I propose creating a global network of barge trains powered by renewable energy. The system would consist of sub-surface wires, which unmanned barges can connect to and get pulled automatically to their destination. The barge trains would be installed on major shipping lanes first. Later the system can be expanded to connect more and more ports all over the world.
Renewable energy can power the whole system. This can be done by placing windmills and solar panels at strategic places near the network. A major challenge with wind and solar power is the varying output depending on shifting weather. The barge train system is an ideal consumer of varying electricity. The barges could be slowed down and sped up in line with the produced electricity. This will enable a closed system where the network does not need to buy or sell electricity externally. It will also not need to store electricity.
Since the barges do not need to have personnel, it will mean huge savings in shipping and ultimately for the consumers buying the transported goods. The barges will be less interesting for pirates as they cannot take hostages, with no personnel on board,
Also accidents like a sinking barge will not cause loss of life with no personnel on board.
The world is facing an ever-increasing number of people who are either forced or wish to leave their countries, searching for a new life abroad. These people often struggle to find countries that will accept them and end up stranded in refugee camps with few prospects to make a better life. The world is en need of a new nation that will welcome everybody, no matter where they come from and no matter what reason they have to leave. This nation could build its economy on the influx of newcomers, building a green and sustainable economy, maybe as a car-banned city state. If done properly it could become one of the most prosperous societies on earth, seeing the migrants as economic opportunities. It could offer everybody on the planet who wishes to go there a free ticket and help getting started working or building their own business.
Where would the money come from to build this? One source could be rich countries who eagerly talk about helping people closer to their home, using the argument that they can afford to help many more refugees closer to home than taking them into their own countries. They would happily support a society that will accept all of them, relieving pressure on their own shores. The new nation could attract industries with the huge number of workers.
Where could this territory be? There is no way around that it will be necessary to find a country which would be willing to give up land to this new nation. It could be given economic incentives and favorable trading rights with the new neighboring country. The people already living there should receive considerable benefits so their lives will improve as citizens of this new nation. Ideally it would be in a territory with a low existing population density.
In many cities all over the world, people are wasting their time in near stand-still traffic. It is especially a growing problem in developed countries where the infrastructure cannot keep pace with growing populations and ever increased numbers of vehicles on the road. Public transport like buses are often stuck in the same traffic jams. A low cost solution could be to embrace cycling. If cycle lanes are build on pylons above the road, cyclists will not add to the congestion on the street level. It will also help poor people, who will get a low cost and congestion free way of moving around the city, relieving the traffic congestion on the streets below. If budgets permit it, they could even be shaded by solar panels above the cyclists, providing both shade and clean electricity for the grid.