B.M. McDowell Bomani and R.C. Hendricks

Glenn Research Center, Cleveland, Ohio

Malik Elbuluk

The University of Akron, Akron, Ohio

Monica Okon

Glenn Research Center, Cleveland, Ohio

Eric Lee

Ohio Aerospace Institute, Brook Park, Ohio

Bethany Gigante

Glenn Research Center, Cleveland, Ohio

NASA’s GreenLab Research Facility: A Guide for a 

Self-Sustainable Renewable Energy Ecosystem

NASA/TP—2011-217208

December 2011
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B.M. McDowell Bomani and R.C. Hendricks

Glenn Research Center, Cleveland, Ohio

Malik Elbuluk

The University of Akron, Akron, Ohio

Monica Okon

Glenn Research Center, Cleveland, Ohio

Eric Lee

Ohio Aerospace Institute, Brook Park, Ohio

Bethany Gigante

Glenn Research Center, Cleveland, Ohio

NASA’s GreenLab Research Facility: A Guide for a 

Self-Sustainable Renewable Energy Ecosystem

NASA/TP—2011-217208

December 2011

National Aeronautics and

Space Administration

Glenn Research Center

Cleveland, Ohio 44135
Available from

NASA Center for Aerospace Information

7115 Standard Drive

Hanover, MD 21076–1320

National Technical Information Service

5301 Shawnee Road

Alexandria, VA 22312

Available electronically at http://www.sti.nasa.gov

This work was sponsored by the Fundamental Aeronautics Program 

at the NASA Glenn Research Center.

Level of Review: This material has been technically reviewed by expert reviewer(s). 
NASA/TP—2011-217208 1

NASA’s GreenLab Research Facility:

A Guide for a Self-Sustainable Renewable Energy Ecosystem

B.M. McDowell Bomani and R.C. Hendricks

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Malik Elbuluk

The University of Akron

Akron, Ohio 44325

Monica Okon*

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Eric Lee

Ohio Aerospace Institute

Brook Park, Ohio 44142

Bethany Gigante*

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Summary*

There is a large gap between the production and demand for 

energy from alternative fuel and alternative renewable energy 

sources. The sustainability of humanity, as we know it, directly 

depends on the ability to secure affordable fuel, food, and 

freshwater. NASA Glenn Research Center has initiated a 

laboratory pilot study on using biofuels as viable alternative fuel

resources for the field of aviation, as well as utilizing wind and 

solar technology as alternative renewable energy resources.

The GreenLab Research Facility focuses on optimizing biomass feedstock using algae and halophytes as the next generation of renewable aviation fuels. The unique approach in this 

facility helps achieve optimal biomass feedstock through 

climatic adaptation of balanced ecosystems that do not use 

freshwater, compete with food crops, or use arable land. In 

addition, the GreenLab Research Facility is powered, in part, by

alternative and renewable energy sources, reducing the major 

environmental impact of present electricity sources. The ultimate goal is to have a 100 percent clean energy laboratory that, 

when combined with biomass feedstock research, has the 

framework in place for a self-sustainable renewable energy 

ecosystem that can be duplicated anywhere in the world and can 

potentially be used to mitigate the shortage of food, fuel, and 

water. 

 *

NASA Lewis’ Educational and Research Collaborative Internship 

Project (LERCIP) Intern

This paper describes the GreenLab Research Facility at Glenn

and its power and energy sources and provides recommendations for worldwide expansion and adoption of the facility’s

concept.

1.0 Introduction

It is widely accepted that green solutions are needed throughout the world. The three primary human needs are freshwater, 

food, and fuel. However, the word “green” is often misused 

when describing many technologies, processes, and products. 

To be truly labeled a green solution, three conditions must be 

met. The solution must be alternative, renewable, and sustainable. An alternative solution is one that is not in mainstream use 

today and has no undesired consequences when compared to 

conventional solutions. A renewable solution is derived from 

sources that are naturally replenished. A sustainable solution 

refers to the ability to maintain ecological processes, functions, 

biodiversity, and productivity into the future. For any technology, technique, or method to be considered green, all three 

conditions (alternative, renewable, and sustainable) must be met 

inclusively.

At the GreenLab Research Facility at the NASA Glenn 

Research Center, we are concentrating on green solutions for 

aviation fuels as well as green energy solutions. Approximately 

97 percent of the world’s water is considered saline, and less than 

1 percent is freshwater that is directly accessible for human use. 

We have developed a green solution for aviation fuels that utilize 

what we call the “Big 3” at Glenn. The Big 3 can be an algae, 
NASA/TP—2011-217208 2

plant, weed, or bacteria that (1) does not use freshwater, (2) does 

not compete with food crops, and (3) does not use arable land. 

We have combined our GreenLab biofuels effort, which focuses 

on biomass optimization with viable alternative energy technologies, to establish the framework for our concept of having a selfsustainable renewable energy ecosystem. 

The primary plant species being researched in the GreenLab 

are halophytes. Halophytes are salt-tolerant plants that are found 

all around the world in saline or brackish environments such as 

mangrove swamps, salt marshes, mud flats, and coastal environments. In the GreenLab we use climatic adaptation techniques 

(i.e., freshwater to seawater acclimation and vice versa) with 

halophytes to ensure that they will be adaptable to a wide range of 

ecosystems around the world. In addition, we are adapting 

microalgae and macroalgae with climatic adaptation techniques 

with the goal of identifying optimal algae species that can adapt 

to real-world conditions. In theory, our GreenLab concept can be 

applied to satisfy fuel, food, and freshwater needs when halophytes and algae are utilized as the primary plant biomass source.

What follows is a description of alternative fuels and alternative energy distributive sources, a description of our indoor 

biofuels lab and our GreenLab Research Facility, and lastly, our 

ideas for global adoption of our concept. 

1.1 Alternative Fuels

By 2026, the world’s liquid fuel demand is projected to grow 

by 20 to 25 percent, implying an increased U.S. demand from 

over 20 million bbl/day (2007) to 24 million bbl/day (Ref. 1). 

To meet that demand with alternative fuels, even if one could 

grow algae on the open seas fed by continent-sized nutrient 

streams under the most opportune of conditions and convert it to 

oils, the equivalent volume demand would require nearly half 

the Gulf of Mexico or 0.8 million km2

. This assumes equivalency between refined barrels of plant oil and petroleum algae 

production using the following estimates (from Ref. 2):

Estimate 1: (0.8×1012 m2)(0.02 kg-biomass/m2-day)

(3/10 gal/kg)(1/42 bbl/gal)(20% bio-oil/biomass)

Estimate 2: (0.8×1012 m2)(4.2×103 gal bio-oil/ha-yr) 

(10–4 ha/m2

)(1/365 yr/day)(1/42 bbl/gal)

Also, by 2026, the world’s jet fuel consumption is projected 

to grow from 95 billion gal (2007) to around 221 billion gal 

(836 billion liters) per year (Ref. 3). Replacing 10 percent with a 

renewable jet fuel would be similar in scale to current worldwide liquid biofuels (ethanol and biodiesel) production. The 

2026 fuel burn goal for future aircraft calls for a 70 percent

reduction (Ref. 3). Even if that goal is met, 66 billion gal (250 

billion liters) annually would still be required. It would take at 

least 10 years for the technology to be injected into the fleet and 

require a biomass-fuel area equivalent of about one-third of the 

Gulf of Mexico.

The need for replacement fueling and the effects of biofuels 

on both legacy and future aircraft performance and design has 

been established in prior publications (Refs. 2, 4, and 5). These

publications illustrate conflicts between fuel types and the crops 

and crop land necessary for alternate aircraft fueling. The 

aviation industry requires specific mobility fuels that meet jet 

fuel specifications, and one cannot just replace jet fuel with 

current renewable fuels (ethanol, higher alcohols, pyro-oils, 

biodiesel, or hydrogen electricity). Industry is now pursuing 

new, large-scale, secure, sustainable biofuels within several “do 

no harm” restraints: (1) not competing with arable land or 

freshwater resources needed for food/feed production, (2) low 

carbon footprints that do not lead to deforestation, and (3) not 

engendering adverse environmental or social impacts. 

