As Solar Energy use soars, adding Battery Storage gives homeowners more power than ever to maximise their clean energy, powering their homes overnight and selling excess solar back to the grid during peak-rate periods through Solar Grid Trading.

If you’re getting serious about exploring Solar Battery options, it’s no doubt you’ve come across two heavyweights of the Battery Storage market.

 

In The Red Corner: Tesla Powerwall 3, The Standard-Bearer 

Widely credited for popularising Home Energy Storage all the way back in 2015 with the original Powerwall design, Tesla are often considered the standard-bearer for Battery Storage. After dominating the market for the best part of a decade with the Tesla Powerwall 2, they released an even more groundbreaking features with their latest offering, The Tesla Powerwall 3.  Bolstered power output, an Integrated Solar Inverter and new architecture for maximised Scalability pioneer the next generation of Battery Storage. 

 

In The Blue Corner: Sigenergy SigenStor, The New Kid On The Block

Sigenergy is a rapidly growing technology company specialising providing advanced Battery Storage solutions for Homes and Businesses. After being founded in 2022, Sigenergy has quickly become a frontrunner in the Battery Storage market, synonymous with it’s capability to integrate power electronics, digital technology, and artificial intelligence (AI)i in an intelligent, all-in-one system.

Their flagship product, the SigenStor battery, is an AI-optimized “5-in-1” energy storage system. This unique and highly integrated design combines a Solar Inverter, EV DC Charger, Battery Pack, Power Conversion System and Energy Management system into a single module. Packed with advanced performance features and real world applications, the SigenStor is a compelling option for any homeowner looking to supercharge their Solar system. 

 

But which of these systems comes out on top for your Storage needs? Leading Solar Installers Naked Solar are on hand to help you make an informed choice. Let’s start with a comparison table of the two systems key performance features. 

 

Feature	Sigenergy SigenStor	Tesla Powerwall 3
Capacity (kWh)	5-48kWh (Modular)	13.5 kWh (Fixed)*
Inverter Type	Hybrid (Modular unit)	Hybrid (In-built)
Warranty	10 Years	10 Years
Powercut Cover	Optional	Optional
AC/DC Coupled	AC & DC	AC & DC
Solar Grid Trading	Yes	Yes
Weather Responsive	Yes	Yes

*The Tesla Powerwall 3’s capacity can be increased in further 13.5kWh increments with DC Expansion packs, more on this later. 

 

Capacity and Scalability 

Tesla Powerwall 3

• 13.5kWh useable capacity per Tesla Powerwall 3 Unit – 100% depth of discharge. 
• Capacity is scalable to 54kWh by adding up  to 3 further Expansion Packs units per Powerwall.
• Considering your property can have up to 4 Powerwall’s per single phase supply (DNO permitting), a maximum capacity of 216kWh is available. 

The Tesla Powerwall 3 expansion packs offer can be stacked or wall mounted to work with your Powerwall unit.

 

Sigenergy SigenStor

• The SigenStor’s modular design allows 6kWh and 9kWh modules to be stacked.
• The system is scalable  to 54kWh per stack (containing 6x 9kWh modules).
• Considering the system can have a total of five stacks per phase (DNO permitting), a maximum capacity of 270kWh is available.

 

 

The SigenStor’s modular design offers great flexibility for homeowners to add capacity as their energy needs increase.

Whilst Tesla’s Powerwall 3 is generally considered easier to scale, by simply adding DC expansion pack modules, it may be that an extra 13.5kWh of capacity is not needed. Sigenergy’s modular design allows the system’s storage to be scaled more incrementally (in 6kWh or 9kWh modules) with a greater level of flexibility. 

 

Home Backup

Both of these advanced battery storage systems offer the capability of home backup,  providing homeowners with peace of mind they can ensuring power through a power cut  at times of grid outage. 

Tesla Powerwall 3

• Backup is provided by the Tesla Gateway 2, and acts as the brains of the system responsible for energy management, time-based control as well as providing full home backup.
• The Gateway 2  is no longer a mandatory specification of Powerwall 3 Installations, meaning backup is optional. For homeoweners looking to drive Installation costs down, this could be an important consideration. 
• The Gateway 2 can be Installed at the same time as your Powerwall, or retrofitted at later date. 

Sigenergy SigenStor

• SigenStor provides backup through the Sigen Energy gateway .
• Like Tesla’s offering through the Gateway, the Sigen Energy gateway is an optional extra, available to be installed alongside the SigenStor or retrofitted at a later day. 
• The SigenStor stands out for it’s unique ability to back up a 3 phase supply with a 3 phase gateway, currently this is a feature not offered by The Powerwall. 

 

Inverter Types

The Powerwall 3 boasts an 11kW inverter rating, primed to support a sizeable Solar PV system. Whilst 11kW is the maximum inverter rating, it has the flexibility to be set at any of the following settings in line with the customers DNO offering: 

• 3.68kW
• 5kW
• 6kW
• 7kW
• 8kW
• 9kW
• 10kW
• 11kW 

Having multiple Powerwall 3 units on the same supply means the inverter must be set to the same rating. 

