Nerdy about Electricity Bills

Darn, Texas Senate Bill 7.

While I may not yet qualify as a full-fledged Texan, I've quickly learned that understanding the state's unique electricity market is crucial for every resident. On June 18, 1999, when Gov. George W. Bush signed Senate Bill 7, Texas embarked on a distinctive path by deregulating its electricity market. This legislation transformed how Texans purchase power, creating a wholesale market where consumers must navigate multiple providers and plans.

This competitive market offers both opportunities and challenges. While choice can lead to better rates, it also requires consumers to make informed decisions about their electricity providers and plans. Having recently faced this decision myself, I decided to take a data-driven approach to understanding my own electricity usage patterns from the past two years.

In this blog, I'll share:

1. How I collected and analyzed my electricity usage data

2. The output of the scripts I developed (with help from Claude) to process this information. Open to sharing the script also.

3. Key insights about my usage patterns

4. How you can use similar methods to make informed decisions about your electricity plan

Thanks to Texas regulations, all electricity providers must make your usage data available to you. This transparency requirement, while seemingly basic, is a powerful tool for consumers (if you know how to use it). In my case, I've been with Green Mountain Energy for the past two years, paying variable rates for my electricity usage. Looking back, this was not a wise approach in Texas's volatile energy market.
Collecting the data should usually be the following:

1. Most providers offer this information through their online portals

2. Look for sections labeled "Usage History" or "Energy Usage"

The longer the history, the better your analysis will be (I collected two years' worth)

Picture of 2024 Usage Broken by Months for 2024

While electricity providers are required to share usage data, the format and accessibility vary significantly. In my experience with Green Mountain Energy, the standard portal didn't provide data in an easily analyzable format. This led me to dig deeper into their website, where I discovered the 'usagehistorydata' page containing detailed JSON-formatted data.

The JSON data breaks down into four key components:

• usageBarskWh: Your daily electricity consumption

• usageBarsCost: The cost associated with each day's usage

• temperatureLines: Daily temperature data to correlate with usage

• usageBarsTick: Timeline markers for the data

• Time (hour/date/month)

This structured data, while not immediately visible through the standard interface, provides the foundation for meaningful analysis. By extracting and processing this information, we can uncover valuable insights about usage patterns and costs. Example of the data is below:

Example of the data format:

"{\"usageHistoryData\":{\"usageBarskWh\":[[1.7304156E12,0.0],[1.730502E12,0.0],[1.7305884E12,0.0],[1.7306784E12,0.0],[1.7307648E12,0.0],[1.7308512E12,0.0],[1.7309376E12,0.0],[1.731024E12,0.0],[1.7311104E12,0.0],[1.7311968E12,0.0],[1.7312832E12,0.0],[1.7313696E12,0.0],[1.731456E12,0.0],[1.7315424E12,0.0],[1.7316288E12,0.0],[1.7317152E12,0.0],[1.7318016E12,0.0],[1.731888E12,0.0],[1.7319744E12,0.0],[1.7320608E12,0.0],[1.7321472E12,0.0],[1.7322336E12,0.0],[1.73232E12,0.0],[1.7324064E12,0.0],[1.7324928E12,0.0],[1.7325792E12,0.0],[1.7326656E12,0.0],[1.732752E12,0.0],[1.7328384E12,0.0],[1.7329248E12,0.0]],\"usageBarsCost\":[[1.7304156E12,0.0],[1.730502E12,0.0],[1.7305884E12,0.0],[1.7306784E12,0.0],[1.7307648E12,0.0],[1.7308512E12,0.0],[1.7309376E12,0.0],[1.731024E12,0.0],[1.7311104E12,0.0],[1.7311968E12,0.0],[1.7312832E12,0.0],[1.7313696E12,0.0],[1.731456E12,0.0],[1.7315424E12,0.0],[1.7316288E12,0.0],[1.7317152E12,0.0],[1.7318016E12,0.0],[1.731888E12,0.0],[1.7319744E12,0.0],[1.7320608E12,0.0],[1.7321472E12,0.0],[1.7322336E12,0.0],[1.73232E12,0.0],[1.7324064E12,0.0],[1.7324928E12,0.0],[1.7325792E12,0.0],[1.7326656E12,0.0],[1.732752E12,0.0],[1.7328384E12,0.0],[1.7329248E12,0.0]],\"temperatureLines\":[],\"usageBarsTick\":[[1.7304156E12,\"11/1\"],[1.7308512E12,\"11/6\"],[1.7312832E12,\"11/11\"],[1.7317152E12,\"11/16\"],[1.7321472E12,\"11/21\"],[1.7325792E12,\"11/26\"]],\"generatedAt\":[2024,11,2],\"key\":null,\"nonSmartMeter\":false,\"hasSmartMeter\":true,\"monthButton\":\"November\",\"yearButton\":\"2024\",\"prevDate\":\"October\",\"nextdate\":null,\"dateRange\":\"November '24\"}}"

