DIESELEC Thistle, the Milngavie-based temporary power specialist, is preparing to expand after shrugging off the uncertainty regarding the economy to record dramatic growth in profits.

Backed by the Pirrie brothers' Nevis Capital, the company has quadrupled profits to £2 million over the past two years helped by its success in winning work from the public sector despite cuts in Government spending.

Dieselec has won a string of contracts to supply standby generators for National Heath Service facilities, including the giant new Southern General Hospital in Glasgow.

It has cashed in on growing demand for back-up systems from private sector firms that want to avoid power outages disrupting operations, like banks and data centre operators.

The company is on course to achieve turnover of more than £20m in the year to June, compared with £8.1m in the preceding year.

After tripling sales in the past two years, directors are confident the company will maintain strong growth.

The company is expanding its Milngavie premises to provide 50% more workshop and warehousing space, an increased yard facility and a doubling of office accommodation.

Brian Aitken, a corporate financier who is a partner in the Nevis Capital business, said: "Dieselec Thistle has experienced a phenomenal period of growth over the last two years."

He said the success vindicated Nevis Capital's decision to invest in the temporary power sector in which John and James Pirrie made their name.

Nevis Capital was formed in 2007 to invest some of the proceeds of the £62m sale of the LCH Generators business that the brothers developed to Speedy Hire.

Nevis acquired a significant stake in Dieselec in a multi-million pound deal in December 2010.

The investment company then backed Dieselec's acquisition of the Thistle Generators business.

Mr Aitken said Nevis directors believe demand for temporary power systems is likely to increase as firms look to gain greater control over factors that can influence performance.

He confirmed Nevis is keen to add more firms in the power supply and related sectors to its investment stable. While directors will have to take account of the eurozone uncertainty, Mr Aitken said: "We are spending lots of time looking for new deals."