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Resilient agriculture with HCC saves land, protects crops, future-proofs farming, saves water & converts CO2 to O2 + biomass/food. Cool.



Much infrastructure is carbon-based, vital,and highly distributed so won't be substituted for decades. That means CO2.

Conventional agriculture is flat (2D), so space-limited. Soil loses nutrient over time, needing clumsy and polluting fertilization, and megatons of valuable water is transpired to atmosphere.

Conventional CCS buries CO2 - expensive, zero payback, and a liability for our kids.

Hydroponic Carbon Capture - HCC - uses captured CO2 to grow biomass or food in a soilless enhanced resilient environment, massively accelerating growth and re-absorbing CO2. Crop is protected from pest, disease and weather threat, so higher yield. Stackable system so not space-constrained. Most water is recycled, and closed-loop fertilization = no pollution.

PLUS higher efficiency allows land previously needed for agri to instead grow timber for construction, locking more CO2.

HCC is:

  • Low-tech + low-cost. Ambient pressure, ambient temperature, simple (so workable regardless of local technical ability).
  • Low-risk combining established technologies.
  • Failsafe; worst-case failure just leaks a little CO2. No pollution, explosion, radiation or other bad stuff.
  • Cheap. It's a prefab "greenhouse" with low-cost high-impact add-ons. Input heat is (mainly) solar; transpired water is recovered and can be recycled without treatment. And HCC EARNS income by producing sellable produce.
  • Really efficient LOSSLESS agriculture. Growth is accelerated 50% by this LED lighting and 30-40% at higher CO2 levels; may outperform field farming by 80-90%. It's immune to pests and weather so this may hit >100%. It's also largely immune to expected climate change effects so "future-proof".
  • Carbon sequestration boosting. High efficiency means less farmland needed; "released" land can grow trees for timber, locking-up more carbon long-term (AND wood can be used for "green" construction)
  • CCS compatible - CO2 can be recovered from any source.

Cut CO2, make O2, grow biomass, feed people, lock-up carbon. What's not to like?

What actions do you propose?

3 project phases are considered; funding & organisational outline; initial research; and development phase. Pilot and subsequent roll-out are not discussed in any detail, being for now too distant.

The “research components” (RCs) – key activities in each area – are identified.


  1. Agree funding outline for initial research.
  2. Set up a sponsoring university-based project for research to prove concepts and pilot baseline technologies.
  3. Assuming successful, establish suitable funding vehicle to obtain wider income. The nature of the project suggests this would be a combination of government and corporate funding.
  4. Build appropriate expert forum of technical, agriculture and hydroponics experts led by suitable expertise (selected by the forum - must of course also be acceptable to the funding providers)
  5. Move to development stage, recruiting additional resources as required. As details are finalized and designs firm-up, seek further funding perhaps through additional funding vehicles.
  6. Pilot in one or two real-world projects to obtain public buy-in and debug processes and technology.
  7. Roll-out. Low-tech construction demands very simple build skills.



Since rather than being entirely new the design combines existing technologies (see for example this Japanese hydroponic farm and this LED system), by partnering academic and real-world expertise research timescale should be short and move to development rapid.

Initially we must identify and prove key feasibility issues. What growth rate and CO2 uptake is achievable, by what crops and in what effective volume/area?

It must be stressed that in the absence at this preliminary stage of any design optimization these initial results will probably be far short of what’s possible.


Concept feasibility research in the form of small-scale experimentation should be to establish CO2 uptake and crop yield, of a selection of test crops fed with CO2 levels optimized for the 30-40% yield boost growing under this LED lighting which should improve output by a further 50%.

Appropriate crops suitable for biomass applications (or potentially for food) should be selected - botanical/plant biology advice is essential. This comprises the first research component.

This component must generate sufficient data to allow a decision on progress to be taken based on 4 primary criteria:

  • demonstrated agriculture resilience
  • CO2 reduction benefits (overall; resilient agriculture with HCC, plus the effects of usage of the land released for eg timber)
  • crop economics
  • required space/volume (for construction economics)


While there is strong evidence that enhanced CO2 levels will - under controlled and enclosed conditions - significantly increase growth rates, there is also evidence from FACE (Free-Air Carbon dioxide Enrichment) trials that at larger scale, under field conditions, this effect is more variable and subject to a number of other contributing factors. This article discusses not only CO2 uptake (concluding that "Across a range of FACE experiments, with a variety of plant species, growth of plants at elevated CO2 concentrations of 475–600 ppm increases leaf photosynthetic rates by an average of 40%", but additionally discusses other factors such as growing medium nitrogen levels and atmospheric ozone. Both lend themselves to precise control under HCC conditions; in particular the fact that "the enhancement of growth by elevated CO2 is much greater under conditions of ozone stress than otherwise" may be significant.

This study finds the effect less pronounced in some species, but concludes that there is considerable potential for development of open-field FACE technology in the form of arrays to control CO2 dispersion across an area.