The SigenStor allows a different inverter rating to be set across multiple SigenStor stacks, offering greater flexibility to maximise the system size in accordance with DNO limitations. The Inverter is housed in the Energy Controller, considered the brains of the battery it combines a Battery Inverter, PV Inverter and  EMS (Energy Management System). Similarly to the Powerwall, the SigenStor can be set at the following inverter ratings. 

• 3kW
• 3.68kW
• 4kW
• 4.6kW
• 5kW
• 6kW
• 8kW
• 10kW
• 12kW

The SigenStor system is unique with it’s Three-Phase Inverter option, a feature not currently available with the Powerwall 3 system. This is a game changer for three-phase properties, opening up increased power capacity, load balancing and system efficiency gains.

Tesla Powerwall 3’S DNO Flexibility – With grid improvements ongoing, many of our customers have had successful reapplications to the grid for an improved DNO offering. With the Powerwall’s flexible inverter adjustment, changes can be made simply to best match your new offering. However the infrastructure of the Sigenergy system, a new Energy Controller would need to be purchased to replace the current one in order to match your new DNO offering.

SigenStor’s Futureproofed Inverter Design – Whilst the Powerwall 3’s design architecture is a tick in the box when it comes to successful DNO re-applications, it’s worth considering the implications of Inverter failure outside of the warranty period. SigenStor’s modular design makes inverter replacement simple, replacing the energy controller without having to touch the battery. An inverter failure for the PW3 would result in replacement of the entire unit.

 

App Monitoring and Real World Usage 

The Tesla App serves a the central hub for Powerwall owners, with a slick interface and a host of tools to monitor, manage and optimise your homes energy usage. If you’re an owner of a Tesla Wall Connector or EV, the app is particularly useful for seeing how the ecosystem is performing. For example,  you’ll get in depth information on how self-sufficient your EV is charging from clean energy vs grid energy. Some key features of the Powerwall app includes:

• Real Time Energy Flow – A dashboard showing real-time display of your homes energy flow, including your Solar Generation level, consumption and home much energy is being stored in your Powerwall 
• Time-Based Control – For homes taking advantage of Time-Of-Use (TOU) tariffs, this function maximises your Solar ROI by automatically charging the Powerwall during off-peak hours and powering your home and selling back to the grid during peak hours. (Visit our Solar Grid Trading page to learn more).
• Storm Watch – Peace of mind in the event of severe weather events with this innovative feature. When a storm is detected, the Powerwall will pre-charge to 100% capacity from your panels or grid, ensuring you have back up in the case of a power outage.

 

 

The “My Sigen” app is a vital component of the Sigenergy SigenStor ecosystem, designed to give homeowners comprehensive visibility and control over their energy system.

• AI mode – Sigen AI mode intelligently learns your energy consumption patterns, factors in real-time electricity tariffs and weather forecasts to optimise your system. The system manages when to charge your battery from Solar, discharge it to power your home, as well as buying and selling energy to maximise your ROI. 
• Smart Home Integration – Manage your storage and set schedules for high-energy appliances (EV Charging or Washing Machines) to run during periods of excess Solar generation or off-peak times. 
• Real-Time Monitoring and Visualisation – Application of Sigenergy’s ‘Snakey Diagram‘ provide a visual representation of your real-time energy flow. You can see precisely where your power is coming from (Solar, Battery, Grid, Generator or EV) and where its going (Home, Battery, Grid, Appliances or EV Charging).

 

 

EV Charging Capabilities

As the popularity of EVs soars and the drive for sustainable living accelerates, homeowners are increasingly looking for the most efficient way to fuel their vehicles with clean energy. Enter SigenStor, the UK’s first DC/EV Charger. It’s advanced technology allows homeowners to draw the DC power directly from the Battery and Solar Panel for faster, more effiicient,  100% green power charging.  The Powerwall 3 is designed to work with AC Charging of EV’s (a capability also offered by the SigenStor), which whilst delivers reliable performance, results in energy loss and slower charging speed.

The SigenStor’s V2H (Vehicle to Home) and V2G (Vehicle to Grid) capability allows homeowners to utilise their EV’s battery to power their home at times of outage or allow excess energy to be sent back to the grid.

 

SigenStor Vs Powerwall – Which is best? 

As leading UK installers of both the Tesla Powerwall and the Sigenergy SigenStor, we (along with thousands of happy customers!) can confidently give our stamp of approval to both systems. Ultimately, the choice between them comes down to your personal priorities and what you’re looking for from your energy storage solution. We advise that you talk through both options with a specialist Solar provider who can help you make an informed decision. 

 

Naked Solar’s Expert Guidance  

When considering two Battery Storage solutions as impressive as Sigenergy’s SigenStor and Tesla Powerwall 3, the importance of understanding your need is paramount.Talking to a leading solar installer with over a decade’s experience and thousands of happy customers can make all the difference. 

If you’re considering solar battery storage, whether as part of a new solar installation or to add to an existing system, we’d love to help. Trust in the South West’s Leading Solar Installer, to provide you with impartial guidance and help you find the perfect system for your needs. Talk to our expert team today. 

 

 

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