Food & Farming Entrepreneurs Network

Task & Finish Workshop 2

Growing in Closed Buildings - Ultimate Intensification

Martin McPherson, STC Ltd

&

Howard Campion, H2O Farms

Growing in Closed Buildings

“Ultimate Intensification in

horticulture”

Martin McPherson MBPR (Hort.)

Science Director

Stockbridge Technology Centre Ltd

A Glasshouse Industry Transformed

The Glasshouse Industry

Much larger glasshouse units

Significantly taller structures

Improved light transmission

Increased efficiency & yields

BUT….

Reliance on solar performance & light

quality & its interception is fixed

They remain energy inefficient

Labour costs, in many cases, are high

Where is the next major step change?

Key Drivers for Change

Population

growth Food

security

Water

availability

Energy

costs

Climate

change

Regulatory

pressures

Environment

issues

Government Chief Scientist

Sir John Beddington

“A perfect storm scenario”

The ‘Foresight Challenge’ and…

….a need for sustainable intensification

“Sustainable Intensification”

….a simple and appealing concept….

– to maximise food production efficiency in terms of

external resource inputs and on the smallest necessary

land area

The term “Sustainable” implies the use of resources at a

rate that does not exceed the capacity of the planet to

replenish them

Vertical Farming is not a new concept

…but it is starting to move

into the 21st Century

Vertical Farming Systems

Various systems designed to

optimise production

The main limiting factor is

light (or lack of it)

In Northern Europe solar

radiation levels are variable

and often limiting

1% light loss is equivalent to

approx. 1% yield loss

Supplementary lighting

HDC-CGA project No. PC201 at STC

Concept to use all latest horticultural technology to see

what the ultimate crop potential was

Highly successful with >100% yield increase

But…uneconomic, primarily due to cost of conventional

lighting using high pressure sodium lamps

This was 5-6 years ago…and technology has already

moved on….

AYR Cucumber Project

Changing Lighting Technology …Is there an opportunity here?

High Intensity Discharge (HID) lights are

inflexible due to heat signature

They can‟t be placed close to the crop so

inappropriate for vertical farming systems

Innovative LED lights offer an alternative

cool & energy efficient light source

BUT…they have not yet been fully validated

in the horticultural sector

Spectral Range for Plant Growth

Plants respond differently to light of differing colour.

In general, red light stretches while blue light encourages shorter plants.

The optimum ‘light recipe’ needs to be developed for each species

Function of Spectral Quality

Light Spectrum Wavelength Band

(nm)

Comments

UV-B 280-320 Deleterious for growth

UV-C 320-400 Might have additive effect

to blue light

Blue 400-500 Necessary for elongation

control

Green 500-600 Less important in

photosynthesis than red

spectral range for certain

plants

Red 600-700 Optimisation is necessary

to avoid abnormal

development

Far red 700-750 Enhancement of flowering

& stem elongation

A cool light source – opportunity to pioneer novel vertical

cropping systems

Low voltage - Improved energy efficiency

Improved spectral control (switchable/dimmable)

Extended durability (reduction in labour costs)

Option for integration into specific lighting „recipes‟

Enhanced safety (lower voltages & operating

temperatures & reduced risk of glass injury)

Sustainable attributes (recycling, absence of mercury etc)

Unique Attributes of LED‟s

Demonstrating the Benefits of Spectral Control

HDC CP19 (2003-2007) Evaluation of Spectrally Modified Plastics

Demonstrating the Benefits of Spectral Control

Colour change observed in cabbage (summer green) grown

under Solatrol (left) and Standard (right) plastics

Demonstrating the Benefits of Spectral Control

Demonstrating the Benefits of Spectral Control

Demonstrating the Benefits of Spectral Control

Black peppermint Rosemary Sage Thyme

Standard 118% 598% 315% 130%

UV-transparent 111% 326% 315% 133%

Solatrol 81% 252% 316% 105%

Field 100% 100% 100% 100%

Luminance 93% 382% 554% 190%

UV-opaque 119% 507% 641% 229%

HDC CP19 : Impact of spectral change on oil yield in

herbs as a % of that in field-grown crops

Each value in the Table is the mean of 19 replicates, calculated using replicate fresh weight data but

a single, bulked oil analysis for each crop.

The story so far… …could LED’s provide the next

step change in horticulture to

enable economic multi-layer

production

Where are we?

High Wire Crops

Interlighting with LEDs Crop Improvement Centre – Bleiswijk, Holland

Already, a 15% yield increase is being

claimed for use of this new technology

BUT…it is not necessarily a good example of

sustainable intensification

Ultimate intensification through

multi-layer cropping

Hi-wire crops not a practical proposition

Other crops potentially are e.g. leafy salads, herbs,

plants in propagation, strawberries (& ornamentals)

Two options to consider here:-

- Glasshouse production

- Warehouse production

What are the advantages & disadvantages of each

approach?

Glasshouse Multi-layer

production Advantages

- Most growers have existing glasshouses

- Can benefit from free solar radiation

- Can use existing HID lights to supplement

Disadvantages

- Poor thermal insulation

- Insufficient light penetration

- Unpredictable scheduling due to weather

- high energy, transport & labour costs

- light wavelength restricted by glass

Warehouse multi-layer

production

Advantages

- Surplus warehouses available & quick/cheap to build

- Can be placed in towns & cities or next to

distribution hubs

- Can be highly insulated & energy efficient

- Mechanisation much easier

- Sealed enclosure so less risk of P&D problems

- Greater level of biosecurity

- Greater potential for environmental control

- Ultimate control over crop scheduling

Warehouse multi-layer

production

Disadvantages

- No free solar radiation (though solar panels on

roof will compensate to an extent)

- All lighting has to be provided artificially

- light „recipes‟ not yet known for many crops

Frands Jepsen, MD, Queen Kalanchoe, Denmark

“The results I have seen convince me that it is possible to grow

plants with LEDs as the sole source of light and I am beginning

to think I may have built my last greenhouse” Feb. 2011

Innovation towards

Sustainable Intensification

Question: Which is the right way

forward for vertical growing

systems –

- a glasshouse environment

or

- a closed shed?

What are the economics and

practical considerations?

Vitro Plus Fern Nursery Burgh-Haamstede, Zeeland, Holland

Is this the ultimate goal……

Developing a New Applied

R&D facility at STC

Conventional

crop HPS lighting

Multi-layer crop

with LED lighting

Multi-layer crop

with LED lighting

Experimental

multi-layer zone

for specialist

studies

2 x 200sq m glasshouses

(conventional glass for

comparative studies)

2 x 200sq m warehouses

(highly insulated to conserve

energy inputs)

F18 & F19 W10 &W11

F18-F19

Warehouse

facility

Proposed Facility Location

QUESTIONS?

Do LED lights provide the key to ‘urban farming’ systems?

Is multi-layer cropping feasible economically?

What is the optimum cultivation system for sustainable

production?

What about mechanisation in a vertical plane?

Is fixed wavelength lighting likely to give problems?

How easily will it be to control temperature & humidity in a

closed building?

Are there other issues & opportunities that need to be

considered?

Finally...is it a case of ‘science into practice’ or merely a

fairytale?