Scott Leibrand
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scottleibrand.bsky.social
Scott Leibrand
@scottleibrand.bsky.social
340 followers 49 following 180 posts
Built Open Artificial Pancreas (OpenAPS) with Dana Lewis. Day job at Netskope. DMs are open or email Scott@OpenAPS.org.
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scottleibrand.bsky.social
…blockers have been practical and regulatory: overhead wires intrude into FAA Part 77 air-space surfaces, complicate gate re-configurations, and create new certification headaches… incremental fixes already harvest ~½ the attainable savings without any concrete or steel.

chatgpt.com/share/6859b7...
June 23, 2025 at 8:22 PM
scottleibrand.bsky.social
Asking that of o3 gives a pretty good overview: chatgpt.com/share/68394e...
Short answer Early telemetry and the ENTSO‑E chronology show that the first two “rounds” were small‐signal oscillations and a 2.2 GW trip of conventional units in Andalucía – no large renewable blocks dropped then. The third event (12:32:57‑12:33:17 CEST) pushed Iberian frequency below ≈49 Hz with a RoCoF >2 Hz s⁻¹ and voltage spikes; at that point most PV and some wind inverters interpreted the disturbance as “loss‑of‑mains” and self‑disconnected. Roughly 15 GW of solar went offline in <5 s, stripping almost all inertia‑free generation and letting frequency free‑fall to 48 Hz, after which load‑shedding and the France tie tripped; the fourth round was the ensuing full island collapse. So yes, non‑compliant or overly tight ride‑through/RoCoF settings on inverter‑based resources (IBRs) were the proximate cause, but they only bit because the system was already low‑inertia and running with minimal synchronous reserve. It’s a combined protection‑settings + system‑strength problem, not a “solar fault” per se. Why the IBRs all bailed out • Ride‑through curves out of date or unenforced – A large share of plants (<5 MW especially) still use pre‑2022 settings: trip below 49 Hz, ±15% V, or RoCoF ≳1 Hz s⁻¹. The grid code today requires 47.5 Hz/52 Hz and RoCoF ≥2 Hz s⁻¹, plus 150 ms LVRT, but many older sites were never re‑parameterised.  • Very low synchronous inertia – At the instant of the fault solar was 55 % of generation; synchronous machines (gas + hydro) were ~20 %. Low inertia let the 2.2 GW trip push ROCOF well beyond the legacy inverter limits.  • Voltage swell on weak buses – The Granada–Seville 400 kV corridor saw a fast +5–7 % voltage step when export power reversed; some string‑inverter firmware will also trip on simultaneous UV/OV flags.  • No grid‑forming IBRs online – Virtually all Spanish utility PV is grid‑following; once the frequency reference drifted the PLLs unlocked and shut down. Open points still under investigation • Whether the initial 2.2 GW trip was a single busbar fault or separate unit trips (REE hasn’t published SCADA yet). • How many MW of wind tripped versus solar – ENTSO‑E’s data dump expected in June should clarify. • The exact RoCoF thresholds used by the three largest PV parks in Extremadura; rumours of 0.8–1.0 Hz s⁻¹ settings are unconfirmed. Open points still under investigation • Whether the initial 2.2 GW trip was a single busbar fault or separate unit trips (REE hasn’t published SCADA yet). • How many MW of wind tripped versus solar – ENTSO‑E’s data dump expected in June should clarify. • The exact RoCoF thresholds used by the three largest PV parks in Extremadura; rumours of 0.8–1.0 Hz s⁻¹ settings are unconfirmed. Implications • Regulatory – Expect REE to mandate a nationwide inverter re‑tune and telemetry requirement down to 1 MW, mirroring the new NC RfG enforcement proposals. • Technical – Spain needs either synthetic‑inertia batteries or synchronous condensers at weak southern nodes if it wants midday solar >60 % share without risking another collapse. • Lesson – High‑renewable systems live or die on protection philosophy. 1990‑era loss‑of‑mains logic on a 2025 grid is a cascade trigger, not a safeguard. ⸻ Bottom line: the third/fourth‑round wipe‑out was a protection‑settings problem exposed by a low‑inertia system, not an inherent flaw in solar itself. Tighten the ride‑through envelopes, add fast frequency support, and the same disturbance would have been ugly but survivable.
May 30, 2025 at 6:26 AM
scottleibrand.bsky.social
chatgpt.com/share/67ea60...
A seed crystal is a small piece of single-crystal material used to initiate the growth of a larger crystal with the same lattice structure. In Semiconductors (e.g., silicon wafers): • Crystal material: The seed is made of high-purity monocrystalline silicon. • Process: In the Czochralski (CZ) process, the seed crystal is dipped into molten silicon and slowly pulled upward while rotating. • Function: The seed imposes its crystal lattice orientation on the atoms that solidify from the melt, ensuring that the entire growing ingot forms a single crystal with uniform structure—critical for predictable electronic behavior in chips. In Other Materials: • Sapphire (Al₂O₃): Used in LEDs, optics, etc. Seed crystal directs the growth of a single-crystal boule. • Gallium arsenide (GaAs), quartz, etc.: Similar seeded growth techniques (e.g., Bridgman or hydrothermal growth) are used. Key roles of a seed crystal: • Defines orientation: Crystal plane alignment determines electronic/mechanical properties. • Promotes uniformity: Reduces defects like grain boundaries. • Scales production: Allows large single crystals to be made from a small starting piece. In short: a seed crystal is a structurally “perfect” template that tells atoms how to line up as they cool and solidify.
March 31, 2025 at 9:31 AM
scottleibrand.bsky.social
Sure. I didn’t meaningfully contribute to shaping its contents, so I don’t (can’t?) claim any copyright to it. Please just be clear it was written by OpenAI’s ChatGPT Deep Research.

