‘We can go further than five years’: CATL on Tener BESS and its ‘zero-degradation’

The industry’s reaction to the claim was mixed, with some praising the firm, some dismissing it as a marketing gimmick and some speculating on what technology CATL was using to achieve it. Details on that technology were given two months later at Intersolar Europe in Germany, with executives including CATL director of ESS Europe Kevin Tang answering questions from journalists, including Energy-Storage.news.

In this Q&A, Tang discusses the Tener product, its zero degradation technology and what that means in practice, vis-a-vis warranties and also for CATL’s existing EnerC grid-scale BESS products. He also touches on the EV market slowdown and the company’s view of BESS pricing.

Energy-Storage.news: Can you explain the reasons for the launch of the new Tener BESS product?

Kevin Tang: CATL began to develop the first generation of liquid-cooling energy storage rack in 2019, which has iterated to the present with Tener Flex being the third generation. CATL racks have always been highly popular in Europe. Tener Flex is developed based on Tener technologies, and is primarily aimed at providing flexible solutions to meet the market demand.

Will you still be selling your EnerC product?

Yes, CATL will continue to sell EnerC.

Where do you see the EnerC product having a place in the market, i.e. which kinds of projects and buyers do you think will continue to buy that instead of Tener? 

Tener products focus on applications with a duration of 2h or more, while EnerC products are still the main products in the application with a duration of 1h.

What drove the decision to develop a product with no degradation for the first five years?

Considering market and profitability, a 5-year zero degradation system can reduce the need for initial sizing of battery capacity and subsequent supplements. The excellent performance can also bring customers higher throughput and consequently more profit.

What is the cost-benefit equation of the benefits of the Tener’s zero degradation? Presumably it costs more than the EnerC (otherwise why would anyone buy the EnerC).

Tener is the brand of CATL’s high-performance energy storage products, which will be more expensive than Ener products. The specific figures need to be defined case by case, because it depends on the user’s application conditions and economic model.

Tener will have more throughput in the whole service life, higher energy density and less site space requirement, and its noise (Maximum 93dBA→75dBA @1m) is significantly improved compared with the previous generation products.

Why five years – is that a technical limit for the no-degradation technology, or could you go further?

CATL can certainly go further. The 5-year zero degradation is based on market demands, with typical market needs for supplements at the 3rd and 5th years. We have a good technical reserve and accumulation for zero degradation technology.

In our demonstration projects, the lifespan of our energy storage cells has already exceeded 15,000 cycles

The no degradation for the first five years, what warranty conditions does that come with?

The zero-degradation technology is based on the condition of one cycle per day, and all warranty conditions are specifically analysed according to operating conditions of every project.

Is there scope to do more than one cycle per day or does that invalidate the zero degradation guarantee? As energy trading becomes a bigger part of activity, and energy markets become more volatile, there may be a need to cycle more than once on specific days of the year. 

Of course, one cycle per day is a typical working condition to evaluate the performance of Tener products. It can be applied to different working conditions. If the number of cycles is more, it will not cause zero degradation failure, but will only shorten the duration of zero degradation. For example, for products with zero degradation in the first year, one cycle per day can maintain zero degradation in one year, but if two cycles per day, the zero degradation time will last for 6-7 months (depending on the working conditions). 

What is your approach to selling your grid-scale BESS into markets? You’ve announced deals both with system integrators (Rolls-Royce) and directly with asset owners (Gresham House), what is your preference?

We are open to cooperate with different types of BESS customers, which include both integrators and direct asset owners.

Have you seen a slowdown in demand for EVs and EV batteries, and has this had an impact on your own manufacturing plans? Will you dedicate more capacity to BESS than previously planned?

EV growth and the overall energy transition may show an occasional hiccup for the moment. But given global EV commitments towards carbon neutrality, the trajectory of EV sales will be move upward over the long term.

We made our manufacturing plans according to customer need and market situation.

So can you confirm you are not adjusting your manufacturing capacity mix in light of the ‘hiccup’ in EV sales? 

Not in the short term, as our overseas production capacity is still in short supply. In the long term, we will make decisions according to customer demand and market situation.  

What are your views on the falling price of BESS – will this continue or have we bottomed out?

We hope the price of BESS products remain stable at a reasonable level, which helps the sustainable and healthy development of the industry.