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Comment by NickC25 | Hacker News Reader

Don't know, but such cities shouldn't be encouraging urban sprawl, should be insisting for solar panels on every roof possible, and at the same time shouldn't be incentivizing people to move there.

I've lived in AZ, and it is nice in the winter, sure. But that's only a few months. It is hot as fuck in the warmer months and I to this day have no idea why people actually live there. the urban sprawl plus the fact that you have to drive everywhere, just blows my mind.

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I live in Phoenix now. My wife and I are planning to move away from here in two years. We were only here because of circumstances outside of our control and now those circumstances are no longer applicable.

Phoenix's main economic driver is real estate development and speculation since the 60s. It has very little in the way of real wealth that serves as a foundation (other than ASU and the two silicon fabs that are there now). A lot of people come here thinking it is affordable cost of living (and it is not that affordable in 2024), but I don't think many residents here really know why they live in Phoenix either.

Best time to get out of a market is before everyone else is running for the door. Lots of stranded assets and sadness ahead for folks who held on to assets too long in the wrong places.

https://www.marketplace.org/2024/05/28/are-we-in-the-midst-o...

http://www.deltaterracapital.com/

I'm curious, do you feel the same for places that reach 40F? 30F? Because heating is a bigger problem than cooling when it comes to contributions towards climate change. Why do I only ever see people railing against people living in hot places, rather than people living in cold places?

It's a lot easier to add heat to survive in a cold place than take away heat in a hot place.

Kinda like how people complain in an office "Can we turn down the thermostat? You can put on a coat but I can't take my skin off".

I think the point GP was making was that hot daytime temperatures in desert climates tend to coincide with peak renewable energy generation, while at higher latitudes in cloudier places the the source of energy is more likely to be from combustion.

If we're only worried about temperature, sure

But fresh water is a pretty huge concern as well and moving/producing large amounts of that in extremely hot areas is going to more than offset the difference in heating costs

Additionally, when you add new construction to a hot place, the additional sidewalk and asphalt makes it hotter. Adding new construction to a cold place doesn't make it colder.

Given the heat pump technology that we have these days, moving heat from A to B is roughly the same as moving it from B to A.

Wet bulb events aren't that simple to deal with. Grid stability doesn't exist in any of the poor and hot equatorial countries. Many people don't even have airtight housing which rules out aircon. If it was too cold instead they could just add clothing and blankets and survive.

Grid stability isn't necessary. It's OK to only run air conditioning when the sun is shining.

There are often blackouts while the sun is shining in lower income countries.

Yes, local solar panels are needed too.

It's cost prohibitive, a small hybrid system costs $4000usd which exceeds the average annual income of many equatorial countries. But you are right that if somehow everyone could install this system (along with an AC and the construction of an airtight room) then wet bulb events would be manageable.

The solar panels to run an air conditioner are a similar cost as the air conditioner.

What difference does it make if heat leaks out or in? The transfer rate is roughly the same.

You can't install aircon into a shack. The cold air will escape.

What happens to heat in a shack?

Its easier, but it isn't more energy efficient, at least not for winters. Average deltaT is smaller when cooling 35 to 25, compared to heating -10 to 20, say.

A problem in cities is that aircos increase outdoor temps, on top of heat from pavement, cars, etc.

There is no way heating isn't more energy efficient than cooling

Heat is even a side effect of cooling, heat is a side effect of basically everything

You’re correct that it is more energy efficient to heat, but the US spends much more energy heating buildings compared to cooling them. As the person you’re responding to pointed out, the difference between cold days and comfortable temperatures is usually much, much higher than the difference between hot days and comfortable temperatures for most people.

That's reasonable

Then again the difference between lethal cold temperatures and comfortable temperatures is also much much bigger than lethal hot temperatures and comfortable temperatures too. EG humans can be pretty comfortable between 32F and 80-90F. The upper limit is pretty much 110F, so only a 20F difference. There's not really any sort of clothing short of some kind of spacesuit with a personal cooling device that can make those temperatures survivable.

Humans can tolerate ridiculously cold temperatures with adequate clothing layers. With clothing you can buy at Walmart you can be pretty comfortable at -40F. With specialized equipment there's basically no limit to how cold the surroundings can be

Not so much with ridiculously hot. Being too hot is just a more complex problem to solve

> the US spends much more energy heating buildings compared to cooling them

I was curious about the stats here:

The latest numbers I can find indicate that the annual US 50-state heating-to-comfort requirement is about 2.5x the cooling-to-comfort requirement. Measured in BTUs.

However: a) These numbers do not account for HVAC energy efficiency (much higher for heating than cooling -- maybe ~90% heat, ~50% cool, so that 2.5x would be closer to 1.5x today) b) Due to warming trends, these numbers have been changing. Was ~3x in 1990, trendlines look like they might converge by the end of the century. With efficiency considered, convergence in about 25 years.

