|
|
|
|
|
|
Further DiscussionThe model uses five primary weather variables: temperature, relative humidity, cloud cover, wind speed and direction, and precipitation. Precipitation is itself more a category than a mathematical variable. In some climates, TESLA only uses rainfall, typically measured as cumulative amount by hour. In other climates, it includes a family of precipitation variables, including rain, snowfall, and other types of precipitation (e.g. freezing rain). Useful extensions of the precipitation variable include the cumulative snowfall over the previous 12 or 24 hours, and the amount of snow and ice on the ground at 7.00am [07:00], when people make their decisions to go to work, and institutional closing decisions are made (e.g. whether or not to cancel school or close governmental administrative functions). Variable Effects of WeatherThe effects of the weather variables vary tremendously across the day, by season, and by day type. The model takes these differences into account through two mechanisms: stratification and variable parameters. These adjustments allow a one degree variation in temperature, for example, to have a different effect on a Tuesday at 3.00am [03:00] in March, than it will on a Monday holiday in September, at 12.00 noon [12:00]. TemperatureNormally, the most significant weather measure is temperature. As with all the weather variables, the relationship between load and temperature is highly nonlinear. We accommodate the nonlinearity with a piecewise linearization, because the response does not follow any common, specific functional form. Electric load as a function of temperature will on average be at a minimum at around 18.3 degrees Celsius (65 degrees Fahrenheit), but this will vary by day of the week, season, and hour of the day, and recent weather history. |
Send mail to
tony.baker_AT_teslaeurope.com (replace
_AT_ with @) with questions or comments about this web site.
|