Twenty-eight years ago, the first oil embargo was a

rude awakening to our vulnerability to energy

supply disruptions. But that oil embargo

spurred Congress to create the Solar Energy

Research Institute—designated a national laboratory and renamed the National Renewable

Energy Laboratory in 1991—to help develop the

technology to make it possible to achieve a transition to a new energy future. 

What has happened since SERI/NREL

first began operating 25 years ago?

America uses nearly 50% more renewable energy than it

did then. We are witnessing the emergence of markets

based on new energy technologies. America is employing

energy efficiency on a grander scale, decreasing its energy intensity (energy used per dollar of gross domestic

product) by about 1% per year. 

Yet, today America is more dependent on foreign oil than

ever. We use more natural gas and 75% more coal than

we did in 1977. Driven largely by economic growth, our

energy consumption has jumped by about 23 quads

(where one quad equals 1015 Btus), with less than 3

quads of that increase coming from renewable energy.

This has resulted in large increases in greenhouse gas

emissions and in air pollutants. 

In light of these facts, is it still possible to achieve sustainable energy use? Yes—in the long run. We must remember that it took 50 years from the building of the first

oil refinery until oil provided 10% of America’s energy

mix, and 60 years for natural gas to do likewise. 

In the short term, with a portfolio of new energy technologies and an enlightened public policy, we will produce incremental changes. But these changes will,

working with the existing energy infrastructure, begin to

build exponentially to become significant in two, three,

or four decades. And in the long term, what started as

small changes will grow to become a paradigm shift in

how America uses energy. 

At the heart of this shift will be technology. And at the

heart of the technology will be NREL. For the past 25

years, NREL has helped build a foundation of renewable

energy and energy efficiency science and technology to

put sustainable energy use within reach. For the next 25

years and more, NREL will remain at the technology forefront to spur various transitions toward sustainable energy. This silver anniversary first biennial 2002 Research

Review lays out a series of key transitions that will allow

us to move toward a sustainable world and indicates ways in which NREL and its partners are

making that possible.

Wind and solar electricity markets, for example,

are growing at rates greater than 30% per year.

With help from advances such as NREL’s advanced airfoil designs, wind power is already

nearly competitive with some fossil-fuel main

i 

The 2002 Research Review

This Silver Anniversary 2002 Research Review is intended

as the first in a series of biennial overview reports on research progress at NREL. These reports will become part of

a series of semiannual journals, with the regular journal issues exploring particular NREL research efforts in depth.
Twenty-eight years ago, the first oil embargo was a

rude awakening to our vulnerability to energy

supply disruptions. But that oil embargo

spurred Congress to create the Solar Energy

Research Institute—designated a national laboratory and renamed the National Renewable

Energy Laboratory in 1991—to help develop the

technology to make it possible to achieve a transition to a new energy future. 

What has happened since SERI/NREL

first began operating 25 years ago?

America uses nearly 50% more renewable energy than it

did then. We are witnessing the emergence of markets

based on new energy technologies. America is employing

energy efficiency on a grander scale, decreasing its energy intensity (energy used per dollar of gross domestic

product) by about 1% per year. 

Yet, today America is more dependent on foreign oil than

ever. We use more natural gas and 75% more coal than

we did in 1977. Driven largely by economic growth, our

energy consumption has jumped by about 23 quads

(where one quad equals 1015 Btus), with less than 3

quads of that increase coming from renewable energy.

This has resulted in large increases in greenhouse gas

emissions and in air pollutants. 

In light of these facts, is it still possible to achieve sustainable energy use? Yes—in the long run. We must remember that it took 50 years from the building of the first

oil refinery until oil provided 10% of America’s energy

mix, and 60 years for natural gas to do likewise. 

In the short term, with a portfolio of new energy technologies and an enlightened public policy, we will produce incremental changes. But these changes will,

working with the existing energy infrastructure, begin to

build exponentially to become significant in two, three,

or four decades. And in the long term, what started as

small changes will grow to become a paradigm shift in

how America uses energy. 

At the heart of this shift will be technology. And at the

heart of the technology will be NREL. For the past 25

years, NREL has helped build a foundation of renewable

energy and energy efficiency science and technology to

put sustainable energy use within reach. For the next 25

years and more, NREL will remain at the technology forefront to spur various transitions toward sustainable energy. This silver anniversary first biennial 2002 Research

Review lays out a series of key transitions that will allow

us to move toward a sustainable world and indicates ways in which NREL and its partners are

making that possible.

Wind and solar electricity markets, for example,

are growing at rates greater than 30% per year.

With help from advances such as NREL’s advanced airfoil designs, wind power is already

nearly competitive with some fossil-fuel main

The 2002 Research Review

This Silver Anniversary 2002 Research Review is intended

as the first in a series of biennial overview reports on research progress at NREL. These reports will become part of

a series of semiannual journals, with the regular journal issues exploring particular NREL research efforts in depth.
The 20th century was the century of the

petrochemical economy. Gasoline and

diesel (made from petroleum) power almost all our vehicles.

Myriad plastics made from

petroleum or natural gas are

used to make our clothes,

carpets, food packaging, and

increasingly, our car parts and building materials.

Most of our chemicals and even toiletries and

pharmaceuticals are petrochemically derived. 

Unfortunately for the United

States, most of the world’s petroleum is located elsewhere,

so we import more than half of

what we use, creating heavy

economic and security burdens. And unfortunately for the

world, whenever gasoline,

diesel, and other fossil fuels are

burned, they release carbon

dioxide that had been locked

up underground for millions of

years, increasing greenhouse

gas levels. 

In the 21st century, use of biomass—plants and plant-based

materials, produced by photosynthesis within biological

rather than geologic time—will

offset this petrochemical dependence. Biomass can’t fully

replace the huge volumes of

petroleum and other fossil fuels that we now

use, but it can

Artistic rendition of a cellulase enzyme breaking cellulose

down to component sugars. NREL’s understanding and continCurrent ethanol production is

primarily from the starch in

kernels of field corn. NREL researchers are developing

technology to also produce

ethanol from the fibrous material (cellulose and hemicellulose) in the corn husks and

stalks or in other agricultural

or forestry residues.

2 

NREL has world-class facilities

for testing technologies that

would be used for biorefineries. These facilities are available to NREL researchers as

well as to NREL’s research

partners, under a variety of

agreements. 

On the biological side, NREL

has a one-ton-per-day-feedstock bioethanol pilot plant

that can take cellulosic biomass all the way from feedstock preparation through

pretreatment, hydrolysis, and

fermentation to distillation of

fuel ethanol. The plant is certified to handle metabolically

engineered fermentation organisms such as NREL’s

Zymomonas mobilis, can use

any of several pretreatment options, and includes complete

process monitoring.

On the thermochemical side,

the Thermochemical Users

Facility simulates thermochemical processes such as gasification, combustion, and pyrolysis.

The facility includes cyclonic

and fluidized bed reactors for

pyrolysis or gasification and

can easily accommodate research partners’ reactors. A variety of secondary reactor and

condensation equipment is

available, and conversion

products can be analyzed online with molecular beam

mass spectrometry, fourier

transform infrared spectrometry, infrared spectrometry, or

gas chromatography.

Biomass Conversion Facilities
The 20th century was the century of the

petrochemical economy. Gasoline and

diesel (made from petroleum) power almost all our vehicles.

Myriad plastics made from

petroleum or natural gas are

used to make our clothes,

carpets, food packaging, and

increasingly, our car parts and building materials.

Most of our chemicals and even toiletries and

pharmaceuticals are petrochemically derived. 

Unfortunately for the United

States, most of the world’s petroleum is located elsewhere,

so we import more than half of

what we use, creating heavy

economic and security burdens. And unfortunately for the

world, whenever gasoline,

diesel, and other fossil fuels are

burned, they release carbon

dioxide that had been locked

up underground for millions of

years, increasing greenhouse

gas levels. 

In the 21st century, use of biomass—plants and plant-based

materials, produced by photosynthesis within biological

rather than geologic time—will

offset this petrochemical dependence. Biomass can’t fully

replace the huge volumes of

petroleum and other fossil fuels that we now

use, but it can

Artistic rendition of a cellulase enzyme breaking cellulose

down to component sugars. NREL’s understanding and continCurrent ethanol production is

primarily from the starch in

kernels of field corn. NREL researchers are developing

technology to also produce

ethanol from the fibrous material (cellulose and hemicellulose) in the corn husks and

stalks or in other agricultural

or forestry residues.

NREL has world-class facilities

for testing technologies that

would be used for biorefineries. These facilities are available to NREL researchers as

well as to NREL’s research

partners, under a variety of

agreements. 

On the biological side, NREL

has a one-ton-per-day-feedstock bioethanol pilot plant

that can take cellulosic biomass all the way from feedstock preparation through

pretreatment, hydrolysis, and

fermentation to distillation of

fuel ethanol. The plant is certified to handle metabolically

engineered fermentation organisms such as NREL’s

Zymomonas mobilis, can use

any of several pretreatment options, and includes complete

process monitoring.

On the thermochemical side,

the Thermochemical Users

Facility simulates thermochemical processes such as gasification, combustion, and pyrolysis.

The facility includes cyclonic

and fluidized bed reactors for

pyrolysis or gasification and

can easily accommodate research partners’ reactors. A variety of secondary reactor and

condensation equipment is

available, and conversion

products can be analyzed online with molecular beam

mass spectrometry, fourier

transform infrared spectrometry, infrared spectrometry, or

gas chromatography.

Biomass Conversion Facilities
raw biomass. NREL scientists are using gasification technology to improve a large innovative biomass power plant in Vermont (see

sidebar “Vermont Gasifier”) and to provide electricity for the first time to isolated Philippine villages with small

electric generators. The syngas also

can be used to produce hydrogen

(see “Hydrogen Economy” on pages

10-13) which, in turn, can be used

as a fuel or to make plastics, fertilizers, and a wide variety of other

products. Syngas can also be

converted to sulfur-free liquid

transportation fuels using a catalytic process (known as the

Fischer-Tropsch Process), or provide base chemicals for producing

biobased products. 

