Georgia Natural Gas (NG) Pricing across Vendors

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I've done tons of research on this and hope to launch a website for it some day. But in the meantime, a few words.


I am asking for input from people who have an interest in Georgia natural gas pricing, such as, but not limited to:

  • People who have tried to play with pricing from different companies (like variable pricing a little while, then switch to fixed),
  • Anyone who has done extended mathematical analysis on natural gas choices. (You can become a co-editor here.)

Please contact me.

Please, no complaints against NG companies. I'm one guy and there are ~1.6 M AGL accounts. I am focusing on extending understanding of the numbers involved.


A Few Abbreviations And Notes before we get into it

The Atlanta GA area is unusual; few other places in the United States let one choose their gas provider.

NG stands for Natural Gas on this page.

GPSC stands for the Georgia Public Service Commission, which kindly represents the interests of Georgia NG users in Georgia.

THIS PAGE IS NOT ABOUT THE COMPANY CALLED GEORGIA NATURAL GAS (GNG), per se. This page advises consumers about natural gas providers in the state of Georgia (USA). One of them is called GNG.


  • Check the Georgia Public Service Commission for the latest month's prices and deals from every single provider.
    • The GPSC list is THE go-to list, compiled by a dedicated, helpful team of Georgia civil servants.
    • I strongly recommend the Fixed Rate contracts. There is no penalty to break them if you have to move. And they're always 2 to 3 times less than Variable rate.
  • The most important column in the GPSC spreadsheet is the one called "Marketer Filed Rate", and the generally lowest (best) rate is highlighted in yellow. (Thanks, GPSC!) Ignore the rest until you know what you're doing.
    • If you don't have time to examine your particulars in detail, just choose the lowest Fixed Rate plan. It's highlighted in yellow, and always the best choice. Unless you have unusual circumstances like a huge or tiny house; see below.
  • Never use the Variable rate - it's for suckers. Variable rates are always 2 or 3 times more than fixed rates. Simply compare any month's Fixed versus Variable rates for any given GPSC month. If you don't see what I'm saying, please contact me.
    • Beware Variable rate Intro promotional rates, which typically last a month or two. It is your choice whether to choose them when first moving to a place. BUT BE SURE to change when the promotional period is up. AND BE SURE they won't charge you $100 or $150 for changing when that month is up.   sucker
      • You can't be charged the cancel fee if you move away before the fixed contract is up.
  • No, gas rates are not higher in winter. In fact, NG prices are lower in winter, based on the the yellow-highlight lowest rates (the only ones you should look at, unless you really know what you're doing). It's paradoxical until you think about global climate warming. More on this below (see Summer Versus Winter Rates below).
  • If you might move away soon, there is no penalty charge to break a contract, as far as I know (correct me if wrong). This is a good thing for people unsure of their situation. Talk it out when signing up with a provider.

That's it! Choose the yellow highlight in the latest GPSC "Fixed Rate Plans" spreadsheet if you are in a position to take a contract. (If you're not sure you'll be there for the length of the contract period, see Important Assumptions, below.)

You don't need to read anything more on this page unless you want to learn about how it all works.

All the rest tells you all the boring details of why you always want a fixed contract, and how much variable-rate ones rip you off.

AGL Base Charges

Until 1998, Atlanta Gas Light (website) was the sole NG provider in the northern Georgia area, and is now a major vehicle for NG sales in various parts of the state and country (PDF of their domains).

For Georgia, details on AGL Base Charges are on this AGL page and this GPSC page. If you want to get really precise, use this "Base Rate Example - Residential" spreadsheet" from the AGL page. (Also see how to hack the spreadsheet to see all months' factors, below.)

All four GPSC Marketer Filed Rate PDFs for May 2018 have a footnote like this:

(3) The Total Annual Bill and Total Monthly Bill include the base charges from Atlanta Gas Light Company. 
The annual base charge for a typical customer with a 1.30 DDDC Factor is $330.47 and is $139.40 for qualifying senior citizens.
The May 2018 base charge is $25.91 for a typical customer with a 1.30 DDDC Factor, and is $7.50 for qualifying seniors with a 1.30 DDDC Factor.

