n3rgy.com offers consumers the option to download their smart meter data and to check on and withdraw permissions of companies with access to the consumer data through n3rgy.com.

Signup on https://data.n3rgy.com/consumer-login using the MPAN and the MAC address of the in-house-display (IHD). The MAC address needs to be entered without the dashes.

Once signed up, zip files with data can be downloaded from the consumer portal. The zip file download contains half-hourly data up to the previous day.

Further to the zip file download, n3rgy.com also offers a consumer API. The API contains data of the current day as well, but it is delayed. Test at 9am shows data up to 6.30am and at 10pm up to 6pm, 10.30pm up to 9pm of the same day.

Example scripts: https://github.com/n3rgy/consumer-data

This page shows details of the smart meters based on MPAN:
https://homebrew.n3rgy.com/

The data demonstrator on https://homebrew.n3rgy.com/consumer-data/ does not appear to work.

Example python code to obtain a pandas dataframe with electricity consumption:

import requests
import pandas as pd
import datetime
 
start = datetime.date.today().strftime("%Y%m%d") + '0000'
end = (datetime.date.today() + datetime.timedelta(days=1)).strftime("%Y%m%d") + '0000'
 
AUTH = "MAC-OF-IHD"
headers = {'Authorization': AUTH}
url = "https://consumer-api.data.n3rgy.com/"
path = 'electricity/consumption/1/'
query = '?start='+start'&end='+end
api_url = url + path + query
r = requests.get(url=api_url, headers=headers)
data = pd.Series({x['timestamp']: x['value']
                   for x in r.json()['values']})
print(data)

Octopus energy offers an API to access historic data and account data. Data is only available up to 1am of the current day.

Some code to access and work with the data can be found here:
https://guylipman.medium.com/accessing-your-octopus-smart-meter-data-3f3905ca8fec
https://github.com/gjlipman/smartmeter