One of Northern Ireland's oldest family-owned businesses has come up with a 21st century idea which it says will revolutionise the solar water heating industry.
Belfast company Willis Heating & Plumbing, which was established by William Willis in 1887, is renowned for the invention of the Willis immersion heater, which was commonplace in households in Northern Ireland in the 1960s and 1970s.
The company, now under the leadership of managing director and fourth generation family member John Willis (55), has developed a new solar water heating system.
Mr Willis predicts that the Willis SolaSyphon will be the biggest industry breakthrough since the immersion heater.
He said the firm's new device enabled existing hot water tanks to be modified, instead of being tossed onto the scrapheap.
"Solar water heating has become the fastest growing sector of the market," he added.
"Our product represents a major change in the way that solar thermal panels produce hot water and is set to reduce home water heating bills by up to 50% and installation costs by 30%."
Mr Willis said that a report carried out by the University of Ulster had verified the performance of the SolaSyphon, which has been developed in conjunction with the Carbon Trust and Action Renewables.
"We estimate sales of approximately 1,000 units in our first year rising to approximately 6,000 within three years, but the potential is unlimited in a worldwide context," said Mr Willis.