Overall there appears to be clear evidence for the benefits on growth rates of enhanced CO2; the question then becomes whether the capital and operating costs of a closed environment such as HCC, compared to open field FACE are outweighed by yield and CO2 sequestration.

In this, it should be recognized that for effective open-field FACE capital costs are likely to remain high; in addition the approach does not provide HCC's benefits of immunity from weather, pest or climate, nor does it offer the fine control over growing environment to maximise output. In addition, as an open-field solution, the land-area savings that are available from multi-tier HCC - freeing up additional land for additional carbon sequestration - are not to be had in open-field FACE.

Assuming overall result to be positive the project can move to the development phase.

RESEARCH COMPONENT RC 2: Hydroponic unit (HU) design

To consider research required for the HU, it is first necessary to review the HU concept.

As mentioned above, HCC lends itself to an ISO-container format pluggable module design. It equally lends itself to a bespoke build, which may be cheaper where appropriate skills and resources are locally available.

Key benefits of a pluggable ISO-container-dimensioned module design are:

  1. Globally-standardized format, permitting cheap mass-production
  2. User support by a universal maintenance/spares infrastructure.
  3. Easy shipping and handling using universally-available container handling equipment
  4. Very dense storage and installation.


All services (water, nutrient feed, power) would be pre-installed on the module allowing very rapid installation of multiple units, even using very low-skilled labor, permitting an installation of any size to be quickly deployed and commissioned.

The design must address parameters of; planting, gas flows, nutrient and water provision, lighting, and crop harvesting. These drive the key research areas.

First is planting and crop selection. Some crops will be more available and will grow better than others in different locations, and there is likely also to be an element of what the local market will want (not all of which may be compatible with HCCAS). Offsetting this is CO2 uptake; a less efficiently-absorbing crop would require more HU capacity to yield the same CO2 absorption. Identification of optimal crops (food/biomass/mixed) for a location will be key.

Current research such as this or this article from on common conventional species indicate that elevated CO2 does increase growth, so combined with this LED option we can expect considerably greater productivity from HCC than from "normal environment" farming.

It may be worth considering that plants similar to some prehistoric species, which flourished when CO2 levels were much higher, may be a better bet for biomass applications.

It should be noted that this is NOT on the critical path. ALL plants absorb CO2 and HCC can be initially implemented to grow most crop(s), immediately bring the benefits of resiliency to the crop (subject to space/weight constraints). These can be later substituted by more optimal choices as research identifies these.

Second is gas flow and path. Higher gas flow will have greater turbulence which may improve CO2 take-up; however not every plant is amenable to windy conditions. Designing/controlling the gas path and flowrate to optimize CO2 take-up, especially in a changing and highly-irregular path such as growing plants will create, will be a challenge. The design will also need to take into account incremental addition of fresh CO2-laden gas.

The third is delivery of water and nutrients. These are already well established in hydroponics, and aren’t discussed further here.

The fourth, lighting, is the proposed LED lighting supplemented by ambient light where possible. Implementation of solar power for the lighting, possibly as proposed by Dennis Wilmeth in his proposal "Next Generation Greenhouse" is a given.

The last element is crop harvesting. Key issues will be:

  1. Handling of the crop mass
  2. Access (including height considerations in multi-level HCC)
  3. Crop robustness (to minimise losses in harvesting process)
  4. Working environment (elevated CO2 levels are an unsuitable working environment for humans).


Taking these into account, a “cassette” system is envisaged which addresses all these aspects effectively. The cassette is configured to slot-in to the ISO container format (an equivalent would work equally well in a bespoke build).

It is envisaged that "services" - water/nutrient and lighting - would be part of the container structure. Accordingly the cassette need comprise little more than a supporting and handling structure for the crop.

The cassette will be pre-planted with crop seed/seedlings – outside the HU, in a human-friendly environment – then slid into the HU. When the crop was ready to be harvested the cassette would be pulled from the HU, and the crop harvested, the cassette then re-planted and so on.

A cassette system offers many advantages:

  1. It allows for any mix of human labor and automation to handle the cassettes, so is suitable for both high-tech and less sophisticated populations/locations
  2. It would permit a high-density hydroponics installation to be configured similarly to a multi-level high-racking warehouse, with cassettes loaded/unloaded using standard or little-modified warehouse equipment
  3. Pre-planting cassettes greatly reduces non-productive time harvesting and changing-over is so yield and CO2 uptake is maximized
  4. A standardized cassette system offers the same standardization benefits as the ISO-container format HU module, as above
  5. The problem of humans working in a high-CO2 environment is removed



The above appears to provide a clear roadmap to design, prototyping and mass production/roll-out of the system.

Who will take these actions?

Initially a sponsor or academic-industrial partnership would need to pick up proof of concept.

Once the potential is demonstrated I would envisage implementation of a funding vehicle (see previous section) for development, this vehicle then growing and being supplemented to move the project forward.

