Working on a rate comparison for Xcel Energy here in Denver between their standard declining block Schedule C and the optional TOU-C rate. Client has pretty variable load patterns. Anyone have an Excel model they're willing to share for this type of analysis? Scott H.
Excel model for comparing declining block vs TOU rates?
Scott - I built one for Xcel Colorado rates about six months ago. The key is getting good interval data to model the TOU properly. Are you working with 15-minute data or just monthly usage? The TOU periods make a huge difference in the analysis. Art K.
I have 15-minute data for the past year, which is great. The challenge is properly mapping Xcel's summer vs winter TOU periods and the different on-peak hours. Schedule TOU-C has some complex time windows that change by season. Scott H.
Scott, TOU analysis requires careful attention to rate effective dates since utilities often adjust time periods. For Xcel Colorado, summer on-peak is 2pm-7pm weekdays June-September, winter on-peak is 6am-9am and 6pm-9pm weekdays October-May. Make sure your model accounts for holidays too - they typically get off-peak treatment. I can email you a template that handles these complexities. Randy D.
Randy's template is solid - he helped me with a similar analysis last year. One thing to watch out for is the demand charge differences between the rates. Schedule C has straight demand charges but TOU-C has separate on-peak and partial-peak demand charges. That can swing the economics significantly. Art K.
Randy, I'd really appreciate that template if you could send it over. My email is scott.h.energy@gmail.com. The demand charge complexity is exactly what's giving me trouble - trying to track coincident peaks during different time windows. Scott H.
This thread is really helpful. I'm dealing with similar analysis for Avista here in Spokane. Their Schedule 25 TOU rate has even more complex time periods with super-peak hours in summer. Has anyone worked with rates that have three or four different energy charge tiers by time? Sarah K.
Sarah, multi-tier TOU rates are becoming more common. The key is building a lookup table in Excel that maps every hour of the year to the correct rate tier. I use a combination of WEEKDAY, HOUR, and MONTH functions to automate the classification. For three or four tier systems, consider using Power Query to handle the data processing more efficiently. Randy D.
Update: Randy's template worked perfectly. The analysis showed the client would save about $1,200 annually on TOU-C despite higher peak hour rates because most of their load is off-peak. Thanks everyone for the guidance. Scott H.