Hacker News: ziga

New comment by ziga in "Claudette: Make Claude stop talking like a BuzzFeed article"

ziga — Fri, 21 Aug 2026 16:28:06 +0000

To avoid these Claudisms, I asked Claude to add instructions to my AGENTS.md. The first line it added:

  Avoid the stock LLM register.

Sigh.

New comment by ziga in "Renewables reached nearly 50% of global electricity capacity last year"

ziga — Thu, 02 Apr 2026 19:19:17 +0000

Unless you add battery storage, which is increasingly the case:

https://pv-magazine-usa.com/2026/02/25/solar-and-storage-to-...

New comment by ziga in "How big a solar battery do I need to store all my home's electricity?"

ziga — Tue, 16 Sep 2025 07:41:24 +0000

> Oh, and also batteries such as the tesla power wall can only be charged and discharged about 1000 times before they have lost a lot of capacity.

Powerwall's cycle life is much better than 1000. The Powerwall warranty guarantees 70% capacity after 10 years of daily cycles (i.e. 3650 cycles). This means they expect the capacity to be substantially above 70%.

We posted an analysis of Powerwall capacity retention: https://www.netzero.energy/content/2025-02/powerwall-analysi...

New comment by ziga in "CO2 Battery"

ziga — Fri, 25 Jul 2025 18:53:51 +0000

Ah, those are wholesale prices. And the form factor will increasingly be prismatic LFP packs, not cylindrical cells.

For buying LFP cells, I would start here: https://diysolarforum.com/

New comment by ziga in "CO2 Battery"

ziga — Fri, 25 Jul 2025 17:55:02 +0000

Grid-scale storage (and increasingly EVs) use lithium-iron-phosphate battery cells, which don't require cobalt/nickel/manganese.

New comment by ziga in "CO2 Battery"

ziga — Fri, 25 Jul 2025 17:52:10 +0000

https://about.bnef.com/insights/commodities/lithium-ion-batt...

New comment by ziga in "CO2 Battery"

ziga — Fri, 25 Jul 2025 17:44:05 +0000

I think 12 years is an underestimate. Lithium-ion batteries will degrade, but they still have usable capacity. There are Tesla Roadsters still going strong, 15 years in. And the battery cell chemistry has since shifted to LFP, which has longer cycle life.

Analysis of Powerwall Battery Retention

ziga — Tue, 18 Mar 2025 14:09:32 +0000

Article URL: https://www.netzero.energy/content/2025-02/powerwall-analysis

Comments URL: https://news.ycombinator.com/item?id=43399614

Points: 2

# Comments: 0

New comment by ziga in "Aluminum batteries outlive lithium-ion with a pinch of salt"

ziga — Thu, 06 Feb 2025 20:37:40 +0000

You can't really generalize cycles based on chemistry alone. Battery management and usage matters. But two examples with NCA/NMC chemistry:

- The Tesla Powerwall 2 battery warranty[1] is for effectively 3650 cycles (daily cycle for 10 years).

- Many cases of Tesla cars at 200k mileage (~1000 cycles, depends on battery size) with less than 15% capacity loss[2].

And these batteries didn't die after reaching the high number of cycles, they just retained less capacity.

[1] https://energylibrary.tesla.com/docs/Public/EnergyStorage/Po...

[2] https://insideevs.com/news/723734/tesla-model-3y-battery-cap...

New comment by ziga in "Geothermal Power in the North Bay"

ziga — Thu, 10 Oct 2024 23:56:16 +0000

> It accounts for 20% of California’s renewable energy.

That doesn't sound right. It seems to come from Wikipedia with a 2019 date, but even then:

The Geysers produced 5,543 GWh in 2022 [1].

California generation from renewables:

2019: 64,336 GWh [2]

2023: 76,153 GWh [3]

[1] https://geysers.com/The-Geysers/Geysers-By-The-Numbers

[2] https://www.energy.ca.gov/data-reports/energy-almanac/califo...

[3] https://www.energy.ca.gov/data-reports/energy-almanac/califo...

New comment by ziga in "Can solar costs keep shrinking?"

ziga — Thu, 29 Aug 2024 19:19:19 +0000

We need all the renewables we can get, and I think you can have both -- utility-scale and rooftop. Rooftop solar (and battery storage) just needs to be cost efficient to offset the rising cost of electricity and make it a good return on investment.

