The City of Johannesburg is pioneering a fresh approach to sustainability and to tackling the issues facing Africa in the new century. The Green City Startup Challenge is a world first, calling on individuals throughout industry to come up with sustainable ideas to overcome the social and ecological challenges the world faces today, and will encounter tomorrow.The competition, run over three phases, provides business support and mentoring workshops to enable even the smallest entrepreneur to develop a ''green idea"."With its large urban forest, Johannesburg is renowned as a green city," says Ravi Naidoo, executive director for economic development for the city."But how do you deal with the challenges of climate change with South Africa as the epicentre of that impact on the continent?"The City of Johannesburg looked at how to turn the challenges of sustainability into opportunity and growth by callingfor fresh ideas under the Green City Startup Challenge."Run in conjunction with University of Johannesburg and Resolution Circle, a UJ-owned company, Green City invited applicants to submit their ideas for change via its Facebook page."Anyone could put forward their idea as long as they were based in Johannesburg, or their idea could unfold in the city," says Naidoo.The 86 entrants were whittled down to 20, and after a week of workshops eight were chosen. Each received a R250000 grant to develop their project or pilot a prototype. In August, two winners will be announced - each will receive a R1-million grant.The finalists include Harold Oswin, a young man studying at Harvard in the US, who has devised an electrical timer switch that can be available to market for a fraction of the cost of current commercial timers. "This is extremely valuable for lower LSM households," says Naidoo. "It helps the city and helps the consumer."Another finalist has created a modified electric bicycle that can help waste reclaimers become more productive.Gabriel Ally is the former mayor of the Johannesburg Junior Council. Inspired by the determination and resourcefulness of "trolley recyclers", Ally developed a model for the transformation of the informal recycling industry. The Recycle e-Trike is a 500w electrically assisted tricycle. It is designed to double the output of trolley recyclers and improve their safety on the road.It can transport 150kg of recyclable waste over a distance of 50km. It is fitted with disc brakes, brake lights, indicators, a headlamp and an interesting-sounding hooter. The 1.2m loading box and the rear hubcaps act as a canvas for recycling awareness campaigns.These bikes not only create micro-entrepreneurs, they may also provide a solution to the city's landfill problem. Should Johannesburg continue to landfill up to 90% of the city's waste, the city will probably run out of landfill space by 2030.''We're so encouraged by what we've seen that we're going to start our fundraising for next year now and ask for new submissions in September," says Naidoo."This is the first version of the competition, so it's important to leverage private sector fund-raising to expand what we can offer. We'll present to investors and the business forums," sats Naidoo."It's been fantastic to be a part of the challenge," says Ally. "The process has gone quickly. We had an opportunity to present our ideas and moved fast into making them a reality. I've met the committee that's helping me with my goals. I'm meeting an intellectual property lawyer through Resolution Circle and in a few weeks I will receive the total of my grant to develop my product and expand my fleet of vehicles."..