There are at least a few different ways of making hydrogen peroxide. One method is electrolytic, very similar to how hydrogen is made from water and electricity. Modern production uses somewhat more involved chemistry and economies of scale.

Hydrogen peroxide will dissociate releasing heat at a high enough temperature, or in the presence of a catalyst. Even though it is quite explosive it really doesn't have overall specific energy comparable to a hydrocarbon fuel. However, it combusts spontaneously with any hydrocarbon fuel, for example ethanol, enhancing combustion. The energy of combustion would be the regular oxidation of the fuel, plus the dissocation energy of the hydrogen peroxide. It's potent stuff. If it is mixed with approx. 30 percent water, it will have freezing/boiling points similar to motor vehicle fuels. It is also a liquid over a wide temperature range, and can be stored in a lightweight plastic container.

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