The "attacks on net metering" are merely acknowledging that the proportion of renewables on the grid is high enough that balancing grid supply and demand is becoming an issue. I'm a big proponent of rooftop solar, but the reality is that 1:1 net metering just doesn't make sense once there's a critical mass of solar installed (the duck curve problem). This is not a problem unique to California or the US. If you look at other places with high solar adoption (Australia, EU), you'll find even stricter policies like negative feed-in tariffs: the utility will charge you for exporting solar to the grid.

Battery storage is a solution to that problem, but that's where prices are still too high. I'm actually surprised that battery storage is not mentioned in the article, because that's a critical component of allowing solar/wind to grow further.

New comment by ziga in "Breaking down a record-setting day on the Texas grid"

ziga — Thu, 22 Aug 2024 05:49:26 +0000

I agree about home batteries being too expensive, hopefully prices will come down with scale.

But the part about battery degradation is not true. Tesla Powerwall has a 10 year warranty[1] with 70% capacity retention. This means that Tesla has data showing that the battery will have higher capacity than 70% after those years. That's a lot of cycles and a lot of renewable energy that the battery will provide in its lifetime.

[1] https://energylibrary.tesla.com/docs/Public/EnergyStorage/Po...

New comment by ziga in "Giant batteries are transforming the way the U.S. uses electricity"

ziga — Tue, 07 May 2024 17:01:13 +0000

Dynamic tariffs (aka real-time or wholesale plans) are becoming more common in the UK an EU. These are usually priced by 30-min periods and announced 24h in advance. More modern utilities will offer apps that control when your car is charged (in exchange for cheaper rates). But I agree, optimizing this is fun too. I'm building support for configuring Tesla Powerwall systems based on dynamic tariffs.

If you have the option, the best time to charge your car would be during the day when there is abundant solar.

New comment by ziga in "Ask HN: What apps have you created for your own use?"

ziga — Wed, 13 Dec 2023 15:30:06 +0000

I wanted a better dashboard for my Tesla solar/battery system: https://www.netzeroapp.io/

New comment by ziga in "The next power plant is on the roof and in the basement"

ziga — Tue, 21 Nov 2023 07:35:03 +0000

PVWatts is a good resource to estimate solar production based on location, system size, roof orientation, etc:

https://pvwatts.nrel.gov/pvwatts.php

New comment by ziga in "The next power plant is on the roof and in the basement"

ziga — Tue, 21 Nov 2023 07:31:15 +0000

Tesla Powerwall is probably the most commercially successful home battery. It comes with a warranty guaranteeing 70% capacity after 10 years, which is not to say it has a 10 year lifetime. It's still early to determine its actual lifetime, but the battery technology is also rapidly improving due to the EV transition.

New comment by ziga in "The next power plant is on the roof and in the basement"

ziga — Tue, 21 Nov 2023 07:03:08 +0000

Lots of variables in sizing a battery system:

- Is your goal battery backup or load shifting?

- How much backup do you need?

- What is your energy usage and peak demand during that time?

Peak demand is a big factor: a single Tesla Powerwall 2 for example has 13.5 kWh of capacity but only 5kW of continuous power. A heat pump or AC can exceed that, which is why many people stack multiple batteries to be able to power their homes. (The new Powerwall 3 can supply more power.)

New comment by ziga in "The next power plant is on the roof and in the basement"

ziga — Tue, 21 Nov 2023 05:39:24 +0000

In case your system is from Tesla: I wrote an app that you can load on a tablet and stare at that energy flow all day :)

https://www.netzeroapp.io

New comment by ziga in "What Is Dbt and Why Are Companies Using It?"

ziga — Fri, 03 Dec 2021 03:20:41 +0000

The dbt community will frequently run Snowflake, and its SQL engine is very good.

https://medium.com/@jthandy/how-compatible-are-redshift-and-...

New comment by ziga in "Show HN: My wife is pregnant; naturally I made a baby-name app to prepare"

ziga — Fri, 05 Nov 2021 19:00:21 +0000

I had the same problem and built this: https://zigam.github.io/ginkgo/