Some obvious unaccounted factors: a) Changes in HVAC fuel or efficiency mix, e.g. heat pumps b) Changes in climate trends c) Migration patterns (more people headed to TX/AZ than AK)

Have a look at how heat pumps work. The difference between cooling and heating is just which end you point inside or outside.

For efficiency it only matter what the delta-T with the outside environment is. Since that is typically lower when cooling than when heating, it is therefore cheaper. Just look at your power bill.

> Have a look at how heat pumps work

Most buildings where I live don't have heat pumps

30F or 40F ain't bad. My familial roots are in Western NY, where 30F or 40F in the winter is outrageously hot...effectively T-shirt and shorts weather.

People rail against those living in the desert because there's often no water and the water needed to sustain a growing metropolis just isn't available without spending a ton of money and diverting it away from other population centers. Most cold places do have access to water in much larger quantities. (Most, but certainly not all)

Honestly we should all just live in San Diego, where it's never below 65 and never above 85. Perfect weather.

I mostly only see people railing against living in hot places that are also deserts.

Unlike Arizona, I don't ever see backlash about people living in Mississippi.

I don't really get the problem? Arid conditions are a bit nicer for humans since the wet bulb temps are lower. If it's about water, then agriculture uses a lot more than cities do.

Interestingly enough, I also mostly only see backlash about agriculture in hot places that are also deserts.

Yep. Southwestern states are eventually going to have to decide between their own residents and, e.g., providing year-round lettuce for the rest of the country (Arizona).

The imperial valley - a single farming region in a literal (rather than metaphorical - LA isn't a desert) California desert - uses enough water from the Colorado river to account for 100% of residential water use in California.

No real issue with installing solar, but the panels are dark. Won't that contribute to the heat island effect, especially considering that among the remediations proposed are white roofs and pavement?

A decade or two ago there was a push to paint as many roofs white as possible, which is why you may intuit dark is bad. Black surfaces convert absorb light energy and convert it into heat. Solar panels do get hot, but part of the point is to turn as much of that light energy as possible into electrical energy.

Arizona is a bit too warm for me, but a lot of people consider driving to be a positive.

I would rather spend 15 mins in my car than 15 mins on a bus. I'd rather live in a place that is sprawling because then everything is bigger - I'd rather have a large house than a small one, a large garden than a small one, and I'd rather shop at a big box store that is more likely to allow me to be hands on with everything I need vs. a teeny high street shop and ordering online.

I currently live somewhere quite urban and barely spend any time in the walkable/public transportable centre because there's not much I want to do there other than pubs and restaurants.

edit: The responses to my post are kind of weird, I'm not telling you to adopt my preferences.

Reworded:

I love that my car lets me travel alone and without paying the full cost of the miles I log. I'm either terrified of public transit and/or the experiences I've had on it have generally sucked. I prefer bigger everything because I rarely think about the downsides and externalities, and was told from birth that bigger is better. I prefer a large house as long because I can afford somebody else to clean and maintain it, along with the utility bills and property taxes. I prefer a larger garden under the same conditions. I prefer stores that dominate and distort the market and allow me to avoid human interactions.

It would be more polite and useful to ask me to clarify rather than producing a strawman.

I don't prefer driving because it is inexpensive, I prefer it because it has greater utility for me. If the cost of fuel doubled or more I would still do it, I'd just be a bit more efficient with the journeys I do make.

I'm not terrified of the tube/trains/buses, I use them. It's just a bit shit, doesn't go to loads of places I want to go, and is generally less comfortable.

I do think that bigger is better. I don't pay for someone to clean or maintain my house, I do it myself.

I haven't been told that bigger is better, it simply is. For example, just yesterday I made a table. In order to do that I needed enough space to work in and store my tools. I could not do this in a smaller house or apartment.

Theoretically I could hire a workshop or go to a hackspace but that would be substantially more hassle than just walking into my garden or the garage or whatever.

I like human interactions. Just not with endless hordes in a super dense city centre. I prefer chatting with my neighbours, or someone on a hiking trail, or having people over, etc.

It sounds as if you just have different preferences to me. Different hobbies, desires, etc. That's fine, that's why you don't prefer driving. I do.

I live in a small village of 250 people in rural New Mexico, 25 miles from the nearest town. To get to almost anywhere I have to drive. When I socialize, it is mostly with neighbors or people on hiking trails. I have a large set of tools out back and space to use them.

Don't assume that my preferences are so different from yours (though your use of "the tube" suggests that you're located in SE England, so many things may be different).

My point was that all the preferences you expressed come with a cost, not only to you, but to everything and everyone else as well. Talking about these things as if they are merely personal choices is misleading, they are actually personal choices that, in aggregate, shape the world we all get to live in. And the specific set of choices that you listed, for the most part, in aggregate, have a negative impact on the world. I'm a participant in that too, clearly.

