DropPanda

Today, kindergarten was closed and I had to take much of the day off to take care of my five-year old daughter. We asked Chat GPT to assume the role of a master board game designer and to lead us through the creation of a novel boardgame, with input from us. She came up with the setting - we are unicorns that need to rescue princes and princesses that have been captured in a scary forest full of monsters. Quickly, the LLM proposed a full list of rules and props to make. We then had fun for around two hours drawing various cards and markers.

The game was playable on the first try with only a few minor and very quick rule tweaks from me. Even I felt we went on a stressful quest in the forest. Honestly among the best games for this age group that I have ever played.

10/10 activity, will try again.

I live in a Scandinavian country. Our welfare system is structured such that people are expected to withdraw from the tax pool during the beginning and end of life, and contribute to the pool in between.

Adult immigrants will benefit less from the system than locals over their lifetime, but may end up contributing as much. Adult immigrants with advanced degrees who come to work here for a few years and then move out are penalized quite severely by the tax system, to the point where I think it makes very little sense to do that.

On my locally quite high $80k annual income (STEM PhD, 40yo), my employer pays an additional $36k in taxes and pension. Then I pay $22k in income taxes and 25% VAT on everything I buy.

Why would anyone with an advanced degree from China, India or the U.S. come to work here? Lowering the taxes for a couple of years following immigration, possibly proportionally to level of education, would encourage immigration and would be ethically defensible.

Maybe I got the unit conversions wrong. The theoretical maximum speed is shown to be on par with world record track cyclists.

The proposed device is predicted to allow almost double that speed. I think it’s pretty cool.

No, the article specifically talks about a device where the legs perform work continuously, as in cycling. The device you linked to only lets the legs work during ground contact.

Can you elaborate on why? Getting hydrogen to an off-grid research station in the Yukon is both difficult and a very poor business case for large-scale investments in off-shore hydrogen production.

The article states that the capital investment cost of an electrolyzer and pipeline is lower than that of a cable and a substation. But what if you want electricity? If you include a fuel cell and grid connection at the end of the pipeline, is the capital investment cost still lower?

The questions I ask on topics I am familiar with are usually very demanding. On these it is clear that there are limits to its comprehension and reasoning abilities, but nonetheless, I find it very impressive.

Questions I ask on topics I am not familiar with are much further from the limits of its knowledge. I find it to be an amazing tool for quickly getting a structured overview of a new subject, including pros and cons of different alternatives and risks I should be aware of.

I used to share your gut feeling that this is stupid, but I’ve done a lot of calculations on this now and it (dynamic charging, not necessarily inductive) starts making a lot of economic sense on major roads when most traffic is electric. The technology has very high base cost and very low marginal cost per additional user. The cost of stationary charging scales fairly linearly with the number of users, with surprisingly minimal scale benefits.

Pros of dynamic charging:

- Substantially reduced need for large batteries, which reduces vehicle cost and contributes to overall lower cost of electric road transportation;

- Easier logistics planning, no queuing for charging, and reduced downtime for commercial vehicles;

- Cost of public daytime charging on par with private night-time stationary charging;

- Same access to charging for all, at the same time, at the same cost;

- Well adapted to high vehicle utilization (e.g., 24h operation, autonomous trucks and car sharing services);

- Greatly reduced need for high power fast charging, which wears out batteries;

- Greatly reduced need to build out infrastructure for stationary charging, which is not easy to do quickly and at scale;

- Potentially easier to connect to the power grid than static charging of equivalent capacity.

Challenges to overcome include:

- The transition phase from zero to many users;

- The transition phase from zero miles to coverage of most major highways;

- Electromagnetic emissions;

- Not in line with how the public and industry perceives that electric cars and trucks should work;

- Initial funding (requires public sector support, but not subsidies);

- Primarily benefits vehicle owners and transport buyers, not vehicle manufacturers and energy companies.

- Unclear if dynamic charging is cheaper beyond ~2045, due to declining levelized battery costs.

As for the argument that it is better to electrify rail - both should be electrified. Europe and Asia wonder why North America hasn’t electrified its rail network already.

A heavy truck uses in the order of magnitude of 100 kW of continuous power for propulsion at highway speeds. Solar panels on the truck can extend range by around 10%, but increase weight, capital and maintenance cost. When trucks are parked, it’s often dark outside.

Cool app. I am not sure how related this is, but during intense physical exercise, I always start yawning repeatedly. Is this an indication of anything and can I use this app to improve this?

One application of negative weights in a cost graph could be energy consumption for battery electric vehicles. Downhill, regenerative breaking can result in a net increase of battery charge.

It’s hard to get data from non-biased sources, given that there are no commercial installations yet.

Some numbers are thrown around here (static inductive): https://insideevs.com/news/425972/momentum-dynamics-wireless...

And here (dynamic inductive): https://www.greencarcongress.com/2022/06/20220614-electreon....

From what I have heard, the transmission efficiency of the dynamic inductive solution is quite sensitive to alignment and they still have some R&D left to do there.

Surprisingly, transmission efficiency (grid to motor) does not appear to be lower with inductive methods than conductive. Numbers above 90% should be expected. A bit lower for the dynamic (in-motion) solutions, but not so much that it’s a deal breaker. There seem to be much larger savings/costs elsewhere in the system that make transmission efficiency of less importance.

Cars that are stationary most of the time are a pretty good reason to put charging infrastructure on the only land they actually share - the roads.

This is very interesting and perfectly logical. I wrote a fairly recent report looking at a very similar question, and reached the opposite conclusion: night time charging is far better for the grid. That study however focuses on Sweden, where solar power only marginally impacts day-time supply.

Link to the study: http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-5752...

If the western US has a surplus in mornings and afternoons, you guys really should invest in dynamic charging using electrified roads (commonly referred to as wireless inductive charging in California, but there are conductive solutions as well).