CIAC (contribution in aid of construction)
A contribution in aid of construction is a payment a customer makes to a utility to cover the cost of facilities built to serve that customer, such as a substation, line extension or gas lateral. For large data center loads, CIAC can be a major early cost and is often paid before construction begins. How it is calculated, refunded or credited varies by utility and state regulation.
The full guide · Power & interconnectionTransmission Upgrades for Data Centers: Who Pays for Them?Who pays for data center transmission upgrades: direct-assignment vs. network upgrades, participant funding, rate-based recovery and the 2026 rule changes.Where CIAC comes up
- Power & interconnectionContribution in Aid of Construction (CIAC) and Line Extensions for Data Centers
- Power & interconnectionLarge-Load Tariffs and Electric Service Agreements, Explained
- Power & interconnectionHow the Large-Load Utility Interconnection Process Works
- Decisions and trade-offsUtility-Owned vs. Customer-Owned Substations for Data Centers
- Power & interconnectionElectricity Rates and Power Costs for Data Center Sites
- Zoning, permitting & communityImpact Fees and Utility Connection Fees for Data Centers: How They Work and What Is Negotiable
- Feasibility, diligence & dealsData Center Construction Costs per MW and the Site Factors That Drive Them
- Power & interconnectionTransformer and Switchgear Lead Times for Data Centers