Micro-Grid Technology
Shimizu's Micro-Grid System: Protecting against Power Outages and Enabling Use of New Energy Sources and Energy Conservation
Through an electric power network, micro-grid technology connects multiple power-generating facilities and electrical storage devices, including natural-energy sources such as solar power, thereby ensuring a stable supply of electricity. The micro-grid system provides optimal control, adjusting and maintaining the balance between demand and supply to ensure a stable supply of electricity. The system makes it possible to connect new, large-capacity energy sources that contribute to reductions in CO2 emissions while facilitating connectivity to legacy electrical power systems.
A Micro-Grid System for Urban and Suburban Applications
A Micro-Grid System for Urban Applications
Self-sustaining power supply for BCP
• Disaster-prevention facility
• Power supply for hospitals, hotels, manufacturing facilities, etc.
• Power-supply system for industrial complexes
For urban areas, Shimizu proposes the construction of a building power-supply system based on a micro-grid system that combines natural gas cogeneration systems and electrical storage devices. This configuration is ideal for customers who require large amounts of electricity and heat energy since the use of cogeneration systems can significantly improve energy efficiency.
Micro-Grid System for Suburban Applications
Promoting solar-power generation and biomass usage
• Power supply for individual buildings
• Improvements in regional energy self-supply ratios created by localizing energy generation
• Power-supply system for remote islands
By combining systems that rely on natural energy with large fluctuations in power output and distributed power-supply units that use biomass or other sources, the micro-grid system for suburban applications ensures a stable supply of electricity while balancing demand and supply. Verification operations are currently under way in Japan with the goal of significantly increasing natural-energy usage, including solar power and wind power.
Contributing to Disaster-Prevention Planning and Business Continuity Planning (BCP)
Realizing a Self-Sustaining Power Supply with Electric Quality Equal to Commercial Power
A micro-grid system that achieves self-sustaining power supply provides electricity continuously even in the event of a commercial power-supply failure, thereby contributing to effective disaster-prevention planning and business continuity planning (BCP). The micro-grid system for urban applications combines natural gas engines and electrical storage devices (nickel hydride batteries and electrical double-layer capacitors) to maintain frequencies within a range of 50 ± 0.2 Hz and voltage fluctuations within 1%, meeting the criteria for self-sustaining operations. The micro-grid system can serve as a self-sustaining power supply while retaining electric quality equivalent to that of commercial power.
Forms of New Energy
The deployment of distributed power-supply units based on new energy sources such as solar electric-power generation, wind and natural energy, natural gas cogeneration, and biomass power generation is urgently required to combat climate change caused by greenhouse gases.
Natural-energy-based power generation
Energy recycling
Natural gas cogeneration
The Micro-Grid System Installed at the Shimizu Institute of Technology
Our micro-grid system, which entered practical operation in August 2006, produces a total output of 600 kW, equivalent to the power consumed by approximately 200 ordinary households. As such, this micro-grid system is suitable for urban applications.
The micro-grid system consists of two main power-generation units and two electrical storage units. The main power-supply units are based on natural gas cogeneration supported by a nickel hydride battery and electrical double-layer capacitor that are deployed in conjunction to respond to sudden load changes. The photovoltaic generation system contributes to the use of power supplies that are based on natural-energy sources.
By providing integrated control to achieve a balance between demand and supply over very short intervals, the micro-grid system at the Shimizu Institute of Technology ensures a stable supply of electric power and heat energy to each laboratory building. It thereby cuts energy costs while maintaining superior electric quality.
