If you switch to Pure Planet through my referral link we both get a £50 voucher, you can choose from John lewis, Sainsbury's, Amazon, National Book Tokens.
I have found them to be the cheapest supplier we've ever used, and their energy is 100% renewable. Been with them for 6 months now, we pay around £50 per month in the winter and £30 in the summer, and it was really easy and fast to switch.
purepla.net/rfm/QMdBpdpc