This is why a burning match is hotter than the impure sample of radium. The radium remains warm for thousands of years, the match burns out in a minute or two. These may not be 'Frequently Asked Questions,' but they ought to be, because power and energy are Frequently Confused Concepts. Power is the rate of energy release at a given instant in time. Energy is power integrated over time.
Power is measured in watts, kilowatts and horsepower.
4.18 joules equal 1 calorie, which is enough energy to raise the temperature of one gram of water by one degree Celsius. One BTU equals 1,055 joules. One horsepower equals 746 watts. This is one of the many unsolved scientific mysteries of cold fusion. Some scientists think that because the effect does not produce intense radiation, it cannot be a nuclear process.