In Ontario, electricity is produced from a number of sources. For a close to real-time supply mix breakdown, please visit the Independent Electricity System Operator website. 

The following table shows Ontario's system-wide Electricity Supply Mix in 2018. (Ontario Ministry of Energy)

2018 Electricity Facts  

Electricity Sources               Ontario's Electricity Mix*   
Nuclear Energy 58.4%
Water Power 23.9%
Natural Gas* 6.2%
Wind 8.0%
Solar PV 2.3%
Bioenergy**  0.5%
Non-Contracted***  0.8%

*Includes Lennox, dual fuel (ng/bio) consistent with IESO.

**IESO's embedded generation data set merges biomass and gas.

***Non-Contracted represents a variety of fuel types that the IESO is unable to categorize due to lack of information from Local Distribution Companies (LDCs).

Note: Figures may not add to 100% due to rounding.