FAQs
What can I use this for?
This tool can help you learn and become familiar with the day ahead projected price of electricity, the real time cost of electricity, and how that price will vary depending upon the time of day.
How does this information help me?
By knowing when prices are projected to be high, consumers on Time-of-Use rates or hourly pricing rates can adjust their power use and save money. Consumers are better able to plan when to use appliances that consume large amounts of energy (dishwashers, air conditioners, clothes washers, dryers, etc.) and if possible adjust their usage to times of lesser demand (i.e., lower prices).
What is PJM?
PJM is a regional transmission organization (encompassing all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia). PJM acts neutrally and independently, and operates the world’s largest competitive wholesale electricity market to ensure the reliability of the largest centrally dispatched grid in the world.
PJM’s wholesale electricity market is similar to a stock exchange. It establishes a market price for electricity by matching supply with demand.
What is Real Time Pricing?
Real time pricing is the hourly wholesale price of electricity that is established by PJM.
Is this the same price I see on my bill?
No. If you participate in a Time-of-Use rate this will be the main component of your bill. However, ancillary costs are added by the generating company to recover the cost of transmitting the electricity to your local electric distribution company (PPL Electric Utilities). Think of these ancillary costs in terms of “paying tolls” along the way.
Why does the price of generation change?
Electricity, as with other products, works on Supply and Demand. If supply is tight, the price may go up. If supply is plentiful, the price may fall.
What factors affect supply?
Weather -
- Summer - air conditioning is an example of usage that drives up demand for electricity.
- Winter - prices may increase if the temperature drops suddenly and significantly, or if an extended cold snap pushes up natural gas prices, which increases the cost of operating gas-burning power plants that generate electricity.
Power Plant Availability–
- If there are unexpected mechanical or technical problems at multiple generating plants across the grid, it can cause a temporary increase in prices. To avoid unexpected problems, many generating companies schedule routine maintenance on their facilities in the off-peak periods (spring and fall). If an unexpected heat wave occurs during this time, it can cause an increase in demand and consequently an increase in price for electricity.
When do prices get updated?
At 5:00 p.m. each night, the day-ahead prices are posted for the next day (shown below in green). The real-time prices are then shown in red as they occur on an hourly basis.