TABLE OF

CONTENTS

INTRODUCTION

GREEN POWER

IS CLEAN POWER

CLEAN ENERGY

AT HOME

SELF GENERATION

FOR FARMERS AND RANCHERS

NEW 

TRANSPORTATION

OPTIONS

Clean Cities, Renewable Fuels, and New Cars

Stand-Alone PV and Small Wind Turbines

Climate Responsive and Solar Architecture,

Building America: Colorado, Solar Water

Heating, and Geothermal Heat Pumps

Wind Power, Solar Power, Hydroelectric

Power, Biomass Power, Concentrating Solar

Power and Geothermal Energy

What is Clean Energy and Why Is It 

Good for Colorado

1

4

14

20

24

Layout and design: Manzanita Graphics, LLC

Darin C. Dickson & Barry D. Perow

717 17th Street, Suite 1400 Denver, Colorado 80202

303.292.9298 303.292.9279

www.manzanitagraphics.com

CHOOSING WISELY 28
Take a stroll in Boulder,

Montrose, Fort Collins, or

Limon on a typical day and

you’ll see and feel two of

Colorado’s most powerful

clean energy resources. The

sun shines bright in the sky,

and there is likely to be a

pleasant 15-mph breeze. It’s

solar energy and wind energy

at your service, part of a broad

spectrum of clean

energy resources

available to us in

Colorado. 

Today, 98% of

Colorado’s energy

is produced from

fossil fuels—coal,

oil, and natural

gas. They are

plentiful and

inexpensive

today, but their

supply is finite

and their combustion has environmental consequences. In contrast, clean energy resources are constantly

replenished and economically

advantageous to the state. Clean

energy systems can be classified

in two general categories:

renewable energy and energy

efficiency. 

Renewable energy comes

either directly or indirectly

from the sun or from tapping

the heat in the Earth’s core:

¥ Sunlight, or solar energy, can

be used directly for heating,

cooling, and lighting homes and

other buildings, generating electricity, and heating hot water.

¥The sun’s heat also causes

temperature changes

on the Earth’s

surface and in the

air, creating wind

energy that can

be captured with

wind turbines. 

¥Sunlight causes

plants to grow

and is the source

of all life. The

organic matter that

comes from plants

and from animal

wastes is known as

biomass. It can be

used to produce

electricity, transportation fuels, or chemicals

for consumer products. The

use of biomass for any of these

purposes is called bioenergy. 

¥Rain, created from water

evaporating when exposed to

sunlight, collected in rivers 

WHAT IS 

CLEAN ENERGY?

INTRODUCTION

1

Newly arrived at Colorado in

1998, wind energy is now

available to the majority of

electricity customers in

the state.

Warren Gretz, NREL, PIX - 07158
and streams, can be turned into

electricity called hydropower. 

¥Geothermal energy taps the

Earth’s internal heat, carried by

steam or hot water. It can generate electricity or be used

directly to heat and cool buildings.

And energy-efficient technologies minimize the energy used

to perform work, whether it be

running a car or lighting a

home.

Why Is Clean

Energy Good

for Colorado?

Renewable energy and energy

efficiency benefits the state in

many ways.

Environmental Benefits

Renewable energy technologies are clean sources of energy that have a much lower

environmental impact than

conventional energy technologies. Energy-efficient technologies minimize conventional energy use and greatly

reduce environmental impacts.

Energy for Eternity

Although projections vary

widely, no one disputes that

we will eventually run out of

fossil fuels. Renewable energy

will not run out as long as the

sun shines on the Earth.

Jobs and the Economy 

Most clean energy investments

are spent on materials and

workmanship to build and

maintain renewable energy

facilities and energy-efficient

equipment, rather than on energy imports. Colorado’s clean

energy investments can be

made within our state. This

means energy dollars stay home

to create jobs and fuel local

economies, rather than going

out of the state or overseas. 

To put it simply, Coloradans

have many clean energy choices

that are available today at reasonable cost. Most of us can

purchase wind-generated electricity from our electric utilities.

All of us can save money by

purchasing energy-efficient

appliances and using energy

wisely at home. Those of us in

remote areas can benefit today

from solar and wind electricity

Clean energy will

help us keep

Colorado’s environment beautiful

for many generations to come. 

2

David Parsons, PIX - 00480
generation. And we can all

drive fuel-efficient cars and

trucks, or even purchase alternative fuel and hybrid electric

vehicles. 