The Bio-Oil Platform. If biomass is heated to

high temperatures in the total absence of oxygen, it pyrolyzes to a liquid that is oxygenated,

but otherwise has similar characteristics to petroleum. This pyrolysis- or “bio-” oil can be

burned to generate electricity or it can be used

to provide base chemicals for biobased products. As an example, NREL researchers have

extracted phenolics from bio-oil to make adhesives and plastic resins. NREL uses several

thermochemical reactor systems—available for

use by outside researchers—to efficiently pyrolyze and control the bio-oil components.

NREL scientists have also used pyrolysis for

“true recycling” of plastics such as nylon carpeting, selectively regenerating the base chemicals from which the plastics were made.

The Biogas Platform. Another way to convert

“waste” biomass into useful fuels and products is to have natural consortiums of anaerobic microorganisms decompose the material

in closed systems. Anaerobic microorganisms break down or “digest” organic material

in the absence of oxygen and produce biogas as a waste product. Biogas produced in

closed tanks, or anaerobic digesters, consists

of 50% to 80% methane, 20% to 50% carbon dioxide, and trace levels of other gases

such as hydrogen, carbon monoxide, oxygen, and nitrogen. NREL has developed an

anaerobic digestion system that handles

much higher solids loading than typical digesters. This system effectively converts cellulosic waste (such as municipal solid waste)

and fatty waste (such as tuna cannery

sludge) to a methane-rich biogas suitable for

power generation (or as a starting material

for biobased products) and usable compost

material. Anaerobic digesters are currently

getting considerable attention as a way to

turn swine and cattle manure into useful fuel

and chemicals. 

The Carbon-Rich Chains Platform. Plant and

animal fats and oils are long hydrocarbon

chains, as are their fossil-fuel counterparts.

Some are directly usable as fuels, but they

can also be modified to better meet current

needs. Fatty acid methyl ester—fat or oil

“transesterified” by combination with

methanol—substitutes directly for petroleum

diesel. Known as biodiesel, it differs primarily in containing oxygen, so it burns cleaner,

Vermont Gasifier

At the McNeil Biomass Power Generating

Station in Burlington, Vermont, NREL researchers helped design and install an

R&D 100 Award-winning gasification

system. The project is one of two major

DOE projects to develop technology to

dramatically improve the efficiency and

air emissions quality of biomass power

systems. The McNeil Station already is

successfully burning up to 200 tons per

day of gasified wood chips in its normal

steam generator. Once the gas is hooked

up to a planned gas turbine, efficiency

should be double that of a combustionboiler generation system. 

The Vermont gasifier, one

of the first large-scale

demonstrations of biomass gasification, supplies clean, renewable

fuel from biomass to the

McNeil Biomass Power

Generating Station in

Burlington, Vermont.

4 

A researcher examines a beaker containing cellulase enzymes, a key element in producing ethanol from lignocellulosic biomass.
raw biomass. NREL scientists are using gasification technology to improve a large innovative biomass power plant in Vermont (see

sidebar “Vermont Gasifier”) and to provide electricity for the first time to isolated Philippine villages with small

electric generators. The syngas also

can be used to produce hydrogen

(see “Hydrogen Economy” on pages

10-13) which, in turn, can be used

as a fuel or to make plastics, fertilizers, and a wide variety of other

products. Syngas can also be

converted to sulfur-free liquid

transportation fuels using a catalytic process (known as the

Fischer-Tropsch Process), or provide base chemicals for producing

biobased products. 

The Bio-Oil Platform. If biomass is heated to

high temperatures in the total absence of oxygen, it pyrolyzes to a liquid that is oxygenated,

but otherwise has similar characteristics to petroleum. This pyrolysis- or “bio-” oil can be

burned to generate electricity or it can be used

to provide base chemicals for biobased products. As an example, NREL researchers have

extracted phenolics from bio-oil to make adhesives and plastic resins. NREL uses several

thermochemical reactor systems—available for

use by outside researchers—to efficiently pyrolyze and control the bio-oil components.

NREL scientists have also used pyrolysis for

“true recycling” of plastics such as nylon carpeting, selectively regenerating the base chemicals from which the plastics were made.

The Biogas Platform. Another way to convert

“waste” biomass into useful fuels and products is to have natural consortiums of anaerobic microorganisms decompose the material

in closed systems. Anaerobic microorganisms break down or “digest” organic material

in the absence of oxygen and produce biogas as a waste product. Biogas produced in

closed tanks, or anaerobic digesters, consists

of 50% to 80% methane, 20% to 50% carbon dioxide, and trace levels of other gases

such as hydrogen, carbon monoxide, oxygen, and nitrogen. NREL has developed an

anaerobic digestion system that handles

much higher solids loading than typical digesters. This system effectively converts cellulosic waste (such as municipal solid waste)

and fatty waste (such as tuna cannery

sludge) to a methane-rich biogas suitable for

power generation (or as a starting material

for biobased products) and usable compost

material. Anaerobic digesters are currently

getting considerable attention as a way to

turn swine and cattle manure into useful fuel

and chemicals. 

The Carbon-Rich Chains Platform. Plant and

animal fats and oils are long hydrocarbon

chains, as are their fossil-fuel counterparts.

Some are directly usable as fuels, but they

can also be modified to better meet current

needs. Fatty acid methyl ester—fat or oil

“transesterified” by combination with

methanol—substitutes directly for petroleum

diesel. Known as biodiesel, it differs primarily in containing oxygen, so it burns cleaner,

Vermont Gasifier

At the McNeil Biomass Power Generating

Station in Burlington, Vermont, NREL researchers helped design and install an

R&D 100 Award-winning gasification

system. The project is one of two major

DOE projects to develop technology to

dramatically improve the efficiency and

air emissions quality of biomass power

systems. The McNeil Station already is

successfully burning up to 200 tons per

day of gasified wood chips in its normal

steam generator. Once the gas is hooked

up to a planned gas turbine, efficiency

should be double that of a combustionboiler generation system. 

The Vermont gasifier, one

of the first large-scale

demonstrations of biomass gasification, supplies clean, renewable

fuel from biomass to the

McNeil Biomass Power

Generating Station in

Burlington, Vermont.

A researcher examines a beaker containing cellulase enzymes, a key element in producing ethanol from lignocellulosic biomass.
Imagine a future in which you drive home from work, plug your car into

your house, and have it provide electricity for evening lights and meals

and even supply electricity to the grid for the community’s benefit. Then,

in the lull of the night, your house or the grid will

return the favor to produce for your car the energy

it will need for the next day. 

This is a technically possible future because your car

could well be a fuel-cell car that uses hydrogen to produce electricity

(see “Hydrogen Economy” on pages

10-13). Your car could become a

distributed generator and your house a producer of

energy and a refueling station. Concurrently, the

emissions resulting from the use of energy for your

house and car can approach zero, if the hydrogen

and the electricity are produced using renewable

energy resources and technologies. 

For America’s transportation sector, striving toward such a future is vitally important. Our transportation is almost entirely

dependent on oil, nearly 60% of which

arrives in tankers from foreign shores.

And our use of petroleum in transportation translates directly into huge emissions of pollutants and greenhouse gases. 

It is against this backdrop that Secretary

of Energy Spencer Abraham announced

the FreedomCAR program, for research

into “advanced, fuel-cell technology,

which uses hydrogen to power automobiles without creating pollution. The

long-term results of

this...effort will be cars

and trucks that are

more efficient, cheaper

to operate, pollution

free, and competitive.” 

6

All major manufacturers are developing

hybrid electric vehicles and fuel-cell vehicles that will produce far fewer emissions

and get greater mileage. Above is a

Honda Insight hybrid electric car and a

GM S10 pickup truck that uses an onboard reformer to produce hydrogen for

use in a fuel cell.

Areas of the country that have air-quality

problems will soon require the introduction of ultra-low-emission vehicles into the

transportation mix. One strategy to meet

the emissions requirements is with hybrid

electric vehicles. By 2010, there may be as

many as 250,000 HEVs sold in America. 

HEVs often use nickel metal-hydride

(NiMH) batteries because they have

greater energy density and last longer

than the more familiar, less expensive

lead-acid batteries.

But things may be about to change,

thanks to an R&D 100 Award-winning

technology developed by NREL,

Recombination Technologies, and Optima

Batteries. Lead-acid batteries have traditionally been charged at a constant current and voltage. This constant-charge

strategy does not sufficiently recharge the

negative plate in the battery, and leads to

a premature end of battery life. 

NREL and its partners devised a clever,

inexpensive technique—a current-interrupt charging algorithm—for charging the

batteries properly. The technique involves overcharging the battery for

5 seconds then allowing it to rest for

5 seconds. The rest period permits the

battery to cool and prevents it from going into a gassing cycle.

This algorithm, which increases battery

life by three- to four-fold, enables leadacid batteries to be competitive with

NiMH batteries in terms of life cycle.

Going Farther for Less

Internal

Combustion

Engine

Energy Mgmt &

Control System

Motor/Generator

Thermal infrared image

of lead-acid

battery during

5-amp overcharge shows

temperature

variation of

26°C to 33°C.
All major manufacturers are developing

hybrid electric vehicles and fuel-cell vehicles that will produce far fewer emissions

and get greater mileage. Above is a

Honda Insight hybrid electric car and a

GM S10 pickup truck that uses an onboard reformer to produce hydrogen for

use in a fuel cell.

Areas of the country that have air-quality

problems will soon require the introduction of ultra-low-emission vehicles into the

transportation mix. One strategy to meet

the emissions requirements is with hybrid

electric vehicles. By 2010, there may be as

many as 250,000 HEVs sold in America. 

HEVs often use nickel metal-hydride

(NiMH) batteries because they have

greater energy density and last longer

than the more familiar, less expensive

lead-acid batteries.

