Tesla Solar Sales Declined for 4 Qtrs. Then Tesla Stopped Publishing the Numbers

The risk reward ratio is way off at most people’s electricity prices. At best, you save yourself a few dollars in electricity costs (unless you’re in super high priced and sunny California).

At worst, you need to deal with a roofing problem.

For backup purposes, a generator and some fuel seems to be a lot more bang for the buck.

Very long term however it generally isn't a better deal. 15 years with solar is generally no maintenance with linear gains beginning about halfway through. Compared to 15 with a combustion engine that loses value the day it's installed, needs permanent maintenance to operate efficiently and effectively, and only generates value (ha) during disruptions.

Generators are garbage, including the standby ones. Maintenance issues are a real problem over the years due to moving parts. Installation also costs a fortune for the standby generators, due to the need for plumbing and electrical going indoors and out —- even though the actual products are cheaper. Battery backup products are just hugely cheaper to install, but the prices need to come down by about 50%. It’s obvious this will happen, because if you look at pricing on battery components and inverters vs. the cost of the “all in one products” it’s obvious there are huge costs and margins in the fancy assembled products that will go away as global manufacturing ramps up (tariffs excepted.)

I'm having a bit of a Gell-Mann moment here - I'm hearing the exact opposite from every residential and C&I installer I talk to, that solar installations are booming right now.

There are very few states in the US where net metering doesn't exist, with California having the NBT (and Arizona and Utah something similar iirc), and Alabama, South Dakota, Tennessee, Idaho, and Texas all have utility-set forms of net metering. Just because California has phased it out and it's a sunny state doesn't mean you can't install a solar roof in Massachusetts and benefit.

The cost of panels is dirt cheap (even with tariffs). You don't need energy storage if you pay $100/month in energy costs, just offset that. Home Depot will install it if you want!

Solar actually runs into inverter problems by year 10. Roof needs to be redone maybe year 20 if you installed with a new roof.

The back up generator is really compared against the energy storage asset and not the solar array. On a multi-day/weeklong winter grid failure generator is a much safer asset to have to protect the home - even including your loss equation.

Agreed generators are a PITA but are pretty useful as well. I hope so - I'd much rather go ESS route but two core issues:

1. Length that the asset can provide power in a grid failure (multi day isn't possible at this point except incredibly small load profiles). As a buyer of a generator/ESS I want multiple day coverage on grid failure not momentary grid failure. 2. Cost is way too much for the power you get.

"I talk to, that solar installations are booming right now" -- where are you located? Rezi installs used to be a 30% year over year growth market. Last year growth went negative... this year is going to be significantly worse.

If you've ever lived through a disaster, then you know fuel availability and demand spikes can make it unobtainable overnight. Solar is great for disaster resilience.

Inverters are built to last for the life of the solar system. They typically have 10-15 year warranty. And no reputable solar installer is going to put panels on a roof that is due for replacement. By the time a roof needs to be replaced, the panels have already paid for themselves and can be swapped out for newer, cheaper, and more efficient models. That's Swanson's law.

I can speak from first hand experience that the comment about inverters is inaccurate. You may need to replace them they are the weakest link in the balance of system.

2nd - much nicer to not have to waste a paid off asset at year 20.

> Length that the asset can provide power in a grid failure (multi day isn't possible at this point except incredibly small load profiles).

You gave some personal experiences, so I will match yours. We had a 6.6kW solar panels, with a 4.8kW battery. We lived in a flood zone at the time, so I got a generator after the second time I dumped the meat in the freezer after loss of power.

With all that in place had the usual episode of weeks of wet weather (the monsoons), became an island, the power is disconnected because houses around us (but not us) are inundated as the power company doesn't like being blamed for killing people. The generator was a fail because it couldn't handle the startup load from the fridge and freezer motors.

I didn't have high hopes for the battery. Boy, was I wrong. Turns out 4.8kW is enough to drive everything overnight except hot water, air-con and 2 hour roasts in the oven. And I do mean everything - lights, TV, internet, cooking (well, fast heating), washing machines using cold water, fridges and freezes. It also turns out that a 6.6kW of solar can bring that battery to full charge during the day, even with blanket cloud cover and pissing down rain.

And to your point - it will happily do that for years, without fuel or maintenance. As for costs - a few days ago I saw 10kW hour battery advertised on Alibaba for $1,200, with 90 day returns. At that price, it will pay for itself in power costs. If you add in an electric car, it's a complete no-brainer as while electricity costs may be very cheap where you live, car fuel costs won't be. If that car is a BYD (it has a 3.6kW household power outlet), you don't need a house battery just for emergencies.

I can also speak to this. Mine have been trouble free since 2015.