This booklet will tell you what

your clean energy choices are,

where they are being used in

Colorado today, and provide

you with contacts to help you

obtain more detailed information. Since we have the power,

let’s make it clean power.

For more information:

Clean Energy

Basics—National Renewable

Energy Laboratory

www.nrel.gov/clean_energy

Provides a definition of the

different kinds of renewable

energy and how they can be

used in the future. 

Governor’s Office of Energy

Management and

Conservation (OEMC)

www.state.co.us/oemc

OEMC is the lead agency for

energy efficiency issues in the

state.

Colorado Energy

www.coloradoenergy.org

Provides information about

events, programs, legislation,

publications, and other information related to clean energy

in Colorado. This Web site is

funded by the OEMC.

3
Today, Colorado consumers

can choose two types of renewable energy for their electricity:

wind and solar. Other types of

renewable energy, such as

hydropower and landfill gas

(methane), are mature technologies and already form part

of the electricity generation

system. These types of renewable energy technologies are

not marketed separately as

clean energy in Colorado as in

other states. Other types of

renewable energy electricity

generation, such as geothermal,

mixing biomass with coal

(cofiring), and some types of

solar technologies (concentrating solar power), do not yet

operate commercially in

Colorado. Nevertheless they

could based on the experience

in other states of operating and

marketing them to consumers

as clean energy. 

Wind Power

You have most likely seen

Colorado wind power in action

on TV newscasts. The

Ponnequin Wind Facility,

located in northeastern

Colorado, provides up to 20

megawatts of power to more

than 15,000 customers, including 300-plus commercial customers and four wholesale customers—making it the largest

and most successful utility

green-pricing program in the

country. 

Through Windsource, Public

Service Company of Colorado

offers residential and business

customers blocks of 100

kilowatt-hours (kWh), with

each block priced slightly

above existing electric rates.

Customers can choose how

many blocks of wind energy

they would like to purchase up

to 100% of their electric load.

One block is approximately

15% of an average home’s

electric usage. The average

home in Colorado uses 600

kWh of electricity each month.

Public Service Co.’s

Windsource is the largest, but

not the only, such program, in

Colorado. Twenty utilities offer

their customers the option to

choose wind energy, including

Colorado Springs Utilities and

Holy Cross Energy, which purchase wind power from Public

Service Co.; and the municipal

utilities of Fort Collins,

Loveland, Longmont, and

Estes Park, which purchase

4 GREENPOWER

IS CLEAN POWER
wind power from the Platte

River Power Authority. In

Aspen and Glenwood Springs,

the municipal utilities provide

wind power to all customers as

part of their regular electric

service. In addition, 14 of

Tri-State Generation and

Transmission Association’s 32-

member rural electricity cooperatives also offer wind power

to their customers. 

Today the majority of

Colorado electricity consumers

have wind power as an option

from their electric power companies.

While the use of wind energy

is growing rapidly, there is

room for much more.

Colorado, like all of the states

that occupy the Great Plains,

has a large wind energy

resource. According to the

National Renewable Energy

Laboratory (NREL) in Golden,

our state has enough wind

energy to supply 9% of the

electricity consumption of the

lower 48 states. In this calculation, urban areas, wetlands,

parklands, and national forests

are excluded from wind power

For more information:

Wind Power: Clean Energy for Colorado

www.cogreenpower.org

Sign up with one of Colorado’s power

companies offering wind energy under a

green-pricing program or find out more

about wind energy. 

Public Service Company of Colorado

www.ncenergies.com

1.800.824.1688

Sign up for Windsource. 

Clean Energy Basics—NREL

www.nrel.gov/clean_energy/wind.html

Has a more detailed explanation about how

wind energy works with links to resources

for homeowners, business owners, and students and teachers. 

U.S. Department of Energy’s (DOE)

Energy Efficiency and Renewable Energy

Wind Page

www.eren.doe.gov/RE/wind.html

Provides links to publications, research,

industry associations, and information about

wind projects around the country. Or call

DOE’s Energy Efficiency and Renewable

Energy Clearinghouse hotline at

1.800.363.3732 for free fact sheets on

wind energy.

Public Service

Co.’s Ponnequin

Wind Facility,

located near I-25

and the Wyoming

border, is

Colorado’s first

utility-scale wind

power plant. 

Warren Gretz, NREL, PIX - 07158

5
development. With a large

resource in the state and low

costs compared with other

sources of renewable energy,

wind is poised to make a

major contribution to the environment and future economy

of the state. 

