How PJM Prepares for Summer & Winter

PJM works with its member companies to assure that the system is positioned to run reliably no matter what the weather brings. Winter and summer are the peak seasons for energy use. Temperatures are more moderate and demand isn’t as high in the months between winter and summer when maintenance outages are typically scheduled.

There are some differences to consider for each season. Both summer and winter operations rely on using a diverse fuel mix for generation. However, in the winter, consumers rely on natural gas for their heating, and some electricity generators rely on natural gas to run their plants. Gas/electric coordination becomes more critical in the winter.

Seasonal Differences

Select the icons to see ways these differences are addressed.

Hot summers drive air conditioning use.
Seasonal Operations Preparation - Summer - Peak
Usually, summer has the highest peak usage of electricity for the year.
Seasonal Operations Preparation - Summer - Heat Wave Prolonged heat waves can lead to increased power load on transmission lines and wear on facilities.
Seasonal Operations Preparation - Summer - Wind Wind generation is not as strong as in winter.
Seasonal Operations Preparation - Summer - Demand Response Typically more demand response resources are available.
Seasonal Operations Preparation - Winter - Gas Cold weather causes high demand for natural gas because of the need for residential heating systems and fueling power plants.
Seasonal Operations Preparation - Winter - Pipeline Delivery of gas from pipelines can sometimes be affected by severe weather conditions.
Seasonal Operations Preparation - Winter - Wind Electricity from wind generation is higher than in other seasons.
Cold temperatures can impair the start-up of plants that aren’t already running.
Seasonal Operations Preparation - Winter - Ice Ice and snow can cause problems on distribution lines.
Seasonal Operations Preparation - Winter/Summer Checklist Seasonal Operations Preparation - Winter/Summer Checklist