Renewable energy supplier Bulb has increased its customer numbers to 870,000 since it launched in 2015.

Ahead of filing its financial report to Companies House, Bulb has updated the firm’s members about its performance, which it says will become an “annual tradition”.

The memo sets out how Bulb is investing in growth so the company “can help more people reduce their bills and their carbon emissions”.

Bulb claims its customers are saving over one million tonnes of CO2 from entering the atmosphere annually.

The financial results will show that in the reporting period April 2017 to March 2018 revenues increased 1,700 per cent from £10 million to £183 million.

Gross profit increased from £1.1 million to £12.1 million, but at the same time losses have also increased from £2.1 million to £23.7 million.

The company put this down to it continuing “to invest in growing its member base in a sustainable way and developing new technology”.

Bulb said it continues to recruit “high calibre staff”, all 270 of which are given equity in the business and work out of its headquarters in East London.

In a joint statement to customers, founders Hayden Wood and Amit Gudka, said: “As a business, Bulb is required to publish an annual financial report.

“We’ll be filing that in a week or so, at the end of the year. But in putting it together it occurred to us that it doesn’t really discuss the things that actually make Bulb tick, or the things that you might be interested in as one of our members.

“So we’re starting a new annual tradition – reporting to our members on how we’re doing, looking at the money, but looking at other things as well.”

In August. the mid-tier supplier announced it received a £60 million injection from two major international investors – DST Global and Magnetar.

Bulb said it will use the investment to help it to hire more “top-class engineers and energy experts who help deliver its top-rated customer service”.

The company increased it prices last month for the third time this year, blaming rising wholesale costs.

Earlier this month, Bulb was named as the UK’s fastest-growing private company in a list compiled by online investment company SyndicateRoom.

The supplier also featured in LinkedIn’s UK “Top Startups” list for 2018 – the only utility company to do so.