[GNC] User defined currencies in "Expense Accounts"

[NoobAlice]

> Date: Sun, 12 Mar 2023 08:45:18 -0700
> From: john <jralls at ceridwen.us>
> To: Charles Crossan <crossan007 at gmail.com>
> Cc: gnucash-user at gnucash.org
> Subject: Re: [GNC] User defined currencies in "Expense Accounts"
> Message-ID: <204D86BA-9B99-470C-960D-B15CD7EF0D36 at ceridwen.us>
> Content-Type: text/plain;	charset=us-ascii

>> On Mar 12, 2023, at 7:51 AM, Charles Crossan <crossan007 at gmail.com> wrote:
>>
>> While doing my monthly ritual of breaking down my utility bill into
>> GNUcash, I had the idea of using a user defined currency for electricity
>> (Kilowatt Hours - kWh) and Water (gallons).  I'd like to be able to chart
>> my "real usage" as well as rate fluctuations.
>>
>> I've been using GNUCash for over 10 years, and have created a bunch of
>> custom currencies for stocks / etc; however, this is the first time I
>> thought about using it for tracking utility units.
>>
>> I got as far as creating the kWh currency when I realized that there's no
>> way to choose a "non ISO 4217" currency for expense accounts.
>>
>> The GNUCash documentation seems to indicate that Income and Expense
>> accounts are only able to use "National Currencies" (12.2.1.1. User-Defined
>> Currencies -
>> https://www.gnucash.org/docs/v4/C/gnucash-guide/currency_manual.html
>> <https://www.gnucash.org/docs/v4/C/gnucash-guide/currency_manual.html>).
>>
>> I'm wondering:
>>
>>   1. Is there a functional reason for this requirement; or is it an
>>   arbitrary UI restriction?
>>   2. Would the application behave erratically if I were to manually edit
>>   the expense account in SQL to use my own currency?
>>   3. How is everyone else handling utility tracking?  I realize I'm
>>   probably a tad crazy for wanting this level of detail.
> 
> It's part of GAAP/IFS: Expense and Income are flavors of Equity and that can only be currency; in fact it's supposed to be only in the book currency, but GnuCash doesn't enforce that in part because it doesn't historically recognize a book currency. 
> 
> I don't see anything in the engine that will misbehave if you do that, but the account edit window might act up if you try to edit the account after making the change.
> 
> I use a spreadsheet to capture the amount of electricity, natural gas, and water we use monthly, but since they installed smart meters a few years ago the utility company has provided a nice usage display on their website with hourly, daily, and monthly charts, though the daily and hourly data is available for only a couple of years back.
> 
> Regards,
> John Ralls

I am a third vote for "use a spreadsheet instead."  And I've taken a 
currency I don't need and repurposed it to track rewards card points 
(not updated with Finance::Quote of course), so I am sympathetic to your 
goals.

At least in my geographic area, part of the US, utility billing for 
electric and gas has enough moving parts that for tracking you really do 
want an entire spreadsheet, not just a "currency."

Some components to consider:
* meter read dates aren't always monthly - officially, our meter reads 
by the utility happen every other month...except when the meter reader 
is sick... or the meter reader gets the wrong number...or there is a 
worldwide pandemic...  (We send in our own readings recently, which 
helps a bit.)
* meter read dates are irregular - sometimes the utility co has meter 
reads (ours and theirs) 25 days apart, up to 35 days, very inconsistent. 
  Averaging out KWH per time period is better done on a spreadsheet.
* bills can include fixed and variable components - "service to your 
home" for gas and electric may be two flat fees
* time-of-day usage - some utility companies do this, another spanner in 
the works
* price per KWH can have multiple components - here, we have the basic 
price per KWH, but then added on are per-unit prices for delivery 
charges, taxes, and more
* energy supply companies - in some states of the USA, you can choose 
your supplier for gas or electric, which can change the rates you pay 
for power
* spreadsheets are nicer for calculations - you can do a 12-month 
rolling average to account for seasonal increases in use to see whether 
you are really increasing/decreasing usage over time, get a trend in 
part of your costs over time