Weather data refers to time series of outdoor weather conditions that are used for applying routine adjustments to energy consumption data. By default, CalTRACK only relies on outdoor temperature as a routine adjustment variable. The open-source eeweather package is used internally in the Recurve platform to match building locations to weather stations and to retrieve the associated weather data. The following procedure is used to fetch quality weather data from the National Oceanic and Atmospheric Administration (NOAA):

• The candidate weather stations are identified and sorted by proximity to the building location.
• The closest weather station is rejected if any of the following are true: a. The candidate station is more than 150 km from the site. b. The candidate weather station’s climate zone does not match the site’s climate zone. c. The candidate station does not have sufficient data quality when matched with site meter data.
• If these criteria are met, use the candidate weather station. If one or more criteria are not met, test the next closest candidate weather station.

EEweather

EEweather is a python package designed to be used in conjunction with the OpenEEmeter to provide weather data for use in fitting temperature-based energy usage models. It comes with a database of weather station metadata, ZCTA metadata, and GIS data that makes it easier to find the right weather station to use for a particular ZIP code or latitude/longitude coordinates.

Features

• Match by latitude/longitude coordinates.
• Convert ZIP Code Tabulation Area (ZCTA) to latitude/longitude coordinates of its centroid.
• Use user-supplied weather station mappings.
• Match within climate zones:
• IECC Climate Zones.
• IECC Moisture Regimes.
• Building America Climate Zones.
• California Building Climate Zone Areas.
• User-friendly SQLite database of metadata compiled from primary sources:
• US Census Bureau (ZCTAs, county shapefiles).
• Building America climate zone county lists.
• NOAA NCDC Integrated Surface Database Station History.
• NREL TMY3 site.
• Plot maps of outputs.

Additional information on running EEweather is available here: http://eeweather.openee.io/en/latest/

OpenEE Platform

There are 4 primary data models in the OEE Platform:

1. Sites - Physical locations where a meter exists such as a building.
2. Projects - Energy efficiency interventions that have been done at a site.
3. Meters - Actual measuring devices that are recording energy usage. (Not required for weather station matching)
4. Meter traces - Meter measurements in time series. (Not required for weather station matching)
   

Projects and meters can both be associated with sites. Site data is used to accurately match a project location to the appropriate weather station, making sure that the most accurate weather data can be applied during analysis.

Weather Matching Process

Site address data gets geocoded into latitude/longitude coordinates as part of ETL. This data is pulled by Open Energy Efficiency and then geocoded to determine the closest available weather station. When data gets loaded into the platform, latitude/longitude has already been assigned.

Data Retrieval

The Platform matches the site’s geocoded data with the nearest station that has sufficient data. Data sufficiency is based on CalTRACK standards, outlined in Appendix A. If data is found to be insufficient, the Platform will go to the next closest available weather station to check for a match.

Once the site is matched to a weather station that meets sufficiency requirements, the Platform will query the NOAA FTP site to download the data. The NOAA FTP site is publicly available, but requires account registration. Open Energy Efficiency queries this site based on the latitude/longitude data that has been assigned to the project site during the ETL process.

In order for the queries to be completed in a timely manner, a weather cache has been built into the Platform.  This automated service goes to the NOAA site daily to refresh weather data and then stores it in the weather cache. The Platform will only query the NOAA site if there is a gap in existing data.  This significantly reduces the time needed to retrieve weather data for each site.  

The Weather Machining process is running in parallel to other data gathering process in order to minimize the time required for analysis.

Weather station matching, in accordance with CalTRACK standards, ensures that your savings calculations are possible.