When burned, 2 tons of jet fuel generates over 1.6 tons of 

carbon and over 2.5 tons of water. Globally, aviation fuel has 

been growing at about 4 percent per year despite a 1 percent per 

year improvement in airplane fuel efficiencies. The resulting 

high-altitude cloud formations and carbon footprint (CO2

emissions) are of increasing concern to the commercial aviation 

industry, which has set a goal that future growth in the industry 

should be carbon neutral. Thus, renewable jet fuels are a critical 

need for this industry. The Commercial Aviation Alternative 

Fuels Initiative (CAAFI) and commercial aviation industry have 

set a goal of certifying a blended renewable jet fuel between the 

2009 to 2012 timeframe. To reach this ambitious goal, a program is underway to establish the technical feasibility, environmental sustainability, and eventual commercial viability of 

renewable biojet fuels. The basic technical feasibility of synthetic paraffinic kerosene (SPK) jet fuels produced from coal or 

natural gas or of hydrogen-treated renewable jet fuels (HRJ) 

produced from vegetable oils or similar sources having the same 

properties as conventional jet fuels has already been proven 

through several flight demonstrations by the U.S. Air Force, 

commercial airline partners, and four aircraft engine original 

equipment manufacturers (OEMs). The next stage is to develop 

secure scalable, sustainable, and economically viable feedstock

for biojet fuels that satisfy the aircraft industry’s “do no harm” 

constraints and reduce their reliance on petroleum-based fuels.

Our society heavily relies on hydrocarbon-energy-generating 

sources but needs to rely on biomass to reduce CO2, NOX, 

nanoparticulate, and emissions to minimize health and climate 

hazards. The challenge is to make our fuel resources secure, 

sustainable, economically viable, and sufficiently available. We 

must use Earth’s most abundant natural resources, which are 

biomass, solar energy, arid land (43 percent), seawater 

(97 percent) with nutrients (80 percent), plus brackish waters 

and recovered nutrients to resolve the environmental triangle of 

conflicts between energy, food, and freshwater; also, we must 

mitigate ultrafine particulate hazards. Accomplishing this 

resolution requires a paradigm shift. We must develop and use 

solar power for energy (in the form of virtually any renewable 

fossil fuel replacement resource: photovoltaic (PV), thermal, 

wind, and drilled geothermal); biomass for aviation; and hybridelectric-compressed air mobility fueling with transition to 

hydrogen and electric or extended range hybrid-electric in the 

long term (Refs. 2, 5, 6, and 7).
NASA/TP—2011-217208 3

1.2 Alternative and Renewable Energy 

Sources

Presently, most of the world’s energy supply comes from 

fossil and nuclear sources. Despite the increasing resource 

limitation and environmental pollution, these sources continue 

to be important for providing energy for the next few 

generations. Global demand for increased energy and for 

decreased environmental pollution have prompted the need for 

alternative or clean energy sources, which do not depend on 

fossil fuels, and have a tolerable environmental impact. 

Alternative or renewable energy sources such as solar PV, wind, 

wave, tidal, geothermal, and hydroelectric energies seem to 

meet the requirement for clean energy. Figure 1 shows a sample 

of some renewable energy sources. Although the energy 

potentially generated by these sources exceeds that generated by 

fossil fuels, they have not yet become a major part of the 

electrical power system grid. Figure 2 shows the alternative 

energy sources contributing 7 percent of the world’s total 

electricity generation. The projection is to double this 

contribution within the next decade. What follows is our 

solution and recommendations for integrating alternative fuels 

and alternative energy concepts into a self-sustainable 

renewable energy ecosystem that can be replicated anywhere. 

Our approach presents a truly green solution, meaning that it is 

alternative, renewable, and most importantly, sustainable.

2.0 Indoor Biofuels Laboratory

We needed to develop a way to conduct high-throughput 

screening of potential algae and plants that can be used for 

alternative fuels. This is achieved by having a controlled 

indoor laboratory that will enable efficient germination of 

potential plant and algae crops. Our indoor biofuels laboratory 

is set up to facilitate the climatic adaptation of seeds that can 

potentially meet our goals of not relying on freshwater, not 

using arable land, and not competing with food crops. 

There are six 40-gal plant control tanks labeled IBF1 to 

IBF6 ranging in true specific gravity from 1.000 (freshwater) 

to 1.025 (natural seawater) in increments of 0.005 (see 

Figure 3). Climatic adaptation is the specific ability to 

salinitize a plant and algae species as well as desalinitize algae 

and plants species for use in varying soil and salinity 

conditions (see Table I). We also have two 40-gal (151-L) 

control tanks consisting of a marine ecosystem (1.025 true 

specific gravity) that also doubles as a mangrove nursery

Figure 1.—Sample of renewable energy sources (Refs. 8 to 13).

Figure 2.—Contribution of renewable energy sources to generation of electricity. Sum of components may not equal 100 percent due to independent rounding (Ref. 14).
NASA/TP—2011-217208 4

Figure 3.—Left side of indoor biofuels laboratory.

(see Figure 4). In addition, we have two 100-gal (379-liter) 

marine ecosystems that are utilized for microalgae and macroalgae experiments. One of these ecosystems is connected to 

a CO2 injection system, and the other is maintained as a 

control ecosystem. It should be noted that all of our control 

tanks are made of glass material to maximize light penetration 

and provide for easy maintenance. This laboratory is a 

climate-controlled laboratory with an average temperature of 

72 °F (22.2 °C) and relative humidity of less than 50 percent. 

These ranges are necessary for us to operate because 

this laboratory is connected to other laboratories, and our 

laboratory controls the entire floor.

2.1 Conditions of a Successful Ecosystem 

To have a successful ecosystem, four conditions must be 

satisfied: (1) sufficient water supply, (2) adequate soil, (3) 

optimum lighting, and (4) nutrition source. In addition to these 

four conditions, life cycle analysis must be taken into account 

for large-scale implementation of the expansion of the indoor 

biofuels laboratory.

2.1.1 Water Supply

The initial water supply was achieved by utilizing reverse 

osmosis combined with deionization (RO/DI) water to provide 

for an ultrapure water source. RO/DI water was placed in all 

tanks and the salinity of each tank was achieved by utilizing a 

high-quality sea salt mixture. Synthetic sea salt was used 

instead of natural seawater to provide ideal laboratory conditions as well as to minimize undesirable organisms that are 

present in natural seawater that may negatively affect the 

ecosystems of our algae and plant life.

2.1.2 Soil

The soil used in the indoor biofuels lab was prewashed 

ocean floor reef sand. It was used because it contained no 

artificial fertilizers or additives and is adaptable to varying 

salinity levels that are present in the laboratory. The diameter

grain size of our sand ranged from 0.049 to 0.077 in. (1.25 to 

Figure 4.—Right side of indoor biofuels laboratory.

1.95 mm) to facilitate seed growth, pH stabilization, and water 

penetration. We initially mixed a sand additive to our ocean 

reef sand composed of an 80 percent oceanic mud-sand mix 

combined with a 20 percent formulation of minerals and trace 

elements to provide initial nutrients for the plants species. The 

depth of the sand in the indoor biofuels lab was 4 in. 

(102 mm).

2.1.3 Lighting

The most challenging part of our ecosystem was lighting.

Based on what is currently used in the plant industry, we 

chose to use metal halide lights for their high light output and

efficiency over fluorescent lights. The first major challenge 

when using these bulbs was choosing the light wattage and 

spectrum. We settled on using 400-W bulbs because of the 

size and application of our laboratory. The 250-W bulbs 

proved not intense enough, and 100-W bulbs were much too

bright and generated a considerable amount of heat. To 

determine the optimal light spectrum, we initially tried 

20,000-K bulbs, but they turned out to be too blue and did not 

maximize the growth of our seedlings. We next tried 10,000-K

bulbs but they turned out to be too white in color. We then 

settled on 6500-K bulbs because they are the most closely 

aligned with the spectrum of the Sun, which is approximately 

5500 K. The higher kelvin bulbs were chosen for the intense 

light, but this did not translate into increased growth rate. We 

have had great success with using 6500-K bulbs and recommend that they be utilized when growing plants and algae in a 

controlled indoor biofuels lab. They are considered a yellow 

bulb (between red-orange and green-blue spectra), but have 

worked out well for our applications.

