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HIGH-VOLTAGE LITHIUM STORAGE - secure + efficient battery storage solution of the next generation

Periodic Reporting for period 2 - HiVOLT (HIGH-VOLTAGE LITHIUM STORAGE - secure + efficient battery storage solution of the next generation)

Reporting period: 2019-10-01 to 2020-09-30

HiVOLT describes the market introduction of a stationary battery storage system, which significantly increases the application possibilities of battery storage and achieves an unprecedented price-performance ratio. The solution is based on a new technology, the high-voltage storage technology, which significantly revolutionizes the current storage approach. Until 2018, high-voltage technology had only been introduced in small quantities in one vehicle class (upper class) in the automotive sector. We have taken the next step towards stationary applications for the broad mass market. Instead of the low voltage range (50 V alternating voltage), the HV70 of TESVOLT works in a voltage range of 700 V. This promises a significant increase in efficiency and cost reductions. Savings result from the elimination of transformers and reduced system costs due to lower currents.

This technological leap was made possible by several TESVOLT innovations. In high-voltage storage technology, for example, several battery storage units must be connected in series - highly complex with appropriate regulation of the currents and voltage of individual battery modules. TESVOLT has developed and patented a unique high-voltage battery management system - the ABO. It can detect differences in the high-voltage battery system and optimize each individual battery cell within a battery module via cell balancing. Further innovations in high-voltage lithium storage are the static switch, the built-in prismatic cells and the modular design of the automatically mountable battery modules. All in all, these innovations offer outstanding cost-effectiveness.
The market for this new generation of stationary battery storage products is gigantic. The higher the proportion of volatile energy fed into the power grid, the greater the growth in electricity storage demand. All over the world, energy grids need flexibility in order to compensate for fluctuations in the supply of wind and PV. Battery storage systems will become system-relevant for all energy networks with a high proportion of renewable energies. Battery storage systems are a key technology in the energy revolution - and can be used for a wide variety of applications.

The technical and commercial objectives defined in the project were largely achieved. HV70 was introduced to the market in many European countries. International projects in Asia, Latin America and Africa complement this. Specifically, our high-voltage storage system meets the following customer requirements:

1) Reduction of the acquisition costs of battery storage systems. Automated production has made it possible to reduce the investment costs per kWh under 600 €/kWh and to lower the specific electricity storage costs to 0.08 €/kWh.

2) Ensuring a safe and reliable power supply. TESVOLT HV70 reliably compensates for fluctuations between power generation and consumption, which serves to stabilize the power supply. Flexible and modular battery storage system enables a controllable energy supply
based on renewable energies.

3) Increasing the application possibilities of battery storage systems in the size range between single-family homes and wholesale markets. Economic multiple use of battery storage (e.g. for the provision of control energy).

4) Reduction of peak power through the use of battery storage. TESVOLT HV70 has been designed to be compatible with a three-phase inverter (allowing connection to the public grid).

5) Enables our target users to generate electricity in an effective and environmentally friendly way. In combination with battery storage, renewable energy sources provide an optimal solution for remote locations. They guarantee a reliable power supply without any
failures. TESVOLT's high-voltage storage can store energy very quickly and release it just as quickly, which is a major competitive advantage.
The technological activities of the second project are:

• Optimizing the efficiency of the storage system
• Establishment and introduction of an integrated production planning system with partial automation, roll-out of production: Use of the established production line at the TESVOLT main site for all future module variants with regard to mechanics and electrics /
Establishment of the TESVOLT main site as an intelligent production hub
• Optimization of the quality assurance function through end-of-line testing on the production line
• Practical implementation of production to the requirements of the individual production steps and components of series production - Proof of the fulfillment of target parameters for quality and productivity of the individual production steps and components
• Demonstration of the system properties in 3 market segments: Energy supply, on-grid solution, off-grid solution

The commercial activities were the focus in the second project year. They included:

• Further development of a multi-stage commercialization strategy: Establishment of a two-stage distribution via a qualified network of specialized partners and supporting country organizations in the defined core markets according to local conditions and market
maturity. In addition, the sale of TESVOLT battery storage units as white label
• Development of a strong pull with potential end customers and direct links to specialist partner networks
• High speed in marketing, especially online marketing
• European tour and training offensive, supported by social media
• Expansion of Key Account Business (Maritime, Utilities etc.) and OEM as strategic core business. OEM mainly use in segments in regions that are difficult to access for TESVOLT.
• Further acquisition of distribution partners, strategic partners
• Realized orders in the amount of ≈20€ million in 2020
The technology of the TESVOLT high-voltage lithium storage is based on the interaction of a high-voltage battery with an adapted inverter. The high voltage level of the battery allows direct connection to the inverter, reducing conversion losses and eliminating the need for an expensive and heavy transformer. Instead, the TESVOLT battery has a simple step-up converter that converts the voltage from low to high voltage. The advantage over conventional storages lies in the significantly lower system costs of more than 50 % in power electronics. Furthermore, the approach leads to a decoupling of the further development of battery and power electronics. The inverter does not have to be adapted to the development of the battery and vice versa. There are also no more restrictions on the battery voltages.

In the past, the consequences of a change in the technology approach have already been seen in PV inverters. With the possibility of increasing string voltage, PV inverters became much cheaper and more efficient. Today there are almost exclusively transformerless PV inverters. At the same time, we expect that our solution will prevail on the market by using a transformerless high-voltage inverter.

With this new product, we offer a product with specific added value compared to state-of-the-art technology. The efficiency of the high-voltage lithium storage is outstanding and is determined by three factors: 1. charging cycles, DoD, efficiency (= cost of stored electricity), 2. investment costs, 3. system costs.