kW happens to be the unit of sale for power (well, technically, the kWh), so it ironically makes sense to use it here.
Anyone sending and receiving power through this project doesn't deal in kW.
At scale that isn't true, it is either MW or GW for instantaneous power and MWh or GWh for energy.
Do you have 8 million kilobytes, or 8 gigabytes of RAM?
At grid scales, kW is a rounding error. Even MW is somewhat the decimal place, especially for a country as large as China.
"Technically"? It's just wrong and I'm not sure which they were intending. Similarly, "miles and miles per hour are different units, it's not just a technical distinction.
A journalist is reporting on something they don't understand.
Should have been 8 billion kWh per 1000 hours...
Anyone well versed in the metric system can easily scale up and down the orders of magnitude, and units like "millions of kilowatts" is just tautology in the end of the day.
Also, like others have pointed out, kilowatts and kilowatt-hours are most certainly not used on grid scale projects. Mega- and giga- are the standard throughout.