Tim Graettinger

Four Questions Our Solar Charts Help Us Answer

Thu, 07 May 2026 00:00:00 +0000

Every week I update a series of charts that help my wife and me monitor the health and performance of our solar panels. Each visual answers a different question, and together they’ve changed how we think about our system. Find out what those questions are and what insights we’ve gained.

4 Years, 100 MWh of Solar Power... in Pittsburgh?

Mon, 13 Apr 2026 00:00:00 +0000

100 MWh of solar power in four years … in Pittsburgh? Who’d a thunk it? But after tracking every day of production during that time, I finally stepped back and asked: What does that number actually mean? Turns out, the stories behind it might be more interesting than the milestone.

How Fast Does a House Get Cold When the Power Goes Out?

Thu, 02 Apr 2026 00:00:00 +0000

If you lose power in cold weather, you might double your stay-at-home time window by retreating to your basement. If you think an outage is likely, pre-heating can buy you a lot more time, too. See how I broke down our data from a recent outage.

Why Bother with Notes? My Web of Notes Manifesto

Mon, 23 Feb 2026 00:00:00 +0000

Why bother with notes? Before you adopt a system or write a line of code, I think you need a clear point of view on your purpose. Here’s mine: my web of notes manifesto.

Ever Wonder What Your (Digital) Mind Looks Like?

Mon, 02 Feb 2026 00:00:00 +0000

Now, I can SEE my digital mind — thanks to a Python script that turns my notes, etc. into an interactive web graph. In this post, you’ll get a close-up look at it, plus some insights into how my ideas and artifacts actually connect. Spoiler alert: they’re NOT a hierarchy of folders within folders within folders.

The Weather-Radon Connection: Surprisingly Simple Rules

Wed, 28 Jan 2026 00:00:00 +0000

Radon, schmadon. I never thought about it — until a big rainstorm flooded our basement. During the cleanup, a good friend asked, ‘While you’re at it, have you ever checked your radon level?’ That little question led to remediation, a radon monitor, a weather station, and some surprisingly simple rules connecting the weather outside and the radon level inside.

Five Books I Recommend to Every New Speaker

Sun, 04 Jan 2026 00:00:00 +0000

Ever since I joined Toastmasters, I’ve read a LOT of books about public speaking. These are the five I keep coming back to. They’ve helped me become a MUCH better speaker. They’ll help you, too.

How to Fix a Cluttered Chart: Addition by Negative Subtraction

Mon, 17 Nov 2025 00:00:00 +0000

Ever make a chart and feel like it’s just… off? It’s supposed to tell a story — but doesn’t. I fixed mine using a process I call “addition by negative subtraction”.

Save Your Windows 10 Laptop from the Landfill — or the bottom of your closet.

Thu, 06 Nov 2025 00:00:00 +0000

Replacing your Windows 10 laptop can cost north of $800. If you use it for yourself — to write, code, or connect with friends while you hang out at Starbucks — switching to Linux might be right for you. Curious? Learn what worked, what didn’t, and why I’m not going back…

Hang It Out to Dry — and Save 300 kWh

Sun, 05 Oct 2025 00:00:00 +0000

Did you grow up in a home where laundry dried on a clothesline? I did. Since we’re trying to conserve energy, we’re doing it again. I wondered if it’s worth it - and the answer surprised me.

Have You Ever Seen the Rain? I Have — 1,387 Times

Wed, 17 Sep 2025 00:00:00 +0000

Ever wanted to be a citizen scientist? I started with a simple rain gauge. Eight years and 1,387 rain days later, here’s what I’ve learned…

What I Learned from My AI Librarian

Mon, 25 Aug 2025 00:00:00 +0000

If you had an in-house, personal, AI librarian, what would you do? Here’s what I did…

Making Marian, Your Personal AI Librarian, in 4 Simple Steps

Thu, 14 Aug 2025 00:00:00 +0000

Tired of the lackluster book recommendations you get from GoodReads or Amazon? Suppose you could converse with someone who really know books, who knows your likes and dislikes. You can create your own, personal, custom GPT today to fill this role.

