewhat, but batteries and panels continue to change at rapid rates. Here are a few of my thoughts regarding this year’s developments, primarily in the residential and off-grid areas.

Inverter Developments

It's great to see SMA and Fronius back in the inverter mix. Their inverters were basically unavailable in the US for almost two years while they worked out ways to deal with the module-level shutdown requirements. The only real solution is adding an RSD device (SunSpec or Tigo) to every module, which is mostly applicable for new builds.

Many customers inquire about replacing older SMA, PVI, or Fronius string inverters. While this is possible, there are caveats. Fronius continues to produce old-school string inverters with no hybrid or battery capability, while SMA has moved to hybrid models. Replacing these older models requires careful consideration of MPPT input limits.

Battery Innovations and Compatibility

A significant development this year was SolarEdge removing compatibility with LG Chem batteries. This leaves SolarEdge users with only one option: SolarEdge's battery and backup interface. The 10kWh and 16kWh LG Chem batteries, now branded under LG ENG, are still available for other inverter brands, but their integration with SolarEdge is no longer supported.

Enphase has transitioned to their new 5P system, leaving behind the 3T and 10T versions. Unfortunately, the 5P system is not compatible with older IQ7 inverters. You can read more about this issue on Reddit: Enphase IQ Batteries 5P Discussion.

Lead-Acid vs. Lithium Batteries

Despite the advancements in lithium technology, we still see a surprising number of lead-acid sales. However, lithium has become the clear choice for most new builds due to its declining price and superior performance. The only issue is the rapid rate of obsolescence as new BMS and app updates roll out, such as those we saw with Renogy this year.

Solar Modules: The Arms Race Continues

The solar module industry has seen chaos as manufacturers race to increase panel wattage, often without considering how these changes impact downstream products like charge controllers. Matching new high-wattage modules to solar generators (e.g., Anker, Bluetti, EcoFlow) can be difficult as current or voltage limits are typically exceeded before reaching the advertised maximum wattage.

Another issue is the varying dimensions of new modules. The 60-cell and 72-cell standards are no longer widely used, forcing older mounting system manufacturers to move to a custom-build-only model.

Replacing Older Solar Panels

Replacing older solar panels has become nearly impossible due to constant changes in panel sizes and availability. We advise customers to claim insurance for broken panels rather than searching for discontinued models that will fit their existing racking systems.

2025-2026 Outlook: Tariffs and Module Availability

The recent tariffs on solar modules are already affecting availability and pricing. Some panels on the market, like Trina, now require installation before December 2024 to avoid retroactive tariff charges. Cheaper panel options, like Aptos and ZNShine, are no longer available, and module prices are expected to remain high for at least another year.

For more information on the expected industry downturn, PVTech has an excellent article: PV Manufacturing Downturn to Extend into 2026.

Conclusion

In conclusion, solar is still in the "early adopter penalty" stage, but that shouldn’t stop you from installing a system now, especially off-grid. We recommend buying and storing extra solar panels for future replacements as rapid technological changes continue to render older models obsolete.