But things may be about to change,

thanks to an R&D 100 Award-winning

technology developed by NREL,

Recombination Technologies, and Optima

Batteries. Lead-acid batteries have traditionally been charged at a constant current and voltage. This constant-charge

strategy does not sufficiently recharge the

negative plate in the battery, and leads to

a premature end of battery life. 

NREL and its partners devised a clever,

inexpensive technique—a current-interrupt charging algorithm—for charging the

batteries properly. The technique involves overcharging the battery for

5 seconds then allowing it to rest for

5 seconds. The rest period permits the

battery to cool and prevents it from going into a gassing cycle.

This algorithm, which increases battery

life by three- to four-fold, enables leadacid batteries to be competitive with

NiMH batteries in terms of life cycle.

Going Farther for Less

Internal

Combustion

Engine

Energy Mgmt &

Control System

Motor/Generator

Thermal infrared image

of lead-acid

battery during

5-amp overcharge shows

temperature

variation of

26°C to 33°C.
The Fuel Pathway 

A hydrogen infrastructure in which the hydrogen fuel-cell car plays a starring role may be

the ideal to which to aspire, but there are

many options available that would enable the

nation to cut its use of petroleum and in the

process reduce its emissions. Among these options are alternative fuels—including compressed natural gas, liquefied natural gas,

ethanol, and methanol—that we can use in our

cars, trucks, and buses. 

The first step in understanding how best to cut

emissions and curtail oil consumption with alternative fuels is to establish a base that enables

us to make comparisons, to measure progress,

and to understand the properties of fuels and the

consequences of its use. NREL is establishing

such a base with a testing program it manages

for the Department of Energy—the Alternative

Fuels Data Center. We test and analyze a wide

variety of cars, trucks, vans, buses, and fleets

that use alternative fuels. This program has enabled us to build an extensive database on alternative fuels, their properties, and their

performance characteristics. The information

from this database is available to anyone who wants

the data, and it is used by

fleet managers, municipalities, manufacturers of

vehicles and components,

the fuel industry, and researchers. 

The next step is to develop alternative fuels, especially ones that are

derived from renewable resources, such as

biomass. NREL

8 

battery. Temperature variations from module to

module can affect performance and life. Our

analysis can point to ways in which to manage the

temperature of the battery subsystems, for best performance (see sidebar “Going Farther for Less”).

Other important subsystems are those that help

determine the comfort of the passenger—heating, ventilation, cooling, and keeping the air

clean. These auxiliary systems can consume a

large amount of energy. NREL uses an optimization approach to analyze auxiliary loads, simultaneously modeling passenger comfort, heating

and air-conditioning, and vehicle performance

to determine how best to keep passengers comfortable while minimizing fuel use and emissions. This systems approach, which can

minimize auxiliary loads while increasing vehicle performance and passenger comfort, could

save the nation billions of gallons of gasoline

per year—to painlessly reduce our dependence

on foreign oil and enhance air quality.

Exhaust

Catalyzed

particle

filter

Two-stage

lean-NOx catalyst

Exhaust

cooler

Secondary

fuel

injector

Fischer-Tropsch

fuel improves efficiency of after

treatment devices

One way of reaching our goals on

energy, emissions, and infrastructure is, to coin a phase, to just do

it—find ways in which to put more

alternative-fuel vehicles (AFVs) on

the road, and ways for those vehicles to use more alternative fuels.

The DOE-sponsored Clean Cities

program is finding ways. This program helps build coalitions among

government agencies and private

companies to promote the purchase of AFVs, the use of alternative fuels, and the expansion of

refueling stations for those fuels.

The coalition members can leverage their resources, collaborate on

public policy issues, promote AFVs

in their community, and help create AFV markets. 

Opportunities are greatest in markets where fleets of vehicles can

share their use of the infrastructure. This includes airports, campuses, military bases, government

agencies, transit agencies, and

freight and package delivery companies. By tapping these markets,

the program and its cooperating

members have built coalitions in

more than 80 cities and 41 states.

There are about 400,000 AFVs on

the road today. And today, drivers

are discovering a growing infrastructure of stations where they

can fill up their tanks with compressed natural gas (CNG), E85

(a blend containing 85% ethanol

and 15% gasoline), and other alternative fuels. 

Two of the aims of this coalitionbuilding effort are to get 1 million

AFVs on the road by 2010 and to

have these vehicles consume 1 billion equivalent gallons of alternative fuels. But the long-term goal is

to build a sustainable alternativefuel market, and thereby enhance

energy security and air quality.

Clearing the Air

SuperShuttle, a van service that provides shared,

door-to-door rides to seven major airports across

the country, operates approximately 300 CNG vehicles. This one is filling up with CNG at the Denver

International Airport.
battery. Temperature variations from module to

module can affect performance and life. Our

analysis can point to ways in which to manage the

temperature of the battery subsystems, for best performance (see sidebar “Going Farther for Less”).

Other important subsystems are those that help

determine the comfort of the passenger—heating, ventilation, cooling, and keeping the air

clean. These auxiliary systems can consume a

large amount of energy. NREL uses an optimization approach to analyze auxiliary loads, simultaneously modeling passenger comfort, heating

and air-conditioning, and vehicle performance

to determine how best to keep passengers comfortable while minimizing fuel use and emissions. This systems approach, which can

minimize auxiliary loads while increasing vehicle performance and passenger comfort, could

save the nation billions of gallons of gasoline

per year—to painlessly reduce our dependence

on foreign oil and enhance air quality.

Exhaust

Catalyzed

particle

filter

Two-stage

lean-NOx catalyst

Exhaust

cooler

Secondary

fuel

injector

Fischer-Tropsch

fuel improves efficiency of after

treatment devices
Hydrogen is the simplest element in the

universe. It is also the most abundant element, constituting more that 90% of the

atoms of the universe and 75% of its mass.

It is the third most abundant element in

the Earth’s surface and is found mostly in

combination with oxygen as water (H2O).

As a gas (H2), it is colorless, odorless,

tasteless, and non-poisonous.

Hydrogen also may be one of the

best bets to fuel the future economy

of America and the world.

Why? First, it is widely distributed in many resources.

Hydrogen is not only present

in water, but is in fossil fuels,

like petroleum, coal, and

natural gas, and it is in

plants and organic waste.

Hydrogen can be produced

from these resources using

electrolytic, thermochemical,

or photolytic processes.

Second, as a fuel, hydrogen

is clean. Solar energy can

provide the electricity to split

water into its constituent elements of hydrogen and oxygen (see sidebar “Solid-State

Water Splitting”). The hydrogen then can be used in a

Scientists have known for decades

that green algae can produce hydrogen. Researchers at NREL, ORNL,

and the University of California at

Berkeley have unlocked the secret to

increasing the hydrogen yield of a

certain type of green microalgae—

Chlamydomonas reinhardtii—which

shows promise of producing hydrogen cheaply, easily, and cleanly. 

The process they’ve developed involves interrupting the algae’s normal

photosynthesis process. These algae,

like all green plants, use photosynthesis—i.e., in the presence of light they

“inhale” carbon dioxide and “exhale”

oxygen. But hydrogenase—an enzyme that produces

hydrogen—shuts down in the presence of oxygen, in

the daylight, during prime photosynthesis time. This

confines the algae’s production of hydrogen to nighttime when photosynthesis does not occur, limiting the

amount of hydrogen produced. 

To overcome this limitation, the scientists developed a

two-step method that allows the algae to make hydrogen while the sun shines. First they grow out (“fatten”)

the algae under normal photosynthetic conditions.

Second, they withhold sulfur which, the scientists discovered, is essential for this green algae to maintain

normal photosynthesis. Without sulfur, the algae stop

emitting oxygen and stop storing energy. Instead, they

switch to a new metabolic pathway—one that exploits

stored energy reserves in the absence of net oxygen

production. This kicks the hydrogenase into high gear

to release large amounts of hydrogen.

This process induces the algae to produce 100,000 times

more hydrogen than they do under normal conditions. Plus,

the researchers have developed a process to fatten the algae

again on a diet of sunshine and sulfur, and then to starve the

algae of sulfur again to produce hydrogen. This cycle can

be repeated several times. Still, much work remains to be

done to make the process feasible on a larger scale.

NASA's space shuttle (top) uses liquid hydrogen and oxygen for propulsion and hydrogenpowered fuel cells to provide onboard

electricity and water. Car manufacturers

(bottom) are beginning to produce vehicles

powered by fuel cells. (Shuttle photo and Eagle

Nebula photo in the background and on the front

cover are courtesy of NASA.) 

A scientist

scrutinizes a

flask containing microalgae

for hydrogen

production.

10 

Harvesting Hydrogen from Microalgae 
Hydrogen is the simplest element in the

universe. It is also the most abundant element, constituting more that 90% of the

atoms of the universe and 75% of its mass.

It is the third most abundant element in

the Earth’s surface and is found mostly in

combination with oxygen as water (H2O).

As a gas (H2), it is colorless, odorless,

tasteless, and non-poisonous.

Hydrogen also may be one of the

best bets to fuel the future economy

of America and the world.

Why? First, it is widely distributed in many resources.

Hydrogen is not only present

in water, but is in fossil fuels,

like petroleum, coal, and

natural gas, and it is in

plants and organic waste.

Hydrogen can be produced

from these resources using

electrolytic, thermochemical,

or photolytic processes.

Second, as a fuel, hydrogen

is clean. Solar energy can

provide the electricity to split

water into its constituent elements of hydrogen and oxygen (see sidebar “Solid-State

Water Splitting”). The hydrogen then can be used in a

Scientists have known for decades

that green algae can produce hydrogen. Researchers at NREL, ORNL,

and the University of California at

Berkeley have unlocked the secret to

increasing the hydrogen yield of a

certain type of green microalgae—

Chlamydomonas reinhardtii—which

shows promise of producing hydrogen cheaply, easily, and cleanly. 

