The storage player taking on utilities

Sonnenbatterie is going to take on utilities, with a residential P2P energy trading model using battery energy storage in Germany. Photo: Sonnenbatterie eco

Sonnenbatterie is taking on utilities in Germany, with a residential P2P energy trading model that uses its Sonnenbatterie eco battery energy storage system and an innovative software platform. Photo credit: Sonnenbatterie

By Jason Deign

An energy storage player could become the first company to seriously undermine the utility business model following an announcement being made today. Sonnenbatterie, a storage firm with around 50% of the residential battery market in Germany, has unveiled a community energy exchange model that could in theory allow users to swap electricity and cut out utilities altogether. The concept has already been pioneered by German companies such as LichtBlick and confirms the importance of residential storage in creating peer-to-peer energy trading networks.

What sets Sonnenbatterie apart is the sophistication of its model. “We know LichtBlick is going in the same direction and we are ahead of [them],” said Sonnenbatterie’s managing director, Philipp Schröder.

The company is offering to give its 8,000 or so German customers access to a software platform that it says could cut electricity costs by 25%.

Residential PV and storage systems

The platform does this by keeping track of the energy use and charge state of all connected residential PV and storage systems.

When one user needs energy beyond what their own PV and battery system can provide, the platform pulls it from the grid but at the same time injects an equivalent amount from another community member who has a surplus.

Net grid consumption therefore remains zero (in theory, at least; until it is certain, Sonnenbatterie is holding some biogas generation in reserve).

At the same time, the system analyses each user’s consumption patterns and marries them to predicted PV output, based on weather forecasts, to make sure self-consumption is maximised.

Sonnenbatterie is initially rolling out its community model in Germany only.

German energy market

The concept is particularly suited to the German energy market because regulators there are already concerned about the level of renewable energy on the grid and are keen to provide incentives to solve the problem.

One example is a €0.0025 payment per kilowatt hour, on top of current feed-in tariffs, for renewable energy producers that are able to find customers for their supply rather than just dumping their production onto the grid.

Sonnenbatterie’s peer-to-peer scheme would qualify for this, giving its members a faster way to offset the cost of PV and battery equipment.

Another feature of the system is that Sonnenbatterie can see how much energy is held in reserve, and unlikely to be used immediately, at any point in time.

It can then use this reserve to provide grid-balancing services, earning fees from the grid operator.

Monthly subscription charge

As well as this income, Sonnenbatterie will make money from a €19.90 monthly subscription charge per household, and from equipment sales.

It is planning to install pop-up retail pods across German shopping malls, airports and train stations, promoting combined PV and battery products.

The battery systems will be from Sonnenbatterie’s current eco range, which goes from 2kWh up to 16kWh, while the PV systems will be sourced from a third-party vendor, with a strong preference for German makes, Schröder said.

Unlike other residential battery products, the Sonnenbatterie PV and storage packs will come with all necessary inverter and coupling systems, making them largely plug-and-play and cutting installation costs.

Sonnenbatterie expects the end result to undercut equivalent offerings from competitor brands such as Tesla. It is also planning to offer further incentives, such as an upfront equipment discount and free kilowatt hours.

Tesla “doing a great job”

But Schröder, who served as Tesla’s German boss until last month, is keen to emphasise that it’s not other storage companies he is after. “We like Tesla because it’s doing a great job of putting the market in place,” he said.

In fact, Sonnenbatterie is praying Tesla does not botch its Powerwall pitch because that could put customers off battery storage altogether. “Our greatest fear is that there will be serious issues with it,” Schröder said.

His greatest hope, meanwhile, is that Sonnenbatterie can forever change the way energy is distributed.

This is less about taking down utilities per se, and more about doing away with the messy centralised distribution model they represent.

Schröder cites growing up near a proposed nuclear waste repository site at Gorleben, Lower Saxony, as a major influence on his renewable energy career path.

There is nothing to stop utilities going down the peer-to-peer route, too, he said. “We think in 10 years time the market will look like this,” he said. “It’s not a system based on subsidies or monopolies.”

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