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

Can I add that outside of the political commentary because thats mainly the only reason this is on hackernews.

There are mounting challenges in climate tech - specifically in residential solar: 1. Residential solar has been under punishing economic headwinds. Tariffs (before this) against imported PV. The market has not been performing. 2. Many of the Public Utilities are making it very difficult for solar to work out financially for home owners - see CPUC in California changing the terms of NEM to the advantage of the Utilities as an example. 3. Energy storage in residential markets has ALWAYS been an insurance product/backup power and not a financially beneficial product. It is tough competition against generators etc 4. Utilities are wisening up and increasing their fees and reducing the benefits of on site power generation. 5. Residential solar has likely already found all the best home owners (ie lowest CAC) so are now pursuing harder to reach.

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.

Sadly, all those points but 5 are also political. The US isn't serious about it, for whatever (political/economic) reasons.

The UK, on the other hand: https://www.fmb.org.uk/homepicks/news/surge-in-solar-panel-i... ; helped by an efficiency mandate on new houses.

Rare win for Germany, the the land of bureaucracy, made it easy to install *small* residential solar.

You can buy small solar panels in the supermarket, and plug them into the wall socket, which normally is a no no. Per household a maximum of 800 watt though.[1] For more you need something proper that does not just connect via a normal wall socket.

[1] Maybe also 2000 watt but only 800 feed into the grid?

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.

Let's compare UK and USA electricity prices.

https://www.statista.com/statistics/263492/electricity-price...

It seems that something is not working that great in the UK...

UK electricity prices are set by the highest priced generator which is normally gas

Eventually more green energy will overcome this issue

Many of the commercial solar and wind farms run on a contracts for difference price - they're guaranteed a price for the energy they produce and when the market price goes over that a rebate get's paid to a Quango and should eventually feed into bills payers prices

You can have up to 2000W panels with an inverter up to 800W. Note that the 800W is what you're allowed to produce, not feed in, but it can still be beneficial to overprovision panels because with 800W of panels you won't produce 800W of power in mornings, evenings and winter. Panels are also cheap af in Germany currently, about 60€ for a 440w panel.

> The US isn't serious about it,

More than 40% of Texas's energy was carbon free already in 2022 [1], and they are still installing solar. Not on public lands, but most solar wasn't installed on public lands anyway.

Having said that, in the big picture the US is far behind China indeed regarding solar renewable installations. Compared to the EU, California is far behind and Texas is a bit behind. Germany for example sits at around 50% renewable [2].

[1]: https://www.noahpinion.blog/p/blue-states-dont-build-red-sta...

[2]: https://ember-energy.org/latest-insights/germany-sets-new-re...

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!

As a Dutch person I'm baffled that you're saying the PV industry has headwinds.

Recently added another 4000kWh of yearly production to my garage for €4000 all in because why not. I also have a 20 kWh LFP battery now, €7000 all-in (and dropping quickly!), which works out fine.

Many people now buy "plug-in" products: small batteries or single PV panel that you just plug into the grid directly, no installation required.

All the issues you list are governmental issues, not PV issues. The global PV indsutry is EXPLODING.

I think the plugin prodicts are pretty cool, especially for renters, but my understanding they're not legal in the US

40% of Texas's electricity, not energy.

There is still a lot of fossil energy consumed, too.

That would, again, be a government problem not a PV one.

Also how would they even know. These things feed in 800 watts max, it's barely anything.

In my country we don't even have to get permission for big products. I have 9kW of PV on my roofs and just put it there, same with the battery. It's the grids companies' job to figure out how to make it work, not mine.

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.

Home solar is mainly a jobs program and rarely makes financial sense, especially if you factor in the opportunity cost of the invested money.

You can do exactly the same in the UK. I am, and I do.

Re "UK electricity prices are set by the highest priced generator which is normally gas"

Worldwide, electricity prices are set by the highest priced generator at the given moment of needed generation -- it's the dispatch curve. And generally, the generators that are the fastest to spin up to meet that incremental load are natural gas fired generators.

As to the GP's point, my intuition (happy to be proven wrong) is more that natural gas, and therefore electricity, is cheaper in the US, simply because it's more abundant in the US.

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.

Throwing it out there that, as a US citizen who has been looking at and wanting solar for about 3-4 years now, it's extremely unaffordable through the installers I've looked at previously. Some installers have quoted a total of double the cost of materials because they maintain the labor of a 1 day installation is worth 100% the cost of batteries and panels - which often brings the total to $30k-$40k USD. Some of these agreements you also have to read closely because there are some total garbage ownership rights in the contract, saying you are renting the panels and don't own them. I haven't looked yet in my new state because interest rates stopped falling after Biden left office, but my previous state made the entire process a racket.

Yeah sorry very silly mistake thanks for pointing it out. It makes a big difference indeed.

> 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.

That is great :)

> Let's compare UK and USA electricity prices.

The USA is a huge place with prices all over the map.

Here are PG&E electricity prices in California from my recent bill:

peak: 53.0 + 18.3 = 71.3 c/kWh

partpeak: 51.3 + 11.1 = 62.4 c/kWh

offpeak: 34.4 + 09.8 = 44.2 c/kWh

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