The process they’ve developed involves interrupting the algae’s normal

photosynthesis process. These algae,

like all green plants, use photosynthesis—i.e., in the presence of light they

“inhale” carbon dioxide and “exhale”

oxygen. But hydrogenase—an enzyme that produces

hydrogen—shuts down in the presence of oxygen, in

the daylight, during prime photosynthesis time. This

confines the algae’s production of hydrogen to nighttime when photosynthesis does not occur, limiting the

amount of hydrogen produced. 

To overcome this limitation, the scientists developed a

two-step method that allows the algae to make hydrogen while the sun shines. First they grow out (“fatten”)

the algae under normal photosynthetic conditions.

Second, they withhold sulfur which, the scientists discovered, is essential for this green algae to maintain

normal photosynthesis. Without sulfur, the algae stop

emitting oxygen and stop storing energy. Instead, they

switch to a new metabolic pathway—one that exploits

stored energy reserves in the absence of net oxygen

production. This kicks the hydrogenase into high gear

to release large amounts of hydrogen.

This process induces the algae to produce 100,000 times

more hydrogen than they do under normal conditions. Plus,

the researchers have developed a process to fatten the algae

again on a diet of sunshine and sulfur, and then to starve the

algae of sulfur again to produce hydrogen. This cycle can

be repeated several times. Still, much work remains to be

done to make the process feasible on a larger scale.

NASA's space shuttle (top) uses liquid hydrogen and oxygen for propulsion and hydrogenpowered fuel cells to provide onboard

electricity and water. Car manufacturers

(bottom) are beginning to produce vehicles

powered by fuel cells. (Shuttle photo and Eagle

Nebula photo in the background and on the front

cover are courtesy of NASA.) 

A scientist

scrutinizes a

flask containing microalgae

for hydrogen

production.

Harvesting Hydrogen from Microalgae 
12

more than 90 billion cubic meters (3.2 trillion

cubic feet) of hydrogen annually. The great

majority of this is used for refining petroleum,

making plastics, and producing fertilizers.

Demonstrations are now under way to prove

hydrogen’s potential for transportation, for producing electricity, and for providing heat and

electricity to buildings—all of which will help

spur the growth of the hydrogen economy.

Take transportation as an example. Initially we

may witness the growth of hydrogen-fueled

internal combustion engines—building on current transportation technologies and infrastructure. Ultimately, however, fuel cells will be

integral to transportation (as well as to buildings, industry, and utilities). We will see fuel

cells being incorporated into hybrid electric

vehicles (which use both fuel-cell electricity

and internal combustion), in which they will

replace the engine. And eventually, fuel cells

will provide the power for advanced fuel-cell

vehicles (see also “Transportation Technologies”

on pages 6-9). 

Producing Hydrogen. Almost all of the hydrogen produced today is made by steam reformation of natural gas. For the near term, this

method of production will continue to dominate. Hydrogen can also be produced by the

gasification of coal or the partial oxidation of

oil. Near-term improvements in these fossilfuel-based processes will allow for the capture of the carbon dioxide byproduct, which

can then be sequestered (stored or locked

away). In the mid term, we’ll see renewable

energy technologies taking a larger role—via

gasification or pyrolysis of biomass (see

“Biorefineries” on pages 2-5) or via electrolysis of water with electricity produced by wind

energy or other renewable electric technologies. Eventually, through long-term R&D, hydrogen will be produced directly using

photobiological or photolytic processes (see

sidebars “Harvesting Hydrogen from Microalgae” and “Solid-State Water Splitting”), in

which hydrogen will be derived directly from

sunlight and water.

Storing Hydrogen. Today, we store hydrogen

as a compressed gas under high pressure or as

a liquid at cryogenic temperatures. These will

continue to be the primary means of storage

for quite some time. There is also a possibility

that we soon may be able to store hydrogen

onboard vehicles or at the point of use as

gasoline, methanol, or some other hydrogenrich material, from

which it could be

extracted using a

reformer (which

breaks down hydrogen-carbon

bonds to produce a gas from

which hydrogen

Today, most all hydrogen

is produced via steam reformation of natural gas at

oil refineries. The great

majority of that hydrogen

is used by oil refineries

and petrochemical plants

to refine fuel and to make

industrial commodities.

The energy density (energy per

mass) of hydrogen is more than

three times that of gasoline. The

problem is, because hydrogen is so

light, it requires a large volume to

store an appropriate amount of hydrogen energy onboard a vehicle.

To overcome this, we can store the

hydrogen at very low temperatures,

under high pressure as a compressed gas, in chemical or metal

hydrides (materials that reversibly

absorb hydrogen), or even in liquid

hydrocarbons that can be reformed

to hydrogen on demand.

A team of NREL scientists is pursuing a novel and promising longterm solution: storage of hydrogen

in carbon nanotubes—hollow

tubes of carbon 1-2 nanometers in

diameter. The walls of the tubes

are made of a single layer of carbon atoms arranged in hexagonal

patterns. These tubes can absorb

and safely store high volumes of

hydrogen in a small space at normal operating conditions. The

stored hydrogen can be released

on demand through small changes

in temperature and pressure. 

Researchers have been able to

make some very pure carbon nanotubes that appear to be able

to store up to 67 kilograms

of hydrogen per cubic meter

(kg/m3). At such a capacity—which surpasses the

goal of 62 kg/m3 set by the

Department of Energy—it

would take only about

0.075 cubic meters to store

5 kilograms of hydrogen,

which is about the size of

gas tanks used in some cars and

small trucks today. With this

amount of stored hydrogen, an

advanced fuel-cell car should

be able to travel farther on a

tank than today’s typical car or

small truck.

Storing Hydrogen in Nanotubes

Carbon nanotubes carry

the promise of being

able to store high volumes of hydrogen and

to release the hydrogen

on demand.
more than 90 billion cubic meters (3.2 trillion

cubic feet) of hydrogen annually. The great

majority of this is used for refining petroleum,

making plastics, and producing fertilizers.

Demonstrations are now under way to prove

hydrogen’s potential for transportation, for producing electricity, and for providing heat and

electricity to buildings—all of which will help

spur the growth of the hydrogen economy.

Take transportation as an example. Initially we

may witness the growth of hydrogen-fueled

internal combustion engines—building on current transportation technologies and infrastructure. Ultimately, however, fuel cells will be

integral to transportation (as well as to buildings, industry, and utilities). We will see fuel

cells being incorporated into hybrid electric

vehicles (which use both fuel-cell electricity

and internal combustion), in which they will

replace the engine. And eventually, fuel cells

will provide the power for advanced fuel-cell

vehicles (see also “Transportation Technologies”

on pages 6-9). 

Producing Hydrogen. Almost all of the hydrogen produced today is made by steam reformation of natural gas. For the near term, this

method of production will continue to dominate. Hydrogen can also be produced by the

gasification of coal or the partial oxidation of

oil. Near-term improvements in these fossilfuel-based processes will allow for the capture of the carbon dioxide byproduct, which

can then be sequestered (stored or locked

away). In the mid term, we’ll see renewable

energy technologies taking a larger role—via

gasification or pyrolysis of biomass (see

“Biorefineries” on pages 2-5) or via electrolysis of water with electricity produced by wind

energy or other renewable electric technologies. Eventually, through long-term R&D, hydrogen will be produced directly using

photobiological or photolytic processes (see

sidebars “Harvesting Hydrogen from Microalgae” and “Solid-State Water Splitting”), in

which hydrogen will be derived directly from

sunlight and water.

Storing Hydrogen. Today, we store hydrogen

as a compressed gas under high pressure or as

a liquid at cryogenic temperatures. These will

continue to be the primary means of storage

for quite some time. There is also a possibility

that we soon may be able to store hydrogen

onboard vehicles or at the point of use as

gasoline, methanol, or some other hydrogenrich material, from

which it could be

extracted using a

reformer (which

breaks down hydrogen-carbon

bonds to produce a gas from

which hydrogen

Today, most all hydrogen

is produced via steam reformation of natural gas at

oil refineries. The great

majority of that hydrogen

is used by oil refineries

and petrochemical plants

to refine fuel and to make

industrial commodities.

The energy density (energy per

mass) of hydrogen is more than

three times that of gasoline. The

problem is, because hydrogen is so

light, it requires a large volume to

store an appropriate amount of hydrogen energy onboard a vehicle.

To overcome this, we can store the

hydrogen at very low temperatures,

under high pressure as a compressed gas, in chemical or metal

hydrides (materials that reversibly

absorb hydrogen), or even in liquid

hydrocarbons that can be reformed

to hydrogen on demand.

A team of NREL scientists is pursuing a novel and promising longterm solution: storage of hydrogen

in carbon nanotubes—hollow

tubes of carbon 1-2 nanometers in

diameter. The walls of the tubes

are made of a single layer of carbon atoms arranged in hexagonal

patterns. These tubes can absorb

and safely store high volumes of

hydrogen in a small space at normal operating conditions. The

stored hydrogen can be released

on demand through small changes

in temperature and pressure. 

Researchers have been able to

make some very pure carbon nanotubes that appear to be able

to store up to 67 kilograms

of hydrogen per cubic meter

(kg/m3). At such a capacity—which surpasses the

goal of 62 kg/m3 set by the

Department of Energy—it

would take only about

0.075 cubic meters to store

5 kilograms of hydrogen,

which is about the size of

gas tanks used in some cars and

small trucks today. With this

amount of stored hydrogen, an

advanced fuel-cell car should

be able to travel farther on a

tank than today’s typical car or

small truck.

Storing Hydrogen in Nanotubes

Carbon nanotubes carry

the promise of being

able to store high volumes of hydrogen and

to release the hydrogen

on demand.
Something as

seemingly simple as saran

wrap. Thin—very

thin —layers of

stacked plastic

sheets could represent the future of

electricity. Those

thin sheets are

conductive polymers with embedded nanorods or

quantum dots of semiconductor material that one

day may produce electricity from the sun to power homes and businesses. 

