Although there are many positives on using hydrogen energy, unfortunately there are also some negative effects of using it. First, hydrogen energy is very expensive because it is so difficult to separate it from other elements.
If it were easier, making it more cost-efficient, to separate it from other components, everybody would be using it to create energy. Also, it is very problematic to transport hydrogen from place to place since it is so light. This means it is challenging and costly to transport it any other way than small amounts of it, making it very unproductive through both cost and time.