Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Vertical farming does not save space

lowtechmagazine.com

Post reply on HN
Print view View original

261–270 of 464 posts

Re: Vertical farming does not save space

#261

Post by guhcampos »

You can place solar panels in urban areas, even sidewalks and streets are being tested, besides solar roofs.

You can use nuclear, fission or fusion. You can use tidal, geothermal, wind energy.

You can concentrate-then-diffuse sunlight with parabolic mirrors and optical fibers.

You can place solar panels in deserts and transmit energy to vertical farms.

You can distribute multiple crops in multiple floors depending on their water, light and soil needs.

You can farm fish and chicken on the ground level of the same vertical farms and use their waste as fertilizer.

You can do all that, or you can keep chopping down the Amazon rainforest to plant soybeans.

Re: Vertical farming does not save space

#262

Post by ardy42 »

worker767424 wrote: post #42

Vertical farming mostly feels like a solution in search of a problem. It uses relatively expensive technology to produce low-value products. Putting seeds in the ground, tilling, and waiting is absurdly cheap compared to building growhouses. For some perspective, what farms actually do extend growing seasons is put "greenhouses" around cold-sensitive crops like tomatoes, but a "greenhouse" in this case is a wire hoop…

> It's interesting if you want to support 50B people on Earth, but the resources required to build it out mean it isn't really even a viable solution for restoring farmland to wildland without massive amounts of mining.

Also it seems to be mainly about producing calorie-poor produce like lettuce. If you actually want to feed people, you need to produce calories, and I don't see how that's helped by putting several extra conversion inefficiencies between the energy source and the plants.

Re: Vertical farming does not save space

#263

Post by sir_bearington »

pfdietz wrote: post #259
sir_bearington wrote: post #245

Earlier quoted context omitted.

California has already saturated the daytime energy demand on sunny days. So does Hawaii. The market forces already exist. But people aren't building storage. Because it's not feasible, short of a decisive breakthrough in storage technology. Maybe one of the proposed storage solutions will pan out. But building out trillions of dollars of infrastructure projects on the hope that a future breakthrough will make storag…

> The market forces already exist. And that is a recent thing there. The global market is still developing, and technologies don't materialize instantly. CO2 taxes are still low (or zero) just about everywhere. But hey, I hope you are also not going to claim nuclear will be cheaper in the future, because I could reflect that argument right back at you. And I could observe that, unlike with renewables and storage, nuc…

No, it's not "worst case we spent a bit more". Total global lithium ion battery production amounts to less than one hour of storage for the United States alone. Things like pulleys and synthetic methane remain in the prototyping stage.

By this logic why not just use fusion? It's possible. We don't know which exact approach we'll use (lasers, magnets, etc.). We don't know how cheap it'll be, but hey it'll happen eventually right? No.

It's not "worst case we spend more money". It's "worse case we never solve climate change". And that's a pretty bad worst case.

We're already at the point where markets are starting to see saturation with renewables. But this unfounded aversion to nuclear power is hampering actual progress to decarbonization. The cost of waiting around and hoping for storage to become viable is not just the cost of building those storage systems, but also the continued release of fossil fuels as we wait for that to happen - and who knows when that will happen, if ever.

Re: Vertical farming does not save space

#264

Post by tohmasu »

Retric wrote: post #234
tohmasu wrote: post #228

Earlier quoted context omitted.

Also one batch of PV panels equivalent to a reactor cost 6x as much and with a lifetime of 20 years to the 60 for a nuclear reactor so you will need to replace these at least twice. All 32.5 Million of them.

Replacing panels is just a cost question which dramatically favors solar. 2c/kWh is massively better than any nuclear reactor ever built or operated. As we are talking land use, construction and decommissioning is a major hit to nuclear. But with solar you can operate continuously by just swapping panels and replacing wires etc as needed. Basically, in steady state a 50 year nuclear power plant spends the first 30 ye…

Just no. Reactor buildings take up a small fraction of the total site area. Constructing additional reactors on existing sites has been done for about as long as nuclear power has existed and multiple reactors coexist simultaneously at the same site.