The next task was to determine the optimal photo period.

We experimented with photo periods ranging from 2 to 8 hr 

per day and settled on a 6-hr photo period. A 6-hr photo period 

based on a 3-month testing period was chosen because it 

maximized the growth of our seedlings in the laboratory.

Another issue with lighting was the height of the lights above 

the tanks. We conducted experiments with the distance and 

settled on a distance of 18 in. (457 mm) above the tanks. At 

this height, we did not experience sunburn on the plants or 
NASA/TP—2011-217208 5

seedlings. Again, there was a trial-and-error period to determine the height distance above the tanks. We also had to 

determine the number of lights to use. We initially settled on 

three because that is what would fit over our plant systems, 

but this proved to be too much light and caused undesirable 

algae to grow in our tank systems. We then settled on using 

two bulbs with an interesting application. We used light 

movers. We attached our lights to a light mover system and 

had the lights move back and forth traversing the tanks while 

they were on. Doing this allows us to have consistent, full 

coverage over all of our tanks while maximizing light exposure as well as simulating direct and indirect sunlight that 

plants are exposed to on a daily basis.

2.1.4 Nutrition

Providing adequate nutrition for our plants and algae is paramount to long-term growth and stability and is the main reason 

to find a fertilizer source that would be sustainable and safe for

the environment. We decided that we would not use any artificial fertilizers in our systems, and based on our plant research, 

nitrogen and phosphorus are the two most important nutrients 

needed to optimize plant growth. The artificial addition of 

nitrogen and phosphorus could lead to the degradation of our 

ecosystems by way of unintended algae blooms such as cyanobacteria. We settled on using fish waste as our natural fertilizer 

in our ecosystems. Where would we get the fish was the next 

question. Using our experience in climatic adaptation, we 

acclimatized freshwater mollies (Mollienesia species) to thrive 

in each of our ecosystems. This process enables us to have 

several breeding pairs of mollies in each one of our plant tanks.

Mollies are prolific breeders and efficient waste producers.

They are also one of the few species of fish that can be subjected to climatic adaptation without any ill effects. We started 

each tank with 10 mollies, and prolific breeding populations 

were established within 1 month and are still intact. It should be 

noted that mollies are excellent algae eaters and have thrived on 

eating diatoms and filamentous algae that grows on the sides of 

the glass ecosystems in our laboratory.

Figure 5.—Microalgae and macroalgae experiments.

Once we optimized the four conditions for a healthy ecosystem, we began to conduct experiments using halophytes, weeds, 

and algae. To date, we have investigated over 19 different plant 

and algae species in the indoor biofuels laboratory with the goal 

of being able to transfer the most viable plant and algae species 

to our GreenLab Research Facility. Figure 5 to Figure 9 some of 

the plant and algae species we have studied. Table I is a list of 

the species that we have tried to grow in our lab along with 

general comments on our findings. 

Figure 6.—Salicornia virginica species.

Figure 7.—Salicornia europaea species.

Figure 8.—Kosteletzkya virginica species.
NASA/TP—2011-217208 6

Figure 9.—Salicornia bigelovii and Salicornia virginica seedlings.

TABLE I.—PLANT SPECIES INVESTIGATED IN THE INDOOR BIOFUELS LABORATORY

Plant name

(Common name)

Comments

Salicornia virginica

(Pickleweed)

This plant species is the best overall plant that had a consistent lipid yield over all salinity levels. The germination was 7 to 25 days.

Salicornia europaea

(Common glasswort)

This plant was by far the largest plant and had adequate lipid content. The germination was 3 to 15 days.

Salicornia bigelovii

(Dwarf glasswort)

This plant was the shortest plant but had the highest lipid yield. The germination was 7 to 15 days.

Salicornia subterminalis

(Parish's pickleweed)

This plant is currently being investigated. Our primary analysis is that this plant is similar to Salicornia virginica. The germination was 15 to 25 days.

Kosteletzkya virginica

(Seashore mallow)

The freshwater weed is a good candidate for climatic adaptation. The germination was 5 to 10 days.

Rhizophora mangle

(Red mangrove)

Used primarily for CO2 abatement and water filtration.

Avicennia germinans

(Black mangrove)

Used primarily for CO2 abatement and water filtration.

Lena camelina The freshwater plant is the fastest plant to grow and seed in our lab. It also had the highest lipid yield. The 

germination was 2 to 5 days. 

Moringa oleifera This plant is very difficult to grow but we have had limited success in our freshwater system. The germination is 

15 to 30 days.

Pueraria lobata

Kudzu sp.

This plant was actually a surprise since it died off quickly when we exposed it to climatic adaptation in the lab. 

It does not like salt, which may be helpful eradicating this plant in the United States.

Sesuvium portulacastrum

(sea pursaline)

This is a co-plant that grows along Salicornia and while it thrived in all salinity levels, its lipid content was quite 

low.

Suaeda maritima

(Sea blite)

This is a co-plant that grows along with Salicornia but has a low lipid yield.

Chaetomorpha sp. This is an excellent macroalgae species that is used as a filter for our tanks but absorbing excess nutrients and 

CO2.

Sea grass This is a co-plant that grows alongside Salicornia in the wild and has the potential to be used for usable biofuels 

via pyrolysis.

2.2 Monitoring and Maintaining Ecosystem 

Parameters

To establish a stable ecosystem, regular maintenance is 

required. Because we are in a closed indoor facility, it is important to replicate nature as closely as possible, meaning we need 

to have an efficient and effective biological filtration system, 

chemical filtration system, and mechanical filtration system to 

ensure long-term stability. Optimal biological filtration is 

achieved by using the reef sand as a biological filter. Because 

the sand is partially submerged in water, beneficial bacteria will 

establish in the sand bed over time and this will result in optimal 

biological filtration since there will be an efficient conversion of 

ammonia, which is the result of fish waste and other decomposing organic matter into nitrates, which are used as a beneficial 

fertilizer for plants and algae. No additional biological filtration 

methods are used in the indoor biofuels laboratory besides sand,

and our systems have been up and running since mid-2008.

Mechanical filtration is achieved by way of utilizing a power 

filter that has a sponge filter attached to it that efficiently 

removes particulate matter from the ecosystem. Water is pulled 

through the filter by a siphon tube and into a chamber that has a 
NASA/TP—2011-217208 7

sponge filter inside, trapping the particles and the water is 

returned to the ecosystem by way of a waterfall, which enriches 

the ecosystem with oxygen by way of surface agitation. Rinsing 

the sponge filter frequently should be a part of normal maintenance. Chemical filtration is achieved by the use of activated 

carbon, which eliminates dissolved wastes that accumulate in 

any ecosystem. Healthy plants can also extract dissolved 

chemical wastes from water through their roots, which is one of 

the reasons we chose to use mangrove plants. Replacing the 

activated carbon at regular intervals will be required to maintain 

sufficient chemical filtration. Lastly, we use submerged power 

heads to ensure adequate circulation inside of our ecosystems.

The placement of the power heads is not critical because water 

movement is the ultimate goal, which increases oxygen levels in 

a closed ecosystem. Nature’s equivalent would be the tides 

coming in and out during the day along the coastline. However,

hypoxic zones can occur in tank corners and bottom edges. This 

is why it is very important to monitor ecosystem parameters

(see next section) in multiple locations in each ecosystem. We 

use a spray bottle to mist the indoor plants once a day to minimize salt buildup that can occur due to the lack of rain. This is 

crucial to a closed saltwater ecosystem because without rain, 

salt would build up on the leaves of the plants, causing stress 

and potentially leading to the plants demise.

Several parameters can be monitored in any ecosystem, and 

we chose the following parameters based on the plant species 

and fish that we have in our ecosystem: pH, temperature, total 

dissolved solids, salinity, dissolved oxygen, phosphate, and 

nitrates. These are the parameters that were ideal to our 

ecosystem, and there were commercially available electronic 

devices capable of accurately reading these measurements.

Table II lists our current readings for each of the parameters 

that we monitor. These parameters have been consistent over 

the life of the lab and have been maintained to create a stable 

ecosystem for our indoor biofuels laboratory. IBF1 through 

IBF6 are our plant tanks that are labeled by true specific

gravity values (salinity). IBF7 and IBF8 are our control tanks 

that have mangroves, fish, shrimps, crabs, worms, and snails.