Monthly Base Charge, Part 1

You can easily get an independent confirmation of the monthly base charge you're receiving using AGL's spreadsheet found on this page. You will need the DDDC from your bill.

Monthly values may be off by one cent because it's just a helpful spreadsheet that has it's own rounding properties; it's not what AGL actually uses.

Work In Progress





Total BC


Ave. Mo.

Total BC

Ave. Mo.




0.0 $247.87 $0.00 $247.87 $20.25 $0.00 0.0%
0.5 $247.87 $40.19 $288.06 $23.56 $3.31 16.2%
1.0 $247.87 $80.38 $328.25 $26.87 $6.62 32.4%
1.3 $247.87 $104.49 $352.37 $28.85 $8.60 42.2%
1.5 $247.87 $120.57 $368.44 $30.18 $9.92 48.6%
2.0 $247.87 $160.76 $408.63 $33.48 $13.23 64.9%
2.5 $247.87 $200.95 $448.82 $36.79 $16.54 81.1%

BC: AGL Base Charge
p.a.: per annum (total for the year)
Fixed and DDDC: The parts of the charge due to fixed portions (not dependent on DDDC) and portions dependent on your DDDC value (at far left in this table)
Ave. Mo.: Average monthly. This is simply the DDDC and Total BC p.a. values divided by 12.
Percent DDDC: This percent is the same as an average whether on a yearly or monthly basis, since it's an average across the year.

1/12 = 8.33%; compare how AGL divides up your DDDC-dependent charges (below). The Ave. Mo. Total BC should be slightly more than your April value (8%) since it is 8.33%, but this won't be true if your DDDC changed.

Annual Base Charge

The GPSC page on "Understanding Your Natural Gas Bills" has a section called "Why is my base charge different each month" which explains that the DDDC component is allocated as such:

Month Percent of AGL

DDDC charge

January 18%
February 19%
March 15%
April 8%
May 4%
June 3%
July 3%
August 3%
September 3%
October 3%
November 7%
December 14%
Total 100%

I think this could be explained better by saying there is a fixed set of base charges and a DDDC-dependent (variable) part. As of May 2018 it looks like this, for DDDC 1.300 (their typical usage) and Peaking Group Yes:

Work in progress. As always, for my wiki pages and others, you can check the History of most wiki pages to see edits and dates (see tabs at top).


Summer Versus Winter Rates

They are actually a little lower in January versus July. Just compare the yellow highlighted Fixed Rate plans for July to January in the past year on the GPSC site.

I will change this text if it comes to be not true. It's been true for the past few years (as of May 2018). NG prices are at all time lows and probably mainly subject to supply and demand, which is subject to anticipated buildup for the winter, which is subject to the fact that we need less each winter than modelled relative to the past, due to climate warming. Thanks, Obama! GRRR. just kidding.

Anyway, the net result is lower prices in winter.

You can observe a lot by watching, as Yogi Berra (and a couple of data analysts) said.

Assumptions if you're in the AGL Group Area

Everything written here assumes that:

  • You are not in a Regulated Provider hard-case group:
    • Regulated Provider Group 1 is for very low income households (as qualified through the state Depart of Human Resources). N.B., RPG1 is actually HIGHER than the lowest (yellow highlight) one! Choose wisely. I don't understand why GPSC doesn't make the lowest Fixed provider be the servicer for Regulated Provider Group 1, at least for Fixed contracts. (And what else is there but fixed contracts for a regulated provider?) I am contacting them about this.
    • Regulated Provider Group 2 is for high-credit risk customers who cannot obtain service from a marketer.
  • There are particular rules about breaking fixed rate contracts, and connection / reconnection fees. Read the fine print.
    • But there is no charge to break a fixed-rate contract if you move away. So you don't need to worry if you're not sure if you'll be at a place for less than 12 months (as long as you don't cancel your gas until you leave).


Hacking the AGL Charges Spreadsheet

Hacking AGL's "Base Rate Example - Residential" spreadsheet is pretty easy, which is no surprise. AGL is not trying to hide anything, as shown by their openness in providing the spreadsheet. But they don't want folks accidentally changing values and getting confused. I think they've made a decent compromise.

