The dispatch is forced to make an optimal decision for the Day Ahead market without knowing what the Real Time market prices will be. After the Day Ahead market optimal dispatch completes a dispatch window (48 hours) the Real Time market dispatch runs with the Day Ahead market dispatch given as a constant. This is not optimal overall, but it is more realistic. If you look just at the Day Ahead prices, you can see that the system tends to buy from the Day Ahead when that price is low, and sell when that price is high.

It is not strictly a prioritization, but instead a sequence that is designed to mimic the real-life process of bidding in to the day ahead market, and later bidding in to the real time market. A dispatch with knowledge of both prices would only act on one market at a time, 100% Day ahead or 100% real time, whichever has the more favorable price. Our market experts and user feedback have indicated that this would not be very realistic.

To simulate a market where the system is only allowed to export and not allowed to import, you can try a Time Of Delivery contract with a "Percent contracted capacity" as a work-around.