What are Thermal Energy Networks?
A thermal energy network (TEN) uses a network of water pipes to interconnect buildings and thermal energy sources to provide space heating, cooling and domestic hot water. The network can harness otherwise wasted thermal energy from buildings, sewage systems, underground transit stations and other “waste” heat sources. Additional baseload thermal sources can include shallow geothermal boreholes, bodies of water, and data centers. When installed, these networks can provide efficient heating and cooling to commercial and residential buildings.
TENs can be supported by different thermal sources to provide heating and cooling for the network, but some key features include:
- They connect multiple buildings with different owners within a shared heating and cooling network.
- They are “bidirectional,” meaning they both supply and receive thermal energy from connected buildings. This enables the management of heating or cooling energy distribution to ensure that demand is met efficiently across all connected buildings or systems, a process known as “load balancing.”
- They transfer renewable, passive, or waste heat from sources to sinks, rather than generating new heat or cooling.
How Network Geothermal Works
At its core, a networked geothermal system includes:
A shared underground loop of piping installed below ground
Ground source heat pumps in individual buildings
A thermal exchange network that allows heat to be shared across the system
In winter, buildings draw heat from the ground or from other buildings with excess heat. In summer, excess heat is transferred back into the network or the ground. Because underground temperatures remain relatively stable year-round, the system operates far more efficiently than traditional heating and cooling methods.
How Networked Geothermal Differs from Traditional Systems
Traditional energy systems are designed around individual buildings and single-direction energy use. Networked geothermal, by contrast, is designed as shared infrastructure.
Key differences include:
Shared systems instead of individual boilers or furnaces
Energy exchange between buildings, not just generation and consumption
Long-lived underground infrastructure with adaptable above-ground components
Lower exposure to fuel price volatility
This approach allows communities to treat heating and cooling as essential infrastructure—similar to water or gas distribution—rather than standalone building equipment.
Why Utilities are Exploring Networked Geothermal
Networked geothermal offers utilities a way to support decarbonization goals while continuing to provide reliable, affordable service to customers.
For utilities, these systems can:
Reduce greenhouse gas emissions
Improve system efficiency and load balancing
Support long-term infrastructure planning
Enable a managed transition away from fossil fuels
Maintain utility–customer relationships during energy transitions
Because networked geothermal systems are designed, owned, or operated by utilities in many models, they offer a familiar framework for oversight, maintenance, and customer protection.
Benefits for Communities and Customers
Networked geothermal can provide meaningful benefits across a range of stakeholders:
Lower and more stable energy costs over time
Improved reliability and resilience
Reduced emissions and local air pollution
Flexibility to serve diverse building types
Long system lifespans with upgradable components
By sharing infrastructure, communities can achieve economies of scale that are difficult to reach with building-by-building solutions.
From Concept to Practice
Networked geothermal systems are already being tested and deployed through pilot projects and early-stage implementations across the United States. These efforts are helping utilities, regulators, and communities better understand system design, cost structures, customer experience, and regulatory pathways.
UNGC exists to support this learning process by bringing utilities together to share experiences, lessons learned, and best practices as networked geothermal moves from concept to scalable infrastructure.