IBF9 and IBF10 are our Chaetomorpha macroalgae tanks with 

IBF9 being the control Chaetomorpha tank and IBF10 being 

the tank that is attached to a CO2 injection system by way of a 

calcium reactor.

All the plants and algae species that survived for more than 

6 months in the indoor biofuels laboratory were analyzed for 

optimal lipid content. The most promising plants and algae 

species from the indoor biofuels laboratory were transferred to 

the GreenLab Research Facility. It is our hope that others who 

are interested in establishing a seedling lab concentrating on 

halophytes will find our information useful. What follows is

an explanation of the GreenLab Research Facility and the 

lessons learned and implemented as a result of the success and 

failures of our indoor biofuels laboratory.

3.0 GreenLab Research Facility

Biofuel use has been gaining popularity over the past few 

years due to their ability to reduce the dependence on fossil 

fuels. They can be a viable option for sustaining long-term 

energy needs if they are managed efficiently. The GreenLab at 

Glenn, shown in Figure 10, is a unique research facility for 

investigating the possible future biofuel alternatives that are 

currently being researched and applied around the world. The 

main research objective is to facilitate the development of

biofuels for aviation. Our program goals are to develop viable 

alternative choices for aviation biofuels feedstock, enable 

“seed-to-fuel” analysis, optimization, and perform performance testing of biofuels. The current research focus is on 

third-generation biofuel candidates: macroalgae and microalgae, and selected halophyte species. A unique bench scale 

laboratory was developed for aviation biofuels research. The 

key experimental techniques are coastline equivalent halophyte beds, open pond algae systems, and photobioreactors.

Figure 11 illustrates a NASA approach to producing aviation 

biofuels using microalgae as an energy source.

TABLE II.—ECOSYSTEM PARAMETERS THAT ARE MONITORED

IN THE INDOOR BIOFUELS LABORATORY

Tank (volume) pH Temperature, 

°C

Salinity TDS DO Phosphate Nitrate

IBFa 1 (40 G/151 L) 8.34 21.6 1.002 4.4 6.40 0.04 8.0

IBF 2 (40 G/151 L) 8.27 21.9 1.005 11.1 6.23 0.03 6.3

IBF 3 (40 G/151 L) 8.20 21.8 1.010 20.2 6.15 0.07 2.0

IBF 4 (40 G/151 L) 8.25 21.3 1.015 28.6 5.96 0.20 7.0

IBF 5 (40 G/151 L) 8.14 21.6 1.020 39.3 5.73 0.15 1.6

IBF 6 (40 G/151 L) 8.13 21.8 1.025 49.1 5.10 0.30 1.4

IBF 7 (40 G/151 L) 7.97 21.1 1.023 49.8 5.20 1.35 4.4

IBF 8 (40 G/151 L) 8.05 20.9 1.023 46.2 5.35 1.65 3.1

IBF 9 (300 G/379 L) 6.7 26.6 1.021 42.1 5.75 0.25 8.2

IBF 10 (300 G/379 L) 8.7 26.0 1.021 38.4 5.61 0.25 8.3 a

IBF stands for Indoor Biofuels Laboratory and the number denotes the ecosystem.
NASA/TP—2011-217208 8

Figure 10.—The GreenLab Research Facility at NASA Glenn.

Figure 11.—Efficient NASA-unique approach to aviation biofuels.

The GreenLab enables us to take successful indoor plants 

and algae and subject them to real-world outdoor field trials.

The GreenLab Research Facility allows us to develop efficient 

iterative processes utilizing modeling, experimental verification, and testing research to identify optimal algae and/or 

halophytes biomass candidates for aviation fuels and processes 

and growth parameters to improve feedstock properties and 

minimize complex and carbon positive refining steps to 

achieve greatest life cycle CO2 reduction benefit. Specific 

systems that comprise the GreenLab are described below.

3.1 GreenLab Systems

3.1.1 GreenLab Ecosystems

There are six main 239-gal (905-L) plant control ecosystems 

labeled Tank 1 to Tank 6 ranging in true specific gravity from 

1.000 (freshwater) to 1.025 (natural seawater) in increments of 

0.005 (see Figure 3, GreenLab-3). These ecosystems are much 

larger than the indoor biofuels laboratory and give us the ability 

to conduct multiple experiments in each ecosystem simultaneously. We have a seventh ecosystem (Tank 7), a 370-gal

(1401-L) ecosystem dedicated to plant growth with a deep sand 

bed to investigate root length and to conduct adaptive biology 

experiments by combining different seed mixtures with the goal 

of cross-pollinating plant species. We also have two 300-gal 

(1136-L) mangrove ecosystems (M1 and M2) in the GreenLab 

to maintain air quality, provide water filtration, and to abate any 

excess atmospheric CO2. In addition, we have two 239-gal

(905-L) microalgae ecosystems (L1 and L2) that are used to 

conduct open-pond microalgae experiments. We also have one 

327-gal (1238-L) fish ecosystem (L3) that houses marine fish to 

investigate ideal parameters for a marine ecosystem. We have 

recently added a 561-gallon (2124-L) ecosystem (A1) attached 

to a 100-gal (379-L) ecosystem that is used to investigate 

utilizing fish waste as an optimal fertilizer for growing 

Chaetomorpha macroalgae systems. Lastly, we have a 90-gal 

(341-L) living reef tank that we use as a marine control tank to 

monitor and compare against our other ecosystems. As in the 

indoor biofuels laboratory, all our plant ecosystems are made of 

glass material to maximize light penetration and facilitate

maintenance.
NASA/TP—2011-217208 9

Figure 12.—Six main ecosystems.

3.1.2 Control

Unlike the indoor biofuels laboratory, which is climate controlled via the use of an air conditioning system and humidifier, the GreenLab is designed to be as environmentally friendly 

as possible. If we were to use an air conditioning system, we 

would not be able to find a feasible alternative energy solution. Our solution to the air conditioning issue is to use an 

evaporative cooling system, which is controlled by a low-watt 

recalculating pump in the rear of the GreenLab (see Figure 12). Water is constantly circulating through porous recyclable cardboard pads. However, we did install a heating system 

so the plants and animals will survive through the winter 

months. On average, the GreenLab temperature is 75 °F (24

°C) and has a relative humidity of less than 80 percent. The

GreenLab is set up so that real-world temperatures and humidity levels can be achieved. This provides an environment 

where we can test the adaptability of the plant and animals in 

nonideal conditions. In addition, we have an automatic heating 

system in our GreenLab that is used only in the winter to 

account for colder temperatures.

3.2 Successful Ecosystem Conditions

As stated in the indoor biofuels section, five conditions 

should be met to have successful ecosystem. What follows is 

our implementation of these five conditions for the GreenLab 

Research Facility.

3.2.1 Water Supply

Just as in the indoor biofuels laboratory, the initial water 

supply for the GreenLab was obtained by utilizing RO/DI 

water to provide for an ultra-pure water source. We used the 

same high-quality sea salt mix to achieve the desired salinity 

for each of our ecosystems. Natural seawater poses several 

contamination issues (e.g., parasites, plankton, cyanobacteria, 

etc.) for a closed ecosystem so we relied on synthetic sea salt 

to give us relatively disease and parasite-free water source to 

begin our experiments.

3.2.2 Soil

We utilized two sizes of prewashed aragonite sand for our 

soil in the GreenLab. This was due to the increased depth of 

the sand in our ecosystems. The total depth of our sand bed in 

our plant ecosystems was 6 in. with the first 4 in. composed of 

0.049 to 0.077 in. (1.25 to 1.95 mm) sand grain size and the 

bottom 2 in. of the sand bed composed of 0.049 to 0.077 in. 

(1.25 to 2.0 mm) sand grain size to avoid excessive clumping 

of the smaller sand sizes. We combined the sand with the 

same additive as used in the indoor laboratory, which was 

composed of an 80 percent oceanic mud-sand mix combined 

with a 20 percent formulation of minerals and trace elements 

to provide initial nutrients for the plants species. After the 

sand was established, there was no need for additional additives or nutrients.

