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“The status quo of energy storage industry is much the same as that of photovoltaic industry ten years ago”, said by many professionals in energy storage industry. The reason why the PV industry has been taken as a benchmark for the energy storage industry stems from the decline in costs and the speed of scale expansion in the past decade, which is also what is happening in energy storage field. To achieve the goal of carbon neutrality, energy storage and new energy will serve as a combined solution to the environmental and economic challenges. Therefore, the future development of energy storage has big shoes to fill.
At the same time, in consideration of the high consistency of customers and channels of the two industries, increasing number of PV companies begin to launch energy storage products, from battery cells to integration services, and “PV+ESS” has become one of the key words in the new energy field. According to the statistics from PV Men, almost all inverter manufacturers have introduced corresponding energy storage systems. In addition, leading component enterprises such as Trina Solar, Risen Energy, Jinko Solar and Canadian Solar have also presented their energy storage solutions.
The energy storage has already become well-known among passersby and presented a stage for swarming crossovers, but can they put up a classy performance on the stage? No final conclusion has yet been reached on this question for now. But what seems certain is that it is not as simple as doing the math problem of 1 + 1 = 2 for single PV power station to move towards the PV+ESS integration. Instead, the synergy effect like 1+1> 2 is required during integrated development process.
The “charm” of 1+1> 2
According to Chen Sixiong, CEO of Kehua Data Co., Ltd., the energy storage system is much more complicated than the PV system. “The photovoltaic system has only two ports, DC input and power grid. Relatively speaking, photovoltaic power supply only is unstable but its power fluctuation is relatively controllable. However, a microgrid system with energy storage includes four ports: photovoltaic DC input, energy storage terminal, power grid and load terminal, among which there are three more volatile variables, demanding more complicated management of energy flows.
Due to its complexity, the same energy storage system may produce drastically different effect. “There will be significant difference between the actual result and the theoretical value for many energy storage or microgrid systems”, Chen Sixiong takes a microgrid energy storage project on an island in southeast coast of China as an example. The power supply mode of the island is complex, the power grid coverage is limited and it mainly relies on diesel generators for power supply, thus problems such as tripping, power failure and unstable power supply often occur during the use of the original power system. Later, as one of the Golden Sun National Demonstration Projects, the island built an off-grid solar system, which, however, cannot achieve the expected goal due to its poor stability and efficiency.
At the end of 2019, in active response to the requirement of customer, Chen Sixiong said: “KEHUA made a thorough investigation, taking consideration of the terrain there and climate factors such as high humidity and high salinity and offered a customized microgrid ESS solution for the project. It integrates the power supplies on the island into a system to form a suitable microgrid. This move has completely solved customers’ pain points. Stable power supply was guaranteed and more importantly, the annual on-grid power was increased by 37.1%, with the total number exceeding 1 million kWh for the first time, which was highly recognized by customers. “Thanks to the solution from KEHUA, we are relieved from the sore point of power failure from time to time over the years. But now, the system is very stable and the power generation has also increased significantly, so we have not used diesel generators for a long time.” said the customer.
“Customer-orientation is the service tenet of KEHUA, and every solution and technological innovation launched by KEHUA will definitely focus on solving a pain point or meeting demand of customers. The feedback from the customer is “KEHUA’s solutions offer us practical assistance and will achieve every commitment they put forward”. When talking about the cases of solving practical problems for customers, the technology expert has an irrepressible sense of achievement.
“Another case is the application of oil well pumpjack power generation project. Previously, the project owner has always used gas generator for power supply, but it fluctuated greatly due to the low POPM. Once, one of the Fortune Global 500 companies tried to optimize this project, but finally failed. Later, backed by strong technical platform, KEHUA made in-depth research, fully understood working characteristics of the gas generator and running characteristics of the loads, solved problems confronted in early operation one by one, and finally adopted multiple technological innovations to conquer the technical application difficulties of microgrid ESS in the industry. These breakthroughs not only provide a stable power supply for the owner but also reduce a considerable electricity cost and wear and tear of gas generator “.
Similar cases are too numerous to count. Chen Sixiong concluded, “Different from residential ESS, the microgrid system often has power above megawatt-level. With the increase of system scale, there will be system risks caused by problems such as IGBT damage. Without strong support from an experimental platform and sufficient experience accumulation, an enterprise is unable to respond to customers’ needs for a rapid solution to engineering problems. Only powerful enterprises like KEHUA, with a deep accumulation of power electronic technology and a certain scale advantage, have the strength to do so and do it well!”
Technology Accumulation in Power Electronic Field
Looking backward, KEHUA has been exploring businesses regarding the energy storage inverter, energy storage system, and microgrid system for more than 10 years, and has had a deep accumulation of power electronic technology for 33 years, with countless application scenarios explored. Chen Sixiong reckons that, for KEHUA, the biggest competitive advantage comes from two aspects. First, KEHUA itself attaches great importance to the continuous investment in products and technologies, which is the basis for innovation; second, the internal management of KEHUA is scientific and rational. Regardless of the ever-changing market, KEHUA can keep up with the pace of market changes from R&D to marketing, which is the absolute guarantee for its long-term development.
Fundamentally, the energy storage system still relies on power electronics for energy exchange, which reveals the very important factor for inverter enterprises to flood into the energy storage field—technical homology. But for KEHUA, the technical homology therein not merely lies in the inverter technology accumulation.
It has so far been 33 years since KEHUA was founded in 1988. KEHUA has independently trained four experts with state council special allowance. It has been ranked first in China for more than 20 years in two business sectors, i.e., uninterruptible power supply (UPS) and micro-module data center market. The two business sectors are also based on the power electronic technology background. “Both the inverter and the energy storage system are technically homologous to the UPS business and also classified into the power electronic field”. Based on these decades of technological accumulation, currently KEHUA’s PV inverter has a cumulative installed capacity of over 18 GW around the globe, and is maturely used in the large-scale ground power station, distributed power station, PV composite project, etc.
In the microgrid field, KEHUA’s energy storage system has a cumulative installed capacity of over 1.1 GW around the globe, and has rich experience in energy storage projects such as power generation side, power grid side, user side, and microgrid. Project cases involve
· the highest substation energy storage project in the world – Sanga and Zhongba 220kV Substation Energy Storage Project of Ali-Middle Tibet Plateau Power Grid Interconnection Project,
· the largest smart energy demonstration project in the world – Guangdong Power Grid DC Microgrid Smart Energy Demonstration Project,
· the first PV technology leader energy storage demonstration project in China – Shaanxi Tongchuan/Shanxi Changzhi PV Technology Leader Base Energy Storage Project,
· the SGCC’s first 100 MW grid-side distributed energy storage demonstration project – Henan Power Grid 100MW/100MWh Grid-Side Energy Storage Project and
· the first large-scale energy storage test demonstration project in the network domain approved by the National Energy Administration – Gansu 720 MWh Large-Scale Energy Storage Power Station
Guided by the goal of carbon neutrality, KEHUA, known for its technology and rooted in rich experience in multi-scenario integration solutions, is evolving toward a ” PV+ESS Solution Expert” in the new energy field. KEHUA takes energy storage as the development focus of its renewable energy business, makes innovations on PV+ESS application based on technologies, and implements the carbon neutrality goal in a scientific and efficient way.