Antihydrogen - a new energy source ?

The answer is: NO !


While antihydrogen production at rest is hoped to be solved within the next years, there is no meaningful idea how to use energy set free by annihilation. StarTreks warp engine may be a clever idea, but in real life it wouldn't work.
Anyhow, the overall efficiency would be smaller than 0.000 000 000 1 % !!!
So, it's better to use the available energy 'directly', even an old steam engine has an efficiency of 10 %.

Some examples:

Detailed calculations
CERN PS-Complex
World electricity in 1993 The originally given value of 5.8 minutes was wrong due to an error in the encyclopedia
Known coal, oil, gas ressources