The top level comment by user philipkglass here was very interesting as it relates to project complexity.
Comment copied here:
"After announcing the project back in September, we have now learned that Tesla and Southern California Edison (SCE) have completed the massive 80 MWh energy storage station using Tesla’s new Powerpack 2 at the Mira Loma substation....While Tesla and SCE haven’t officially launched the new substation yet, sources familiar with the new Powerpack installation told Electrek that it was completed a few weeks back – late December – and brought online so that the electric utility can start using it to manage peak demand.Deploying this project in only 3 months is really impressive.I think there's a pattern here: energy systems built from repeating small modules have systematically lower risks of cost/schedule escalation.
See for example "Construction Cost Overruns and Electricity Infrastructure: An Unavoidable Risk?"
Look at Figures 2 and 3 in particular. The mean overrun by project type goes:
solar < wind < thermal (fossil) < nuclear < hydroelectric.
That's basically the same ordering as "minimum viable project size." Coincidence? I don't think so. A small solar project can be a handful of panels. If you want to scale up to hundreds of megawatts, just tile a
much larger area using the same panels and basic repeating structures. A lot of work can execute in parallel and sections can start generating output/revenue rapidly as they're completed, sometimes years
before the project's last panel is installed. No such luck with a nuclear or hydro project: you can be on year 7 of an 8 year schedule and it's still generating zero watts because so little can happen in parallel. (This is also why I consider small modular reactors the last, best hope for a nuclear renaissance, but the latency for nuclear R&D is so high that renewables might "eat the world" first.) I rather expect that this Tesla installation, despite its impressive speed, was not particularly cheap. But if battery costs keep declining, in 5 years it could still be lightning quick to build another installation like this and cheaper than gas/diesel peakers. If that happens then storage-backed renewables become the very cheapest electricity source across large swaths of the Earth, threatening huge chunks of coal and natural gas demand. There may be a parallel risk to oil demand if Tesla and other auto makers execute well on their EV plans currently in the pipeline. I think Tesla faces some significant risks from the SolarCity acquisition, and execution risks on the Model 3, but I sure can't fault the ambition."