The company, led by entrepreneur Alex Mardapittas, has created a new research and development centre and manufacturing facility to meet growing global demand for its voltage optimisation products.
Mr Clegg said: “EMSc is a great example of another outstanding local business which is exporting the Made in Sheffield brand throughout the world.
“I’m hugely impressed by their products and welcome the fact that their research, development, sourcing and manufacturing is all done right here in the UK.
“Going green is good for the economy and good for climate change.
“The UK green sector is a success story – it is the sixth largest in the world and has a crucial part to play in building a strong economy.”
Dr Mardapittas, a Greek Cypriot entrepreneur who has made Sheffield his home, said: “The move to a new, larger facility is an important step for us, as it will allow us to continue manufacturing our products in the UK.
“It will also give us the capacity to grow our team of people.”
He added: “While we recognise the worldwide economy is experiencing a sustained period of insecurity and instability, it remains an exciting time for EMSc, as we continue to escalate our activities and expand.
“As a company we are firmly behind the belief that manufacturing represents a major opportunity to kick-start the UK economy. Made in the UK is a key marketing differentiator and we hope our success will help inspire other manufacturing companies and innovations.”
The new facility totals 23,620 sq ft and includes winding, curing, assembly and testing equipment to develop the company’s equipment.
EMSc products have been installed in properties owned by the NHS, Whitbread and Asda. The company has also supplied energy-saving products to the Palace of Westminster.
The £12m-turnover company has consolidated various sites in Rotherham at its new home in Smithy Wood Business Park.
Dr Mardapittas has been a champion of UK manufactu- ring.
“The UK has a tremendous amount of innovation.
“Everybody around the world likes British products because of reliability and quality and they know they will be designed to last.
“These are the aspects that make British-made products favourable all over the world,” he told the Yorkshire Post last year.
EMSc makes the Powerstar voltage optimisation range.
It reduces site voltage to cut carbon emissions and reduce electricity bills.