Solar Power 

Electricity from the sun is

becoming an increasingly

viable option for Colorado

consumers. Coloradans interested in generating their own

electricity using solar-electric

photovoltaic (PV) technology

have been waiting in line to

participate in the Solar Rebate

Program. Funded by the

Governor’s Office of Energy

Management and

Conservation, the Colorado

Solar Energy Industries

Association ran the successful

program in 1998 and 1999 to

give rebates to more than 70

installations on homes.

Altogether, more than 100

families applied for rebates. 

PV Goes Mainstream

As of January 2000, more than

100 Coloradans have chosen to

generate their own electricity

using solar-electric PV technology, while remaining connected to the utility power

grid. Thanks to dramatic price

drops and growing consumer

interest in clean energy options

that offer self-sufficiency, PV

technology is becoming more

popular. The technology is

often the cheapest source of

power for small and standalone applications, but has

only recently become affordable to homeowners.

A number of Colorado electric

utilities have even begun offering voluntary incentives to

their customers who choose

solar electricity to meet some

or even all of their household

electrical needs. Public

Service Co., Fort Collins

Utilities, Holy Cross Energy,

Colorado Springs Utilities and

Delta Montrose Electric

Association offer retail credit

to their customers who feed

excess solar electricity back

into the utility power lines.

Public Service Co. has teamed

up with Altair Energy, a

Golden-based energy service

company, to offer turnkey

solar electric services through

an unregulated program called

Solarsourcesm

.

6

The Renewable

Energy Trust supported installation

of these PV-integrated roofing

shingles at the

Mount Evans

Observatory in

1997. The roof

generates about

65% of the electricity needed by

the observatory.

Joe Burdick, PIX - 07521
A Shining Example

In February 1999, the Aspen

Community Office for

Resource Efficiency, the City

of Aspen and Holy Cross

Energy launched Sun Power

Pioneers, the first solar production incentive program in

the country. Participating

businesses and homeowners

who install a grid-connected

photovoltaic (PV) system are

paid a solar production incentive of $0.25/kWh. Incentives

are capped at $3,000 per system, and the production incentive is good for three years. 

The goal of Sun Power

Pioneers is to install 30 to 60

kilowatts (kW) of gridconnected PV in the Aspen

area. 

Solar on Schools

PV systems are going up on

schools around the state. The

installations are funded by the

Governor’s Office of Energy

Management and Conservation,

the Utility PhotoVoltaic Group

(UPVG), and Public Service

Co.’s Renewable Energy Trust.

The Trust is a special tax

deductible fund created to

develop renewable energy

sources for nonprofit, educational use across Colorado. It

is managed by the Denver

Foundation and supported

through contributions by

Public Service Co. customers

on their monthly utility

bills. Today 12,000 Public

Service Co. customers contribute a few pennies each

month to make the program

possible.

Because of these contributions,

26 school buildings now boast

the latest in PV technology on

their rooftops. The systems

are typically rated at 2 kW and

cost $20,000 to install. The

systems reduce the utility bills

of the school and support science curriculum for students.

Each PV system comes with a

computerized display so students can track electricity generation and weather data

minute by the minute. 

Teachers take advantage of the

schools’ solar systems to explain

the physics of solar energy, the

electromagnetic spectrum, how

the components of PV systems

function, and more. According

to Bill Alley, principal of

Carbondale Elementary School,

"The solar electric system on our

school will allow our students to

learn firsthand about an important natural resource, the sun." 

7

This 2-kW PV

system mounted on the roof

of the Powell

Middle School

in Littleton

meets some of

the electricity

needs of the

school and

provides students opportunities to learn

about solar

energy.

Altair Energy, PIX - 09075
In addition to schools, the Trust

installed 35 renewable energy

projects for use by nonprofit

agencies and community organizations throughout the state. 

Hydroelectric

Power

Hydropower is the largest

source of renewable energy for

both Colorado and the entire

country as a whole. About 4%

of Colorado’s electricity comes

from hydroelectric generating

stations, mostly from a handful

of large dams built by the U.S.

Bureau of Reclamation in the

1950s and 1960s.

Theoretically, any flow of

water from a higher to lower

elevation can be used to generate electricity, including dams

and pipelines. Small-hydro

projects avoid the environmental problems of habitat destruction and fish mortality normally associated with large dams.