When analyzing my electricity usage data, I focused on several critical factors to help determine the most cost-effective plan choice:

1. What days had the highest consumption?

2. Which months consistently showed higher usage?

3. How much electricity did I use on weekends vs. weekdays?

4. What was my total weekend cost over the year?

5. Would a free weekend plan actually save money?

6. What percentage do they differ from each other?

7. What was my average daily consumption and cost?

This questions are important because when shopping for electricity in Texas, you'll typically encounter three main plan structures, each with its own trade-offs:

1. Free Nights (9:00 PM - 7:00 AM)

   • Offers zero-cost electricity during overnight hours

   • Usually comes with higher daytime rates

     

2. Free Weekends (Saturday and Sunday)

   • No electricity charges during weekends

   • Typically higher rates on weekdays

   

3. Fixed-Rate Plans

   • Consistent price per kWh

   • Often advertised as the "cheaper price" option

   • More predictable billing

However, the lowest advertised rate isn't always the most economical choice. Your actual savings depend heavily on your household's usage patterns and lifestyle. This is why analyzing your historical usage data becomes crucial for making an informed decision. The below are some of the key statistics on the analysis:

Based on your data from October 2023 through October 2024, here are the key findings:

1. Peak Usage:
   Highest daily usage: 142.55 kWh on July 13, 2023
   Temperature during peak: 93°F
   This peak usage occurred during a summer heatwave

2. Peak Cost:

   Highest daily cost: $29.85 on July 13, 2023

   Usage during peak cost: 142.55 kWh

   There’s an Strong correlation between high costs and high temperature days. This means the AC unit working overtime!

3. Weekend vs. Weekday Patterns:

   Average weekday usage: 41.23 kWh

   Average weekend usage: 45.87 kWh

   Weekends show approximately 11.3% higher usage than weekdays

   This pattern is most pronounced during summer months

Now let’s analyze the plan to determine what plan we should choose. Let's analyze when "free" periods make financial sense. In this comparison:

• Standard Rate: 10.6 cents per kWh

• Special Plans (Nights/Weekends): 16 cents per kWh (51% higher)

For these plans to break even:

Free Weekends Plan:

• Weekday rate is 51% higher

• To offset this increase, you would need approximately 34% of your total usage to occur on weekends

• Example: For every 100 kWh used

  • Standard plan: 100 kWh × $0.106 = $10.60

  • Weekend plan: 66 kWh × $0.16 = $10.56 (weekdays) 34 kWh × $0.00 = $0.00 (weekends) Total = $10.56

Free Nights Plan:

• Same principle applies

• You would need about 34% of your usage during the free night hours (9PM-7AM)

• Any usage below this percentage during free periods means you're paying more overall

• Any usage above this percentage means you're saving money

Outcome:

There’s potential to do Free Nights plan if we make additional modifications at home like charging the car, and washing the clothes after the 9:00pm mark to tap into those benefits. In general, it looks like the cheapest option would probably be best… if you hit the average KWhs. That’s another story though :lol:

If you enjoyed this deep dive into data analysis and energy cost optimization, consider subscribing to stay updated on future content. I can always provide the script if you send a message. While this blog typically focuses on security topics, I couldn't resist sharing this analytical approach to a common Texas challenge. Sometimes the best security is protecting your wallet – in this case, through data-driven decisions about your electricity plan. Y'all stay smart with your energy choices!