There are lot of smart meters to measure the energy of renewable sources at home or large generation sites. In these smart meters NPES, TES and L&T energy metrrs are used in domestic level for solar energy measurement.

Usually, the decent inverters have an internal microchip with sensors used to measure and transfer to the computer through either RS232 cable or wifi the electrical quantities (current, voltage, power, energy, frequency, etc). So, you can measure and save in excel file and deal with them. From the other hand, you can build you won measurement and monitoring system using CT, PT and different sensors. I used both in my lab, and it was found interesting since I can compare and verify my measurement.

If you are looking for a product to track the energy generation of your photovoltaic system you can check the following:

1) TED5000 ( https://www.theenergydetective.com/ )

also, refer to package page

( https://www.theenergydetective.com/solarpackage.html )

2) Locus energy , or 'Locus'

( https://www.solaris-shop.com/inverter-monitoring-equipment/ )

also, refer to page ( https://www.solaris-shop.com/brands/Locus-Energy.html )

3) Sense ( https://sense.com/ )

*) Also, in the following link there is an article highlighting some companies that provide solar monitoring solutions:

( https://solarfeeds.com/solar-monitoring-systems-in-the-world/ )

Moreover, monitoring PV system energy using the inverter is provided by the following companies:

1) ENPHASE ( https://enphase.com/en-us/products-and-services/microinverters )

2) SolarEdge ( https://www.solaredge.com/products/pv-inverter/single-phase#/ )

* If you are doing research, make sure to buy an I-V curve tracer to measure IV and power (graphs):

for instance:

( https://www.ht-instruments.com/en/catalogues/i-v500w-i-v-curve-tracer-1500v/ )

Also, don't forget to measure the input to the system using a pyranometer (& a weather station for other parameters that can impact the performance of the system - if needed, such as wind speed, relative humidity, ambient temperature, etc.).