Hi,
In the nodal price and volume files at Electricity Authority - EMI (market statistics and tools), the rundatetime is usually one minute before the intervaldatetime. Does this mean that the generation and demand in a case are forecast instead of actual for the time period in the case?
Regards,
Ziming
In all SPD schedules, load (or demand) is a parameter given to the model. In the case of RTD schedules, which is what we're talking about here, the load parameter is obtained from meters that provide an instantaneous reading at the time the SPD model is run. Maybe there is a second or two of lag between the meter snapshot and the model being run, I'm not really sure. But the load measurement should be interpreted as the load at that node at that moment.
The generation megawatts is a variable in SPD. So the generation value is what the model says the unit needs to generate in order to meet the fixed load at all nodes, given all of the other constraints in the model - transmission limits, losses, plant capacities, security constraints, etc. So generation is definitely not a metered measurement and I wouldn't call it a forecast either. It becomes the basis for dispatch instructions.
Phil
Hi Phil,
I have some questions about the load from meters.
Regards,
Ziming
No. Load is not sent from smart meters (retailers) to the SO or SPD. You ought to have a good read of part 13 of the Code - it will explain more than you care to know about the operation of the wholesale market.
Part 13.27A and 13.27B explains how 'conforming' and 'non-conforming' nodes are identified. The SO makes forecasts of load at conforming nodes and purchasers (primarily large industrials) submit load bids for non-conforming nodes. See 13.7A and 13.7AA and other parts of the Code for details.
The meters that are used by the SO are meters at grid points.
Hope this helps.
Phil
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