I disagree that these things have a negative impact on the world when you or I do them.

I think that if billions of people do them, we have issues, sure.

But there is a finite carrying capacity regardless of what we do.

We could live plugged in like the Matrix and there would still be an upper bound somewhere.

It is patently nonsensical to take the behaviour of one person or even a million people, scale it to 8 billion, and then claim that it's unsustainable as a result.

We have plenty of mechanisms to prevent that from happening. One obvious one is that, as a Brit, I'm legally not permitted to move to the US and live in the same way that someone in Arizona does, which puts a cap on my lifestyle. Most people are in situations like that - ever heard of the "golden billion"?

Kind of amusing, then, that I'm a Brit :)

What brought you all the way from the UK to rural New Mexico?

Nothing like that direct. I've lived in Seattle and Philadelphia before this. The rest of my history is easily discoverable online if you're really interested. Basically, my wife and I really like our house and the region where we live.

At least where I am 10 mins in a car can be up to 1.7 hours in a bus. And the same back.

If it was an apples to apples comparison then I would rather be driven than drive. But its not.

Take a bike. Might not be 10 minutes, but will be under 30. and cheaper than taking a bus, too.

Taking a bike when it's 110 F out may be better than walking to a bus stop and then waiting for a bus, but it's still not something that many people want to do...

Bikes are not great. Ebikes might be able to keep up with traffic but not legally. No bike lanes mean your in traffic with posted speeds of 35-40 MPH and actual speeds of 40-48 MPH.

Not to say I disagree with bikes. Ive got all the parts for an ebike just need to mount them. But its not really viable transport around here if you add in the dangers.

How does that work if everyone wants that? We don't have enough Earths to support 8 billion people living in sprawl.

Does it need to?

Why should everyone live the same way? I know tons of people who prefer city life, and more still who frankly don't really think about it either way.

Surely we all operate this way? My mate goes fishing, if everyone went fishing it doesn't work, but we don't all go fishing.

We might.

If we have 54 million square kilometers of habitable land that is not used for agriculture, and we scatter 8 billion people across it, then we end up with a population density of about 148 people per square kilometer -- which is approximately what Florida is today.

If that is your plan you need teleporters for everybody so you don't need to pave the world to get basic access.

It's not my plan. I was just evaluating one aspect of its practicality. It would be a shitty idea to propose that everyone live in exactly the same way.

Diversity is generally good. It's nice to have some options available.

(Even with universal teleporters, diversity is generally good.)

Do we have the resources to support such a sprawly civilization? It's not just the land, it's all the infrastructure (roads, plumbing, power, etc.) which isn't free.

No, of course not.

But the claim was about the unavailability of space, not of man-made infrastructure.

I said we don't have enough earths to support everyone living in sprawl. That's talking about resources, not just land.

If the fair distribution is that we have 150 people per square km i.e. approx 6500sqm or 1.5 acres per person, then realistically the answer has to be that some people have a lot more than that and some people have a lot less, because 1.5 acres isn't a large amount of land at all once you get outside of the city.

I much prefer hot af to an icy hellhole. Heating takes up a huge amount of energy and you can’t really do it in an environmentally friendly way unless you get creative. The good thing about the heat is when it’s the hottest, solar panels generate the most energy. It’s a cooling solution that scales itself with the temperature.

> when it’s the hottest, solar panels generate the most energy

That's not true.

> It may seem counterintuitive, but solar panel efficiency is negatively affected by temperature increases. Photovoltaic modules are tested at a temperature of 25° C - about 77° F, and depending on their installed location, heat can reduce output efficiency by 10-25%. As the solar panel's temperature increases, its output current increases exponentially while the voltage output decreases linearly. In fact, voltage reduction is so predictable that it can be used to measure temperature accurately. [0]

> Home solar panels are tested at 25 °C (77 °F), and thus solar panel temperature will generally range between 15 °C and 35 °C during which solar cells will produce at maximum efficiency. However, solar panels can get as hot as 65 °C (149 °F), at which point solar cell efficiency will be hindered. [1]

[0] https://www.greentechrenewables.com/article/how-does-heat-af...

[1] https://www.energysage.com/solar/solar-panel-temperature-ove...

Either ways, if it’s hot there is going to be a lot of uninterrupted sunlight.

It can be hot, cloudy, and humid all at the same time.

Sincerely,

Ohio

Also GA lol

The coldest days around here are the ones where the sky is completely clear.

That doesn't mean that hot days tend to be cloudy.

> The good thing about the heat is when it’s the hottest, solar panels generate the most energy.

Incorrect. Peak PV efficiency occurs at relatively low temperatures.

Perhaps you mean "when it is hot, there tends to be lots of sunshine, and so there's lot of PV generation" ? That's true of some places (Southern CA, AZ, NV, NM) but less true of others (Louisiana, Alabama, Mississippi, Georgia etc).

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