This is truly good news, but is it really worth calling out that a record was broken when it's been trending down regularly over time?
If you extrapolate the downward trend, it's very obvious that anything you build right now that burns fossil fuel is going to be a problem in terms of being able to compete throughout its projected life span. Prices are trending to the point where it will become economical to shut down existing and operational plants in favor of replacing them with solar or wind.
The next milestone will be when existing coal/gas plants will start getting decommissioned. This will start with the older ones but very soon after may be followed by the new and shiny ones Trump is trying to build right now. That is if he manages to get investors to back that at all. It would be kind of a dumb investment given the above.
And to preempt the battery comment, batteries were included with this bid, as is common these days.