World’s 1st Fully-Certified Solar Balloon

The world’s first successful fully-certified solar hybrid balloon was unveiled at the Tribute Bristol International Balloon Fiesta and took its maiden flight on the 6th of August 2015, to mark to Bristol’s status as the UK’s first European Green Capital.

The balloon, designed and manufactured by Cameron Balloons, is the first solar-powered certified lighter-than-air hybrid aerostat in the world. The black and silver, Superlight fabric,150,000cu.ft. balloon is a hybrid aircraft, partially powered by the sun and partially powered by a conventional hot air propane burner; an eye-catching and simple demonstration of the power of the sun.

For this project, Cameron Balloons selected fabrics that absorb the sun’s rays. They were then cut and sewn together to create the balloon envelope, at our Bristol-based 42,000sq.ft factory. Work on the specialist aircraft was completed in late July, allowing time for all the final tests and thorough inspections. Hot air balloons fly because the air inside them is hotter than the air outside. To make the solar balloon work well, we had to minimise the temperature difference between the inside and outside air, and maximise the absorption of solar heat while minimising heat loss.

To minimise the temperature difference required, we also built the balloon from lightweight fabrics and very strong, but very light, load tapes to reduce its overall physical weight. We fitted a lightweight basket and the balloon is around twice the size we would normally use to carry the size of payload.

In order to maximise the absorption of solar heat, we made one side of the balloon black. The sun heats the black fabric skin and therefore the air inside the balloon too.

To minimise heat loss, the shaded side of the balloon was insulated using a double layer of fabric with an insulating air-gap between the layers. The fabric on the shady side was also aluminised to minimise heat loss via radiation.

Nick Purvis, Sales Director at Cameron Balloons explained: "The Bristol 2015 Solar Balloon is a fully certified hybrid balloon. It is a fantastic innovation and even in the first few flights, we have had great results. Pete Dalby of Phoenix Balloons who operates the balloon for Bristol 2015, flew with Dave Boxall, Cameron Balloons’ Chief Design Engineer, who reported that he only did three burns using the conventional burner during the whole flight - from the Bristol Fiesta arena to the point of landing, which was over 3kilometres away!".

Andrew Garrad, Chairman of Bristol 2015 said: “One of the reasons Bristol won the title of European Green Capital is the city’s impressive track record in pioneering new forms of green technology. It feels extremely fitting that Bristol – the current Green Capital, and the home of ballooning – is now developing the world’s first certified hybrid solar-powered hot air balloon. I enjoyed celebrating its maiden voyage in August and hope that this project will inspire many more firsts for Bristol.”