3.2.3 Lighting

While the lessons learned concerning lighting was done 

indoors by choosing 400-W and 6500-K lights along with light 

movers, the optimal photo period turned out to be very different than indoors due to direct sunlight and the requirements of 

each type of ecosystem. Since 2009, we have settled on the 

following photo period for our GreenLab ecosystems:

Tanks 1 through 7 (1.000 to 1.025): 8 hr of metal halide 

(MH) lighting per day with the lights on from 3 to 8 p.m.

Tanks M1 and M2: 6 hr of MH lighting per day (4 to 10 p.m.), 

which is sufficient for our mangroves nurseries. Tanks L1 and 

L2, which are algae tanks, received the most MH lighting and 

the photoperiod ranged from 12 to 16 hr per day depending on 

the algae species. Tank A1, which is our wastewater treatment 

experiment using Chaetomorpha, received 12 hr of MH 

lighting per day. Tank L3 and reef receive 8 hr of MH lighting 

per day with the lights coming on at noon and going off at 8

p.m. All photoperiod times were controlled by the use of 

digital timers that simultaneously control the light movers so 

that the light movers turn on when the lights turn on. The 

height of the lights above the ecosystems was 32 in. (813

mm). We have approximately 34 MH lights in our GreenLab

compared to 6 in the indoor biofuels laboratory.

3.2.4 Nutrition

The GreenLab poses different challenges than the indoor 

biofuels lab because of the many different ecosystems. The 

indoor biofuels laboratory only had two main types of ecosystems: Salicornia seedling ecosystems and macroalgae ecosystems. The GreenLab has seven different types of ecosystems:

Salicornia seedling ecosystems, adaptive biology ecosystems, 

mangrove ecosystems, microalgae ecosystems, wastewater 

treatment ecosystem, fish control ecosystem, and reef control 

ecosystem. Each system poses different challenges. The 

Salicornia plants systems nutritional needs re-met by maximizing the mollies in our system to provide optimal fertilizer 

by way of nitrogen and phosphorus. The mollies feed primarily on filamentous algae that grow on any available 

surface. Occasionally, they are also fed dry flake food to 
NASA/TP—2011-217208 10

minimize predation and to ensure that baby fry get additional 

nutrients. We have approximately 300 mollies in each of our 

Salicornia ecosystems. Our climatic adaptive biology ecosystem has both plants and fish, and the fish are fed dry pellet and 

flake food periodically to maintain a varied diet and reduce 

predation. All plants in the GreenLab get energy from natural 

sunlight and MH lighting as well as from fish waste. The 

mangrove ecosystems, which simulate a coastline environment, get nutrients through natural sunlight, MH lighting, and 

fish waste. The mangrove ecosystem’s primary job is to be a 

CO2 sponge for our GreenLab and provide a model for water 

filtration via its roots. The microalgae ecosystems are primarily grown on atmospheric CO2 with its primary nutrients 

coming from our MH lighting and natural sunlight. Our reef 

ecosystem nutrients also get it primary nutrients from natural 

sunlight and MH lighting and minimum nutrients from dry 

food additions. Our fish control tank is provided with as close 

to natural food as possible in order for us to accurately monitor our GreenLab parameters. This tank is fed a varied diet 

from frozen food to flake food to dried seaweed with the waste 

from this system going to our wastewater treatment experimental tank that has a Chaetomorpha filter attached to it to 

absorb all excess nutrients from this ecosystem. This ecosystem consists of approximately 30 large marine fish that are 

prolific waste producers. This ecosystem is fed the same 

varied diet as our fish control tank. It must be noted that all 

ecosystems are in the same environment and have been 

thriving together since 2009. We did not take very long to 

stabilize our ecosystems in the GreenLab due to our experience in the indoor biofuels laboratory. We did, however, 

investigate fewer species in the GreenLab based on the potential for long-term success. To date, we have investigated 

approximately 13 plants species in the GreenLab, and 

Table III lists the plant species grown in the GreenLab along

with general comments. Figure 13 to Figure 18 show a few of 

the plant and algae species we have studied.

TABLE III.—PLANT SPECIES INVESTIGATED IN THE GREENLAB RESEARCH FACILITY

Plant name

(Common name)

Comments

Salicornia virginica

(Pickleweed)

S. virginica is the most successful plant that we have had to date. It has excellent growth, seeding, and adequate lipid production.

Salicornia europaea

(Common glasswort)

S. europaea was the largest Salicornia plant species we have had, and it is also the fastest to germinate.

Salicornia bigelovii

(Dwarf saltwort)

S. bigelovii was the shortest Salicornia plant species we have had, but it had the highest lipid content.

Kosteletzkya virginica

(Seashore mallow)

We have been able to successfully use our climatic adaptation techniques to get seashore mallow to seed and 

grow in the first four ecosystems, which shows that a freshwater weed can be adapted to saline environments 

and to become a harvestable crop.

Rhizophora mangle

(Red mangrove)

Used primarily for CO2 abatement and water filtration.

Avicennia germinans

(Black mangrove)

Used primarily for CO2 abatement and water filtration.

Laguncularia racemosa 

(White mangrove)

Used primarily for CO2 abatement and water filtration.

Lena camelina This freshwater plant is the fastest plant to grow and seed in the GreenLab. We have been able to successfully 

grow this plant in all of our ecosystems and are investigating its potential for climatic adaptation. 

Moringa oleifera This plant has grown successfully in at least three different salinity values and we are investigating it as both a 

fuel and food crop.

Sesuvium portulacastrum

(Sea purslane)

This is a co-plant that grows along Salicornia and always seems to grow back. We did not find any use for this 

plant in the GreenLab. Investigating cellulosic extraction via pyrolysis.

Suaeda maritima

(Sea blite)

This is a co-plant that grows along Salicornia and always seems to grow back. We did not find any use for this 

plant in the GreenLab. Investigating lipid extraction via pyrolysis.

Chaetomorpha sp. This is an excellent macroalgae species that is used as a filter for our tanks but absorbing excess nutrients and 

CO2. In the GreenLab, it is being used as a wastewater treatment experiment.

Sea grass This is a co-plant that grows alongside Salicornia in the wild and has no usable biofuels value. Investigating 

cellulosic extraction via pyrolysis.
NASA/TP—2011-217208 11

Figure 13.—Salicornia europaea.

Figure 14.—Microalgae tanks showing open-pond and hybrid 

photo-bioreactor system.

Figure 15.—Salicornia bigelovii ready to seed.

Figure 16.—Seashore mallow flower ready for 

pollination.

Figure 17.—Salicornia bigelovii seedlings.

Figure 18.—Microalgae from our open-pond system.
NASA/TP—2011-217208 12

3.2.5 Maintenance

The maintenance required in the GreenLab is significantly 

more than the indoor lab due to the increased number of power 

filters and pumps. Daily maintenance is required for the 

GreenLab to remain in optimal working order. Biological 

filtration occurs by way of a 6-in. (152-mm) partially submerged sand bed that has an established bioload. Mechanical 

filtration is achieved with two large power filters, and chemical 

filtration is achieved by using activated carbon in the plant tanks 

with additional chemical filtration through phosphate absorption 

media in the fish control tank and reef tanks. We mist the plants 

in the GreenLab for 30 sec each day to minimize salt buildup.

This simulates natural misting by dew or light rain, which helps 

the plants eliminate salt residue on its leaves. We also use two 

high-output submerged power heads to ensure adequate circulation inside of our ecosystems, being aware of potential hypoxic 

zones near tank corners and edges. Wave generators are used in 

our microalgae open-pond systems to maximize mixing of the 

algae. The biggest issue with maintenance is the frequency of 

cleaning the power filters and pumps. The power heads need to 

be cleaned at least three times a week while the power filters 

need to be cleaned daily to ensure optimal conditions. This is a 

time-consuming task but required because the failure to do so 

may result in less than ideal conditions for the plants and 

animals.

3.3 Monitoring Ecosystem Parameters

We monitor the same parameters in the GreenLab that we 

do in the indoor biofuels lab: pH, temperature, total dissolved 

solids, salinity, dissolved oxygen, phosphate, and nitrates.

