What is new with hydrogen powered vehicles. Cost was 3 times equivalent of gasoline, pure enough for fuel cells will be even more costly.?

There is a push for hydrogen powered vehicles. This seems to be coming from the fossil fuel industry rather than the public. 96% of hydrogen is made from fossil fuels now and in the foreseeable future as it is the cheapest source. Some car makers are "inspired to develop a hydrogen fuel cell electric car (FCV.) It is emphasized that it is powered by hydrogen rather than that it is an electric vehicle. However it is similar in operation to a hybrid that makes electricity for batteries and an electric motor but uses a fuel cell rather than an internal combustion engine and generator.

Fuel cells powered by methane (primary component of natural gas and primary feed stock for making hydrogen) are just beginning to reach a sufficiently cost effective level as a stationary co-generation device. They are useful when the waste heat can be used to also heat a building. In a car they are only slightly more efficient than a diesel engine because like a petrol car engine lots of waste heat is produced rather than the energy to move the vehicle.

There are thermoelectric devices that can capture waste heat and turn it into electricity. Unfortunately they are not sufficiently efficient either. As you mentioned fuel cells also tend to be very expensive.

The only real advantage the FCV potentially offers over a battery electric car (BEV) are those things associated with any hybrid: shorter fueling time and longer range. Although the FCV is a ZEV like an electric car because almost all of its fuel is made from fossil fuels all of the pollution is simply transferred to the fuel manufacturing facility. At least the BEV can use solar panels or other renewables and because it is using electricity directly without conversions it is far more efficient.

Before a cost effective FCV is developed it is likely that a long range reasonably priced BEV will be offered. Unless the fossil fuel industry pushes subsidies from lawmakers to far below what is available for the BEV it is likely that competition from present day ICE vehicles and future BEV will not permit much of a market share for a FCV. Looking at the FCV from an energy conservation, efficiency or cost perspectives they don't really make much sense.

Nothing. The most efficient thing to do with hydrogen these days is to burn it in an internal combustion engine. But there is no reason to this as hydrogen fuel is extracted these days from natural gas. By throwing away the carbon part that contains about 3/4 of the energy and dump it into the atmosphere as CO2. It is way better to just burn compressed natural gas in an internal combustion engine. A conversion kit for this is about $5000. In the city where I live, we have city buses running on compressed natural gas.

I believe electric cars will eventually take most of the market share once they become as good and as cheap as gas vehicles.