Redback Hybrid Inverter Review

Redback Technologies have now entered the solar inverter market. I first heard about Redback inverters last year and wrote a not so glowing review about the Brisbane-based product. James from Redback read my review and invited me to meet him at Redback’s HQ to see if he could change my mind, and my blog. I jumped at the chance and last Friday I made my way out to the University of Queensland at St. Lucia to have a close-up look.

The first thing that struck me was the inspiring location at the “iLab” in the Univesity of Queensland. Sure we are talking about a Brisbane-based start-up, but it’s not based out of a Tin shed in Acacia Ridge. UQ’s ilab has helped “grow the ideas” of over 100 start up business like none other that the disruptive Redflow Batteries. Redback Technology’s approach reflects their surroundings. Creative, energized, innovative and disruptive. They are not about reinventing the wheel, but on leveraging on the help of existing quality R&D. The brains of the hybrid inverter is the Microsoft Azure platform, and the guts are the reputable Chinese built GoodWe inverter. The support of ilab means the Redback is developing in collaboration with UQ’s renewable energy research facilities, partnered by the Queensland Govenmanet.

It’s an impressive resume, but how does it stack up? I’ll list the pro’s and cons of the Redback from a Solar designers point of view, and explain how they overcome one glaring objection.

I’m in the process of re-writing this post. We’ve installed 7 Redback inverters and I’m not at all impressed. In one word I would say that Redback over-promises and under-delivers. We didn’t get what we were sold. 

However, I have talked with Redback about my concerns and they have invited me back to their office to discuss my concerns. At that point, I’ll update again.

Redback inverter Spec sheet

Con’s of the Redback Hybrid inverter

• Restrictive Voltage Limit. At 500v, this means we can only install a maximum of 12 panels (standard 250 or 260w panels)*
• Restrictive current limit. We can only install one string of panels in each tracker. See the solution in the next point*
• With the restrictive power and current, this means on our standard 260W panels; we have one option. A string of 12 and a string of 11. If your roof line suits this, not a problem. If it doesn’t, you’ll need to add Tigo Optimizers*
• Restrictive power Limit. On a single phase home, we can install up to 6.6kW of panels according to Energex and CEC regulations. The Redback only allows 6kW. When looking for a storage solution, that extra 10 percent of production would be nice
• At face value, it is expensive. Even more expensive than the Fronius Symo Hybrid. But read the Pro’s of the inverter and the price seems rather reasonable

*The Voltage and current design problems listed above can be solved with Tigo optimisers.

Pro’s of the Redback Hybrid

• The Redback comes with no hidden costs. The KWH meter comes in the box
• Plug and play. James showed me just how simple it is to install the battery. This cuts down labor cost
• Load shifting. Running a pool or a hot water system only on excess solar power can reduce the amount of comparatively expensive batteries. Redback solves this problem with two inbuilt 20 Amp relays. Further cost savings. I don’t know of any other inverter that does this
• The Internet of Things. To bring the last point to its extreme, IOT enabled appliances can talk with your Redback inverter to enable further intelligent load shifting. The prime example of this is having the air-con ramp down or ramp up depending on import or export power. The reality of this is you probably don’t have an IOT aircon. However with technology moving so rapidly, it’s likely that your next air con will be IOT enabled, or we’ll be able to retrofit appliances with IOT relays
• It can run completely off-grid. This brings it into the league of the ridiculously expensive SMA and Sunny Island and Selectronics

• The Charge and discharge rate. When coupled with a Pylon Tech batteries, they can charge and discharge at an incredible 4600W. With a 5 year warranty at 8000 cycles, you’ll be able to rapidly charge and discharge the battery through the day. Further calculations on this will be for another blog

Objection overcome

There was still a huge objection that I needed to overcome. Redback as a company is all of 2 years old. The founder is Philip Livingston. Why should we assume Phil’s latest start-up business will outlast the 5-year warranty? Hearing it has support from the University of Qld and GoodWe inverters as a major investor; I feel a little more at ease. But it wasn’t until I spoke with David from Solar Plus Solutions, part of the 130-year-old Sonepar group. Sonepar is the importer of Redback in Australia. If Redback goes bust, your warranty is safe with Sonepar.

Conclusion

While the Redback may not be the most flexible inverter on the market for panel design, it’s restrictions can be overcome with Tigo optimizers. It’s remaining flaw is it input limitation. However, the pro’s outweigh the cons with the inbuilt load shift capability and more notably the charge and discharge rate when coupled with the Pylon Tech Batteries. Although the company is only two years old, you’re dealing with a quality start-up company with impressive backing. Should that all go wrong, you can rely on Sonepar to back the warranty.