Great news. At last, our dream of an integrated generation-with-storage-and-EV-charging household energy system suitable for a three phase home has been answered - Santa - AKA Sigenergy - has delivered early for us! Sigenergy’s Sigenstor energy system is set to revolutionise home energy on several levels - rapid EV charging, vehicle to grid (V2G) capability, extraordinary efficiency and next level fire safety protection. But before we delve into the details, let me recap a bit to help explain what a great deal this is…
Here in Brisbane our home already had a small amount of solar but with prices going up, the arrival of our first EV (a BYD Atto 3) and a pool pump in operation several hours a day, we felt it was time to upgrade to a bigger system. All well and good, but a new system requires a new inverter so of course the Tesla Powerwall 3 - the battery with an inbuilt inverter - seemed like an option worth waiting for. But when that did finally arrive we were disappointed to learn the Tesla Powerwall 3 is not really set up for a three-phase house because the inverter only connects to a single phase and it would have had to be limited to 5 KW of output (not ten). Back to the drawing board…. And then along came Sigenergy.
Sigenergy has just brought into Australia the Sigenstor 5-in-1 energy system. In our view (and that of Sigenergy) the Sigenstor is a game changer. It’s Australia’s first fully integrated 5-in-1 energy storage system including a modular battery pack; a sophisticated power conversion system (PCS) (integrating a hybrid inverter and a PV inverter); an energy management system (EMS) and a DC charger for your EV. The Uninterruptible Power Supply (UPS) (ie. blackout protection) is available in a separate energy gateway.
Sounds fancy - but actually, what does all that mean? Let’s unravel this a little bit more…
About the battery pack
The battery pack is a slender, fully modular unit that allows customers to mix and match combinations of 5 KWh and /or 8 KWh of storage modules. Each battery is truly modular meaning you can keep adding extra storage over time with each unit operating at its individual optimal performance. Each storage unit also has exceptional fire protection with internal fire extinguishers, temperature sensors, aerogel-insulated pads, decompression valves and high-temperature-resistant insulated pads. Wow!
If customers are happy with the battery design so too are installers. Sigenergy has designed the Sigenstor with almost no external wiring (thanks to the introduction of quick connectors). This makes for a rapid 15 minute installation time leading to substantial cost savings for installers - and hopefully their customers as well.
The versatility and scalability of this system is truly impressive with huge potential for small and medium scale business operations. For example, in grid-connected scenarios, the system accommodates up to 10 parallel connections, enabling a maximum of 400 KW of direct current input and a maximum of 250 KW of alternating current output. That’s a lot of power. It has a maximum energy storage capacity of 480 KWh and still allows for rapid two-person installation. Wow again I say!
About the power conversion system (PCS)
The Sigenstor PCS smoothly integrates a hybrid inverter and a PV inverter allowing it to seamlessly direct AC and DC power wherever it is needed and to access your EV battery in the same way as the household battery. The PCS allows the DC current coming from your solar power to enter straight into your car battery with no loss of efficiency due to inverter conversions.
About the Energy Management System
The EMS lies within the PCS (which sits atop the battery modules) and is the brains of the whole gig. The absolute masterpiece feature here is that it also operates in a modular fashion allowing each battery to be optimised independently of the others.
About the charger
Last but not least, the EV charger is also ground-breaking (it was simply the must have for my husband). For $7,000 we have a DC charger module sitting between the PCS and the batteries. It delivers 12 KW per hour of charging into our EV with 98% efficiency. The DC charger allows DC from our solar panels to efficiently enter straight into the BYD or, due to the intelligence of the PCS, charging with a seamless combination of solar, battery and grid energy. The more expensive charger will allow for charging at 25 KW per hour but we didn’t need that. Before our Sigenstor arrived, we were trickle charging at 1.8 KW per hour relying on OVO’s great overnight tariff rate (8c a KW from midnight to 6.00 am) and the BYD’s dodgy timer. Now we have finally entered the modern age of solar charging bliss!
But the story gets even better because the icing on the cake is that the Sigenstor DC charger includes V2G (vehicle-to-grid) capability. Yes, the opportunity for bidirectional charging from my car to the grid has finally arrived in the Brisbane suburb of Wishart. Quite possibly a first for Queensland! As Sigenergy tells me, my EV and others adopting this technology will “[C]ease to be mere energy consumers; they become active participants in the energy ecosystem, engaging in power exchange and collaboration with smart grids.” The technology has arrived and it’s sitting in our garage.
So, I now have all the technology I need - an EV with a big battery, ample solar power and a charger that is capable of V2G charging without any hardware updates to my car …. But I’m still not fulfilling my civic responsibility to help reduce the duck curve by exporting green electricity into the evening grid. After all this investment! So what’s the missing link? Last weekend, Chris Bowen announced standards for V2G charging in Australia have finally been approved by Standards Australia … but there’s still a couple more roadblocks. Car companies - and presumably device providers - still need to get approval from the Clean Energy Council and the local distribution networks before I can actually plug in my V2G charging capability. So will they get this done by Christmas? Chris Bowen is not the only one hoping they do!
V2G charging is available in Japan, the USA and several countries in Europe but not in Australia (except South Australia) - yet. A recent report for Solar Citizens and the National CER Roadmap encourage all states to adopt the nationally approved standards as soon as they are ready… which is RIGHT NOW! I’ve invested and I’m ready to go … So let’s get this show on the road and get V2G charging into action across Australia in time for Christmas.
Post written by Philippa England, Solar Citizens' Clean Energy Campaigner for Queensland
Further reading
Residential ESS | Commercial Solar Solution | Sigenergy
'Batteries on wheels' How we can accelerate vehicles to grid in Australia - Solar Citizens
National Consumer Energy Resources Roadmap
SigenStor: Revolutionizing Industry Norms with Ten Breakthroughs | LinkedIn