A couple of young adventurers from Spain and Vietnam who began a journey around the world on electric bicycles in Beijing two years ago reached Athens on Wednesday, making a plea to Greeks and citizens of the world to support their campaign to protect the environment.

Guim Valls Teruel launched the "Electric Bicycle World Tour" in June 2009 in Beijing. He was introduced to commuting daily by electric bicycle right on the first day of his stay in Beijing where he worked as a manager.

The young adventurer from Barcelona set out on the electric bicycle tour to promote the eco-friendly means of transport across the world. Ever since, he experienced warm hospitality in China, met his wife in Vietnam and, after 18,000 kilometers on his hybrid solar bike, has made more friends in Greece.

"Despite difficulties in communication due to the language, I remember in a village in south China all the farmers collecting money to offer me air-conditioned accommodation," he told Xinhua, recalling his most memorable experience during his journey so far.

In Hanoi he met Thuy Anh Nguyen, a journalist who became his wife and joined him on his global escapade a few months later. They claim to be the first couple to perform such a journey across the world on hybrid solar electric bicycles.

Nguyen spoke about the challenges of pedalling in temperatures of up to 50 degrees celcius for 100 kilometers a day in India and the adventure of cycling in a city without bicycle lanes, such as Athens.

"Athens hopes to harness the power of the sun and bicycles. We are optimistic about the future and hope to increase awareness of environmentally-friendly transportation," said George Amiras, Athens municipal council member and an avid cyclist, welcoming the couple in Greece.

Teruel and Nguyen will join their Greek friends late Friday evening for a mini marathon from the center of Athens to the seaside by bike, before setting out for a tour around Peloponnesus in southern Greece. The next destinations include Italy, Spain and Portugal followed by Latin America.

The couple can not yet estimate when they will complete their journey. They aim to be in London before the 2012 Olympic Games, as long as they do not run out of money. They depend on a few sponsors and the articles, pictures and videos they make at the end of the day.

The bicycles they use on their world tour are an offer from sponsors. They cost some 2,300 euros (3,300 U.S. dollars) and reach speeds of 25 kilometers per hour, covering 90 kilometers before requiring a battery recharge.

Nguyen hopes people of all ages and levels of physical fitness will try riding an electric bicycle. She told Xinhua that regular bicycles can easily and inexpensively be converted into an electric one using a conversion kit.

"The advantages of going electric are numerous, ranging from a reduced carbon footprint to enjoying low-cost, speedy travel without much hassle," she added.