Fanciful? Perhaps. But plastic solar cells serve as a

benchmark for how far we’ve come since the middle of the 1970s, when solar electricity was only a

reality for powering satellites and was still too expensive for uses on Earth. And they are a harbinger

of what is to come. The first steps toward plastic

solar cells have been taken by researchers at universities and research organizations under an NREL

program. Scientists can convert from 2% to nearly

5% of sunlight to electricity (depending on the approach). And prospects look good for bumping

conversion efficiencies well beyond 10%, toward

viability and toward solar electricity that could

someday cost less than 2¢/kWh.

This is part of the promise of the emerging solar

electric revolution. Solar electricity is the ultimate

distributed energy. Solar electric systems can

provide electricity anywhere in any

amount—from a few watts to billions of

watts. Solar electricity is coming

to America along two general

technological pathways. One

of these pathways is photovoltaics (PV or solar cells)—

in which photons dislodge

electrons in solid-state materials to directly convert sunlight to electricity. The other

is concentrating solar power—in which the heat of

concentrated sunlight is used

to generate electricity.

Solar-Cell

Generations

In 1977, when NREL first began its research on solar

cells, the world produced

less than 50,000 watts of solar cells; they were based on

crystalline silicon wafer tech

BP Solar’s new semitransparent amorphous

silicon modules—developed through participation in the Amorphous

Silicon National

Research Team—are

used to provide power

to run pumps, lights,

and other loads at BP

gasoline stations.

14

Nanorods and Quantum Dots

NREL and its research partners have been

investigating semiconductor-related nanotechnology since the early 1980s. In 1984,

NREL researchers were among the first to

report on quantization effects in nanosize

semiconductor particles related to solar

cells. Today, this pioneering research is

showing promising results in the form of

nanorod and quantum-dot solar cells. 

Nanorods are semiconductor “wires” that

are a few nanometers wide and up to 100

nanometers long (a nanometer is one-billionth of a meter). Embedding nanorods in

conductive plastic sheets results in thin,

flexible solar cells. The nanorods absorb

light of specific wavelengths to generate

electrons and holes (vacancies in the material that move around similar to electrons).

The rods conduct the electrons along their

length. Holes are transferred to the plastic,

which

conducts

them to an electrode. 

Quantum dots

are dots of semiconductor material containing

from just a few

atoms to tens of

thousands of

atoms. Like

nanorods, dots

can be embedded

in conductive polymer, or can be used with

other materials, such as titanium dioxide. By

varying their size, quantum dots can be tuned

to absorb specific wavelengths of light and so

represent an avenue toward multi-multijunction devices that could theoretically convert

as much as 66% of sunlight to electricity.

Two innovative organic solar

cells: The top cell employs

nanorods of cadmium selenium embedded in conductive

polymer. The bottom cell also

uses a conductive polymer

substrate, but with extremely

thin embedded multilayers of

organic molecules.
Something as

seemingly simple as saran

wrap. Thin—very

thin —layers of

stacked plastic

sheets could represent the future of

electricity. Those

thin sheets are

conductive polymers with embedded nanorods or

quantum dots of semiconductor material that one

day may produce electricity from the sun to power homes and businesses. 

Fanciful? Perhaps. But plastic solar cells serve as a

benchmark for how far we’ve come since the middle of the 1970s, when solar electricity was only a

reality for powering satellites and was still too expensive for uses on Earth. And they are a harbinger

of what is to come. The first steps toward plastic

solar cells have been taken by researchers at universities and research organizations under an NREL

program. Scientists can convert from 2% to nearly

5% of sunlight to electricity (depending on the approach). And prospects look good for bumping

conversion efficiencies well beyond 10%, toward

viability and toward solar electricity that could

someday cost less than 2¢/kWh.

This is part of the promise of the emerging solar

electric revolution. Solar electricity is the ultimate

distributed energy. Solar electric systems can

provide electricity anywhere in any

amount—from a few watts to billions of

watts. Solar electricity is coming

to America along two general

technological pathways. One

of these pathways is photovoltaics (PV or solar cells)—

in which photons dislodge

electrons in solid-state materials to directly convert sunlight to electricity. The other

is concentrating solar power—in which the heat of

concentrated sunlight is used

to generate electricity.

Solar-Cell

Generations

In 1977, when NREL first began its research on solar

cells, the world produced

less than 50,000 watts of solar cells; they were based on

crystalline silicon wafer tech

BP Solar’s new semitransparent amorphous

silicon modules—developed through participation in the Amorphous

Silicon National

Research Team—are

used to provide power

to run pumps, lights,

and other loads at BP

gasoline stations.

Nanorods and Quantum Dots

NREL and its research partners have been

investigating semiconductor-related nanotechnology since the early 1980s. In 1984,

NREL researchers were among the first to

report on quantization effects in nanosize

semiconductor particles related to solar

cells. Today, this pioneering research is

showing promising results in the form of

nanorod and quantum-dot solar cells. 

Nanorods are semiconductor “wires” that

are a few nanometers wide and up to 100

nanometers long (a nanometer is one-billionth of a meter). Embedding nanorods in

conductive plastic sheets results in thin,

flexible solar cells. The nanorods absorb

light of specific wavelengths to generate

electrons and holes (vacancies in the material that move around similar to electrons).

The rods conduct the electrons along their

length. Holes are transferred to the plastic,

which

conducts

them to an electrode. 

Quantum dots

are dots of semiconductor material containing

from just a few

atoms to tens of

thousands of

atoms. Like

nanorods, dots

can be embedded

in conductive polymer, or can be used with

other materials, such as titanium dioxide. By

varying their size, quantum dots can be tuned

to absorb specific wavelengths of light and so

represent an avenue toward multi-multijunction devices that could theoretically convert

as much as 66% of sunlight to electricity.

Two innovative organic solar

cells: The top cell employs

nanorods of cadmium selenium embedded in conductive

polymer. The bottom cell also

uses a conductive polymer

substrate, but with extremely

thin embedded multilayers of

organic molecules.
of the Periodic Table of the Elements—such as

gallium arsenide, indium phosphide, and gallium indium phosphide. Thus far, the best device is a three-layer (three-junction) cell that

converts up to 34% of sunlight to electricity

(see sidebar “From Space to the Earth”).

Typically, this approach uses concentrated

sunlight, where lenses focus large amounts of

solar energy onto a small cell. 

3rd Generation—Beyond the Horizon. To

drastically lower the cost of solar electricity—

below 2¢/kWh—you have to leapfrog the

conventional to the innovative. This third generation is mostly at the basic research stage,

but these are concepts that auger very low

cost or very high efficiency (three or four

times that of current state-of-the-art siliconwafer cells). The plastic cells mentioned

above are part of this future generation. Other

concepts include: 

• Hot-carrier solar cells (which capture and

convert electrons in excited states before

they return to stable energy levels).

• Cells that can convert a photon into two or

more electron-hole pairs to carry the current, in contrast to conventional cells, in

which a photon produces one electronhole pair.

• Quantum-dot solar cells, in which nanosized dots of semiconductor material are

tuned to capture and convert specific wavelengths of the solar spectrum (see sidebar

“Nanorods and Quantum Dots”). 

Concentrating Solar Power

Solar Troughs. When the federal research program began in the late 1970s, there were no

concentrating solar power systems in existence.

By 1991, thousands of acres of solar troughs in

the Mojave Desert were generating 354 MW of

power, thanks in large part to R&D by national

laboratories (including NREL, along with Sandia

National Laboratories) and industry that

dropped costs three- to five-fold by 1990. 

A solar trough uses parabolic-shaped mirrors to

concentrate sunlight onto a receiver (a heat-collection element) running along the focus of the

curved surface. For latitudes within the United

States, the trough tracks the sun from east to

west to maximize solar energy captured by the

receiver. This concentrated solar energy heats

oil flowing through the receiver, which is then

used to generate electricity via a conventional

steam generator. 

At 12¢ to 14¢/kWh, the troughs in the Mojave

Desert produce electricity more cheaply than

other solar electric alternatives. As such, they

provide supplementary power to a highly competitive market—that of peaking and intermediate-load power for grid-scale applications.

Moreover, with a federal R&D strategy that will

help reduce the cost of electricity to about

6¢/kWh by the end of the decade, solar troughs

will be able to compete directly with conventional power generation for peaking markets.

This strategy may also reduce trough electricity

to less than 5¢/kWh by 2020, making it com

For decades to come, satellites launched

into Earth orbit will depend on power

provided by innovative solar cells pioneered by NREL scientists and perfected in partnership with industry. These

devices are lighter, more powerful,

and more efficient than all previous

solar-cell power systems shot into

space. And more durable—they will

easily withstand 15 years of particle

storms sent by sun and solar wind. 

The devices are double- and triple-junction

cells based on gallium indium phosphide,

gallium arsenide, and germanium. They

convert about 30% of sunlight to electricity,

far greater than other space solar cells.

They’re not just good for space, though.

NREL and Spectrolab—an industrial partner—redesigned the cell for use on Earth

under concentrated sunlight. This Earthbound version, which is especially

suited for use under direct sunlight,

can convert up to 34% of sunlight

to electricity, a world record for

photovoltaics.

This research resulted in two prestigious R&D 100 Awards—one for the space

cell and one for the redesign that brought it

to Earth. But even more important, it has

led to breakthroughs in understanding solid-state materials, their growth processes,

and their optical and electronic properties. This understanding is leading

the advance toward devices with

four and more junctions and efficiencies

beyond 40%.

The IMAGE (Imager for

Magnetopause-toAurora Global

Exploration) satellite

was one of the early

satellites to use the

new III-V multijunction

cells to provide power

for operations. IMAGE

was launched in March

of 2000 to study the

Earth’s magnetosphere

and related phenomena, such as the aurora

borealis. (Graphic

courtesy of NASA.)

16

From Space to the Earth
of the Periodic Table of the Elements—such as

gallium arsenide, indium phosphide, and gallium indium phosphide. Thus far, the best device is a three-layer (three-junction) cell that

converts up to 34% of sunlight to electricity

(see sidebar “From Space to the Earth”).

