Thanks for your interest in our SDK! The accuracy for power/energy measurements you will get is the accuracy of the power analyzer you will use with the SDK. For example, if you are using a WT210 from Yokogawa (for which the SDK has a built-in support), then the basic power accuracy is 0.1%. You can refer to the manufacturers web site for more details, and to the SDK documentation for other supported power analyzers. If you already have a power analyzer and if it is not supported by the SDK, you will have to develop a small support module for it (as explained in the SDK documentation).
Assuming that the power analyzer you will use has hardware support for power integration (to measure energy), then the accuracy of the measurement will be what the analyzer provides you. If your analyzer doesnt have hardware support for power integration, then the SDK will do it for you, by software. The accuracy will be much less, since the sampling rate is 1Hz. In contrast the hardware integration in the Yokogawa WT210 is on the order of 50,000 samples per second.
They may be some unique attributes or specific requirements for the embedded environment. Can you please share some more info on your plans/setup for this? We will be happy to help you adapt how to use the Intel Energy Checker SDK to support your activity.