Table IV lists our current parameter readings that we monitor 

in the GreenLab. These parameters have been the most important for our ecosystem health and created a stable environment. Tanks 1 through 7 are our plant tanks that are labeled

by true specific gravity values (salinity) ranging from 1.000 to 

1.025 true specific gravity. M1 and M2 are our mangroves 

ecosystems that have primarily mangroves, fish, snails, and 

crabs. A1 is our wastewater treatment ecosystem, L3 and reef 

are our fish control and reef control tanks. L1 and L2 are our 

microalgae tanks investigating potential freshwater microalgae 

species that can be climatically adapted.

All of the plants and algae species listed in Table I have survived in the GreenLab for more than 2 years, and we have 

analyzed each species for optimal lipid content using chemical 

extraction processes. We have been maintaining our GreenLab 

Research Facility since 2009 and wanted to present our findings 

to assist others in establishing GreenLabs around the world.

3.4 GreenLab Lessons Learned

If one is going to create a GreenLab, it is important to 

understand that it is not a trivial task and there are certain 

unique challenges that should be addressed before a climatic 

adaptive GreenLab is established. The first challenge is the 

actual environmental conditions. The GreenLab is essentially 

a saltwater ecosystem, and the number one problem is corrosion due to the relatively high humidity and salt spray in the 

lab. We have learned that the ideal material to use in the 

GreenLab is stainless steel 316 or higher. Failure to purchase 

equipment or tools not rated at this level will result in rust in a 

matter of days. The general rule in the GreenLab is that 

everything is considered disposable, and just about everything 

has been replaced through trial and error over the past few 

years. Another challenge will be electrical connections. One 

needs to be sure to have ground-fault interrupts on each and 

every receptacle to minimize any potential electrical problems. 

Deep covers were installed on each receptacle to minimize 

moisture penetration and water exposure. Another issue is the 

flooring. We chose to use a gravel bed contained in a PVC 

TABLE IV.—ECOSYSTEM PARAMETERS THAT ARE MONITORED IN THE GREENLAB RESEARCH FACILITY

Tank (volume) pH Temperature, 

°C

Salinity TDS DO Phosphate Nitrate

Tank1 (239 G/905 L) 8.52 22.5 1.002 3.5 7.98 0.07 5.1

Tank 2 (239 G/905 L) 8.43 22.4 1.005 5.6 7.31 0.42 9.4

Tank 3 (239 G/905 L) 8.53 22.5 1.010 12.4 7.13 0.40 3.9

Tank 4 (239 G/905 L) 8.37 22.5 1.015 26.4 7.18 0.33 0.3

Tank 5 (239 G/905 L) 8.09 22.4 1.020 28.9 6.13 0.81 1.7

Tank 6 (239 G/905 L) 8.04 23.2 1.025 34.3 5.29 0.47 3.6

Tank 7 (370 G/1401 L) 8.08 24.7 1.023 42.3 5.01 2.01 30.0

M1 (300 G/1136 L) 7.88 24.2 1.022 44.9 3.83 2.50 17.8

M2 (300 G/1136 L) 7.88 25.0 1.021 39.4 4.38 2.50 15.8

A1 (561 G/2124 L) 8.06 24.6 1.022 45.7 5.04 2.50 15.3

Reef (90 G/341 L) 8.19 25.6 1.019 40.1 5.94 0.34 3.7

L3 (327 G/1238 L) 8.06 24.6 1.022 47.9 4.90 1.62 5.3
NASA/TP—2011-217208 13

cage using a polyurethane mesh because of its ease of maintenance and relatively low cost. Be sure to get prewashed gravel 

because it will reduce dirt in the lab. We did not choose a 

cement floor because it is always wet in the GreenLab, and a 

cement floor would be a major slipping hazard. Air circulation 

is also a big concern and we went through three iterations 

before we found the optimal numbers of fans. We have six 

small fans and four large fans in the GreenLab that circulate the 

air to avoid dead zones. At least two sinks are needed to clean 

the equipment. Additional fluorescent and flood lights may 

have to be installed as well. Lastly, one must plan on replacing 

tools frequently because we have yet to find stainless steel tools 

that can withstand the GreenLab environment.

3.5 Making the GreenLab Energy Efficient

One of the goals of the GreenLab is to have it ultimately be a 

self-sustainable climatic adaptive renewable energy ecosystem, 

which means that we need to make sure that the GreenLab can 

be operated without the use of direct electricity from a power 

company. To that end, we have installed two wind turbines 

capable of up to 2.4 kW of energy each to supplement the 

GreenLab. We plan on adding additional wind turbines in the 

future. We are also connecting solar arrays to the GreenLab, 

which would put up as 100 percent renewable power at least 

6 hr a day. What follows is an explanation of the available 

alternative energy sources and options for the GreenLab to 

reach our goal of having a working biofuels lab that produces 

and uses clean energy.

4.0 Alternative Energy Integration

Renewable or alternative energy sources such as solar PV

and wind are clean technologies that can reduce the major 

environmental impact of present electricity sources. The

electricity obtained from these energy sources is normally 

unregulated and cannot be directly connected to the power 

system grids or to non-grid-connected loads. Therefore, 

regardless of the power ratings of the renewable energy 

generation unit, it has to be converted to a suitable form by 

utilizing power electronic converters and other controllers.

When connected to the grid, the role of power electronic 

converters and controllers is not only to convert electricity to a 

suitable form, but also to ensure that the distributed generation

(DG) unit connected to the grid will not create problems that 

can impair the quality of the power supply and the safety of all 

other equipment connected to the point of common coupling 

(PCC). Examples of these systems are discussed for solar and 

wind energy systems. Figure 19 shows typical power electronic 

converters arrangement for solar systems. The unidirectional 

bidirectional power converters are required to ensure that the 

energy storage devices (ESDs) and loads can be supplied by the 

grid or the PVs.

For wind systems, several possible power electronic topologies are used that can be classified into two groups: direct-inline wind turbines and doubly fed generator wind turbines. An 

example of the first group that uses a squirrel cage induction 

generator is shown in Figure 20. The generator is mechanically 

coupled to the wind turbine via a mechanical gearbox. The 

variable frequency voltage of the generator is rectified and fed 

to the inverter to produce a constant frequency voltage that can 

be connected to the grid. 

There are a few possible sources of energy from which the 

load can obtain the power, either from the alternative energy 

sources, from the ESDs, from the grid, or from the combinations 

of these sources (Figure 21). The choice of source or 

combination of sources used to supply the loads has to be made 

carefully to ensure maximum and efficient energy utilization. 

This depends on several factors, such as the instantaneous 

power available from the sources, energy on the ESD, load

Figure 19.—Power electronic converters for photovoltaic systems.
NASA/TP—2011-217208 14

Figure 20.—Power electronic converters for wind turbine.

Figure 21.—Distributed energy resources (DERs) and interface with the utility grid

(Ref. 8) (photovoltaics (PV)).

characteristics, price of energy from the grid at that instant, and 

the desired power factor. Integrating these factors with a 

decision tree in the power electronic interface modules for 

optimum energy utilization and cost constitutes the energy 

conversion conditioning system (ECCS). During power outage 

on the grid, the energy sources and the ESD supply power to 

the loads and fulfill instantaneous peak power demand. The 

ESD can be charged up either by the grid or energy sources 

depending on the instantaneous power available and the load 

demand. The sizing of the ESD has to be determined, based on 

the anticipated loads, outage times, and energy sources characteristics. The ESD are used to compensate the high transient 

power demanded by the loads that cannot be delivered by the 

energy sources due to their slow response.

In photosynthesis, sunlight and artificial lighting provide 

photon distributed energy resources (DERs). These DERs are 

collected in special cellular constructs termed “antenna” that 

function as microgrid networks (MGNs) connecting DERphotons with chlorophyll cellular energy to ECCS with the 

Calvin cycle where water, nutrients, CO2, and sunlight react to 

produce CH2O (glucose) and O2 products (with some H2O and 

plants salts). These products provide energy for biomass 

foliage and root mass growth with seed, salt, and root mass 

ESDs.

We are investigating expanding this concept to DER sources 

connected through MGNs to collect and store energy provide 

energy and power to the GreenLab as well as establish a DERMGN-ECCS-ESD methodology. Our goal is to achieve a selfsufficient climatic adaptive GreenLab ecosystem that is 

transportable worldwide.

