Thanks to the IESO for contributing to this post.
Are you aware that the Save on Energy program can help you to complete energy efficient upgrades in your greenhouse? You may have participated in this program in the past, but the current iteration can help you to retrofit items like ventilation fans and upgrade to LED lighting in the warehouse and the greenhouse.
The IESO has developed tools that can help you identify areas where an upgrade might be able to help you save energy. These include a checklist that walks you through the greenhouse, and some videos and other information on their web page.