Bulb Energy offers just one tariff, with 100% renewable electricity and carbon-neutral gas. Bulb was set up in 2015 to ‘make energy simpler, cheaper and greener’.
It says it is the biggest buyer of green gas, produced from renewable sources such as food or farm waste, for homes in the UK. The remainder is offset by Bulb supporting carbon reduction projects around the world.
Bulb's variable tariff is usually among the cheaper deals available in England, Scotland and Wales. It doesn’t charge exit fees and says it will refund you if your old supplier charges you exit fees to leave and join Bulb.
Bulb Energy says it keeps prices low by investing in technology to reduce costs.
It has grown quickly and now has almost 1.5 million customers in Great Britain. In March 2020, it took on 9,000 customers from Gnergy when the smaller firm stopped trading. Homes with prepayment meters can now join Bulb and, following a partnership with PayPoint agreed at the end of 2020, can top up their meters in convenience stores.
The graphic below shows the breakdown of its score in our latest survey.
Scroll down to read our verdict on Bulb, plus what customers think about different aspects of its service.
Which? verdict on Bulb
Bulb has gained customers quickly since its launch five years ago. Indeed, 58% of its customers in our survey said they joined it in the past two years. In contrast, just 25% of British Gas customers in our survey joined it over the same period.
Its rapid growth hasn't affected Bulb's ability to keep its customers happy over the four years it's been included in our survey, although it's dropped in the rankings this year, going from joint-third place last year to joint-tenth, with lower ratings for bill accuracy, complaints handling and value for money.
Customers gave their highest ratings for bill accuracy, bill clarity, customer service and complaints handling, with four stars for all of them. It got a three-star rating for value for money.
Bulb had a fairly low level of complaints in the first half of 2020 among the companies included in our survey, but it was well below average for resolving them on the same or next working day. It was about average for resolving them within eight weeks – 91% of complaints were resolved in this timeframe. While that may not sound terribly speedy, the worst companies resolved less than 60% in the same period.
Bulb answered calls in just under 10 minutes on average (9 minutes 56 seconds) in our latest snapshot investigation into energy companies' call-waiting times. This was faster than last year (19 minutes 2 seconds) but not as fast as the overall median average of the 31 companies we phoned (5 minutes 57 seconds).
It took a similar amount of time for Bulb to answer live chat. It took an average 9 minutes 29 seconds, against an average of 3 minutes 4 seconds for all companies we contacted this way.
Pros: Customers rate it well for billing, customer service and handling complaints
Cons: Slower than average to respond on the phone in our snapshot investigation
Bulb electricity sources
Bulb Energy says it's the biggest buyer of green gas for UK homes. This gas comes from biomethane produced from organic matter such as sewage and manure. The rest is carbon offset.
Bulb Energy in the news
Bulb Energy in 2020
December: A deal was struck with PayPoint, allowing Bulb prepayment customers to pay for energy top-ups at 27,500 retailers including convenience stores.
October: Bulb launched what it says is the UK's first 100% renewable smart prepayment tariff, priced at below the prepayment price cap set by energy regulator Ofgem.
September: Bulb ventured into the US energy market by launching in Texas. It aims to simplify the market there, which it says is one of the most complex. It already provides power to homes in Spain and France. In the same month it increased its UK electricity prices for the second time in a year.
August: Bulb paid out £1.76 million to around 61,000 customers in August 2020 for failures relating to switching, billing and not properly maintaining its Priority Services Register. Ofgem said Bulb has since made changes to improve its processes. Most of the payment comprised compensation and refunds, as well as a £157,350 payment into the energy industry voluntary redress fund to support vulnerable customers.
March: Bulb took on 9,000 customers from Gnergy when the smaller supplier stopped trading. Ofgem said it would offer a competitive tariff plus honour customers' credit balances and any owing to existing and former customers.
Bulb Energy in 2019
February: While other firms were announcing price rises, Bulb told customers it would lower its gas prices, saving them £20 per year on average. Bulb explained that wholesale gas price have dropped since December, so it’s ‘passing on the saving to our members’.