A German state-backed venture capital fund this week invested “several million euros” in Tesvolt, a startup that is claiming the world’s longest-lasting lithium-ion battery.
IBG Risikokapitalfonds III, a Sachsen-Anhalt state fund managed by Berlin-based venture capital investment house bmp Beteiligungsmanagement, announced the backing for Tesvolt after the three-year-old battery maker unveiled its new TS system this month.
“Tesvolt has developed an innovative storage system that features a new safety standard and a service life of 30 years,” noted bmp in a press release. “The IBG investments will go toward the further development of Tesvolt technology.”
The cash injection will also help Tesvolt expand its production lines to meet predicted demand, as well as financing national and international marketing and sales activities, bmp said.
Tesvolt’s TS system, designed for the commercial and industrial market, is due to go on sale at the close of the Intersolar Europe trade show in June this year. The company aims to shake up the lithium-ion battery market on several fronts.
Although it will come with a 10-year warranty, the system is mechanically designed to last for up to three decades, compared with 15 to 20 years for competing products.
Tesvolt CTO and co-founder Simon Schandert told GTM this is important because for some applications, such as self-consumption, cycle rates might be as low as 250 cycles a year.
Since Tesvolt claims the TS can offer 6,000 cycles with 100 percent depth of discharge. This means the battery could in theory still be performing as new after a couple of decades of use, when other products might start to suffer from mechanical failure.
The actual number of cycles covered by the warranty is 4,500 at 23ºC.
Outside this temperature range, the company will use a dynamic calculation process to offer warranty conditions for between -10ºC and 50ºC, “and not only between 18ºC and 28ºC,” Schandert said.
Tesvolt also claims a DC round-trip efficiency of 98 percent, with a warranted minimum of at least 85 percent after 10 years.
Schandert said Tesvolt could provide these warranty conditions by analyzing the state of each TS unit via data pulled from the battery management system and the inverter. The TS is being offered as a modular unit in sizes ranging from 15 kilowatt-hours up to 1 megawatt-hour.
For a “normal commercial system” of up to 50 kilowatt-hours, “we are nearly in the range of €600 to €700 [$650 to $760] per kilowatt-hour [of installed capacity] for the battery,” Schandert said.
Based on standard use, this would yield a cost of energy of around €0.10 to €0.12 ($0.11 to $0.13) per kilowatt-hour, he said. A 50-kilowatt-hour system could be installed within an hour, he claimed.
Tesvolt customers would have to buy an SMA Sunny Island or Sunny Central inverter (for low-voltage or high-voltage systems, respectively), on top of the battery system.
The all-in costs for an entry-level 15-kilowatt-hour system, including installation and a 4.6-kilowatt Sunny Island inverter, would be between €13,000 and €15,000 ($14,000 and $16,000), said Schandert.
This price could drop now that SMA has integrated its power measurement and energy management into a single Home Manager unit, he said. Even so, Schandert admitted the Tesvolt could not meet market leaders such as Tesla on upfront cost.
Nor is it trying to, he said. “We are not low-cost engineering. Our systems are a little bit more expensive than Tesla’s, but our cycle life is quite higher. When you compare all the technologies and costs, you will see the storage cost per kilowatt-hour for our system is lower than other solutions.”
Like Tesla, Tesvolt gets its batteries from Samsung SDI. However, Tesvolt uses larger, prismatic cells that can be monitored individually and are equipped with safety features to prevent fire in the event of a puncture.
Tesvolt also has a decent installation record for a company that only started shipping products in 2015.
Last June, the company installed what it said was the world’s largest decentralized off-grid storage system, a 4-megawatt, 2.68-megawatt-hour project in Rwanda. And in November, it sealed a deal for 3 megawatt-hours of capacity in Mali.
The backing from IBG will allow Tesvolt to build on this success, but Schandert said the company is not aiming for runaway growth or a stock market listing. “We want to grow very healthily,” he said. “We need capital for batteries but not for growing the company.”