Is there a piece of technology that you really want that doesn’t exist? (i.e. flying cars, teleporta

I wish that there is technology that can generate electricity without using natural resources. For instance, cars need fuel such as gasoline or diesel which is based on petroleum to operate. Unfortunately petroleum is not infinite and it will be consumed up sooner or later. Although, there are power plants that can convert sunshine, wind, or water that is permanent natural resources and no side effects to electricity, their production volume is so small and we should still rely on conventional types of energy sources. When all types of energy sources are exhausted, humans will face serious difficulties. In order to avoid the situation, we need to develop alternative energy resources. Another technology we need is an automatic language interpreter. When we travel to other countries or having a conference with various nations, we can communicate with local people without an interpreter. What about a stem cell technology that can make human organs that can be transplanted?