Typically, this approach uses concentrated

sunlight, where lenses focus large amounts of

solar energy onto a small cell. 

3rd Generation—Beyond the Horizon. To

drastically lower the cost of solar electricity—

below 2¢/kWh—you have to leapfrog the

conventional to the innovative. This third generation is mostly at the basic research stage,

but these are concepts that auger very low

cost or very high efficiency (three or four

times that of current state-of-the-art siliconwafer cells). The plastic cells mentioned

above are part of this future generation. Other

concepts include: 

• Hot-carrier solar cells (which capture and

convert electrons in excited states before

they return to stable energy levels).

• Cells that can convert a photon into two or

more electron-hole pairs to carry the current, in contrast to conventional cells, in

which a photon produces one electronhole pair.

• Quantum-dot solar cells, in which nanosized dots of semiconductor material are

tuned to capture and convert specific wavelengths of the solar spectrum (see sidebar

“Nanorods and Quantum Dots”). 

Concentrating Solar Power

Solar Troughs. When the federal research program began in the late 1970s, there were no

concentrating solar power systems in existence.

By 1991, thousands of acres of solar troughs in

the Mojave Desert were generating 354 MW of

power, thanks in large part to R&D by national

laboratories (including NREL, along with Sandia

National Laboratories) and industry that

dropped costs three- to five-fold by 1990. 

A solar trough uses parabolic-shaped mirrors to

concentrate sunlight onto a receiver (a heat-collection element) running along the focus of the

curved surface. For latitudes within the United

States, the trough tracks the sun from east to

west to maximize solar energy captured by the

receiver. This concentrated solar energy heats

oil flowing through the receiver, which is then

used to generate electricity via a conventional

steam generator. 

At 12¢ to 14¢/kWh, the troughs in the Mojave

Desert produce electricity more cheaply than

other solar electric alternatives. As such, they

provide supplementary power to a highly competitive market—that of peaking and intermediate-load power for grid-scale applications.

Moreover, with a federal R&D strategy that will

help reduce the cost of electricity to about

6¢/kWh by the end of the decade, solar troughs

will be able to compete directly with conventional power generation for peaking markets.

This strategy may also reduce trough electricity

to less than 5¢/kWh by 2020, making it com

For decades to come, satellites launched

into Earth orbit will depend on power

provided by innovative solar cells pioneered by NREL scientists and perfected in partnership with industry. These

devices are lighter, more powerful,

and more efficient than all previous

solar-cell power systems shot into

space. And more durable—they will

easily withstand 15 years of particle

storms sent by sun and solar wind. 

The devices are double- and triple-junction

cells based on gallium indium phosphide,

gallium arsenide, and germanium. They

convert about 30% of sunlight to electricity,

far greater than other space solar cells.

They’re not just good for space, though.

NREL and Spectrolab—an industrial partner—redesigned the cell for use on Earth

under concentrated sunlight. This Earthbound version, which is especially

suited for use under direct sunlight,

can convert up to 34% of sunlight

to electricity, a world record for

photovoltaics.

This research resulted in two prestigious R&D 100 Awards—one for the space

cell and one for the redesign that brought it

to Earth. But even more important, it has

led to breakthroughs in understanding solid-state materials, their growth processes,

and their optical and electronic properties. This understanding is leading

the advance toward devices with

four and more junctions and efficiencies

beyond 40%.

The IMAGE (Imager for

Magnetopause-toAurora Global

Exploration) satellite

was one of the early

satellites to use the

new III-V multijunction

cells to provide power

for operations. IMAGE

was launched in March

of 2000 to study the

Earth’s magnetosphere

and related phenomena, such as the aurora

borealis. (Graphic

courtesy of NASA.)

From Space to the Earth
What IS distributed energy resources, or DER? The term

refers to modular power generators that can be combined with energy management in storage to improve

the electricity delivery system. In the future, DER will

be the umbrella that connects exciting new technologies—fuel cells, building-integrated photovoltaics, and microturbines—

together into power-generating packages that are located at your business

or in your community. But, according

to Dick DeBlasio, NREL’s DER technology manager, “DER

refers as much to the way that people will relate to energy—the way it will be distributed to your home, office, or

school—as to the way the electricity is generated.” DER is

the way electricity will work in the future, but it is also the

way we’re going to make the transition to a more secure

energy future, where businesses, hospitals, and schools can

still operate even in emergencies and when the power grid

is down.

Changing the Way We Grid

When you flip on a light at home today, electricity comes to

you from the power grid—a giant system of distribution and

transmission lines that radiate out from large power generation

plants to send electricity to where we need it. Increasingly, as

DER is integrated into the system, these lines

will form two-way networks that, in turn, will

contain embedded distributed generators. In the

same way that computer technologies have

In the future, distributed

energy resources will be

the way energy works––

connecting exciting new

technologies into powergenerating packages located at your business or

in your community. In

addition to central power

plants, distributed energy

means that a variety of

electricity sources are

distributed close to

where they will be used,

allowing for more efficient use of heat that is

“wasted” at power plants

today. It also provides

greater security, spreading out sources of electricity so that operations

can continue even if one

source is not operational.

18
What IS distributed energy resources, or DER? The term

refers to modular power generators that can be combined with energy management in storage to improve

the electricity delivery system. In the future, DER will

be the umbrella that connects exciting new technologies—fuel cells, building-integrated photovoltaics, and microturbines—

together into power-generating packages that are located at your business

or in your community. But, according

to Dick DeBlasio, NREL’s DER technology manager, “DER

refers as much to the way that people will relate to energy—the way it will be distributed to your home, office, or

school—as to the way the electricity is generated.” DER is

the way electricity will work in the future, but it is also the

way we’re going to make the transition to a more secure

energy future, where businesses, hospitals, and schools can

still operate even in emergencies and when the power grid

is down.

Changing the Way We Grid

When you flip on a light at home today, electricity comes to

you from the power grid—a giant system of distribution and

transmission lines that radiate out from large power generation

plants to send electricity to where we need it. Increasingly, as

DER is integrated into the system, these lines

will form two-way networks that, in turn, will

contain embedded distributed generators. In the

same way that computer technologies have

In the future, distributed

energy resources will be

the way energy works––

connecting exciting new

technologies into powergenerating packages located at your business or

in your community. In

addition to central power

plants, distributed energy

means that a variety of

electricity sources are

distributed close to

where they will be used,

allowing for more efficient use of heat that is

“wasted” at power plants

today. It also provides

greater security, spreading out sources of electricity so that operations

can continue even if one

source is not operational.
quality. In fact, the Electric Power Research

Institute estimates that power outages and

poor power quality cost American businesses

more than $100 billion each year.

Third, there is greater energy security in a grid

network in which many generators are providing the electricity. If all of a region’s electricity

is supplied by one central power facility, for

example, and that facility goes down—

whether by natural means or through sabotage—then the entire region will be shut

down. This would not happen with a

well-designed distributed energy network, which provides inherent

redundancy and safety. 

DER also benefits utilities. A network that depends on a wide variety of mini- and microgenerators can add capacity incrementally,

when and where it is needed.

Such a network can avoid the

expensive financial and time

commitment demanded by the

construction of large, central facilities. 

Using All the Heat

But efficiency may be the most compelling argument for distributed energy resources.

Traditional power generation plants burn coal

or gas. But only about

one-third of the primary energy used

is captured and

converted to electricity. Then, as

much as another

10% can be lost

through transmission and distribution of the

electricity. Since

the point of DER,

on the other

hand, is to generate electricity

close to where it

is to be used, you

can minimize

losses due to

transmission or

distribution. Plus,

heat that is traditionally “wasted”

can be converted

to power in other

ways. Using

waste heat efficiently, a micro-grid at your

home will power your appliances; heat, cool,

and adjust humidity levels in your home; and

heat your water. In industrial settings, waste

heat will power industrial processes. 

Researchers are working on additional and

more effective ways to use that waste heat and

make power generation more effective. As we

find ways to be more efficient, as much as

60% of the power used to generate electricity

will be captured. 

Making the Rules

As the brave new world of creating our own

electricity evolves, we need to think strategically about the rules that will govern its use.

Like codes and standards governing the way

buildings are made or commerce is conducted, standards for the way that people can

connect into the power grid, how they can

send electricity back to the grid, and rules

governing the way that utilities relate to these

mini-grids are critical. Right now, businesses

that install photovoltaic systems and try to tie

in to the power grid face different procedures

with different utilities, and states and local

governments also have different rules.

Microturbines are representative of just one of the many

kinds of distributed power

generators that are ideal for

use in a distributed network.

Microturbines, which can be

powered by natural gas or

biofuels, provide a reliable

source of electricity and heat

for commercial businesses

and industries.

20

This stand-alone system creates a mini-grid wherever

it goes and creates enough power to run a

small home. It consists of a 1.8-kilowatt

photovoltaic panel, a diesel generator for backup, and inverters to convert direct

current power to

alternating

current.
quality. In fact, the Electric Power Research

Institute estimates that power outages and

poor power quality cost American businesses

more than $100 billion each year.

Third, there is greater energy security in a grid

network in which many generators are providing the electricity. If all of a region’s electricity

is supplied by one central power facility, for

example, and that facility goes down—

whether by natural means or through sabotage—then the entire region will be shut

down. This would not happen with a

well-designed distributed energy network, which provides inherent

redundancy and safety. 

DER also benefits utilities. A network that depends on a wide variety of mini- and microgenerators can add capacity incrementally,

when and where it is needed.

Such a network can avoid the

expensive financial and time

commitment demanded by the

construction of large, central facilities. 

Using All the Heat

But efficiency may be the most compelling argument for distributed energy resources.

