The firm says that these third-party charges apply to the non-energy costs of distributing and transmitting energy to the customer and incentivising lower carbon supplies.

It adds that non-commodity charges are rising sharply. Around six years ago they accounted for around 30% of an electricity bill, but today that's more than 50% and they are predicted to exceed 60% by 2020.

"Manufacturers now spend more on third-party charges than they do on their actual energy, so it's vital that they can understand how these rising costs might impact their business energy bills", said Michael Dent, MD of Inprova Energy. "Our calculator provides an indication of the charges over time, enabling energy buyers to forecast and budget better."

The calculator enables businesses to estimate the potential impact of third-party charges according to their regional location, voltage, sector and annual energy consumption profile.

It also provides a full breakdown of each non-energy charge for the next five years, together with illustrations of the potential effect of recent policy changes.

The calculator also indicates the impact of rising Climate Change Levy charges, which will increase in April 2019 following the closure of the Carbon Reduction Commitment (CRC) scheme.

Take a look at the Inprova Energy third-party energy cost calculator here