Chellow
A web application for checking UK electricity and gas bills for organizations with a large number of supplies and / or high consumption.
Website: https://www.chellow.org/
Licence
Chellow is released under the GPL v3.
Introduction
Chellow is a web application for checking UK electricity and gas bills. It's designed for organizations with high electricity consumption. The software is hosted at https://github.com/WessexWater/chellow.
Installation
Chellow is a Python web application that uses the PostgreSQL database. To install Chellow, follow these steps:
- Install PostgreSQL
- Create a PostgreSQL database:
createdb --encoding=UTF8 chellow - Install the btree_gist extension with the SQL:
CREATE EXTENSION IF NOT EXISTS btree_gist; - Set up the following environment variables to configure Chellow:
| Name | Default | Description |
|---|---|---|
PGUSER |
postgres |
Postgres user name |
PGPASSWORD |
postgres |
Postgres password |
PGHOST |
localhost |
Postgres host name |
PGPORT |
5432 |
Postgres port |
PGDATABASE |
chellow |
Postgres database name |
In bash an environment variable can be set by doing:
export PGUSER=postgres
in Windows an environment variable can be set by doing:
set PGUSER=postgres
- Install Python
- Create a virtual environment:
python3 -m venv venv - Activate the virtual environment:
source venv/bin/activate - Install Chellow:
pip install chellow - Start Chellow:
waitress-serve --host=0.0.0.0 --port=8080 --call chellow:create_app - You should now be able to visit
http://localhost:8080/in a browser.
Azure
SSH into the machine and you'll be in /home/site/wwwroot.
- Create a virtual environment:
python -m venv antenv - Activate the virtual environment with:
source antenv/bin/activate
In /home/site/wwwroot create a file called app.py containing the following:
import chellow
app = chellow.create_app()
If you're using Entra ID to access Postgres, include the environment variable POSTGRES_AUTH=entra.
If you're using Azure Easy Auth for user authentication, set environment variable
USER_AUTH=MS_EASY_AUTH.
Database Permissions
If you need to grant a user app_user read-write privileges then connect as superuser to the chellow
database and do:
GRANT CONNECT ON DATABASE chellow TO app_user;
GRANT USAGE ON SCHEMA public TO app_user;
GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO app_user;
GRANT USAGE, SELECT, UPDATE ON ALL SEQUENCES IN SCHEMA public TO app_user;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA public TO app_user;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO app_user;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT USAGE, SELECT, UPDATE ON SEQUENCES TO app_user;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT EXECUTE ON FUNCTIONS TO app_user;
Manually Upgrading Chellow
To upgrade to the latest version of Chellow do: pip install --upgrade chellow
Automatically Upgrading Chellow
The bash script chellow_upgrader.sh will check for a new version of Chellow and if one's there it will stop Chellow, then do the upgrade, then start Chellow.
Using with systemd
Copy the following files into the /etc/systemd/system directory:
and modify them as appropriate. The chellow_upgrader.service uses the
chellow_upgrader.sh script above. The you should be able to use the following
commands:
- Start Chellow:
sudo systemctl start chellow - Make Chellow run on startup:
sudo systemctl enable chellow - Start the Chellow Upgrader:
sudo systemctl start chellow_upgrader.timer - Make Chellow Upgrader run on startup:
sudo systemctl enable chellow_upgrader.timer
Using A Different Webserver
Chellow comes bundled with the
Waitress webserver, but
the is also a Python WSGI web application so Chellow can be used with any WSGI compliant
application server, eg Gunicorn. The WSGI app that should be specified is chellow.app.
Getting Started
This is a brief guide to setting things up after you've installed Chellow. It assumes that you have a basic knowledge of UK electricity billing. It goes through the steps of adding a half-hourly (HH) metered supply, and producing virtual bills for it, and then importing an actual bill and running a bill check.
Chellow can handle non-half-hourly supplies as well as half-hourly, and it can also deal with gas supplies, but we'll use a half-hourly electricity supply for this example.
View the Chellow home page
Assuming you've installed Chellow correctly, you should be able to open your browser, type in the URL of the Chellow application, and see the Chellow home page.
Users
Before any users are added, if you access Chellow from localhost you'll have
read / write access. Once users are added, you have to log in as one of those
users. Users are added from the 'users' page.
Importing Market Domain Data
Follow the instructions at /e/mdd_imports to import the Market Domain Data into
Chellow.
Add HHDC Contracts
Every supply must a have a data collector. Add in a new HHDC by going to the 'HHDC Contracts' page and then clicking on the 'Add' link.
