Sonnenbatterie, the battery company that recently poached Tesla’s top German team, is announcing an all-in-one residential PV and storage system for €9,999 ($10,645).
The price, being unveiled in a Berlin press conference today, includes a 2 kilowatt-hour eco 2 Sonnenbatterie battery, a German-made PV panel, an inverter, an intelligent control system and 19 percent sales tax (called value added tax or VAT in Europe).
The only cost not included is installation, since this varies according to location. Philipp Schröder, Sonnenbatterie’s managing director, told GTM a “low-end” installation cost could be in the region of €700 ($745), including VAT.
Customers wishing to buy just the battery and control software to attach to an existing PV system will be able to do so for a starting price of €3,599 ($3,830), including VAT.
This compares to a price of €3,035 ($3,234) for a 7-kilowatt-hour Tesla Powerwall in Germany, Austria and Switzerland. However, the Powerwall price does not include VAT. VAT would take the price up to around €3,612 ($3,848). And GTM understands this list price is the wholesale rate, for distributors only. The Powerwall could actually cost consumers around €6,000 ($6,385) before VAT.
The Sonnenbatterie PV and storage system is fully integrated, while the Powerwall needs to have DC-to-DC coupling, worth another €1,000 or so before VAT, estimated Schröder.
To date, the only known published pricing for a Tesla battery and PV system in Europe is €17,900 ($19,075) -- for a Powerwall plus 4-kilowatt Solovoltasolarsystem in Austria.
Sonnenbatterie relies on Sony Fortelion lithium-ion batteries for its storage systems, claiming they can be used for up to 10,000 charge cycles. Tesla CEO Elon Musk has said he expects the 7-kilowatt-hour Powerwall batteries to cycle about 5,000 times.
Sonnenbatterie’s control system tracks solar output, home electricity usage patterns, energy prices and weather forecasts in order to charge and discharge the battery in a way that optimizes the financial return for the homeowner.
Schröder said the Sonnenbatterie pricing being announced today should result in a payback time of nine to 12 years, depending on location and energy consumption patterns. This calculation does not include any allowance for increasing grid electricity rates.
Nor does it include the 30 percent discount available if the equipment is bought with a low-interest loan provided by the German state-owned development bank KfW.
The KfW incentive scheme is due to end this year, although Sonnenbatterie is planning to replace it in January with a €1,875 ($1,995) discount for customers that join a new community energy exchange program also being unveiled today.
The program, initially only available in Germany, comes with a €19.90 ($21.19) monthly service fee and allows Sonnenbatterie customers across the country to share energy and thus potentially cut electricity costs by around 25 percent compared to standard utility rates.
In addition, the arrangement will allow homeowners to get a quarter of a euro cent ($0.0027) bonus on the feed-in tariff for residential solar, which currently varies between €0.09 and €0.12 cents ($0.10 to $0.13) per kilowatt-hour, as part of a German renewable energy commercialization incentive.
Sonnenbatterie itself will use the spare storage capacity across this user base to generate income by providing balancing power for the German grid. This will help pay for the hardware discount being introduced in January.
Furthermore, Sonnenbatterie’s community storage capacity will allow it to acquire and store energy during periods of negative pricing in the German electricity market. As well as profiting from the sale of this energy, the battery company hopes to use it as a further incentive for users.
It intends to give away 1,000 kilowatt-hours of capacity per year to each customer taking on 8 kilowatt-hours or more of storage.
Sonnenbatterie is expecting to launch the community initiative today with its 8,000-strong customer base.
Schröder said this community exchange model, rather than Sonnenbatterie’s pricing, was the key part of today’s announcement because of the benefits it brings to storage customers. “This model of sharing electricity makes conventional utilities in Germany obsolete,” he said.
With the community platform, he said, “We can bundle applications with your storage unit and increase PV use. If you have a storage product, you can use 100 percent of your PV investment and get a quicker amortization of your system, as well as increasing storage utilization through grid services.”
Sonnenbatterie has a roughly 50 percent share of the German residential battery market and also operates in Australia, Italy, Switzerland, the United Kingdom and the United States. It is looking to roll out the community model in these other markets “as soon as possible,” Schröder said.