Several cities that obtain their

drinking water from mountain

sources also generate electricity from small-hydro stations

on their municipal water supply systems. Boulder began

using hydropower almost 20

years ago, and it has proven to

be very popular because it

lowers water costs to the city.

Including one facility under

construction, there are seven

generating stations on the

Boulder water supply provid8

For more Information:

Public Service Co.

www.ncenergies.com

1.800.824.1688

Provides information about how to

make a contribution to the

Renewable Energy Trust and how

to apply for funding. 

Colorado Consumers Guide to

Purchasing a Solar Electric

System , published by OEMC in

1998.

www.state.co.us/oemc/pubs/

conguide/index.htm.

For a list of lenders and brokers

who will finance a PV system on

a home, visit

www.state.co.us/oemc/pubs/

pvlenders/index.htm.

The Colorado Solar Energy

Industries Association

www.coseia.org

1.800.633.9764

Provides information about solar

installations and contractors in the

state. 

Altair Energy-Solar Schools

Program

www.coloradosunshine.com/

alliances/school.htm 

Describes services provided to

schools by the Renewable Energy

Trust. 

Schools Going Solar

www.schoolsgoingsolar.org

Lists suggested classroom activities of other utility-school partnerships across the country.
PV systems operate almost anywhere. The system output varies less than 15% from

the best solar resource in the state to the worst. Most days in Colorado are sunny,

but even on cloudy days PV systems produce about 25% of their output.

This map represents average output for a 1-kW system facing south tilted toward the

sky at the angle of the latitude, typical for a rooftop application. To estimate the yearly output for a system of a different size, multiply by the system rating (kW). Take,

for example, a 2-kW system located in Durango. Using the average retail price of

electricity in the state as $.074 per kWh, you can calculate the number of years to

pay for the cost of the system, simple payback, as follows

System Rating Yearly Output Yearly Savings Simple Payback

2 kW 4,200 kWh $310 20 to 40 years

Electricity Production from a 1-kilowatt

Grid-Connected PV System

9

This mountain home features a

3.6 kilowatt (kW) PV system

that meets about 50% of the

family’s household electric

needs and provides back-up

power to the family’s critical

appliances during weatherrelated utility outages. The

family receives credit from

Public Service Co. for excess

solar electricity they sell back

to the utility. 

Altair Energy, PIX - 07899
ing more than 11,000 kW of

electric power. Today the city

of Boulder generates enough

electricity at its small-hydro

stations to supply 7% of the

city’s needs. 

Biomass Power

Biomass is the second largest

source of renewable energy in

the country and makes a small

contribution to Colorado’s

energy mix. Just about anything that is, or once was a living organism can be classified

as biomass—forestry residues,

grasses, and animal wastes.

Biomass has been used to create bioenergy in the form of

electricity and liquid fuels.

Today there are a three types

of biomass facilities operating

in the state, including biogas

from landfills, wastewater

facilities, and animal farms.

Potentially trash wood current

ly going to landfills could also

be used for energy. 

Biogas

Colorado has four biogas facilities that harvest methane produced from the decomposition

of biomass in landfills and

wastewater treatment facilities.

Common bacteria that appear

in nature consume the waste

and produce methane.

Methane is a very powerful

greenhouse gas that can be

harmful to the environment and

health if left to vent to the

atmosphere. However, when

contained, it is quite suitable

for producing heat and electricity, much the same as natural

gas. One landfill methane

recovery plant is operating in

Littleton, and a total of three

wastewater recovery plants are

operating in Denver and

Boulder. They range in size

from 200 kW in Boulder to

8,000 kW in Denver.

10

The city of

Boulder obtains

the equivalent of

7% of its energy

from small hydroelectric facilities,

such as this one

at the Betasso

Water Treatment

Facility.

Bill Monk, PIX - 08248
Animal Farms

Animal manure can present an

environmental problem when

it is concentrated on largescale animal feedlots. But this

animal manure was once

plants and grains; thus, it is

biomass that can be source of

clean energy when converted

to a gas in an anaerobic

digester and combusted in a

turbine generator. The anaerobic digester uses bacteria to

break down the manure, producing gas in much the same

way as a municipal treatment

facility does. 

Colorado has one animal feedlot facility near Lamar that

operates an anaerobic digester

to produce energy from animal

waste. In general, such facilities are not as common in

North America as they are in

other parts of the world.

While there are fewer than 100

such facilities operating in the

United States, there are more

than 600 operating in Europe

and as many as a million

small-scale facilities in Asia. 