>"Replacing panels is just a cost question"

Sure, I bet you won't need more than 2 guys and a pickup truck to install, maintain and replace the 120 million panels it would take to create the equivalent to a site with 4 modern reactors. After all, that's only 35 000 panels to install every day if you want to build the site in 10 years. Everything is magical with solar.

>"2c/kWh"

That's a hypothetical figure for 2050.

Re: Vertical farming does not save space

#265

Post by sir_bearington »

dale_glass wrote: post #251
sir_bearington wrote: post #241

Earlier quoted context omitted.

Yes, nuclear hardly costs any more to run at 100% capacity than it does at 50% capacity. That's why decarbonization with renewables as a primary source doesn't make much sense. Solar and wind are both intermittent. Wind is dependent on the weather and experiences situations with near zero production for long stretches of time. Solar is also weather dependent, and has day-night cycles on top of it. This is fine if you…

The issue as I see it is that pretty much nobody is looking at decarbonizing a grid, money be damned. Unless your power production is run by the government, generation is done by companies looking to make a profit. Solar and wind companies don't mind in the slightest that they're screwing up the business model of nuclear. The fact that their production is intermittent isn't important to them -- it's already accounted…

Introduce carbon taxes and all of a sudden nuclear becomes a lot more viable. Existing plans for renewables are for them to exist in a primarily fossil fuel grid, supplementing them when the conditions are right. Make it so that using fossil fuels for even 20% or 10% of electricity generation is prohibitively expensive, and people will switch to nuclear power.

Last time I checked France was a democratic nation. So was Belgium. Both of those have achieve majority nuclear power generation, and France over 70%.

The cynical reality, though, is that you're right. People would rather make a token effort on intermittent sources, while continuing to burn fossil fuels for most of their energy. The damage to the environment caused by the continued use of fossil fuels in this approach, though, will eventually take a toll. But that toll will mostly be borne by poor people in the global south, not in the countries that had the capability to build nuclear but chose to primarily use fossil fuels supplement it with intermittent sources.

Re: Vertical farming does not save space

#266

Post by Aeolun »

a1369209993 wrote: post #256
dataflow wrote: post #232

Earlier quoted context omitted.

What signs do you see that it might work at all (and that it's not a hopeless endeavor)? As a layman it's so hard to understand how something so hot and so confined could ever be made to react reliably with continuous fuel and energy production to produce power on a large scale.

I don't think anyone is proposing continuous fuel (even fission reactors typically don't work like that - you have to shut them down to swap out the fuel rods periodically). The idea is that you inject (say) some deuterium into a blast chamber, it explodes like a miniature thermonuclear bomb, and you gather the explosive energy in vaguely the same way a internal combustion engine (like in cars) gathers energy from fu…

Wait, are you saying we know how to build a World Wonder that produces infinite energy, but we’re not doing it? What’ll we do if Ghandi builds it first?

Re: Vertical farming does not save space

#267

Post by tinco »

pfdietz wrote: post #239
tinco wrote: post #235

Earlier quoted context omitted.

Fission is only not competitive because of regulation and safety measures, is it not?

Not. Nowhere has it done well. It's just too complex with too many interdependent parts. Construction has proved to be beyond the competency of those trying to build plants. And now, it's just too late. The iteration time for nuclear designs is measured in decades, going up against renewable and storage technologies iterating in periods of a few years. Fusion would make fission look dead simple. If fission reactors c…

It was an honest question. I don't know which specific regulations, I've never built one but I have heard those who did lament the cost and trouble in even obtaining a site.

From what I can see fission reactors are doing just fine in France and Belgium. I don't know the specific numbers but the French don't seem worse off economically, despite having the greenest grid on the planet.

Fission has a number of disadvantages over fusion that make it a reasonable possibility of it being economically more viable than fission.

Because there's no compounding risks it is way more attractive to mass produce smaller reactors.

