thanks for the references... i would question this statement: "that is well underway, and you can see a great proportion of today's Tesla EV's are actually already sun and clean energy powered"... as simply what makes "a great proportion?"
but I will let it go as this thread has a finer focus on the stock.
Sure. It's a bit hard as a Californian in Silicon Valley driving around seeing dozens of Tesla's per day and hundreds of homes with solar panels on them and parking lots with solar canopies every day to be thinking I need to have this huge internal fear that we need a renumeration of this activity right now because I'm not seeing any, so I understand my prejudice on this. But, here's one of the sites I sometimes study to find out what the utility-scale (not home-scale which is a huge proportion too) clean energy provision in California is:
California ISO - Daily renewables watch
California ISO - Todays Outlook (although it's not working right now (rare; I've been following it for years, and it almost always works --- check the "ISO Today" app on iPhone
ISO Today on the App Store ))
(I find the ISO Today app to be less complete than the Today's Outlook page, when it is working.)
You can take a sampling of the last decade's worth of Daily Renewables Watch's, and look at the utility scale solar rising slowly but steadily over the decade. At about the same time, non-ISO tracked solar resources come from homes, businesses, and parking lots, growing at a similar (but slightly varying) rate -- teasing that out is a bit harder, but Google searches can find some indications.
If you look at the PDF from "Daily Renewables Watch", you will see the first page totals the one day totals for Monday (a little non-representative because it was the hottest day of the year where I live (a fairly typical regional "indian summer", so nothing odd, except to its average extent)) at 782GWh use, with 110GWh being "renewables", and of that, 58GWh being "solar". "Solar" on the chart is only utility scale solar. So, just counting utility scale solar, 7% of the hottest day of the year was supplied by solar power, and if you look at the averages over the years, that amount has been steadily rising. In addition to utility scale solar, there is a huge amount of non-utility scale solar not counted (my rough rule of thumb is half of the real total, so another 7%, for a total of 14%, but this fluctuates wildly from year to year, so subject to confirmation). So, we're on our way, and there's still a huge market for Tesla to fill.
Here's a sentence in WikiPedia, so subject to question:
"California has the technical potential to install 128.9 GW of rooftop solar panels, which would generate 194,000 GWh/year, about 74% of the total electricity used in California in 2013. 128 GW, though, is three to four times as much electricity as is used, which requires that most of the noon output will need to be stored (for example by producing hydrogen) or exported on a sunny day." Note how the politicians who wrote that said "hydrogen" even though that's not what is being done (Tesla is doing battery, and there are a dozen other methods being implemented in the next decade, none of which are hydrogen). That comes from a report that talks about the nationwide ability to provide electricity:
"Table ES-1 shows our aggregate results.3 The total national technical potential of rooftop PV is 1,118 gigawatts (GW) of installed capacity and 1,432 terawatt-hours (TWh) of annual energy generation. This equates to 39% of total national electric-sector sales, and it is significantly greater than a previous National Renewable Energy Laboratory estimate of 664 GW of installed capacity and 800 TWh of annual energy generation (Denholm and Margolis 2008). The difference can be attributed to increases in module power density, improved estimation of building suitability, higher estimates of the total number of buildings, and improvements in PV performance simulation tools that previously tended to underestimated production."
"These results are sensitive to assumptions about module performance, which is expected to continue improving over time. For example, this analysis assumed a module efficiency of 16% to represent a mixture of various technology types. If a module efficiency of 20% were assumed instead, which corresponds to current premium systems, each of the technical potential estimates would increase by about 25% above the values stated in this report. Furthermore, our results are only estimates of the potential from existing suitable roof planes, and they do not consider the immense potential of ground-mounted PV. Actual generation from PV in urban areas could exceed these estimates by installing systems on less suitable roof area, mounting PV on canopies over open spaces such as parking lots, or integrating PV into building facades."
The industry is already headed way into the 20% efficiency range, and we are already seeing a large number of solar installs in places other than "suitable rooftops". Furthermore, with a solar roof like Tesla is planning to introduce, a lot of the roof which was previously considered "unsuitable" might be covered anyway, collecting even more; we shall see what Elon reveals October 28, 2016 to find out more about that.
Solar efficiency and cost progress has been steady, and it is becoming affordable.
If you add the numbers up, we have to fill almost every rooftop with solar plus a bunch of solar farms in barren lands to power everything, but that's what we're headed to do. We're already about 3% of the way there nationwide, and closer to 7% of the way there in California, and those numbers are always outdated because we're adding more and more.