Nevertheless, a small number

of owners in Colorado are

investigating the practicality of

turning manure into energy,

especially after passage of

Amendment 14 in the 1998

election regulating the operation of hog farms. The

Governor’s Office of Energy

Management and Conservation

is currently assessing technical, economic, and environmental aspects of biogas-toenergy possibilities at commercial swine production centers in the state. 

11

Solar Troughs

Parabolic troughs collect the sun s energy as heat for generating electricity in a conventional

steam turbine.
Used Wood in Urban Areas

A recent study sponsored by

DOE suggests that the amount

of used wood in urban areas is

proportional to the size of the

local population. Wood trash

comes from industries that use

and then dispose of wood

products, such as beams and

studs used in construction, pallets used in trucking, and even

tree trimmings. Most of this

used wood winds up in landfills.

This wood going to landfills

can potentially be used for

electricity production. Several

utilities in the East are conducting experiments with mixing used wood in small percentages with coal in their

power plants. 

Concentrating

Solar Power

One type of solar power technology marketed in California

has the potential to operate just

as well in Colorado. Called

concentrating solar power, the

technology combines the environmental benefits of solar

with the control of natural gas

power generation. Such

hybrids, combinations of conventional and newly developing solar technologies, are

clean energy options to consider for the near future.

Today, concentrating solar panels are used at a small number

of locations in Colorado,

including the Adams County

Detention Center in Aurora and

the Jefferson County building

in Golden. These —facilities

use the concentrating systems

to generate hot water for showers, laundry and other needs,

but not for electricity. 

The principle these systems

operate on, however, is similar

to those that generate electricity. Sunlight is focused along

the (focal) line of series of parabolic mirrors. For electricity

generation, more mirror area

and higher concentrations of

sunlight generate steam instead

of hot water. The steam runs

through a conventional turbine

generator to produce electricity. When it is cloudy, gas-fired

backup burners kick in to generate the steam. 

The world’s only operational

concentrating solar power

plants are located in the

Mojave Desert near Barstow,

California. Altogether there are

nine such power stations with a

combined rated capacity of 350

megawatts that have been

operating since the 1980s.

They take advantage of the

large amount of direct sunlight

available in the Mojave Desert. 

A similar solar resource exists

throughout the southwestern

United States, including the

San Luis Valley and Four

12
Corners regions in southern

Colorado. In Alamosa, for

example, each square meter

receives about 2,500 kWh

per year of direct sunlight,

90% as much as Barstow. 

Although feasible, no plans

are currently underway to

build a concentrating solar

power plant in southern

Colorado. The main reason

is cost. The average (levelized) cost of electricity

from such a plant would be

about $0.13 per kWh, substantially more than the average cost from conventional

power plants and almost

twice the average retail price

of electricity in Colorado.

The cost of concentrating

solar power is not, however,

more than some green power

programs already operating

in Colorado or other states.

Whether concentrating solar

power can become a viable

option for Colorado consumers remains an open

question for now. 

Geothermal

Energy

Geothermal energy, already

the third largest source of

renewable electricity in the

country, is a promising

resource in the West. Where

available, geothermal energy

can provide electricity or

inexpensive heating for

homes and other buildings.

13

For more information:

DOE’s Denver Regional

Office

www.eren.doe.gov/dro

303.275.4826

Provides information about

biomass development and

demonstration projects supported by the Western

Regional Biomass Energy

Program. 

Governor’s Office of Energy

Management and

Conservation

www.state.co.us/oemc/

programs/wetlands.htm

For information on a program

for using constructed wetlands

to treat wastewater at livestock

farms. 

Green Power Network

www.eren.doe.gov/greenpower

For information on green electricity markets and utility

green pricing programs around

the country. 

Colorado Renewable

Energy Society

www.cres.gen.co.us

303.806.5317
Colorado’s home designers,

builders, and homeowners are

national leaders when it comes

to clean energy systems. The

clean energy combination of

renewable energy systems,

energy-efficient design and

energy-efficient appliances (like

those with an Energy Star¤

label) can reduce utility bills

and help us maintain Colorado’s

high environmental standard far

into the future.

Over the past two years, home

builders have constructed more

than $1 billion worth of "green

homes" in Colorado, far more

than any other state in the

nation. These homes are part of

the Built Green Colorado program, sponsored by the

Colorado Home Builders

Association and other regional

home builders, Public Service

Co., E-Star¤ Colorado, and the

Governor’s Office of Energy

Management and Conservation.

