Renewable energy supplier Bulb has announced plans to raise prices for its members following “substantial increases” in the wholesale cost of gas and electricity.

Bulb said its 450,000 members will see tariffs rise by 5.1 per cent on average when its new pricing comes into effect on 12 August.

A typical annual bill will now be £923, up from £879.

The company’s standard tariff remains cheaper than the average of the Big Six providers, all of which have increased prices in recent weeks.

Wholesale energy costs have jumped by 21 per cent since Bulb last changed its prices in February, the company said.

Bulb Co-founder Hayden Wood said: “Bulb is committed to supplying energy at a fair price. That’s why we have one tariff for all our members, which reflects the true cost of energy. When wholesale energy costs change, our tariff does too. These costs have climbed throughout 2018, and are now 21 per cent higher than they were in February. As a result, from August, our price will be going up by £4 per month for the average Bulb member.

“All our members receive 60 days’ notice of the rise, double what Ofgem recommend. And because we don’t charge exit fees, our members can leave at any time, at zero cost.