- Beyond Sustainability - The Case for Regenerative Design
- Understanding Place - Climate, Site, and Solar Geometry
- The Six Integrated Systems - An Overview
- Building with the Earth—Natural Materials
- Passive Solar Design - Heating and Cooling Without Machines
- Off-Grid Energy Systems - Power from the Sun
- Water - Catching, Storing, and Cycling
- Liquid Waste Treatment - Botanical Systems
- Food Systems—Buildings That Feed
- Community Design - Scaling Up
- The Integrated Design Process
- Appendix A: Glossary of Key Terms
- Appendix B: The Pangea Textbook Series
- Appendix C: Key Design Principles at a Glance
- The Regenerative Community Vision
- Site Assessment and Land Reading
- Land Use Law and Legal Frameworks
- Master Planning for Regenerative Communities
- Infrastructure Systems Integration
- Housing Typologies and Density Design
- Community Governance Structures
- Economic Models for Community Development
- Phased Development Strategy
- Community Resilience and Long-Term Stewardship
- Appendix A: Legal Entity Comparison Chart
- Appendix B: Community Design Checklist
- Appendix C: Glossary of Community Development Terms
At community scale, the energy systems of individual buildings can be interconnected into a microgrid: a local network of generation, storage, and loads that operates either connected to or independent of the utility grid. Community microgrids offer significant advantages over individual off-grid systems: battery storage can be shared across multiple buildings (reducing total storage requirements), generation can be distributed across a larger area (improving total solar harvest), and critical loads can be prioritized during low-generation periods.
The design of a community microgrid requires careful attention to protection, control, and metering systems that are more complex than single-building off-grid systems. Shared governance structures must also be in place to manage shared energy resources equitably. When well-designed and managed, community microgrids provide greater energy security and lower cost per household than individual off-grid systems, while maintaining full independence from utility infrastructure.
Review Questions
1. What is a load analysis and why is it the essential starting point for off-grid energy system design? What information do you need for each electrical device to complete a load analysis?
2. How are peak sun hours used in sizing a solar PV array? If a site has 5 peak sun hours per day and a building needs 4 kWh per day of electricity (after system efficiency adjustments), approximately how large should the PV array be?
3. Compare lithium iron phosphate batteries and lead-acid batteries for off-grid storage. What are the key advantages of each technology?
4. What is the function of a charge controller in an off-grid solar system? Why are MPPT controllers preferred over PWM controllers?
5. What are the advantages of combining solar PV with wind generation in an off-grid system? What site conditions are necessary for wind turbines to be a viable contribution to the energy system?
