"Transforming matter to energy" != "burning". According to Wikipedia, you can get about 24-35 MJ/kg by burning coal, which is a tiny tiny tiny fraction of what

"Transforming matter to energy" != "burning". According to Wikipedia, you can get about 24-35 MJ/kg by burning coal, which is a tiny tiny tiny fraction of what you can get by magically transforming matter to energy. (In other words, transforming one kg of matter to energy releases 9*10^16 J of energy, equivalent to burning 2.6 million ton of coal.) As far as I know, the most physically realistic way of transforming matter to energy involves throwing it into a black hole and capturing the incoming radiation. So... I'll bet it won't be commercially available any time soon.