Meet Marian: How 11 Questions Evolved Into My Personal AI Librarian

Wed, 30 Jul 2025 00:00:00 +0000

Suppose you could consult with your bookshelves. That’s the idea behind Marian, my personal AI librarian, a custom GPT I built around my preferences and reading history.

Collab: Exploring Radon Levels with Data Analyst GPT

Wed, 16 Jul 2025 00:00:00 +0000

I’ve been tracking radon levels in our home for 9 months. Collaborating with Data Analyst GPT to analyze them was actually fun…

Spark Notes: Ten Things I Wanted from Our Netflix Ratings: Prelude to a Custom GPT

Mon, 07 Jul 2025 00:00:00 +0000

Not long ago, I found myself thinking about our old Netflix DVD ratings. I wondered what I could do with them that would be cool…

Lab Notes: Taming the Tangle: Custom Cords for the Outage to Come

Sun, 06 Jul 2025 00:00:00 +0000

A recent power outage exposed a weak link in our emergency setup — not enough usable extension cords. I designed and built a custom set for powering our home from our Jackery. Here’s how I tailored them to our layout.

Lab Notes: Lessons from a 24-Hour Power Outage

Mon, 30 Jun 2025 00:00:00 +0000

When the power went out this time, we were ready. Sort of…

It Was a Dark and Stormy Afternoon: How We Used Data to Prepare for Our Next Power Outage

Sun, 25 May 2025 00:00:00 +0000

The power went out and stayed out… for three days. How do you prepare for the next time?…

The Day the Water Stopped: What I Learned During a Seven-Month Drought

Mon, 21 Apr 2025 00:00:00 +0000

We lost water to the house. What do you do next when you’re in a drought?…

Where Can We Meet? Making an Informed Choice for our Toastmasters Club

Thu, 20 Mar 2025 00:00:00 +0000

Our Toastmasters Club needed a new home. But where?…

Is Our Solar Surplus Big Enough to Drive an EV for Free?

Mon, 03 Mar 2025 00:00:00 +0000

Can our solar system power our house AND an electric vehicle?…

Want to miss out on some real insights from your data: ignore the missing values.

Tue, 07 Jan 2025 00:00:00 +0000

Suppose I told you that deep insights about your data can come from seeing what’s not there?…

About

Mon, 01 Jan 0001 00:00:00 +0000

Hi and welcome!!

Thanks for stopping by – I’m glad you’re here.

My name is Tim Graettinger. I’m a data scientist by profession, a writer by habit, and a lifelong student.

I like data.

I like to collect it, explore it, visualize it, model it… you name it. And I write code to do all of it.

Data helps me ask better questions and think more clearly. It offers me a thoughtful way to engage with the world.

Connect

Mon, 01 Jan 0001 00:00:00 +0000

If you’re doing projects like those you see here — or if you have similar interests — let’s get in touch. Here are a few ways we can connect:

Email: tim [at] timgraettinger [dot] com

Tell me what you’re working on — or just say hi. Whether it’s feedback on an article, a shared interest, or a conversation you’d like to start, please reach out.
LinkedIn
Occasional posts, project updates, and thoughts on the practice of data science.

Now

Mon, 01 Jan 0001 00:00:00 +0000

Last updated: May 10, 2026

What I’m working on

Building my “web of notes”, a DIY project to :
- Search: Find what I’ve already thought, written, or seen.
- Browse: Wander and stumble into connections.
- Write: Capture thoughts with clarity and perspective.
- Visualize: See links, clusters, timelines.
- Interact: Let the system push back, recommend, and surprise me.

What I Just Shipped

Four Questions Our Solar Charts Help Us Answer - Posted May 7, 2026
4 Years, 100 MWh of Solar Power… in Pittsburgh? - Posted April 13, 2026
How Fast Does a House Get Cold When the Power Goes Out - Posted April 2, 2026
Why Bother with Notes? My Web of Notes Manifesto - Posted February 27, 2026
Ever Wonder What Your (Digital) Mind Looks Like? - Posted February 5, 2026
The Weather-Radon Connection: Surprisingly Simple Rules - Posted January 28, 2026
Five Books I Recommend to Every New Speaker - Posted January 4, 2026
How to Fix a Cluttered Chart: Addition by Negative Subtraction - Posted November 17, 2025

Open Questions I’m Exploring