Add MOP Contracts
Every supply must a have a meter operator. Add in a new MOP by going to the 'MOP Contracts' page and then clicking on the 'Add' link. For now just put in a simple virtual bill for the MOP, so in the 'script' field enter:
from chellow.utils import reduce_bill_hhs
def virtual_bill_titles():
return ['net-gbp']
def virtual_bill(data_source):
for hh in data_source.hh_data:
bill_hh = data_source.mop_bill_hhs[hh['start-date']]
if hh['utc-is-month-end']:
bill_hh['net-gbp'] = 10
data_source.mop_bill = reduce_bills_hh(data_source.mop_bill_hhs)
Add Supplier Contracts
Click on the 'supplier contracts' link and then fill out the 'Add a contract' form. For the Charge Script field enter:
from chellow.utils import reduce_bill_hhs
def virtual_bill_titles():
return ['net-gbp', 'day-kwh', 'day-gbp', 'night-kwh', 'night-gbp']
def virtual_bill(data_source):
bill = data_source.supplier_bill
for hh in data_source.hh_data:
bill_hh = data_source.supplier_bill_hhs[hh['start-date']]
if 0 < hh['utc-decimal-hour'] < 8:
bill_hh['night-kwh'] = hh['msp-kwh']
bill_hh['night-gbp'] = hh['msp-kwh'] * 0.05
else:
bill_hh['day-kwh'] = hh['msp-kwh']
bill_hh['day-gbp'] = hh['msp-kwh'] * 0.1
bill_hh['net-gbp'] = sum(
v for k, v in bill_hh.items() if k[-4:] == '-gbp')
data_source.supplier_bill = reduce_bill_hhs(
data_source.supplier_bill_hhs)
This will generate a simple virtual bill based on a day / night tariff. Supplier contract scripts can be much more sophisticated than this, including DUoS, TNUoS, BSUoS, RO and many other standard charges. These will be addressed later on in this guide.
Also, don't worry about the 'properties' field for now.
Add a Site
Go to the 'sites' link on the home page, and click 'add'. Fill out the form and create the site.
Add a Supply
To add a supply to a site, go to the site's page and click on 'edit'. Half-way down the page there's an 'Insert an electricity supply' form. For a standard electricity supply the 'source' is 'net'. Make sure the profile class (PC) is '00' to indicate to Chellow that it's a half-hourly metered supply. The SSC field is left blank for a half-hourly as they don't have an SSC.
A supply is formed from a series of eras. Each era has different characteristics to capture the history of a supply.
Run a Virtual Bill
At this stage it should be possible to run a virtual bill for the supply you've added. Go to the supply's page and click on the 'Supplier Virtual Bill' link. That should return a page showing the virtual bill for the supply.
Of course, the consumption will be zero because we haven't added in any half-hourly data yet.
Add Some HH Data
On the page of the supply you've created, you'll see that there's a 'channels' link, with an 'add' link next to it. Add an active import channel for the half-hourly data to be attached to.
Back on the supply page a link to the channel you just created will have appeared. Click on this and fill out the form for adding a half-hour of data.
If you then re-run the virtual bill for the period in which you added the half-hour, it should show up in the virtual bill.
It's tedious to add HH data one by one, so if you go to the page of the HHDC contract that you've created, you'll see a 'HH Data Imports' link. Click on this and there's a form for uploading HH data in bulk in a variety of formats. Chellow can also be set up to import files automatically from an FTP server.
Virtual Bills For A Contract
To see the virtual bills for a supplier contract, go to the contract page and follow the Virtual Bills link.
Data Structure
- Site
- Supply
- Supply Era
- Site
- MOP Contract
- DC Contract
- Profile Class
- Imp / Exp Supplier Contract
- Imp / Exp Mpan Core
- Imp / Exp LLFC
- Imp / Exp Supply Capacity
- Imp / Exp Channels
- HH Data
- Supply Era
- Supplier Contracts (Same for DC and MOP)
- Rate Scripts
- Batches
- Bills
- Supply
- Register Reads
- Bills
- DNOs (Distribution Network Operators)
- LLFCs (Line Loss Factor Classes)
General Imports
The menu has a link called 'General Import' which take you to a page for doing bulk insert / update / delete operations on Chellow data (eg. Sites, Supplies, LLFCs etc.) using a CSV file.
Common Tasks
Merging Two Supplies
Say there are two supplies A and B, and you want to end up with just A. The steps are:
- Back up the data by taking a snapshot of the database.
- Check that A and B have the same header data (LLFC, MTC etc).
- See if there are any overlapping channels, eg. do both A and B have import kVArh? If there are, then decide which one is going to be kept.
- Load the hh data for the required channels from the backup file. First take a copy of the file, then edit out the data you don't want, then further edit the file so that it loads into the new supply.
- Delete supply B.
Local Reports
Core reports come with Chellow, but it's possible for users to create custom
reports. Reports are written in Python, and often use a Jinja2 template. You
can display a link to a report of user reports by adding the local_reports_id
to the configuration non-core contract.
Default users
Default users can be automatically assigned to requests from certain IP
addresses. To associate an IP address to a user, go to the non-core contract
configuration and add a line to the 'properties' field similar to the
following:
{
'ips': {'127.0.0.1': 'implicit-user@localhost'}
}
Note that multiple IP addresses can be mapped to the same user.
It's also possible to use Microsoft Active Directory to authenticate users
with a reverse proxy server. Edit the configuration non-core contract and add
something like:
{
"ad_authentication": {
"default_user": "readonly@example.com",
"on": true
}
Design Decisions
Why don't you use the +/- infinity values for timestamps? The problem is that it's not clear how this would translate into Python. So we currently use null for infinity, which naturally translates into None in Python.
Contributing
The web interface uses HTML, CSS and HTMX.
3 maintainers
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