4.1 Role of Energy Storage Devices

DERs respond relatively slowly to a sudden increase in load 

demand. It is reported that for microturbine and fuel cell systems, 

the time constant for the power output can range from 5 ms to 50 

s. If the DER system is not connected to the utility grid and no 

ESDs are installed, because of this slow response, a sudden 

increase in load power demand will result in a voltage reduction 

to achieve energy balance. There are a few types of ESDs that 

are being used and researched in power system applications: 

batteries, flywheels, ultracapacitors (or supercapacitors), superconducting magnetic energy storage systems (SMES), pumpedhydro, and mixed-salts. Battery technologies, particularly the 
NASA/TP—2011-217208 15

lead-acid batteries, are widely used in power system applications 

due to their low cost, high energy density and capability, and 

their established and mature technology. A fuel cell has energy 

storage similar to a battery in that an electrochemical reaction is 

used to create electric current. However, batteries carry a limited 

supply of fuel internally whereas in fuel cells, the reactants are 

gases (hydrogen and oxygen) that are constantly replenished;

therefore, the unit will be limited by supply of gases, but may not

run down like a battery. Fuel cells are suited for distributed 

storage (DS) due to their low emission and high efficiency. 

Power rating of a fuel cells system can be from 100 kW to a few 

MW. Heat produced from the electrochemical reaction for 

electricity production can be used for combined heat and power 

(CHP) application. The direct current (dc) voltage generated 

from the fuel cells may be too low for an inverter to operate 

efficiently; therefore, a dc-dc converter is normally used to step 

up the voltage to a higher level. Other ESDs such flywheel 

technologies are gaining popularity and have been applied in 

wind turbine technologies. Mixed salts are considered in solarthermal systems. Pumped-hydro is reliable and more commonplace in electric power systems. At present, ultracapacitors or 

supercapacitors are mainly used for low-energy, high-peakpower applications. They have been used in drive systems to 

improve ride-through capability during voltage sags; their 

applications in DER have yet to be found. SMES are known for 

their fast response and high efficiency; however, compared to 

other energy storage systems they are presently expensive and 

require cryogenic support systems. In power system applications, 

SMES have been used for voltage sag compensation and to 

improve stability performance 

4.2 Interconnections of DERs

DERs are small-scale power generation technologies, typically 

in the range of a few kilowatts to tens of kilowatts, used to 

provide an alternative to or an enhancement of the traditional 

electric power system. A microgrid is a small power distribution 

system that includes a variety of these sources in combination 

with ESD and loads. When included with DG and DS, a microgrid is also referred to as a DER. Recently there has been considerable research and development on implementation of DERs, 

their interconnections, and the security requirements of future 

electric power systems, in which DERs are likely to be an 

essential component. DERs generate electricity from many small 

energy sources such as solar and wind sources. The electricity 

obtained from the energy sources is normally unregulated and is 

not in a suitable form to be directly connected to loads, as 

common commercial products, or to the grid. Therefore, regardless of the power ratings of a DG unit, the electricity has to be 

converted to a suitable form by utilizing power electronics 

converters (part of the ECCS). Figure 22 shows different interconnections of DERs operating in grid-connected mode with the 

loads connected directly or in parallel with the grid. The interconnections can be with power only drawn from the grid or with 

power drawn and supplied back to the grid. The interconnection 

is a concern to the utility provider, especially with regard to the 

power quality and safety of personnel or connected equipment.

The grid-connected mode may or may not include ESD, with 

several factors that determine this choice. If the grid is intended 

as a backup supply to the load, ESD may not be required. Power 

is obtained from the grid when power from the energy sources is 

unavailable. With no ESD, power required for a sudden load 

change or during peak power demand is obtained from the 

grid and the alternative energy sources. However, power outage 

on the grid will result in the power supplied to the load 

being totally dependent on the energy sources. Thus, because 

of the slow response of the energy sources to react to an 

instantaneous sudden load demand, the power quality supplied to 

the load will be impaired. In the worst case, when the energy 

sources are not generating power, a power outage on the grid

Figure 22.—Example of interconnection of distributed energy resources with the utility (Ref. 12).
NASA/TP—2011-217208 16

will result in no power available at the load. If the energy 

sources are sized to supply the load only during average 

power usage, then during power outage on the grid, peak 

power demand cannot be fulfilled. Excess energy generated 

by the energy sources can be fed back only to the grid.

5.0 Green Laboratory Power Systems

The current power consumption of the GreenLab is about 

20 kW per day. This is used by the many pumps, lights, fans,

and filters as shown in Table V. Initiated in the summer of 

2011, an ongoing task will develop a structure and 

implement a power system architecture that will feed the 

electricity needs of the GreenLab from the commercially 

available resources of renewable energy. Emphasis is put 

into energy from windmills, PV, and backup power devices.

Figure 23 shows the proposed grid-connected DER system 

architecture to supply energy from windmills and PV with 

battery backup systems. The dc loads are connected to the dc 

link via a dc-dc converter (diversion unit).

Figure 23.—Tentative green laboratory power system architecture.

TABLE V.—GREEN LABORATORY POWER REQUIREMENTS

Item No. Rating,

W

Total 

power

Tunze 6205 pumps 19 55 1045

Tunze 6305 pumps 6 64 384

Tunze 6105 pumps 2 45 90

Aquaclear 500 filter 16 14 224

Dual-voltage Homer Head pump 2 246 492

Reeflo Snapper (universal motor) 4 104 416

Wave Generator Tunze 6261 pumps 6 50 300

Blue Line Aqua pump 1 390 390

Tunze Protein Skimmers pump 2 22 44

Delta Star Chiller 4 1104 4416

Ad Smith fans 2 373 746

MAG24 pump 1 237 237

Motors for moving the lights 7 6 42

Galaxy Lights 26 400 10400

Evaporative cooling 1 93 93

Total 99 19320
NASA/TP—2011-217208 17

Figure 24.—Demonstration of commercially available wind 

energy. (a) NASA Johnson Childcare Center. (b) NASA 

Glenn GreenLab Research Facility.

Renewable energy systems are commercially available for 

both residential and industrial applications. Advances in 

power electronics and energy storage devices are helping to 

reduce weight and size and to increase reliability. Commercial 

wind power development, in which large wind turbines are 

connected to the electric grid and produce electricity for 

widespread distribution, is a relatively recent phenomenon. 

During the early 1980s, hundreds of commercial wind turbines 

were installed in three areas in California. There are several 

single-phase wind and solar energy systems with all of the 

required power electronics and battery backup energy system.

Some systems are fully integrated, utility-connected wind 

generators designed specifically for homes and small businesses. Several single-phase wind power systems have been 

installed worldwide at different power levels. Figure 24 shows 

two examples of these systems. Figure 24(a) shows both solar 

and wind applications in powering a childcare center at NASA 

Johnson Space Center, and in Figure 24(b) a windmill is used 

to supply power to the GreenLab Research Facility at NASA 

Glenn. Currently there are two windmill systems that are 

partially supplying wind energy to the GreenLab facility.

6.0 Conclusions

In this report we have provided a description of the 

GreenLab Research Facility at NASA Glenn Research Center 

that is composed of two complementary components: the 

indoor or incubator facility and the outdoor growth facility. 

Each possesses a variety of climatic adaptive ecosystems, 

power and energy sources, and requirements. The goal is to 

enable worldwide expansion and adoption of the research and 

development facility to enable the commercialization of 

biomass production for energy, fuel, food, feed, and freshwater recovery.

Our primary motivation flows from the large gap between 

the production and demand for energy from alternative fuel 

and alternative renewable energy sources. The basic issues 

center on sustainability of humanity, as we know it, which 

depends directly on the ability to secure affordable energy, 

food, feed, and fuel with conservation of arable land and

freshwater. These issues are addressed directly in the 

GreenLab Research Facility where focus is directed to optimize biomass feedstock utilizing primarily, but not exclusively, 

algae and halophytes as the next generation of renewable 

aviation fuels.

