Perpetual AMA for Caleb

@Caleb Awesome post! Have you published any of the food server energy and price calculations you mentioned? That’s super interesting.


Nope they were proof of concept in a leaky farm with bad software :wink: Thats why Im building the new lab in middleton! thats what all this work is about @wsnook !

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I didn’t realize that’s what you had in mind with the new lab. Very interesting. @rbaynes fyi, I’m interested in this angle of things. I’m curious about ways I might be able to help and about how to tie the food server work back to the MVP stuff so the software is reusable.

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Thanks @Caleb for the detailed and rigorous post on my comments and sharing this great TED talk. It has given me some great perspective on your position towards the economics and sustainability of vertical farming and I also learned many things that I for sure didn’t know about.

With regards to the comparison between vertical and traditional farming I have also started to develop these metrics on already existing systems (BrightAgrotech, UrbanCrops…) using the data available on their website and through given brochures… and the results were quite similar one to the other:

UrbanCrops: 7-15 kwh/kg produce (depeding on if its lettuce or basil) which is around 0.3-0.6 USD/lettuce.
BrightAgrotech: 8 kwh/kg

So it seems results are consistent to those obtained in your CityFarm. Water usage was also quite similar for both and around 6-10 L/kg of crop and if using Sweden as the base for calculations (we are quite carbon free :P) the CO2 was around 0.5-1 kg CO2/kg product. So taken into consideration all the labour, equipment costs… there is still at least 50% margin on the final price in Sweden.

Definitely Cornell and that video i attached… not the best sources for encouragement… these are just my source of motivation to prove them wrong.

I would also like to bring to you another topic. I am starting my own hydroponics venture to sell greens and vegetables directly to the consumer market in Stockholm (hopefully i can also prove you wrong and not end up in bankrupcty…:S). In that endeavor I would be very interested in sharing and collaborating with OpenAg but i am not sure if these collaborations are possible and how would they have to be developed. In that effort, my goal is to start with a small prototype (50-350m2) and at the same time develop our own OpenAg research in KTH (my university) building first a PFC v2.0 and later on working on developing our own food data center. We have gathered already potential KTH Researchers interested in the working on CEA and it would be great to hear your feedback on that.

Finally as I have seen that you will be presenting in Stockholm for the food forum in June, is there a way to arrange a short meeting to discuss this a bit further?

And final final question, is there a way for arranging short-term stays at your MIT Lab (for students at other technical universities for example during the summer?). This could be a great initiative to increase the OpenAg community throughout the world.

Thank you for reading and love to hear your thoughts.

have a great weekend.



Hi @Caleb

I am an agricultural scientist and microbiologist who currently works in public health and food safety in Australia. I have recently developed an interest in sustainable food production and urban agriculture as a novel way of satisfying the requirements of feeding a growing global population. As part of this, I have been reading extensively on the OpenAg project and hope to commence construction of my own food computer in the near future to better contribute to the community.

My question is more one that is focussed towards the work that I currently do, particularly around food safety and public health. As you may be aware, traditional horticultural produce is responsible for a significant amount of global foodborne illness (e.g. the E. coli O107 outbreak in Europe during 2011, the Jensen Farms cantaloupe outbreak also during 2011). A large proportion of this produce is consumed with little or even no preparation and pathogens such as Salmonella, Listeria, norovirus and E. coli associated quite readily with this produce can cause severe illness, particularly in vulnerable individuals. Additionally, there is quite an amount of research going on in the field of plant/human pathogen interactions, particularly in the area of internalisation of pathogens in horticultural produce, and the jury is still widely out as to how to guard against these potential routes of exposure.

Whilst there is no doubt that there are significant nutritional benefits for public health associated with fresh home grown produce and the risks associated with long supply chains are largely negated, food safety is often overlooked in home grown produce. I searched through the forums but I haven’t been able to locate any discussions surrounding food safety and the PFC. My question is: Has the OpenAg project had any discussions or given any consideration to implications for food safety when using production systems such as the PFC?

Thanks for your time - I would be more than interested in hearing your thoughts.



Hey @andrewW the short answer is no! Its pretty crazy all these CEA projects are spinning up without much thought to food safety! (containers, factories, etc). In fact there is no USDA certification process I am aware of so its up to the developers. You sound like you have really special and useful knowledge on the subject. Why not start a thread in the forum around it and start imparting your wisdom? This forum is meant to be a place people come together to collectively problem solve and share knowledge - Feel free to call me out in your posts so I can learn too


Thanks for your reply @Caleb. Great idea and definitely something that I will get going in the community forum.

