NAICS 221116

Overview

The North American Industry Classification System (NAICS) is the framework federal statistical agencies use to categorize business establishments for data collection, analysis, and publication across the U.S. economy. Developed under the Office of Management and Budget with the U.S. Economic Classification Policy Committee, Statistics Canada, and Mexico’s INEGI, NAICS replaced SIC in 1997 and is updated on a five-year cycle; current U.S. statistical programs are transitioning to the 2022 vintage. ¹

NAICS 221116 covers establishments primarily engaged in operating geothermal electric power generation facilities that use heat from the Earth to produce electric energy supplied to transmission or distribution systems. It sits within Electric Power Generation and is distinct from transmission and distribution activities classified under 221121 and 221122. ²

See also on G2X:

• G2X — NAICS 221114
• G2X — NAICS 221115

What this NAICS covers

• Operation of geothermal electric power generation plants. ²
• Use of geothermal (Earth-derived) heat to drive electricity production. ²
• Provision of generated electricity to power transmission systems. ²
• Provision of generated electricity to power distribution systems. ²
• Electric energy production at utility-owned or independent geothermal facilities categorized as generation, not transmission/distribution. ²
• Inclusion within the Electric Power Generation subsector alongside hydro, fossil, nuclear, solar, wind, biomass, and other generation industries. ²

Related NAICS and PSC codes

Type	Code	Descriptor
NAICS	221114	Solar Electric Power Generation
NAICS	221115	Wind Electric Power Generation
PSC	S112	Utilities – Electric
PSC	9105	Electric Power Supply from a Third Party Generation Entity

Key exclusions (where similar work is classified elsewhere)

• Incineration facilities that dispose of solid waste and also generate electricity are classified in 562213, not in electric power generation. ²
• Transmission system operation and voltage control fall under 221121, not 221116. ²
• Distribution of electricity to end users is classified in 221122, not generation. ²

History and structure notes

NAICS 221116 was created in the 2012 revision by splitting former “Other Electric Power Generation” (221119 in 2007) into separate renewable generation industries (solar, wind, geothermal, biomass) and a residual “other” category; this delineation remains in subsequent vintages. ³

Frequently asked questions

• What activities define NAICS 221116? Establishments operate geothermal power plants that convert Earth-derived heat into electricity for delivery to transmission or distribution networks. Activities are limited to generation; transmission and distribution are classified elsewhere. ²

• What kinds of work are explicitly outside 221116? Electric power transmission/control and power distribution are coded to 221121 and 221122, respectively; trash-to-energy incinerators are in 562213. ²

• Is NAICS 221116 current under NAICS 2022? Yes. The Census Bureau is implementing NAICS 2022 across programs through 2027, and electric power generation industries, including 221116, remain in scope. ¹

• What is the SBA small business size standard for 221116? SBA’s table sets the size standard for 221116 at 250 employees (employee-based measure). ⁴

• Which PSCs often align with electricity buys related to geothermal generation? PSC S112 covers utility electric services; PSC 9105 covers electric power supply from a third-party generation entity where permitted. ⁵

Useful resources

• G2X — NAICS 221116 page: https://app.g2xchange.com/naics/221116
• Census — 2017 NAICS Manual: Sector 22 Utilities (industry definitions for electric generation, including 221116). ²
• Census — Implementation of NAICS 2022 (transition timeline and context). ¹
• Census — “New in 2012” (creation of 221114/221115/221116/221117/221118 from 221119). ³
• SBA — Table of Small Business Size Standards (current size standard for 221116). ⁴

References

1. U.S. Census Bureau — The Census Bureau’s Implementation of the 2022 NAICS: https://www.census.gov/library/reference/code-lists/naics/2022/implementation-timeline.html
2. U.S. Census Bureau — 2017 NAICS Manual (PDF), Sector 22: Utilities (pp. 119–121): https://www2.census.gov/library/reference/naics/publications/2017-NAICS-Manual.pdf
3. U.S. Census Bureau — Economic Census “New in 2012” (electric power generation breakouts): https://www.census.gov/programs-surveys/economic-census/year/2012/about/new.html
4. U.S. Small Business Administration — Table of Small Business Size Standards (Effective March 17, 2023): https://www.sba.gov/sites/default/files/2023-06/Table%20of%20Size%20Standards_Effective%20March%2017%2C%202023%20%282%29.pdf
5. General Services Administration — Product and Service Codes (PSC) Manual (April 2025) (PDF): https://www.acquisition.gov/sites/default/files/manual/PSC%20Manual%20April%202025.pdf