The unique approach is directed to the achievement of 

optimal biomass feedstock through climatic adaptation of 

balanced ecosystems that do not use freshwater, do not compete with food crops, or use arable land. The incubator laboratory screens both seeds, seedlings, waste treatment, 

ecosystems with a variety of controlled saline, lighting, and 

nutrient conditions preliminary to transitioning to the outdoor 

laboratory. Successful biomass treatments are then transported 

and implemented on a larger scale more realistic of actual soil 

and water conditions in six parts of the world in the outdoor 

facility. The climatic adaptive approach enables saline-tolerant 

plants to prosper in freshwater environments as well as adapting freshwater species to prosper in saline environments. The 

adaptation is extended to fish, which in turn supply rapid 

growth, reproduction, and nutrients. Aquatic life, primarily 

fish, becomes the health-monitoring system for the GreenLab. 

Reclamation of contaminated waters becomes a necessity, and 

those algae from the incubator laboratory are both tested for 

reclamation and sources of fueling biomass. 

To date, plants, fish, and soil have been adapted to salinity 

conditions from freshwater (specific gravity = 1) to seawater 

(specific gravity = 1.025) in increments of 0.005. Thirteen 

seedlings and plant varieties have been tested and studied in 

the indoor or incubator laboratory and several varieties of 

algal species along with 13 plant varieties in the outdoor 

facility. Biomass plants adapted include Salicornia, seashore 

mallow, and mangroves to some degree, with native algae 

species as the most sustainable algal form. 

To offset the GreenLab Research Facility power consumption, alternative and renewable energy from wind and photovoltaic (proposed microgrid) technologies reduce the major 

environmental impact of commercial electricity. The ultimate 
NASA/TP—2011-217208 18

goal is to have a 100 percent clean energy laboratory 

dedicated to biomass research within the framework of a selfsustainable ecosystem that can be duplicated anywhere in the 

world and can potentially be used to mitigate the shortage of 

food, fuel, and water.

Biomass derived biofuels represent viable alternative fuel 

resources for the field of aviation with byproducts for feed or 

direct use as food and residuals as energy sources. Utilizing 

wind and solar technology as alternative renewable energy 

resources supplements the GreenLab energy and power 

demands.

We hope to join with other entities that are interested in 

Green solutions for long-term human needs and invite others 

to copy our concept and share their solutions with the world. 

A very simple recommendation is that we need to put forth an 

effort to solve the world’s fuel, food, and water crises and the 

development of the GreenLab Research Facility can begin the 

debate on how to successfully implement solutions.

Glenn Research Center

National Aeronautics and Space Administration

Cleveland, Ohio, December 23, 2011

References

1. Reilley, John; Paltsev, Sergey; and Choumert, Frederic: Heavier 

Crude, Changing Demand for Petroleum Fuels, Regional Climate 

Policy, and the Location of Upgrading Capacity. MIT Joint Program on the Science and Policy of Global Change, Report No. 

144, 2007. http://web.mit.edu/globalchange/www/MITJPSPGC_ 

Rpt144.pdf Accessed September 8, 2011.

2. Daggett, D.L.; Ben-Amotz, A.; and Benemann, J.: Feasibility of 

Algal Oil for Renewable Jet Fuel. Submitted to J. Appl. Phycol., 

2011.

3. NASA Aeronautics Research Mission Directorate: N+2 Advanced 

Vehicle Concepts NRA Draft Solicitation Synopsis. 2010. 

http://www.aeronautics.nasa.gov/calendar/era_preconference_syn

opsis.htm. Accessed September 8, 2011.

4. U.S. Energy Information Administration: World Energy Demand 

and Economic Outlook. International Energy Outlook 2009, 

DOE/EIA–0484(2009), 2009. http://www.eia.gov/oiaf/ieo/pdf/ 

0484(2009).pdf Accessed September 8, 2011.

5. U.S. Energy Information Administration: World Energy Demand 

and Economic Outlook. International Energy Outlook 2010, 

DOE/EIA–0484(2010), 2010. http://www.eia.doe.gov/oiaf/ieo/ 

world.html Accessed September 8, 2011.

6. Daggett, D.L.; Ben-Amotz, A.; and Benemann, J.: Feasibility of 

Algal Oil for Renewable Jet Fuel. Submitted to J. Appl. Phycol., 

2011.

7. Daggett, D., et al.: Alternative Fuels and Their Potential Impact on 

Aviation. NASA/TM—2006-214365 (ICAS 2006–5.8.2), 2006.

8. California Distributed Energy Resource Guide: The California 

Energy Commission. 2011. http://www.energy.ca.gov/distgen/ 

equipment/energy_storage/energy_storage.html Accessed September 9, 2011 

9. http://www.windenergy.com/

10. http://www.xantrex.com/

11. OutBack Power Radian Series. 2011. 

http://www.outbackpower.com/ Accessed September 9, 2011.

12. Argonne National Laboratory: Electrochemical Energy Storage. 

Argonne National Laboratory, 2011. http://www.cmt.anl.gov/ Electrochemical_Energy_Storage/default.shtml Accessed September 9, 

2011. 

13. http://www.power-thru.com/

14. EIA. Renewable Energy Consumption and Electricity Preliminary 

2007 Statistics. Table 1: U.S. Energy Consumption by Energy 

Source, 2003–2007 (May 2008).

Bibliography

Daggett, D.L., et al.: Alternate Fuels for Use in Commercial Aircraft. 

NASA/TM—2008-214833 (ISABE–2007–1196), 2008.

Elbuluk, M.; and Idris, N.R.N.: The Role Power Electronics in Future 

Energy Systems and Green Industrialization. IEEE 2nd International Power and Energy Conference, 2008, pp. 1– 6.

Evans, A.L.; Reid, R.L.; and Hendricks, R.C.: A Feasibility Study of a 

Combined Wind-Solar System for Space and Domestic Hot Water 

Heating. Proceedings of the International Solar Energy Society Annual Meeting, Sections 14–25, 1977, pp. 19–41 to 19–45. Accessed 

September 8, 2011.

Hendricks, R.C.: Sustainable Secure Alternate Aviation Fueling. 2007 

NASA Seal/Secondary Air System Workshop, NASA/CP—2008-

215263/VOL1, 2008, pp. 75–99.

Hendricks, R.C.; Bushnell, D.M.; and Shouse, D.T.: Aviation Fueling: 

A Cleaner, Greener Approach. Thirteenth International Symposium 

on Transport Phenomena and Dynamics of Rotating Machinery, 

ISROMAC–13, 2010.

http://www.cmt.anl.gov/Electrochemical_Energy_Storage/default.shtml

http://www.energy.ca.gov/distgen/equipment/energy_storage/energy_st

orage.html

http://www.nrel.gov

McDowell, M., et al.: Biofuels as an Alternative Energy Source for 

Aviation—A Survey. NASA/TM—2009-215587, 2009.

National Renewable Energy Laboratory. 2011. http://www.nrel.gov

Accessed September 9, 2011.

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NASA’s GreenLab Research Facility: A Guide for a Self-Sustainable Renewable Energy 

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14. ABSTRACT

There is a large gap between the production and demand for energy from alternative fuel and alternative renewable energy sources. The 

sustainability of humanity, as we know it, directly depends on the ability to secure affordable fuel, food, and freshwater. NASA Glenn 

Research Center (Glenn) has initiated a laboratory pilot study on using biofuels as viable alternative fuel resources for the field of aviation, 

as well as utilizing wind and solar technology as alternative renewable energy resources. The GreenLab Research Facility focuses on 

optimizing biomass feedstock using algae and halophytes as the next generation of renewable aviation fuels. The unique approach in this 

facility helps achieve optimal biomass feedstock through climatic adaptation of balanced ecosystems that do not use freshwater, compete 

with food crops, or use arable land. In addition, the GreenLab Research Facility is powered, in part, by alternative and renewable energy 

sources, reducing the major environmental impact of present electricity sources. The ultimate goal is to have a 100 percent clean energy 

laboratory that, when combined with biomass feedstock research, has the framework in place for a self-sustainable renewable energy 

ecosystem that can be duplicated anywhere in the world and can potentially be used to mitigate the shortage of food, fuel, and water. This 

paper describes the GreenLab Research Facility at Glenn and its power and energy sources, and provides recommendations for worldwide 

expansion and adoption of the facility’s concept. 

15. SUBJECT TERMS

Biomass; Green aviation; Fueling; Energy; Conservation; Climatic adaption 

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