The original linked article is the kind of stuff that can make a difference: changing commercial large scale practices to be more efficient. Trying to add some amateur part time production isn’t going to make any appreciable difference.

particularly in the growing season

And if you’re getting 10% of your calories from your garden for 10% of the year, that’s 1%.

Especially as I’m talking about a community patchwork, where people share their overabundance of squash for someone else’s potatoes.

Yes, so that’s why I’m saying per person, because each person needs to eat. Yes, people should work together, too, but if you’re talking about a few households adding up to 10 people, then you’re talking about 10 times the food needs (and wants). A community of 100 people needs 100 times as much.

The amount produced by gardening is never going to be more than a rounding error, while imposing significant efforts on the people who participate. A serious conversation about fertilizer and energy use is going to address the sheer amount of feed and energy that goes into dairy and beef.

Gardening is a fun hobby and an enriching activity, but it’s not going to move the needle in aggregate ecological statistics like national fertilizer consumption or demand for commercially farmed product.

So keep growing the things that make economic sense with the resources you have. For me, it’s herbs, alliums, and spicy capsicums, where I go for things high in flavor so that the tiny amount I produce can still make an impact on the dishes I make, for at least a few weeks out of the year. But I’m not laboring under any kind of misconception that I’m appreciably changing my demand for farmland, fertilizer, agricultural inputs like fertilizer or pesticide, water, or energy. And there’s nothing wrong with gardening for flowers or other plants that don’t produce food, either.

For these large scale problems, we need hard numbers, not just feelings of one’s perceived personal sacrifices. Follow the math.

If even just 10% is from elsewhere

I’m saying that’s really hard to do. Even 1% is ambitious. If the average person is eating 2000 kcals of food per day, and 10% is 200, then you’ll still want to generate 73,000 kcals per year per person.

From this source, growing wheat is about 1000 kcals per square meter. Dry legumes (peas, beans, lentils) seem to mostly be between 200 and 500 kcals per square meter, although soybeans are especially productive at 1000. And generally if you’re growing while minimizing fertilizer use you’re probably rotating a grain, a legume, and a fallow year. So every 3 square meters you’re getting 1500 calories per year.

So to get 10% of your caloric needs, you’ll want to set aside 150 square meters of farmland per person you want to feed.

Meanwhile, beef requires about 50 square meters per kg. So just eat 3 kg less beef per year, and that’s the equivalent of farmland covering 10% of your caloric needs.

It’s hard to provide significant calories from home gardening, so I don’t think it’s practical to reduce reliance on commercial farming from a pure sustenance standpoint. But home gardening can fill in the need for lots of flavor and variety.

Perhaps the most significant thing one can do for reducing reliance on commercial farming output and the associated fertilizer/fuel inputs is to reduce consumption of the least efficient meats (beef, lamb) and shift towards more ecologically efficient foods. It doesn’t even have to be full plant based, either, as shifting from beef to chicken or fish goes a long, long way.

The signal to noise ratio problem is analogous to trying to pick out a specific voice in a crowded stadium. It’s too loud to be able to pick up one source.

So the desert is like that, where there’s a lot of background electrical noise that’s louder than the electrical signals that a human heartbeat makes.

Honda and Toyota both slow played full electrification, emphasizing non-plug-in vehicles even as plug in models started moving real volumes.

But Toyota was at least putting a real push in increasing their hybrid lineup, and lining up increasing amounts of electric drivetrains (batteries, motors, regenerative braking chargers, etc.) in their supply chain.

In 2025, Honda sold 1.4 million vehicles in North America, 430,000 of which were electrified vehicles (50,000 of those being the GM-manufactured Prologue and ZDX), mostly non-plug-in hybrids. Honda has refused to bring a plug-in hybrid to market. Looking at the actual manufacturing, Honda has only partially electrified something like 25% of their vehicles.

Meanwhile, Toyota moved 2.5 million vehicles, 47% of which were electrified. About 50,000 of them were plug-in hybrids and 22,000 were full electric. That’s not a lot, but at least they developed their own EVs, have a supply chain for literally millions of (small) batteries and regenerative chargers and electric motors in finished cars.

When it comes time to really put out EVs, Toyota is in a much better position to survive the transition than Honda is.

Today’s new cars are tomorrow’s used cars. What happens in the new car market now will directly affect what is available on the used car market 5, 10, 15 years from now.

I wonder how much energy is in a liter of sunshine.

Photovoltaic panels capture energy from the photons that hit it, at a finite speed of light.

At Earth’s distance from the sun, solar radiation is about 1450 W/m^2 . Each watt is 1 joule/second. And a liter, which is 1000 cubic centimeters, would basically represent a volume that is the 0.1cm of space above a 1 square meter panel (100 cm x 100 cm x 0.1 cm = 1000 cubic centimeters).

So how much energy hits a 1 square meter panel in the time it takes for light to travel 0.1 cm? Light travels at 3.0 x 10^8 m/s, or 3.0 x 10^10 cm/s, so we’re talking about the light that hits a panel over the course of about 3.3 x 10^-12 s. At 1450 joules per second, times 3.3 x 10^-12 s, we get 4.83 x 10^-9 joules.

