SigenStor: The Most Interesting Solar Product Ever?

When it comes to solar batteries and inverters, you may dare say that on a fundamental level, all innovation has already been done. When you compare solar products today, it's easy to think that all solar products are more or less the same, except for a few minor differences.

Enter SigenStor – a product that truly stands out thanks to a revolutionary design that integrates solar batteries, inverter and New Zealand’s first DC home EV charger. China-based Sigen Energy may just be two years old, but it boasts a presence in over 50 countries and hundreds of patents, which is why we thought it is a good idea to take Sigen Energy’s Sigenstor seriously.

Let’s dive deeper and see how the Sigenstor stands apart from the crowd of solar storage solutions on the market.

What is Sigenstor?

Essentially, the Sigenstor is a home energy storage solution (ESS). But the product is so much more than just an ESS. It implements a clever design that integrates a home battery, a DC EV charger and an inverter-controller unit all in one sleek package. The Sigenstor is a stackable device that saves your home from numerous boxes and wirings when you install a solar power system with batteries and an EV charger.

Here’s a closer look at the product:

Design

Let’s start with the most innovative aspect of the Sigenstor – its design. At first glance, the device looks like any other stackable battery, but not all modules of the device are the same. 

The top rack of the Sigenstor is a controller, which handles inverter duty and has a sleek-looking Sigenergy logo and a minimal menu ring, which Sigen calls an ‘Eagle eye’. Below that is a bidirectional, DC electric vehicle charger that boasts a whopping 25 kW power supply to your car. 

Lastly, the bottom racks are occupied by Sigen LFP batteries. The whole machine can be big or small depending on how many batteries you use in the rack. You can also choose to have an absolutely minimal system by installing just the controller and skipping the EV charger and batteries.

The sides of the Sigenstor have a textured design with a thin, blue LED running all around the unit, adding a futuristic touch to its looks. Needless to say, the whole thing is considerably heavy, which is why Sigen has created a ground-mounted design, which includes a sturdy base to hold everything on top of it.

Besides the Sigenstor, you will also need to install the Sigen Gateway. The Gateway houses controlling electronics for the batteries, allowing you to switch seamlessly between modes. The Gateway is also compatible with generators, heat pumps or other comparable loads. It comes in both single and three phase options and also supports both whole home and partial home backup. 

Specs and Features

It is not just innovative design where the Sigenstor impressed us. The machine’s specifications promise some remarkable capabilities. For example, the Sigenstor claims a noteworthy switching time of 0 microseconds when changing between grid and backup only mode. In comparison, most batteries on the market today take anywhere between 1-3 seconds. 

Sigen’s complex electronic architecture also promises negligible voltage fluctuation, as shown in the following image. This means that nothing in your home will restart or switch off when your system switches to backup mode.

The Sigenstor houses lithium iron phosphate (LFP) batteries, which promise longer life and better thermal resistance than the more commonly used nickel-manganese-cobalt (NMC) batteries (did someone say Tesla Powerwall?). Thanks to the modular design, you can stack up to six batteries in one unit, getting a massive 48 kWh of energy storage.

Here’s a chart with all the main specifications of the Sigenstor:

Every battery module of the Sigenstor has an 8 kWh storage capacity and a 4 kW power rating. You can also opt for smaller battery modules that store 5 kWh and produce 2.5 kW of power. Interestingly, you can also mix and match modules, going for an 8 + 5 kWh storage, which equals the specifications of the Tesla Powerwall without equaling the price (more on that later).

The device is available in both single and three phase options. It comes with an IP66 rating, which should protect it from all sorts of precipitation, in case you decide to install it on the exterior of your home. The unit also has WLAN connectivity for over-the-air updates and remote monitoring. Speaking of monitoring, Sigenergy offers an excellent app for system monitoring, showing even small details like each battery’s real-time voltage. 

The Sigenstor’s EV charger is one of the most outstanding aspects of the product. It is the first home DC charger in New Zealand, and offers 25 kW of charging power. If you have a Tesla Model 3, you can charge it in a little over two hours. In comparison, most other home chargers in NZ are AC chargers with about 7 kW of power rating – which is barely a third of the Sigen’s. You can also choose a 12.5 kW DC charger for your stack, but the price difference between both charger options is so small that it makes more sense to get the 25 kW model. 

That’s not all. The charger comes with bidirectional capability. This means if you have a compatible car, you can use your car’s battery to power your home. Lastly, the batteries have a performance guarantee that promises 70% of rated capacity after its 10-year warranty, which is similar to most other batteries on the market.

Pricing

And now we turn to what is the most important aspect of any solar battery for many of us. The price of a Sigenstor ESS depends on how many batteries and which EV charger you choose. If you install a system with an 8 kWh and a 5 kWh battery, a 5 kW inverter and the gateway, you can expect to shell out AUD 11,500 or about NZD 12,800. This setup will be similar to many popular models on the market today, including the Powerwall. The good news is that its price is significantly lower than that of a Powerwall!

The EV charger module, however, comes with a somewhat painful price tag of AUD 8,500 or about NZD 9,400. This is nearly three times that of other AC home chargers, but when you consider how powerful the machine really is, you may find the pricing worth it. You can save around $1,600 by choosing the 12.5 kW DC charger instead of the 25 kW one, but like we said before, it’s wiser to just spend a little more and get the 25 kW beast.

As for the inverter, it costs a reasonable AUD 1,800 or about NZD 2,000 for the single phase model. Overall, if you’re going for a sizable system with 3-4 battery modules, 25 kW charger, gateway and a neat installation from an experienced solar company, you must prepare yourself to spend over $30,000, and this does not include the solar panels. This may sound hefty, but this is a future-proof system, and for the next 10-15 years, you’ll have a reliable ESS that will have proven its worth quite well.