I am doing some piezo and energy harvesting tests, but I am having a hard time calculating the available energy balance. I setup a voltage and current measurement for both the energy harvesting input and output. As the scheme below: The graphs below demonstrate a test performed, the capacitor voltage is limited to 6.5v and when it reaches 3.5v the output is opened.
The main question I need to answer is:
- Is this piezo / harvester set capable of powering a "sersor" that consumes how many Watts for how long? That is, what power do I have available from how long?
- This measurement setup is correct, should the load / ampere resistor have a smaller value?
- What is the correct method for calculating the energy balance available at the energy harvesting output? Multiplying voltage and current and integrating in time gives me the total energy, right? Dividing energy by time would give me the average power?