Electric Power: The Ideal Backend for Hydraulic Systems
Hydraulic transmission converts mechanical energy from one form to another without generating new energy. Electric motors, however, can provide mechanical energy, establishing electricity as the ideal backend and foundation for hydraulic systems. Modern electric motor technology offers mature, efficient solutions that perfectly complement hydraulic components including hydraulic solenoid valves.
Power Solutions for Mobile Hydraulic Equipment
Mobile equipment has traditionally relied on internal combustion engines due to wiring challenges. However, growing concerns about emissions—including exhaust gases, PM2.5, and CO₂—have driven the need for cleaner alternatives to protect public health and reduce greenhouse effects. Two primary solutions are currently being advanced:
1. e-Fuel Technology
e-Fuel, derived from "electrofuel," refers to synthetic gasoline—high-purity hydrocarbons produced by artificially combining hydrogen with CO₂ from the air. These fuels can be used in gasoline engines, producing only water and CO₂ when burned, achieving carbon neutrality without other pollutants.
The European Union passed a resolution in 2023 that will ban new internal combustion engine vehicles from 2035 onward, with an exception for those using e-Fuel. However, a significant limitation is that nearly all trucks and construction machinery currently use diesel engines, which are not compatible with synthetic gasoline.
2. Electric Power Transition
The second approach involves replacing internal combustion engines with electric power. This transition affects the entire power chain, from energy storage to hydraulic pump operation and the control mechanisms like hydraulic solenoid valves that regulate fluid flow in these systems.
While this shift represents a more fundamental change, it offers greater long-term benefits in terms of emissions reduction and operational efficiency, especially when paired with advanced hydraulic components including precisely controlled hydraulic solenoid valves.
System Architecture Comparison
The diagram illustrates the fundamental differences between traditional combustion-driven hydraulic systems and modern electric-powered hydraulic systems. In electric systems, the internal combustion engine is replaced by an electric motor that drives the hydraulic pump, with sophisticated control systems including hydraulic solenoid valves that manage fluid distribution with greater precision and efficiency.
Energy Storage Solutions for Electric Hydraulic Systems
Battery Technology Considerations
If electrical energy is provided solely by batteries, the limited energy storage capacity requires carrying large quantities of batteries. This creates two significant challenges: the need for frequent recharging and the additional energy consumption required to accelerate and decelerate with the added weight—particularly problematic for equipment that starts and stops frequently.
Furthermore, the recycling and environmentally sound disposal of large quantities of electric vehicle batteries represent a substantial challenge that cannot be ignored. These factors have led to exploration of alternative energy storage solutions for mobile hydraulic equipment where hydraulic solenoid valves and other components demand consistent power delivery.
Fuel Cell Technology
What are commonly referred to as fuel cells are actually fuel-powered generators that use hydrogen (or methane, CH₄) and atmospheric oxygen in a chemical reaction that produces electricity while generating water as a byproduct. To achieve sufficient reaction speeds and power output, these gases must be stored at high pressures (70MPa or higher).
While these high-pressure fuels offer energy density comparable to diesel and gasoline, their storage and control equipment is technically complex, expensive, and relatively heavy. Additionally, hydrogen refueling stations cost more than 10 times that of traditional gasoline stations.
Fuel cell systems integrated with hydraulic components represent a promising middle ground, offering longer operation times than batteries while maintaining the environmental benefits of electric power. These systems require specialized hydraulic solenoid valves designed to operate efficiently with the unique characteristics of fuel cell-powered hydraulic systems.
Practical Applications and Industry Adoption
In Germany, waste collection vehicles that travel through neighborhoods, collecting waste from households with frequent stops and starts, consume significant amounts of energy. Standard 26-ton vehicles traditionally required 200-300kW diesel engines to operate their complex hydraulic systems, including numerous hydraulic solenoid valves that control lifting, compaction, and ejection functions.
Case Study: Fuel Cell Waste Collection Vehicles
The Zöller Group, a specialist in waste collection vehicles, collaborated with Mercedes-Benz Trucks to develop fuel cell-powered waste collection vehicles. By the end of 2022, over 100 units had been sold, demonstrating the growing maturity and acceptance of fuel cell technology in demanding hydraulic applications.
These vehicles integrate advanced hydraulic systems with precise hydraulic solenoid valves that optimize energy use during the frequent start-stop operations characteristic of waste collection routes.
Hydrogen Infrastructure Developments
Recent years have seen numerous reports of hydrogen deposits, or natural hydrogen, being discovered worldwide. At the 2024 Hannover Messe, hundreds of companies showcased their developments in complete hydrogen industry chains, from storage and transportation to utilization—including components specifically designed for hydrogen-powered hydraulic systems with specialized hydraulic solenoid valves.
These developments suggest a growing ecosystem that could support wider adoption of hydrogen-electric solutions for hydraulic equipment, addressing both environmental concerns and operational requirements.