EMO:Getting Good Data
When solving EMO to reproduce dispatch solves from SPD (i.e. solves done by SPD when calculating final prices), or to look at what-ifs, it is essential that you have good data feeds into EMO. The following are our recommendations, and tips.
When comparing the market to EMO dispatch solves, always keep in mind that there are differences between what actually happened in the market and what EMO solves.
This arises for three main reasons:
- Dispatch is based on forecast demand whereas SPD solves for final prices with metered half hourly demand.
- Frequency keeping stations operate within their respective frequency keeping bands and not at exactly their dispatched MW values.
- The large hydro systems are generally allowed to block dispatch, under which they are given their station dispatches but they can change individual station outputs as long as the total system output equals the total MW dispatch for the block (the exception is when a block is split by a line constraint within the block). As a result, you will often see one station in a block up and one down by the same amount relative to the dispatch given by EMO.
The above is based on the assumption that you set EMO up to access actual generation data (from SCADA on em6) from your database for use in Market View mode. You could also choose to extract generator dispatch from the daily SPD data files available on the EA web site, in which case the agreement between EMO and the SPD generation data will be much better.
You also need to make sure that you have EMO download the latest data files from our web site, by going into File>>File Inputs and clicking on the "Check for New Files Box". The data that we make available for EMO is extracted from the SPD daily data files on the EA's web site, which is the data used by the Pricing Manager for final pricing. However, it is easy to end up working with the wrong set of inputs because these files come out in different versions, so you need to make sure that you are using the latest version that matches final prices.