DC Coupled vs. AC Coupled Solar Systems: Find the Best Fit for Your Setup

In this video, Kelly from Signature Solar dives deep into the crucial distinctions between AC and DC Coupled solar battery systems, offering a clear and comprehensive guide for anyone exploring solar power solutions. You'll learn how each system operates, from energy conversion processes to installation requirements, making it easier to understand which solution fits your specific needs. With real-world examples and hands-on demonstrations, Kelly highlights the advantages and limitations of both AC and DC coupling, empowering you with the knowledge to make an informed decision whether you're setting up a new solar system or enhancing an existing one.

We also take a closer look at the versatile EG4 18K inverter, showcasing how it seamlessly integrates with both AC and DC Coupling for a reliable and flexible energy solution. From blackout protection to maximizing energy efficiency, this inverter offers a powerful combination for homes and businesses alike. By the end of the video, you’ll have a clear picture of which system aligns with your energy goals, making it easier to move forward with confidence in your solar investment.
--------------------------------------------------------------------------------------------------

[gdegarimore]

Great video. I learned something new. Especially the AC coupled portion. As an off grid guy, I never fully understood the AC coupled path and advantage. Now it makes more sense. Like adding the hybrid to an existing solar setup.

[dennislyons]

Kelly did a great job of describing the differences & operation of both DC & AC coupled systems. I have had an AC coupled system for 24 years now. I've added panels & batteries & 2 electric vehicles to our use case over the years. I have also replaced three inverters because of failure over the years. Nearly everyone can benefit from well designed solar systems.

[AveRage_Joe]

Excellent Job!!! Easily the most informative video on this subject I have ever seen!!!💥🤘

[Dan-kvvz]

I'm just starting to learn about solar and this is the most informative video that I have found that really helped me understand what I'm doing with all the different components. Thank you so very much!

[securityvlogger]

I hope she’s a millionaire; well-deserved, great clarity

[nated]

One thing I didn't hear mentioned about AC, and the reason AC was chosen over DC for transmitting power over distance, is AC's ability to efficiently move power over longer distance with lower losses. This allows you to move your panels farther away from your home/load and not have the power loss due to wire length.

[junkerzn]

I've done both over the years but these days I far, far prefer DC coupling because you have less electronics up on the roof. In the old days you had no electronics on the roof at all but these days regulations typically require per-panel rapid shutdown, so there has to be something up on the roof per-panel to do that. But the equipment is dead simple and unsophisticated compared to micro-inverters.

Generally speaking, maintenance on DC coupled systems is far, FAR easier and far less expensive because the equipment most likely to break is at ground level and doesn't require partial disassembly of panels up on the roof. DC coupled systems are cheaper to install and cheaper to maintain.

Another big advantage of DC coupling is that you don't need to wiggle the line frequency around during a blackout (UL1741SA) to regulate AC micro-inverters. It can just stay locked at 60hz. And there are fewer voltage overshoots and undershoots with variable loads.

-Matt

[kaf]

Thanks Kelly that’s a great comparison video!

[scottbalak]

It seems like the major down side to AC coupling is price. I've seen several videos where it is claimed that "power optimizers" are now longer necessary with today's modern panels. If power expansion is the goal it would seem like two hybrid DC coupled inverters would offer all the benefits compared to a combination AC coupled + DC coupled.

never been a fan of microinverters. They are the most expensive path and the redundancy benefit is a double edge sword. The probability of failure go up at the same time.

[ibenglish]

I always learn something new from these videos. Can you do a video on which microinverters work best with different wattage panels? Also my grid tied SolarEdge inverter and SolarEdge optimizers were not cheap. I would prefer to utilize the optimizers and ditch the inverter for the 18kpv and add EG batteries. Our local power outages are getting ridiculous and this grid tied set up is starting to really wear on me. I would still like to back feed to the grid but their control over my 24/7 power use needs to come to an end. “So my question would be if the SolarEdge optimizers will work for me with the 18kpv and minus the SolarEdge inverter. Also if I doubled my array and added micro inverters to that section of panels would this work well”?

[ter]

Researching solar installation. Correct me if i am wrong, but the whiteboard has grid to the main load/panel to the inverter. Should it not be grid to inverter to main load/panel?

[WAsolarguy]

The conversion losses in a AC coupled system is 3% more than a DC coupled system. Typical DC coupled will loss around 6% during the entire process, it can store up to 3% higher efficiency than AC coupled systems. That is huge impact on a commercial/utility scale eco system but residential…. Fractional IMO. DC is ⚠️ high voltage ⚡️ unsafe. Why should your solar be at voltages 300-600v when there’s a better and safer alternative but question the conversion loss over safety 🔥? So you lose 3% big deal safety should be the priority. RSD devices help yes but that’s a separate component added in conjunction with your single point of failure inverter that micros have integrated. All homes run off 240V.. not 600V why should your solar be different.

[philippserrin]

I am curious how much power you actually lose in total with
Panel to Inverter DC to AC, then
Inverter to Battery AC to DC, then
Battery to Inverter for actual use in the home
Is it possible that one kWh of power harvested by the Solar Panels only produces 80% of one KWh by the time it is used in the house ?

[stibbs]

Do you have a solar for dummies or Solar 101 video?