4.8 nanojoules in a liter of sunshine. That’s way less than a liter of gasoline/petrol!

Then again, using a solar panel you’re able to capture a column of light 3.0 x 10^8 meters tall using that 1 square meter panel. So you’re catching 3.0 x 10^11 liters per second worth of sunlight, which makes the relative low energy per liter still add up to a lot.

Gasoline needs a precise air/fuel ratio to ignite

Yes, and it forms fumes in those ratios as soon as it spills. A puddle of gasoline is flammable. And once it ignites, it creates a runaway condition where the heat output of the reaction ignites the fuel around it, too.

If you have fast charging, why do you need a big battery?

Road trips. Being able to drive 4-5 hours between stops is better than being able to drive 2-3 hours, even if you don’t have to stop for all that long. Small fuel tanks are annoying in gasoline powered vehicles, even if a fill up can be less than 3 minutes.

Isn’t that also true of literal gasoline?

A 15-gallon tank of gasoline has about 1800 megajoules or 500 kWh stored, ready to combust when mixed with oxygen and heat.

You crash test the actual modules and make sure it doesn’t short when encountering highway crash forces, same as you do for gasoline tanks.

1100kW means 18.3 kWh/minute, which for a 3 mi/kWh car is 55 miles (almost 90km) added to a car’s range in just one minute of charging. For a 4 mi/kWh car, that’s about 73 miles (almost 120 km) in a minute. That’s wild.

A gasoline pump delivers about 10 gallons per minute, so for a 25 mpg car, a gasoline pump gets about 250 miles (400 km) per minute, so there’s still a gap. But the gap is shrinking.

they could have bought a <$25k used EV last year and saved $4k with the EV tax rebate.

The people who were in the market for a car last year are by and large not the same people who are in the market today.

Plus let’s not forget, the actual EVs on the used market 12 months ago were different than today’s. Someone looking to buy a 3-year-old car today has to look for something originally sold in 2023, whereas 12 months ago they were looking at 2022 vehicles, with fewer models available and significantly fewer vehicles actually manufactured and sold.

For everything the Trump administration has done to make solar and wind power less economically feasible, it turns out his war in Iran has done way more to make fossil fuel consumption less economically feasible as well.

There really was a huge increase in the number of EV models available between model years 2018 and 2023.

So now, when you’re looking to buy a 3-year-old car, you have so many more EV options to choose from even compared to just 2 years ago.

You can choose different form factors (small cars, sedans, wagon/crossover/small SUVs, medium SUVs, literal pickup trucks), and basically any price tier from economy to ultra luxury high end.

Not every ecological niche was filled in the past 5 years, and some still need a bit more competition, but even with some pullback over the last year there are still plenty of new EVs hitting new categories (e.g., true three-row SUVs and minivans) that will feed into tomorrow’s used market.

And not every model will survive. The future of all-electric full size pickups looks pretty grim. Some entire companies might not survive the EV transition (looking at you, Honda). But overall, the used market will fill out with what was hitting the new market 5-10 years ago, and we’ll start to see a lot of consumer preferences start showing what the future of cars will look like.

goshery store

The spec say 1.8x3-3.5m

Are you talking about the entire width and length of the vehicle? The roof is smaller than the total footprint. Especially because the width of the vehicle includes the mirrors sticking out.

10% seems rather low.

No, it’s pretty high for the use case you describe. Utility scale solar with panels pointed toward the sun tends to achieve about 20-25%, with some American desert installations at 30%.

Home balcony solar tends to get 10% in places like Germany, with the higher latitude and higher likelihood of overcast skies.

Putting it on a vehicle roof would be lower than that.

So 2 kwh per day is optimistic.

i don’t really need more than 30km a week.

So why buy a vehicle at all? Seems like the resources that go into an underutilized vehicle would be better used for things like paying fares on taxis.

You’re better off just charging with 100% utility solar/wind from the grid and paying money for it, rather than trying to combine a mediocre solar array in a costly way that kills your vehicle efficiency.

Plus there are probably some efficiency losses in an inverter taking the DC output of the solar-charged battery and generating an AC waveform expected by the car’s ICCU, to be redirected into charging the cells of the actual car.

Yeah, that’s why I used a capacity factor of 10%, which is pretty normal for fixed solar panels. That should be enough to account for clouds/weather, nighttime, etc.

Looking at that roof, it looks like it’s about 3m x 1.5m, for 4.5 m^2. Typical solar panel gets about 200W/m^2 at max sunlight.

So that’s a peak generation of 900W. With a 24 hour day and a capacity factor of 10%, that’s about 2.16 kWh of energy per day. For a van like that, with the weight and aerodynamics of a bulky solar system on the roof and the systems for storing that energy in another battery and cleanly providing that power in a way that the car charging system can accept? I’d be skeptical that’s good for more than 8km per day, on a sunny day.

The Slate truck doesn’t exist yet, at least not as a street legal mass produced vehicle. They’re aiming for a late 2026 launch, but they’re not there yet.