Voltage meter and change-based data logger

I am attempting to create a power-from-the-grid reliability metric. Along those lines I am looking for a device that records any instance of two events: a change in power state (i.e. available versus unavailable) a change in power quality (i.e. under or over voltage), I am not looking to measure current but voltage. I do not need remote connectivity/reporting of any kind. It should have either an SD card writer or USB flash drive writer for data logging. Ideally it would also have a rechargeable battery that can be recharged from the source it is monitoring. It should run for at least one month with limited or no power. At boot/setup/first run it should have a simple interface to set date and time and format the data logger’s drive if necessary and thereafter will only log the date and time of when there is a change in the power. I am in Puerto Rico which abides by US electrical codes. The data will be used to determine what locations are best served by auxiliary on-site power generators like solar panels, wind turbines, or fossil-fuel power plants.

My question then is: Is the hardware available from OpenEnergyMonitor’s shop overkill? As in too many features and hence a higher price tag than the bare minimum I need.

I don’t think a device in the shop exactly matches your requirements. The emonTX shield device could be used and if modified to include an SD card logger then that could be made to work - but you would have to write new code !

I don’t mind writing new code as long the price-point per complete hardware package makes it affordable to deploy multiple units within the allotted budget, however if it turns out the project can only afford one hardware package then it is too time consuming to rewrite the code base for only one functioning unit. For the time being I will continue to investigate other available alternatives.

Thank you very much for your time.