Unfortunately, government regulators all too often reactive in these sorts of instances. Instead of exploring novel food industries, engaging with them to work collaboratively and ensuring food safety is built in to their development processes, they wait until something has gone seriously wrong and then regulate the hell out of it. We have fewer issues we can park the ambulance at the top of the hill so to speak and I am lucky to be involved with a food safety regulator that embraces this philosophy.

P.S. I will be visiting Boston for work in mid-July and it would be great to link up and have a chat with your group about this.

Hi @Caleb Harper.
I’m Jin Hyuck Lee in Korea

I’m Korean Polytechnic University student
I’m majoring in mechanical design
I am crazy about Food Computer

so I made a start-up club recently and gather my crew

there are 10 people who want to build PFC

They are competent students and workers in each field.

i have a plan to supply PFC in korea

and build a web site to service about all of PFC ( recipe, expendable things , korean community etc)

and finally we can share korean unique recipe (i really hope so)

we are really care about safe food in urban and sustainable agriculture system

we are starting to hardware parts in Digital blacksmith in Seoul now

few days ago, i went to urban agriculture forum hosted by a public agency

and i can have a chance contact with the mayor of Siheung.

Go to the main thread

can i ask you for help in any way.

to convince business plans or just your message to officially

or objective data or even keywards to google it


if you want to receive business mail

please reply me and really thank you!

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@Caleb do you have entry tickets for Nerdfarmers in EAT forum? I would love to come and hear you talk :slight_smile:

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Hey!!! I have no idea…hmmmm…want to just show up at the Clarion Sign hotel tomorrow and we can try? Im a big fan of begging forgiveness instead of asking permission :wink:

Hey @Caleb that would be awesome. What time should we meet? Thanks, Albert

@Caleb Hello. I enjoyed your EAT Forum talk. It’s here for anybody that hasn’t see it.

With my food computer prototypes, my focus has been on reducing cost. I am curious what I should be aiming for to improve viability of food data centres. AeroFarms appears to have been built at a cost of >7000USD per square metre.

What is the cost of your food servers per m2 of growing area, and what is the target cost for them and the food data centres?

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@Caleb Any chance that you could share more info/code/papers on your “Plant AI: Bayesian Optimization and Gaussian Process Regression” slide from the EAT Forum? It’s a bit hard to read the slide in the video. It looks like you are comparing three different lighting systems on one axis, while the other two are illegible. Based on my read it looks like you have 5-6 actual data points (green and gray points), while the others are just estimates from the model. How did you tune your hyper parameters with so few data points?

As for the methodology for effective modeling of ~3.2M data points per plant, how are you preventing over fitting? Are you using a time dependent PCA to shrink your search space? How do you account for different environmental conditions needed at each plant life stage in your models? Have you found a way to simplify how you think about plant recipes or found any differences in aggregating information? For instance, does applying a total of 600 W*hrs/day to a plant differ matter if the light is 50 W for 12 hrs vs 100 W for 6 hrs? If it makes no difference, then you could think in terms of total light allocated. However, my guess is that you can’t do this since there is an upper bound to the rate of reaction that a plant can perform.



@Caleb I wrote a post on another section, not sure if you are able to help here but it would be awesome. We just got the funding from KTH to build and develop a food computer :slight_smile:



Another question. What is the purpose behind the name OpenAg? I guess, how much Open Agriculture innovation are you hoping to foster here on the forum? I ask because the community and the discussions themselves are quite limited at this point in time to topics relating to PFC and specific growing conditions like hydroponic growing.

Are you looking to foster openness in all areas of agriculture? I personally would love to see the forum grow beyond where it is today and also include discussions and a community for regular plant breeding and/or regular growing even without the PFC or artificial environments. But maybe that’s just me. I really don’t know who is really interested in that kind of stuff on this forum since it has not been talked about much at this point.

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@Caleb I am visiting a very good friend of mine from MIT at the end of February and I was wondering if it is possible for me to meet the you and the team even if its just for 20 min to see around your facility in Cambridge?
Thanks Most likely between 26-2 march?

thats the beauty of it…just …add a thread :wink:

Dear Caleb,

I am getting in touch with you, following Rob Baynes answer from our queries.

We are La Grangette, a French company creating autonomous kitchen garden which will be part of TechHub during the Indoor AgTech summit in New York (June 19-20).

As an open-minded corporate we want to break the borders and humbly contribute to resolving the issue of the lack of data sharing.

I will be delighted to meet you during AgTech Summit, so we could have a talk about the opportunity of contributing of sharing data and researches with you.

Please could we organise a meeting during the summit?

Best regards.


Tel. 33 (0)6 12 58 39 37

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/cc @hildreth or @rbaynes (the post above is a contact request for @Caleb)

Thanks for the ping, Will!