About Save On Hydro

How We Started

Save On Hydro began with a personal search for a practical way to reduce electricity costs for EV charging under Ontario’s changing hydro plans. We subscribed the Ultra-low Overnight (ULO) plan in November 2023, not long after it was introduced. We installed a smart water heater controller to prevent our tank from heating water during on-peak hours. The controller also provided daily energy-usage reports, allowing us to monitor our water-heating consumption with accuracy.

What We Found

Using this real usage data, we applied a statistical model and methodology to evaluate how the controller affected water-heating costs under both ULO and Time-of-Use (TOU) pricing. The results were encouraging: the controller not only avoided higher on-peak charges under ULO, it also reduced our overall water-heating cost by about two-thirds. More importantly, the analysis showed that savings under ULO are not automatic. Without shifting water heating to overnight hours, overall annual electricity costs would have increased, even when EV charging was scheduled overnight. All assumptions, calculations, and findings are documented in our research and case study report for anyone who would like to review the full analysis.

Why We Created Save On Hydro

After year long study, we found that what matters most to homeowners is the overall outcome on their household electricity bill, not isolated savings from individual appliances. Save On Hydro was created to share that perspective and the practical lessons behind it.