Traditional power generation plants burn coal

or gas. But only about

one-third of the primary energy used

is captured and

converted to electricity. Then, as

much as another

10% can be lost

through transmission and distribution of the

electricity. Since

the point of DER,

on the other

hand, is to generate electricity

close to where it

is to be used, you

can minimize

losses due to

transmission or

distribution. Plus,

heat that is traditionally “wasted”

can be converted

to power in other

ways. Using

waste heat efficiently, a micro-grid at your

home will power your appliances; heat, cool,

and adjust humidity levels in your home; and

heat your water. In industrial settings, waste

heat will power industrial processes. 

Researchers are working on additional and

more effective ways to use that waste heat and

make power generation more effective. As we

find ways to be more efficient, as much as

60% of the power used to generate electricity

will be captured. 

Making the Rules

As the brave new world of creating our own

electricity evolves, we need to think strategically about the rules that will govern its use.

Like codes and standards governing the way

buildings are made or commerce is conducted, standards for the way that people can

connect into the power grid, how they can

send electricity back to the grid, and rules

governing the way that utilities relate to these

mini-grids are critical. Right now, businesses

that install photovoltaic systems and try to tie

in to the power grid face different procedures

with different utilities, and states and local

governments also have different rules.

Microturbines are representative of just one of the many

kinds of distributed power

generators that are ideal for

use in a distributed network.

Microturbines, which can be

powered by natural gas or

biofuels, provide a reliable

source of electricity and heat

for commercial businesses

and industries.
What if your house were a mini-power

plant, generating the power you need to

live? Imagine—solar panels in the form of

roof shingles, heat-collecting walls, and fuel

cells powering your

appliances, heating

your home, and even

charging your car. And

buildings of the future

will be “smarter,” with

windows that automatically darken to shade during

the heat of summer and open or close to allow

natural ventilation. Computer systems will automatically control lighting levels and turn on and

off your appliances. All of these technologies

and concepts will make the buildings of the future more productive and comfortable, extremely energy efficient, and secure—continuing to

run even if the electric grid is down. 

Living Laboratories 

We might be further along the path to this future

than you realize. Researchers are testing home

and office designs today that are up to 80% more

energy efficient than those built when NREL first

began operating. These new building designs

combine renewable and energy-efficient technologies in ways we could not have imagined in

past decades.

In fact, much of the focus in improving buildings today is taking knowledge gained in past

research into the real world to test it there.

These real-world test sites, or living laborato

22 

Even high in the Colorado mountains, where winter temperatures

cause heating challenges for any

building, BigHorn’s large, retail

spaces and warehouse are consuming 62% less energy than a

similar, conventional space.

NREL’s researchers helped to design and test, and continue to

monitor the complex, which is

breaking ground for the future of

retail space with a lot of “firsts.”

The complex is one of the first retail buildings in the United States

to use daylighting and natural ventilation cooling systems, the largest

commercial photovoltaic array in

Colorado (9-kW capacity), the

state’s first commercial building

to have a standing-seam, roofintegrated PV system, and the

first retail center in Colorado

to have a net metering agreement (where electricity produced over the amount used is

sold back to the utility). Inside

the building, customers experience radiant floor heating, and

large, operable windows that let

in Colorado’s bright sun and look

out on the Rocky Mountains. A

computer system automatically

balances the ventilation and lighting levels to make sure customers

have the optimum comfort levels

for shopping. 

The BigHorn high-performance building features PV,

clerestory windows, daylighting, diffusing skylights,

and solar wall. Anticipated energy cost savings from

all the features, not including PV, is 62%.

Shopping Mile High
What if your house were a mini-power

plant, generating the power you need to

live? Imagine—solar panels in the form of

roof shingles, heat-collecting walls, and fuel

cells powering your

appliances, heating

your home, and even

charging your car. And

buildings of the future

will be “smarter,” with

windows that automatically darken to shade during

the heat of summer and open or close to allow

natural ventilation. Computer systems will automatically control lighting levels and turn on and

off your appliances. All of these technologies

and concepts will make the buildings of the future more productive and comfortable, extremely energy efficient, and secure—continuing to

run even if the electric grid is down. 

Living Laboratories 

We might be further along the path to this future

than you realize. Researchers are testing home

and office designs today that are up to 80% more

energy efficient than those built when NREL first

began operating. These new building designs

combine renewable and energy-efficient technologies in ways we could not have imagined in

past decades.

In fact, much of the focus in improving buildings today is taking knowledge gained in past

research into the real world to test it there.

These real-world test sites, or living laborato

Even high in the Colorado mountains, where winter temperatures

cause heating challenges for any

building, BigHorn’s large, retail

spaces and warehouse are consuming 62% less energy than a

similar, conventional space.

NREL’s researchers helped to design and test, and continue to

monitor the complex, which is

breaking ground for the future of

retail space with a lot of “firsts.”

The complex is one of the first retail buildings in the United States

to use daylighting and natural ventilation cooling systems, the largest

commercial photovoltaic array in

Colorado (9-kW capacity), the

state’s first commercial building

to have a standing-seam, roofintegrated PV system, and the

first retail center in Colorado

to have a net metering agreement (where electricity produced over the amount used is

sold back to the utility). Inside

the building, customers experience radiant floor heating, and

large, operable windows that let

in Colorado’s bright sun and look

out on the Rocky Mountains. A

computer system automatically

balances the ventilation and lighting levels to make sure customers

have the optimum comfort levels

for shopping. 

The BigHorn high-performance building features PV,

clerestory windows, daylighting, diffusing skylights,

and solar wall. Anticipated energy cost savings from

all the features, not including PV, is 62%.

Shopping Mile High
facing curved roof provides half of the electrical

energy for the building. Overhanging eaves and

trusses shade the summer sun while allowing

winter heat gain. Natural light comes into the

building through clerestories and south-facing

windows, reducing the need for electrical lighting.

At the center, electronic sensors track light intensity, electricity produced by the solar electric

panels, and energy consumed by the heating

and ventilation systems. A monitoring system

helps students and NREL researchers understand

how a building interacts with its environment

and how it behaves as a system. 

In many schools, students and researchers alike

learn about energy efficiency and renewable

technologies through partnerships—like the

one with Oberlin—and programs like DOE’s

EnergySmart Schools. NREL’s EnergySmart

Schools Coordinator Patricia Plympton says

that these programs are transitioning our

schools to new ways of using and teaching

about energy. “Sometimes students can teach

us how to make classrooms more comfortable

and productive using energy efficiency and renewable technologies,” she says. “We’re all

learning from these living laboratories.”

Changing the Way We Live

In the desert community of Civano, outside

Tucson, Arizona, all homes use 50% less energy

than a traditional home. The sun is used to heat

water for swimming pools and homes, and photovoltaics help to offset electricity consumption.

A network of bike and walking paths connect

office buildings with homes to reduce the need

for driving. Native landscaping and efficient

building materials help the community live

within the desert ecosystem, reducing water

consumption and the need for air-conditioning.

Research on communities like Civano is helping scientists measure the effectiveness of

technologies and improve designs. Energy performance is monitored and put into a computer system to model ways to make the homes

even more efficient. This huge network of living laboratories is a catalyst for change in the

home-building industry. Many large builders

are starting to see the benefits of producing

homes on a community scale that use 30% to

50% less energy, reduce

construction time and

waste by as much

as 50%, and

provide new

product opportunities to

manufacturers. 

“We work with builders

and designers, who are

changing the way homes are

built,” said Paul Norton, NREL

project manager for DOE’s

Building America program. “Our

24 

For eight days in 2002, 14 student

teams will participate in a competition that will be a living laboratory for future designers, engineers,

researchers, and communicators.

The student teams will compete to

capture, convert, store, and use

enough solar energy to power a

“home” they will build themselves

on the Washington, DC, mall.

Solar Decathletes will be required

to provide all the energy for an

entire household, including a

home-based business and the

transportation needs of the household and business. During the

event, only the solar energy available within the perimeter of each

house may be used to generate the

power needed to compete in the

ten Solar Decathlon contests. The

Solar Decathlon, sponsored by

DOE and administered by NREL,

will educate consumers about solar energy and energy-efficient

products and also guide the next

generation of researchers, architects, engineers, and

builders as they prepare to

begin their careers.

Competing for the Future

The 2002 Solar Decathlon team from the

University of Colorado at Boulder developed the

design of their house in a collaborative effort between engineering and architecture students.
facing curved roof provides half of the electrical

energy for the building. Overhanging eaves and

trusses shade the summer sun while allowing

winter heat gain. Natural light comes into the

building through clerestories and south-facing

windows, reducing the need for electrical lighting.

At the center, electronic sensors track light intensity, electricity produced by the solar electric

panels, and energy consumed by the heating

and ventilation systems. A monitoring system

helps students and NREL researchers understand

how a building interacts with its environment

and how it behaves as a system. 

In many schools, students and researchers alike

learn about energy efficiency and renewable

technologies through partnerships—like the

one with Oberlin—and programs like DOE’s

EnergySmart Schools. NREL’s EnergySmart

Schools Coordinator Patricia Plympton says

that these programs are transitioning our

schools to new ways of using and teaching

about energy. “Sometimes students can teach

us how to make classrooms more comfortable

and productive using energy efficiency and renewable technologies,” she says. “We’re all

learning from these living laboratories.”

Changing the Way We Live

In the desert community of Civano, outside

Tucson, Arizona, all homes use 50% less energy

than a traditional home. The sun is used to heat

water for swimming pools and homes, and photovoltaics help to offset electricity consumption.

A network of bike and walking paths connect

office buildings with homes to reduce the need

for driving. Native landscaping and efficient

building materials help the community live

within the desert ecosystem, reducing water

consumption and the need for air-conditioning.

Research on communities like Civano is helping scientists measure the effectiveness of

technologies and improve designs. Energy performance is monitored and put into a computer system to model ways to make the homes

even more efficient. This huge network of living laboratories is a catalyst for change in the

home-building industry. Many large builders

are starting to see the benefits of producing

homes on a community scale that use 30% to

50% less energy, reduce

construction time and

waste by as much

as 50%, and

provide new

product opportunities to

manufacturers. 