Once development is done and Resilient Agriculture with HCC is real I'd hope that industry, NGOs and governments would pick up and run with the idea on a global scale. The economics, food security, and social acceptability should be WAY better than anything offered by the alternatives - especially current "down-a-hole-in-the-ground" CCS - and I believe momentum will simply take over.

Where will these actions be taken?

Can be in any location. Ideally I'd like to see a global project with contributing experts from everywhere. The key word in "global warming" is global - it's everyone's problem and our leaders need to act together.

It's essential we recognize that local factors can affect implementation. It's highly unlikely we can agree on one single model in detail that will work everywhere - ideal crops for example are unlikely to be the same in Russia as in Brazil - but the concept is very portable and should be deliverable in a standardized format to allow the economic and practical benefits - as discussed in previous section "proposed actions"  - of standardization to be leveraged.

Nonetheless, detailed implementation at local level will inevitably differ and the project must not get bogged down - like so many have before - in endless discussion of a "one size fits all" model. That will fail, and will consume valuable time.

How much will emissions be reduced or sequestered vs. business as usual levels?

All figures per year.

1000 m2 biomass absorbs 2.5 tonnes CO2 to yield 6 tonnes of biomass +1.7 tonnes O2. HUs stacked 4-high need ¼ this area = 0.00025km2.

One sq km => 24,000 tonnes biomass and 10,000 tonnes of CO2 uptake.

In addition, as we’re obtaining same output from ¼ of area, HCC frees up other 3/4 for re-foresting, i.e. 3km2 per km2 of HCC.

Mature forest takes up 9,826 lbs of CO2 per acre = 4.4 tonnes per acre = 3,300 tonnes for 3 km2.

Total CO2 reduction against “business as usual” = 13,300 tonnes per km2 of 4-high HCC, with 24,000 tonnes of valuable biomass, 10,000 tonnes of O2 by-product, and large amounts of timber.

Is this permanent capture?

Yes. Where biomass grown is used as biofuel carbon is locked into a biofuel-CO2-biofuel closed loop.

Additional capture from foresting freed-up agricultural land is “permanent” on a “trees” timescale; if the timber is used for sustainable construction the locked-in carbon is permanently sequestered.

Plus, there's this concept...

What are other key benefits?

  1. Highly resilient, v. efficient agriculture largely immune to climate change, pest, disease, and weather; strongly future-proof
  2. Only needs brownfield land
  3. Frees-up farmland for re-foresting or people
  4. Reduces CO2 emissions
  5. Increased O2
  6. H2O saving - recycles transpired water and prevents it going to atmosphere
  7. Savings in transportation costs and emissions by substituting shipped biomass
  8. Point fertilizing means no run-off pollution
  9. Reduced residual CO2 so less CCS needed; extended CCS facility life as fill more slowly
  10. Employment opportunities in clean, green environment
  11. Cheaper more plentiful food, particularly in less fertile areas where hydroponic solution may massively improve lives.
  12. Potential resource conflict reduction in food-short areas.
  13. It's big & visible & VERY green, and if also reduces food costs will be popular, encouraging belief in benefits of environmental projects which will pave way for other projects.

What are the proposal’s costs?

A detailed cost analysis for an ISO container-based implementation (probably the most expensive build option), operated on normal "open-field" plant spacing (far less dense than HCC will permit) is presented for hemp crop in my other proposal "Hempdroponic Carbon Capture", which essentially demonstrates subsidy-free financial break-even with significant carbon capture even at this worst-case scenario.

Optimized build and high-density planting, augmented with - for example - controlled ozone stress to increase growth rate further should result in a significantly positive cost outcome.

That will be further enhanced where higher value crop can be grown; although - for example - strawberries will not sequester carbon long-term, by employing multi-tier HCC - which for strawberries could be as much as 10-12 layers in an ISO container format, at high-density planting -  the land released as a result will allow considerable reforestation and associated long-term sequestration, particularly where the timber is used for construction (locking-up the carbon long-term).


Time line

Time line

This is established tech that's simply being brought together, so we should be looking at incremental development only.


6-12 months to prove feasibility

2 years to develop

5 years to pilot and debug

5 years to build a significant installation. HOWEVER, since modules are common multiple installations can go up simultaneously. HCC could be operational within a few months of breaking ground, accepting more and more CO2 as the build extends.

Related proposals

This won't be cheap, and in view of the many benefits offered would be a good candidate for funding via my other proposal, in the Global part of the contests, of "Quantitative Easing for Climate Change Mitigation + Adaptation"

The "Next Generation Greenhouse" proposal is referred to above and relates to powering the LED lighting used.

My "Hempdroponic" (sorry...) proposal offers further development scope for extended carbon capture and lock-up.


Please refer to the hyperlinks embedded in the different areas above.

Particular thanks go to CoLab Member katilyst who brought some excellent FACE material to my attention - thanks very much Kati!