If you want to reproduce, feel free to user or modify my prompt:
Please do some Deep Research on this topic. I want to understand whether and how Germany prevents source+load circuit overload (beyond simply relying on the breaker safety margin) with balcony solar, and whether there are any additional electrical devices in play that would prevent back feeding in the event total household usage went below 800W on a sunny day. You can also include anything pertaining to batteries integrated into balcony solar systems, if that changes anything regarding those two topics. I’ll conduct deep research on how Germany prevents source+load circuit overload with balcony solar, beyond relying solely on the breaker safety margin. This includes investigating any additional electrical devices that prevent backfeeding when household usage drops below 800W on a sunny day. I’ll also look into whether battery integration into balcony solar systems affects these factors. Before I begin, do you have any preferences on the level of technical detail (e.g., high-level overview vs. in-depth electrical engineering analysis)? Also, would you like information on any specific German regulations, standards, or case studies? Please both summarize and go deep on the EE, but no need to go too deep on the specific legal basis, just what the law requires and what they actively recommend.
March 16, 2025 at 4:26 PM
scottleibrand.bsky.social
I’ve found it surprisingly useful to have ChatGPT read me off (modified) recipe directions one step at a time. I made a GPT (chatgpt.com/g/g-678096a6...), and now I give it a recipe and whatever random extra instructions, and then put it into voice mode to walk me through it.
GPT Prompt: This GPT is designed to guide users through cooking tasks, such as recipes or other text-based instructions, by breaking the process into extremely short, clear, step-by-step guidance optimized for voice mode. When a user uploads or describes a recipe or cooking task, the GPT will extract the shortest possible individual steps and provide them one at a time. Steps should be single tasks, such as adding a single ingredient, or stirring. If a “step” has multiple bullet points, it’s too long, and should be broken down into single subtasks, and only one of those subtasks provided at a time. Users can indicate when they have completed a step, and the GPT will respond with the next step in the sequence, ensuring only one simple action is provided at a time to avoid missing any steps. If users ask clarifying questions, the GPT will use the provided instructions to answer as precisely as possible. If the answer is not specified in the instructions, the GPT will explicitly state this and clarify if any response is speculative. It maintains an organized and user-friendly approach while staying accurate to the provided directions.
February 3, 2025 at 6:55 AM
scottleibrand.bsky.social
Some stills of the leucistic mink I saw today.
January 30, 2025 at 12:48 AM
scottleibrand.bsky.social
Leucistic mink was not in my bingo card for today. 😻
January 30, 2025 at 12:48 AM
scottleibrand.bsky.social
Sounds like that is a grid-tied inverter that requires a system controller and electrician installation to do grid-forming when islanded. Can you think of a way to DIY install it for balcony solar?
January 7, 2025 at 3:06 AM
scottleibrand.bsky.social
They turn on automatically when you lose power at or upstream of the breaker, but stay off if you switch them off. Electrical engineering indistinguishable from magic, until I interviewed o1 about the mechanism. chatgpt.com/share/6760e4...
CHARGING TIME AND USAGE TIME Charging Time: Connect the bulb to the bulb base, and it can be fully charged within 7-8 hours of normal use. Usage Time: The bulb can be used for 3-5 hours during blackout. INSTRUCTIONS Emergency bulb contains a rechargeable battery, the plug will be automatically charged when there is power, the external power will be detected when there is no power whether the positive and negative poles are conductive, conductive will be lighted. Due to the high sensitivity of the detection circuit of the emergency light bulb, a slight resistance can be detected to light up, so we need to pay attention to the following matters: 1. When the power is normally on, the working principle of the emergency light bulb is the same as that of the ordinary light bulb, so it can be used as an ordinary light bulb. 2. During a power outage, you need to keep the main power switch in your home energized. The power supply forms a complete circuit before the bulb can be activated. 3. All emergency bulbs are not compatible with wall dimmers. 4. When a switch controls multiple bulbs, if the positive and negative wiring of the bulb’s socket is inconsistent, the line will still form a circuit after the switch is turned off, which will start the emergency function of the bulb, and the bulb won’t be able to go out. So the positive and negative wiring of each socket must be consistent. 