Tesla charge for power received by car, others for power sent to car (which will be more), so assuming same price, Tesla is cheaper.
Zap map free chargers
Charge at shops, WORK, friends, relatives (eg visit parents once a week and graze elsewhere).
It might help if OP said where they were, commute to or otherwise regularly visit, some old timers might know some local tricks.
Search the forum for Gridserve, Osprey etc
Eventually Gridserve and others will be setting up local Electric Forecourts to serve areas (Gridserve Electric Hubs are for motorways etc).
The biggest motorway EV charging upgrade to date in the UK will soon be underway, with the announcement from Gridserve of 11 new ultra-high-power 'Electric Hubs', plus two new 'Electric Forecourts' including a world-first flagship charging site at...
eandt.theiet.org
Daft Gridserve map as no key, not clickable - but shows ambitions -
GRIDSERVE | EV Charging price is 30p/kWh
Osprey doing similar local/route hubs/forecourts
A UK-first electric vehicle (EV) dynamic charging hub has opened in Wolverhampton. The site is the first of over 150 charging hubs being delivered across
www.traffictechnologytoday.com
Osprey’s charging hub rollout will see a total of 1,500 150-175KW rapid chargers installed over the next four years. Each hub will be located on strategic A-roads and adjacent to motorways, hosting up to 12 high powered chargers.
“The opening of our high-powered charging hub in Wolverhampton – the first of 10 in construction this year
Not a great answer, but when I was looking around I found a couple of articles, The Brighton one discusses a few things that might be coming up and might be useful for others finding post through search.
How do people with no driveway charge their electric cars?
electricbrighton.com
Portable EV Charging | ZipCharge Go - a powerbank for your EV | London 20-40 miles per charge - pre-orders for 2022 - looks expensive - from article - "also a number of companies in the US selling portable EV solutions like EV Rescue, EV CubiCharge, Blink Mobile and Lightning eMotors"
Charge Fairy charges your car so you don’t need to
chargefairy.com
Co Charger app matches hosts and ‘chargees’ who can ‘enjoy living in a cleaner, greener neighbourhood’
www.theguardian.com
Rent out your home EV charger and help others go electric with Co Charger Community Charging
co-charger.com