An inventor couple who masterminded a new type of solar panel which could replace roads and car parks raised more than $2.2 million (£1.3m) from donations around the world.

Julie and Scott Brusaw ran a crowdsourcing campaign on the Indiegogo site to gear up for production of their solar road panels.

Cash poured in for the next step of their business after a Youtube video promoting their work went viral. To date it has been viewed more than 17 million times.

Mr Brusaw told AP news agency last week: “Once we’ve perfected everything, our ultimate goal will be highways.”

Not everyone is convinced: though one commenter on the video called it “freaking important!” another claimed the idea is “incredibly unrealistic and impossible”.

The couple had already won funds from the US Federal Highway Association (FHWA) and has so far developed a 108 solar panel prototype parking lot in Sagle, Idaho.

Their website claims to have several projects lined up in their hometown of Sandpoint including the tarmac at the local airport, city pavements and platforms of a train station.