5. The use of power indicator sockets and power strip, because the indicator will be connected to the positive and negative poles to generate a circuit, will start the emergency function to light up the bulb. 6. When there are multiple switches on a switch panel, the wiring may form a circuit due to the mutual influence of the wiring, which may activate the emergency function to light up the light bulb. (If you’re not sure if the bulb is working, use a table or floor lamp to test it.) Here’s what happens in detail when the power is out but the switch is open: 1. Normal wiring scenario: Typically, the switch is in series with the hot (line) conductor. When that switch is open (off), the path back to neutral is supposed to be broken. With a standard bulb and simple wiring, the bulb would simply go dark because there is no complete circuit. 2. Emergency bulb’s detection circuit: The emergency bulb has a built-in detection circuit that draws a tiny current—often just a small test current. This circuit is very sensitive and can detect extremely small resistances or alternate paths. When the power fails, the bulb automatically tries to switch to battery mode. But before it does that, it checks if there’s a conductive path. If it senses any continuity at all, it treats that as a “line present” condition (even though the main supply is off) and turns on the LEDs from its battery. 3. Where the detection current flows when the switch is open: If the wiring in the home or device setup creates a subtle path—through indicator lights on power strips, neon testers, or the presence of parallel wiring to other switches—this small detection current from the bulb can still return to neutral. For example, some power strips have tiny neon indicators or LED indicators that connect line to neutral through a very high resistance. The emergency bulb’s detection circuit can send a tiny current out through the bulb’s socket (line side) and return through the neutral side via that indicator or another unintended path. In other words, the open switch breaks the main high-current path, but the detection circuit only needs a minuscule current. Even a small, unintended resistive path—such as a night light in another outlet, a pilot lamp in a switch, or certain appliance indicator circuits—can complete this micro-ampere-level circuit. The bulb’s detection logic sees this as enough to declare the circuit “closed,” and therefore it lights up on battery power. The key concept is that the emergency bulb isn’t just looking for full mains voltage. It’s looking for any conductive loop. When the power goes out, the small test current it uses to detect line presence can find a return path through unexpected wiring arrangements, neutral connections, or devices plugged into the same circuit. This allows the emergency LED to turn on, powered by the internal battery, as long as it “thinks” there’s still a closed circuit. Why doesn’t it detect such a current through other normal LED bulb on other sockets on the same lamp? Because a standard LED bulb’s internal circuitry does not allow low-level current flow in the absence of full line voltage, it doesn’t provide a return path that the emergency bulb’s detection circuit can use. The emergency bulb’s detection circuit tries to send a tiny current through the wiring to check for continuity. Normal LED bulbs, when unpowered, essentially present an open circuit. They have no design feature that would conduct this small test current. As a result, from the emergency bulb’s perspective, a standard LED bulb on another socket looks like a break in the line rather than a path to complete its detection loop.
December 17, 2024 at 3:14 AM
scottleibrand.bsky.social
Everyone should buy a pack of these and put one in a non-dimmer switched lamp in each room. They switch off normally, but when power goes out (and the switch still on leaves a path to another linear load) they stay on via internal battery. We got these: bit.ly/3VGpgxU
ENERGY SAVING EMERGENCY BULB Automatically recharges during normal use Continuously illuminates during power failure Convenient power cap to take anywhere
December 17, 2024 at 3:14 AM
scottleibrand.bsky.social
@fredericjacobs.com FYI you have an impersonator pumping crypto in DMs:
November 24, 2024 at 10:26 PM
scottleibrand.bsky.social
Looks like you’ll want to avoid using Twitter’s link shortener here so that previews can be displayed properly.
November 20, 2024 at 7:17 AM
scottleibrand.bsky.social
archive.org/details/home...

www.amazon.com/Critical-Inf...

chat.openai.com/share/ca6a41...
February 22, 2024 at 5:08 AM
scottleibrand.bsky.social
Tried a few free image upscaler tools on it, and the best one (create.pixelcut.ai/upscaler) produced this version.
February 11, 2024 at 4:19 AM
scottleibrand.bsky.social
Looks like Jackson Prairie is back up now, but they’re continuing to restrict supplies while they repack pipelines?

Cross-posting your RT:
January 14, 2024 at 5:54 AM
scottleibrand.bsky.social
Graph in the top right of the page shows that: nsidc.org/data/seaice_...

Looks like it’s almost back within normal ranges, but most of the catch-up was in Dec not Jan.
January 6, 2024 at 8:01 AM