Analyzing Extreme Weather Events in Energy Planning

The Regional Technical Forum models how heating and cooling equipment performs in various climates as part of its work and provides climate specific energy savings for weather dependent measures. It does this using ‘typical meteorological year’ weather. The RTF works hard to ensure the data represents the region’s climate so they can accurately capture the performance and energy savings of important HVAC measures. The data are regularly updated as more up-to-date information becomes available.

Recent weather events in the region – think April snow or June heat dome – suggest that the past may no longer be a reliable predictor of the future. Climate change is warming the planet, however it is not doing so uniformly. These extreme weather events have significant implications for the energy grid, affecting how people use energy. As a result, the Council and RTF have been exploring methods for improving its analysis, mindful of climate change impacts.

To better understand the energy impacts of atypical weather events, the RTF contracted with Ben Larson of Larson Energy Research, and Justin Sharp of Sharply Focused, to conduct an analysis on the performance of weather-sensitive technology under extreme weather conditions and identify opportunities for improving equipment performance. Larson presented the findings and conclusions from this exercise at the Council’s September meeting.

Highlights of this study include:

• Extreme events are much colder/hotter than the coldest and warmest events captured in the typical meteorological year data used for most efficiency analysis. The study identified historical proxy events similar to the ‘extreme events’ occurring roughly every 1 in 10 years over the last 30 years.
• Modeling using these proxy events demonstrated several ways extreme weather affects energy use and the grid. First, extreme weather significantly increases both energy use and peak power, underscoring that extreme weather is a strain on the grid, something to plan for going forward.
• There are ways that the system might cope with these extremes. In extreme cold events, heat pumps can reduce both energy use and peak power compared to electric resistance only heating, but those savings are very dependent on weather, with colder climates seeing less benefits. The analysis also showed that in the most extreme cold events, the heat pump can no longer operate in its efficient mode, resulting in the backup electric resistance heating being used for the house. Since electric resistance heating requires much more energy than a heat pump, this would result in significant impacts on the grid.
• Insulation upgrades demonstrate a clear benefit to both energy use and peak power, in addition to comfort benefits for occupants. Results also laid out how thermostat schedules are a large contributor to reducing peak load in a single system. Demand response programs with control of that schedule could be a very effective tool in this.
• Analysis also identified that future hot weather may exceed the cooling capacities of currently installed systems, which is relevant to the region’s growing summer load.

Additional research is needed to better understand the impact of extreme events stemming from climate change on the power system, and how these results need to be considered in future planning. This work makes clear that there are measurable impacts and opportunities for more work in this space in the Council’s efforts to most accurately capture the region’s power system and needs.