To expose all past monthly rates (the spreadsheet's Rates worksheet), google unprotecting an Excel spreadsheet. One way is to simply upload it to Google drive and reveal it in Google Sheets, as follows:

  1. First, you'll need a Google Drive account. They're free for up to 15 GB, and you already have one if you have or make a Gmail account. Once you have one,
  2. Download the AGL spreadsheet to your PC
  3. Upload it to Google Drive
  4. Open it in Google Sheets. Note: This is not the same as simply clicking on it in Google Drive (which only opens a viewer). On a PC, right click, then "Open With" > "Google Sheets".
  5. /View /Hidden Sheet(s) > Rates
  6. Save to PC, or work with it in Google Sheets

Now the Rates for every month are revealed, all the way back to November 1998. Here's an example of a hacked AGL spreadsheet as of May 2018.

The dropdown will let you select months after May 2018, but they have no data. Apparently it is updated approximately the 20th of each month, for the next month. For example, AGL updated/uploaded the spreadsheet with May 2018 data on April 20.

Which "Rates" columns are DDDC-dependent?

On the Rates worksheet are 11 columns. Here's how they relate to the all-important DDDC. Sort on DDDC to group them together:



Description X


1 Month n/a
2 Customer Charge No
3 DDDC Charge Yes
4 Meter Reading Charge No
5 Peaking Charge Yes
6 Social Responsibility Charge No
7 Pipeline Replacement Program No
8 Customer Education No
9 Environmental Response Cost Rider Yes
10 Franchise Recovery Rider Yes
11 Synergy Savings No

If a column is "X DDDC" (times DDDC), then its value is multiplied by your DDDC. And yes, if your DDDC is 0, all those values go to zero. (Apartments can easily be less than 1.) The GPSC Marketer Pricing spreadsheets use a DDDC default of 1.30 for a typical customer.

My DDDC values

If it helps for comparisons' sake, my DDDC is currently 1.280 with a 3600 sq.ft. house in northeast Atlanta. I've done a lot to insulate it, and in winter, we keep our thermostats at 67° F main level and basement, and 65° F upstairs.

The DDDC we inherited (when we first moved in three years ago) was 1.689, which dropped sharply after the first year. I wouldn't be surprised if the drop from 1.7 to 1.3 was mainly due to us being more frugal, because I really doubt that my moderate amount of insulation work (relative to the house as a whole) can result in a 24% drop in usage. But still it shows that even the same house can have non-trivial variation, all depending on the many factors involved.

Don't take the DDDC definition too seriously

The DDDC (Designated Design Day Capacity) says it accounts for how much gas (defined as pipe volume) you used on the coldest day of the year. While it sounds perfectly reasonable,

Unless AGL advises me otherwise,

Please realize that their DDDC is only a modeled concept. There isn't actually some poor AGL guy running all over Georgia on the coldest day of the year checking everybody's meters, while his fingers freeze off.

AGL only takes monthly readings, as far as I know. I believe they have a truck that drives around neighborhoods once a month. It's got about a quarter mile radius to read your meter remotely. The actual day ones' meter is read surely varies across the state. And they won't otherwise take any particular interest in reading your meter unless you're doing something special, like starting or stopping service.

So they're never actually specifically recording your true coldest-day usage. They're using a model of how much everybody used, over those coldest days.

So if you just happened to have your garage door stuck open across that billing period (lots of heat needed), or conversely were out of town with the thermostat set real low (little heat needed), it would affect the DDDC portion of your bill for the next 12 months. They reevaluate DDDC values in or around September. (A wise choice since it's toward the end of summer, when all the past winters' data is in.)

In theory you could game this. But wound't that be a lot like simply keeping your thermostat low? Perhaps a True Detective could tell the difference.

As we saw in my case, the previous owners of our house had a DDDC of ~1.6, but we quickly reduced it to ~1.3. It's the same house, but we probably had our thermostat lower, and we did other things like install better insulation and a primo attic door.

Upshot: Don't take the stated definition of "how much you used on the coldest day of the year" too precisely. They don't measure every day. It's just a general estimate of your usage. Relative to everyone else. No big deal.