This really is an innovative piece of work. Like most people I’ll stick to the easy solution of just keeping the energy usage down between 4-7pm. Maybe its just easier for me as the storage heating and hot water heating overnight ensure a lot of my energy is used at this time.
Mine’s nicher than yours …
Sign in to your account*, then in a new tab visit https://smartpaymapi.ovoenergy.com/usage/api/half-hourly/nnnnnnn?date=yyyy-mm-dd
having substituted your own account no. for nnnnnnn and putting the date you’re interested in at the end.
With any luck, this will reveal a page of JSON data with all the half-hourly quantities to the nearest Wh, which I’m sure you’ll be able to manipulate. Since this is the basis for the webpage as displayed, you won’t get any more data from it than you can see in the browser: you just get more precise data.
* The access token currently only lasts for 30 minutes; if you get an error message, return to the account tab and refresh it to trigger a new sign-in. Then refresh the API page.
And if this does happen to you, please consider upvoting this idea 
PS Check your PMs: Inbox overview
You’ll find lots of other API goodies by checking where the site gets its data from in the network tab.
Or create a bookmark, edit it and change the url to
javascript:(()=>{let e=document.querySelectorAll("(data-testid='usage-table-data']"),t=0;for(let a=32;a<=37;a++)t+=parseFloat(e(a].innerText);alert(t.toFixed(2))})()
Then click that on the usage page for electricity only.
Now I know you can get all the data from the API I’ll knock up a page to do the whole lot and calculate the percentage for the whole month. I’ll either post it in here or do a new thread. It’ll be a few days as I’ve got things to do.
Did something similar in MS Excel by a simple formula. However didn't have the in depth knowledge to get around any anomalies such as missed readings.
Won't be trying Tron's method as I don't know Klingon!
However this is highly imaginative and entertaining stuff from the contributors. So keep it coming.
Regards to all.