“We work with builders

and designers, who are

changing the way homes are

built,” said Paul Norton, NREL

project manager for DOE’s

Building America program. “Our

For eight days in 2002, 14 student

teams will participate in a competition that will be a living laboratory for future designers, engineers,

researchers, and communicators.

The student teams will compete to

capture, convert, store, and use

enough solar energy to power a

“home” they will build themselves

on the Washington, DC, mall.

Solar Decathletes will be required

to provide all the energy for an

entire household, including a

home-based business and the

transportation needs of the household and business. During the

event, only the solar energy available within the perimeter of each

house may be used to generate the

power needed to compete in the

ten Solar Decathlon contests. The

Solar Decathlon, sponsored by

DOE and administered by NREL,

will educate consumers about solar energy and energy-efficient

products and also guide the next

generation of researchers, architects, engineers, and

builders as they prepare to

begin their careers.

Competing for the Future
With rotor diameters longer than football fields,

wind turbines of the future will stand on towers

400 feet high, operate even in low-wind areas, and

have adapting blades that change shape according

to wind speed and direction. As researchers develop the technology to grow turbines to gargantuan size, they also are working to

shrink efficient designs—small turbines effective for homes or small businesses.

Already, wind power has made great leaps

in technology and price competitiveness during the

past two decades. Since the early 1980s, the cost of

wind power has decreased from 80¢/kWh (in 2002

dollars) to about 4¢/kWh in high-wind-speed areas.

And market use of wind power is growing at record

speed—in the past two years alone, the amount of

electric capacity produced by wind energy in the

United States has almost doubled to 4,500 MW. 

The challenge for wind power as we make the

transition to our energy future is to hone the technology to be even more cost competitive and to

operate under even lower wind speeds. By operating efficient turbines at low wind speeds—an average of 13.5 miles per hour annually versus the 15

miles per hour necessary now—20 times more

land in the nation will be able to cost effectively

access wind power. With this goal in mind, the U.S.

Department of Energy, NREL, and

other wind research organizations

are focusing on developing, testing,

and lowering the costs of turbine components that operate in lower speeds.

“We’re putting our whole research program

behind this—aerodynamics, understanding turbulence, advanced controls, advanced materials, power electronics,” says NREL’s Sue Hock,

wind energy technology manager. According to

Hock, only with continued low-wind research

will wind power reach its goal of being cost

competitive at low wind speeds with fuels by

2010—by bringing low-wind costs down from

6¢/kWh to 3¢/kWh, and even to below 2¢/kWh

by 2020. The Components of Wind Turbines A wind turbine is composed of blades turning a

rotor that is situated on top of a tower. Drivetrain

components (which can include generators, gearboxes, shafts, and bearings) transfer the slow-rotating mechanical energy from the rotor and

convert it to electrical energy. Researchers are

studying all of these components to make them

more effective and less expensive to manufacture

and operate.

26 

To develop wind turbines that

produce inexpensive electricity

(3¢/kWh or less) in low-windspeed areas, researchers are

studying all the components of

a wind turbine—rotors (which

include blades and hub), towers, gearboxes, generators,

shafts, and controllers—to

make them more effective and

less expensive.

Rotor

Shafts

Controller

Gear Box

Break

Tower

Generator
With rotor diameters longer than football fields,

wind turbines of the future will stand on towers

400 feet high, operate even in low-wind areas, and

have adapting blades that change shape according

to wind speed and direction. As researchers develop the technology to grow turbines to gargantuan size, they also are working to

shrink efficient designs—small turbines effective for homes or small businesses.

Already, wind power has made great leaps

in technology and price competitiveness during the

past two decades. Since the early 1980s, the cost of

wind power has decreased from 80¢/kWh (in 2002

dollars) to about 4¢/kWh in high-wind-speed areas.

And market use of wind power is growing at record

speed—in the past two years alone, the amount of

electric capacity produced by wind energy in the

United States has almost doubled to 4,500 MW. 

The challenge for wind power as we make the

transition to our energy future is to hone the technology to be even more cost competitive and to

operate under even lower wind speeds. By operating efficient turbines at low wind speeds—an average of 13.5 miles per hour annually versus the 15

miles per hour necessary now—20 times more

land in the nation will be able to cost effectively

access wind power. With this goal in mind, the U.S.

Department of Energy, NREL, and

other wind research organizations

are focusing on developing, testing,

and lowering the costs of turbine components that operate in lower speeds.

“We’re putting our whole research program

behind this—aerodynamics, understanding turbulence, advanced controls, advanced materials, power electronics,” says NREL’s Sue Hock,

wind energy technology manager. According to

Hock, only with continued low-wind research

will wind power reach its goal of being cost

competitive at low wind speeds with fuels by

2010—by bringing low-wind costs down from

6¢/kWh to 3¢/kWh, and even to below 2¢/kWh

by 2020. The Components of Wind Turbines A wind turbine is composed of blades turning a

rotor that is situated on top of a tower. Drivetrain

components (which can include generators, gearboxes, shafts, and bearings) transfer the slow-rotating mechanical energy from the rotor and

convert it to electrical energy. Researchers are

studying all of these components to make them

more effective and less expensive to manufacture

and operate.

To develop wind turbines that

produce inexpensive electricity

(3¢/kWh or less) in low-windspeed areas, researchers are

studying all the components of

a wind turbine—rotors (which

include blades and hub), towers, gearboxes, generators,

shafts, and controllers—to

make them more effective and

less expensive.
September 11 changed America. It changed our

belief that our shores were immune to attack. It

changed the way in which many of us do business. It changed our idea of how our freedoms

and our security are intertwined. 

And it changed our concept of how important energy security—especially in the form

of homegrown and diverse energy supplies—is to national security. 

President Bush has stated that “one of the keys to

energy security in America, and national security,

is to have a diversified energy base,” and that

“Over-dependence on any one source of energy,

especially a foreign source, leaves us

vulnerable to price shocks, supply interruptions, and...blackmail.” 

Blackmail, indeed, and worse—sabotage of energy supplies in an effort to

choke the vitality of our economy,

eviscerate the vigor of our way of life,

and curb our hard-won freedoms. 

It is no wonder, then, that

Secretary of Energy Spencer

Abraham has stated that “. . . energy and science programs should

be judged by whether they advance this nation’s energy—and

hence, national—security.” 

The R&D that NREL performs

for the Department of Energy

on renewable energy and energy efficiency is well

placed in this regard. 

When NREL began its mission 25 years ago, the popular

refrain was, “No one can embargo the sun.” Well, no one

can embargo or disrupt energy that isn’t spent, either—

such as the energy saved through energy-efficient technologies. We can incorporate energy efficiency into every

home, building, business, industry, and vehicle. And the

simple fact is, the more efficient you become, the less

vulnerable you are to disruptions of energy supply. 

And renewable energy? The technologies and the energy resources for renewable energy are homegrown. We

unravel the science, develop the technologies, and

manufacture the systems here, in America. And the resources themselves—sunshine, wind, water, biomass,

and the heat of the Earth—are vast, ubiquitous, safe,

and uninterruptible here, in America.

And it is in America that we can use these resources

and technologies to enhance national security. We can

enhance it directly through our national defense by using energy efficiency technologies to improve fuel efficiencies for a wide range of weapons platforms and to

(Top) Wind turbines generate

electricity for a U.S. Naval base

on San Clemente Island.

(Center) Solar wall provides heat and ventilation for a

helicopter maintenance hangar

at Fort Carson

in Colorado

Springs.

(Bottom) A solar electric panel

supplies power for refrigerating vaccines at a remote health

center. (Background) Biomassderived fuel supplements fossil

fuel used in a U.S. Army vehicle.

Solar arrays provide 15 kW of

supplemental power

for the Pentagon.

28
September 11 changed America. It changed our

belief that our shores were immune to attack. It

changed the way in which many of us do business. It changed our idea of how our freedoms

and our security are intertwined. 

And it changed our concept of how important energy security—especially in the form

of homegrown and diverse energy supplies—is to national security. 

President Bush has stated that “one of the keys to

energy security in America, and national security,

is to have a diversified energy base,” and that

“Over-dependence on any one source of energy,

especially a foreign source, leaves us

vulnerable to price shocks, supply interruptions, and...blackmail.” 

Blackmail, indeed, and worse—sabotage of energy supplies in an effort to

choke the vitality of our economy,

eviscerate the vigor of our way of life,

and curb our hard-won freedoms. 

It is no wonder, then, that

Secretary of Energy Spencer

Abraham has stated that “. . . energy and science programs should

be judged by whether they advance this nation’s energy—and

hence, national—security.” 

The R&D that NREL performs

for the Department of Energy

on renewable energy and energy efficiency is well

placed in this regard. 

When NREL began its mission 25 years ago, the popular

refrain was, “No one can embargo the sun.” Well, no one

can embargo or disrupt energy that isn’t spent, either—

such as the energy saved through energy-efficient technologies. We can incorporate energy efficiency into every

home, building, business, industry, and vehicle. And the

simple fact is, the more efficient you become, the less

vulnerable you are to disruptions of energy supply. 

And renewable energy? The technologies and the energy resources for renewable energy are homegrown. We

unravel the science, develop the technologies, and

manufacture the systems here, in America. And the resources themselves—sunshine, wind, water, biomass,

and the heat of the Earth—are vast, ubiquitous, safe,

and uninterruptible here, in America.

And it is in America that we can use these resources

and technologies to enhance national security. We can

enhance it directly through our national defense by using energy efficiency technologies to improve fuel efficiencies for a wide range of weapons platforms and to

(Top) Wind turbines generate

electricity for a U.S. Naval base

on San Clemente Island.

(Center) Solar wall provides heat and ventilation for a

helicopter maintenance hangar

at Fort Carson

in Colorado

Springs.

(Bottom) A solar electric panel

supplies power for refrigerating

vaccines at a remote health

center. (Background) Biomassderived fuel supplements fossil

fuel used in a U.S. Army vehicle.

Solar arrays provide 15 kW of

supplemental power

for the Pentagon.