Once the key hurdles are solved it will be a simple calculation to decide how much investment will yield how much return, that means it will be an interesting investment opportunity.

Contrast this with fission, where a project is usually just one or two reactors, with tens of billions invested, loads of risk, slow and steady reward with various threats.

It is not the complexity that makes power plants intractible, we build more complex things than fission reactors every day. Its the lack of supply chain because of the unsteady build rate.

The iteration time of fusion reactors is measured in years, not decades by the way. Tokamak Energy is building its third iteration in 12 years, and plans to start the 4th in 2025.

Obviously we aren't there yet, but if it's possible, and a relatively small company like Tokamak Energy can build a proof of concept, then I don't see why we wouldn't have thousands of reactors spread through cities all over the world within the next 20 years.

Re: Vertical farming does not save space

#268

Post by Retric »

tohmasu wrote: post #264
Retric wrote: post #234

Earlier quoted context omitted.

Replacing panels is just a cost question which dramatically favors solar. 2c/kWh is massively better than any nuclear reactor ever built or operated. As we are talking land use, construction and decommissioning is a major hit to nuclear. But with solar you can operate continuously by just swapping panels and replacing wires etc as needed. Basically, in steady state a 50 year nuclear power plant spends the first 30 ye…

Just no. Reactor buildings take up a small fraction of the total site area. Constructing additional reactors on existing sites has been done for about as long as nuclear power has existed and multiple reactors coexist simultaneously at the same site. >"Replacing panels is just a cost question" Sure, I bet you won't need more than 2 guys and a pickup truck to install, maintain and replace the 120 million panels it wou…

There are actual current contracts that agree to sell solar at under 2c/kWh. Construction of multiple reactors on the same location is very common, constructing a new reactor next to a reactor being decommissioned isn’t.

https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating... https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Stat... https://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_...

Etc

I mean in theory sure it seems like it should happen, but in practice not so much.

Re: Vertical farming does not save space

#269

Post by extropy »

asimpletune wrote: post #255
skissane wrote: post #126

Earlier quoted context omitted.

> If we look into the relatively near future, fusion energy is going to account for a rapidly increasing share of energy production by the end of this decade. I really don't think by the end of this decade there will be any commercial fusion production. I'm sure we will be closer but it is still some decades away. ITER proposes to follow up their current research reactor with a successor (DEMO) which they plan to sta…

One problem with ITER is that it’s only point is to demonstrate ignition. It’s completely unfeasible as an actual power plant. I’m not saying it’s not useful, but rather it has a close to 0% chance of producing a scalable power plant, whereas some of the other smaller scale operations are less likely to reach ignition, but if they do so more likely to result in a viable design at scale.

It's purpose certainly is to demonstrate net positive energy production.

https://en.m.wikipedia.org/wiki/ITER

Thereby the machine aims to demonstrate, for the first time in a fusion reactor, the principle of producing more thermal power than is used to heat the plasma. The total electricity consumed by the reactor and facilities will range from 110 MW up to 620 MW peak for 30-second periods during plasma operation.[6] Being a research reactor,[3] thermal-to-electric conversion is not intended, and ITER will not produce sufficient power for net electrical production. Instead, the emitted heat will be vented.

Re: Vertical farming does not save space

#270

Post by jshevek »

wffurr wrote: post #110
charlesju wrote: post #98

Earlier quoted context omitted.

1. We have nuclear waste already 2. We will continue to have nuclear waste if we want to have nuclear weapons 3. You can store all the waste you need to store in a football field ( https://www.energy.gov/ne/articles/5-fast-facts-about-spent-... ) Nuclear waste management is messy, but it's something we need to solve no matter what. It is now a sunk cost we have to deal with because of what we have already done and wh…

I have this giant pile of nuclear waste that's stored haphazardly and needs to be dealt with at a cost of $XXX billions of dollars. I know! I'll keep shoveling more waste into the haphazard piles! Perfect!

I see a sarcastic misrepresentation of the parent's comment, and nothing of substance here. Is there a deeper, substantial point you wish to make?
Post reply on HN