The previous post got thousands of views and Twitter comments, inspiring me to write a thread on the related topic of solar-Powerwall-Tesla car as an ideal of independence for green consumers. It’s compressed and minus the usual citations, but it explains why the dream Elon Musk is selling isn’t anywhere close to realization. The thread:
1) Experts also know $TSLA fantasy setup of solar/Powerwall/Tesla car doesn’t work without grid connection to net metering utility. The battery capacity is too low, it can’t supply surge startup for AC units and the like, and grid power down means no power for anything.
2) Special circuits supplying only a subset of the house’s critical appliances have to be installed to allow use while grid is down. Big AC units can’t be included. Cost for the gridless setup in the extra $10,000s as a retrofit.
3) Year-long net metering, required to make solar ROI reasonable in most locales, is a huge subsidy to wealthy rooftop solar owners and is rapidly disappearing as it impacts rates for poor people.
4) Electric utility rates are set by law to guarantee profit to the utility, so a subsidy to solar users raises the rates for everyone else. CA already generates so much solar electricity around noon in spring that the state has to pay other states to take some of it.
5) Rooftop solar can only be a small portion of generation without distorting management of the other forms of generation, turning them into peak-nighttime plants only and raising costs further.
6) Big battery storage installations can help a lot in special cases (islands, “over-solared” states like Germany) but cost far too much to compete with conventional or existing nuclear plants for base power needs.
7) Tesla’s fantasy world is at least decades away. Utility-scale solar farms are cheaper and more easily maintained. The public sentiment supporting home rooftop solar will melt away when people understand they are paying twice as much so others can escape paying for the grid.
8) Tesla’s only real success was the Model S, which caught the imagination of wealthy Silicon Valley types who wanted to show their virtue and have the shiny thing few people had. But that market is small and fickle.
9) As governments around the world discover they have subsidized and required alternative energy too much (every pol seemed to love raising the percentage required), those subsidies are being rolled back or removed. Deadly for Tesla car and solar sales. /end
Rooftop Solar: Trendy Boondoggle or The Future of Power?
Mansion Engineer 