An inverter is an electrical device that converts direct current (DC) to alternating current. This conversion is necessary for a variety of applications, including solar power systems, in which photovoltaic panels generate DC and the inverter converts it to AC for usage in residential and commercial properties

PEM electrolysis for hydrogen production utilizes a solid electrolyte called “perfluorosulfonic acid proton exchange membrane,” which is selected for its excellent chemical stability, proton conductivity, and gas separation. It replaces the asbestos membrane used in traditional electrolysis, effectively preventing electron transfer and improving the safety of electrolyzer.

Structure: The principal components of a PEM electrolyzerare as follows: Proton exchange membrane (PFSA), anode and cathode catalyst layer (Pt/C, IrO2, RuO2), anode and cathode gas diffusion layer (titanium felt, titanium mesh, carbon felt, carbon paper, etc.), and anode and cathode bipolar plate (nickel-plated stainless steel). The diffusion layer, catalytic layer and proton exchange membrane form a membrane electrode assembly, which is the main site for material transport and electrochemical reactions in the entire electrolyzer. The characteristics and structure of the membrane electrode assembly have an immediate effect on the performance and lifespan of PEM electrolyzer.

Characteristics: PEM provides insulation and gas-tight separation, ensuring better safety and achieving hydrogen purity of up to 99.99%; operating at a current density of up to 2A/cm2, PEM is compact and features low energy consumption for hydrogen production, which can be as low as 4 kWh/Nm3H2; additionally, it offers a wide pressure regulation margin and exhibits excellent responsiveness.

Limitations: Despite its technological advantages, PEM systems are associated with extremely high investment costs. PEM electrolyzers operate under acidic conditions, requiring materials with excellent corrosion resistance. They also rely on catalysts made of precious metals such as platinum and iridium; moreover, the electrolysis cells must be made of materials like titanium or even platinum-coated.

Pressure vessels are classified into five types:

1、Fully metallic structure, typically made of steel.

2、 2、 Predominantly metallic with fiber wrapping in the circumferential direction, often constructed with steel or aluminum, along with glass fiber composite. The metal vessel and the composite material share approximately the same structural load.

3、Featuring a metal liner and complete composite material wrapping, often made of aluminum with carbon fiber composite materials. The composite material carries the structural load.

4、Entirely composed of composite materials with a polymer lining, typically polyamide (PA) or high-density polyethylene (HDPE), and incorporating carbon fiber or carbon/glass fiber composites. The composite material carries all the structural load.

5、No lining; made entirely of composite.

Hydrogen energy storage complements electrochemical energy storage, making them suitable for longer time spans and larger spatial ranges in energy management. Wind power and solar PV systems fluctuate on an hourly, daily, and seasonal timeframes, thus requiring the assistance of energy storage systems customized to different intervals of time. Considering factors such as cost-effectiveness, flexibility, and storage characteristics, hydrogen energy storage is the highest suitability and can be effectively utilized on generation, grid and consumption sides.

In addition to seasonal fluctuations, the spatial distribution of wind power and PV outputs is very heterogeneous, so long-distance transportation is unavoidable: Electrochemical energy storage is not well-suited for long-time and large-space energy storage. It is hard to store electricity in lithium batteries during the summer and keep it until winter; Hydrogen, which has exceptional complementarity to electrochemical energy storage in both temporal and spatial dimensions, is an ideal option.

Our solution involves hydrogen energy for long-term, large-capacity energy storage, while electrochemical energy storage provides supplemental power for small-capacity, high-frequency requirements. As a result, by integrating hydrogen energy storage with wind and solar power generation, electrochemical energy storage, and “production, storage and utilization of hydrogen,” we strive to provide optimal clean energy support to every household and community.

Since hydrogen energy plays an important role in the carbon-neutral “hydrogen + electricity” energy system.

Alkaline water electrolysis (ALK) is the most extensively used method for hydrogen production in current practice. The application of direct current in a high concentration potassium hydroxide solution initiates electrochemical reactions, causing water molecules to undergo transformation at the electrodes. At the cathode, water molecules decompose into hydrogen ions (H+) and hydroxide ions (OH-). Hydrogen ions combine with electrons from the cathode to form hydrogen gas, while the hydroxide ions migrate to the anode to generate oxygen gas and water.

Structure: Electrolyte——High concentration KOH/NaOH solution; separator——Primarily made of asbestos along with certain polymer composite materials; electrodes——Ni, Co, and stainless steel.

Characteristics: This process exhibits low electrolysis efficiency, usually at 60% to 75%; it also consumes a significant amount of energy; the hydrogen produced has a purity of 99% and requires purification to eliminate alkali mist and moisture; it lacks the ability to swiftly start or stop, making it unsuitable for renewable energy; the electrodes are susceptible to corrosion by alkaline liquor.

Limitations: The separator is made of porous material, making it prone to gas permeation; additionally, its thickness leads to substantial electrical energy loss; sudden changes in load may upset the pressure balance on both sides, leading to excessive hydrogen seepage, which poses a risk of explosion; the resulting low responsiveness makes it difficult to integrate with wind and solar power supply; the low current density, the large volume of electrolyzer, the high heat capacity, and the cold start impose limitations on temperature response.

In contrast to ALK and PEM technologies, high-temperature SOEC for hydrogen production utilizes solid oxide as the electrolyte material. At temperatures ranging from 800 to 1000°C, this technique shows considerable increases in electrochemical performance and greater efficiency.

Structure: For SOEC electrolyzers, non-precious metal catalysts are used for the electrodes. The cathode is made of porous metal ceramic Ni/YSZ, while the anode is made of perovskite oxide. YSZ, an oxygen-ion conductor, serves as the electrolyte. The utilization of an all-ceramic structure in the SOEC technology helps avoid material corrosion.

Characteristics: The SOEC system efficiency is expected to reach 85% to 90% by utilizing high-quality waste heat from industrial output (for example, the energy input consists of 75% electricity and 25% thermal energy from water vapor)SOEC electrolyzers are fed with water vapor, and the introduction of carbon dioxide allows for the generation of synthetic gas, which can be subsequently utilized to produce synthetic fuels like diesel and aviation fuel. Therefore, SOEC technology holds great potential for extensive applications in carbon dioxide capture, fuel production, and chemical synthesis.

Limitations: The high-temperature and high-humidity operating conditions impose limitations on the selection of materials for electrolyzers, favoring those with high stability, durability, and resistance to degradation. Thus, it becomes more difficult to choose and implement SOEC hydrogen generation technology widely across a range of applications.. Durability is the foremost challenge in current SOEC technology. Thermal chemical cycles, particularly during system shutdown and startup, accelerate degradation and reduce the operational.