Built Green Colorado homes

must meet strict energy efficiency and water conservation standards. 

Each registered home must

receive an energy rating of at

least four stars (80 points as

certified by E-Star¤ Colorado)

or be built to national Model

Energy Code 1993 standards.

The E-Star¤ Colorado program, conducted by the statesupported Energy Rated Homes

of Colorado, gives E-Star¤

energy ratings for both new and

existing homes. The E-Star¤

energy rating is a score

expressed on a scale from 0 to

100 points, and can be thought

of as a residential miles-per-gallon sticker. E-Star¤ evaluations have been done on almost

5,000 Colorado homes, both old

and new, since 1995. 

A Built Green or E-Star¤ compliant home is energy efficient,

comfortable, and economical to

run. The rating can help home

buyers and owners more easily

qualify to purchase energyefficient homes or make energyefficient improvements in the

purchase, home equity, or refinancing process.

CLEANENERGY

AT HOME

This McStain

Enterprises home

at Lexington

Fairway in

Lafayette is an

energy-efficient,

single-family home

constructed using

Colorado Built

Green criteria.

14PIX - 07769
Climate

Responsive

and Solar

Architecture 

Colorado homeowners and

builders have a wide range of

choices when it comes to

incorporating clean energy

systems into their homes and

buildings. 

Everything from the materials

used to build the exterior envelope to the insulation, roof

overhangs, landscaping,

siding, heating and cooling

systems, lighting, and appliances and equipment that service the building can add to or

minimize its overall energy

use. Several federal and state

programs around Colorado are

promoting the concept of the

"whole house" strategy, tying

all of these components

together to create high performance clean energy

systems.

In Clear Creek County,

Colorado, Otto Van Geet is the

proud owner of a high

performance home. Built

using Van Geet’s own architectural design, the home is located at an altitude of 9,200 feet.

The passive solar home is constructed with dry-stack concrete blocks. Some of the

homes energy-efficient features include: ¥1,200-watt PV system

for electricity

Appliances and equipment with the

Energy Star

¤ label can help you

save energy and money in your home

or business.

For more information:

Energy Star¤

U.S. Environmental

Protection Agency, and DOE

www.energystar.gov

888.STAR.YES (782.7937)

For information on energy-efficient appliances and equipment. 

American Council for an

Energy-Efficient Economy

www.aceee.org

For a list of the most efficient

appliances, information on efficiency standards and technologies for buildings, and publications. See, for example,

Consumers Guide to Home

Energy Savings, 1999, at

aceee.org/consumerguide/index.

htm.

Energy Rated Homes

of Colorado

www.e-star.com

1.800.877.8450

Rate your own home or contact

a professional to come do it

for you. 

15
16

¥Active solar water-heating

for domestic hot water and

heating

¥Passive solar design for heating

¥Energy-efficient lighting

using T-8 and compact fluorescent lights.

Because of the home s small

cooling requirements, no

cooling system is needed.

Natural ventilation cools thehome in the summer. An

active solar water-heating

system and wood-burning

stove provide heating in the

winter.

(Top)

The Van Geet residence in Idaho

Springs obtains

the majority of its

energy needs from

the sun. 

(Bottom)

This energy-efficient home in

Broomfield features low-e windows; radiant floor

heating; highly efficient furnace,

water heater,and

engineered wood

wall framing. 

For more information:

DOE’s Solar Buildings

Program 

www.eren.doe.gov/solarbuildings/sbm.html 

For calculating savings

from a solar hot water system at your house. 

Colorado Solar Energy

Industries Association

www.coseia.or

1.800.633.9764

Find a contractor or find out

about cost and performance

of specific systems. 

DOE’s Office of Building

Technology, State and

Community Programs

www.eren.doe.gov/buildings

A great source of information on energy efficiency

and low-energy buildings. 

Dave Parsons, PIX - 08226 Warren Gretz, NREL, PIX - 07921
Building

America:

Colorado

Wonderland Custom Builders is

one Colorado home builder

moving toward high performance housing. Wonderland participates in DOE’s Building

America program, which unites

members of the building industry in an effort to produce higher quality, more energy-efficient

homes. The primary goals of

the program are to reduce energy use, construction time, and

waste by as much as 50% without increasing costs. In addition

to improving the quality and

performance of today’s homes,

research conducted by Building

America teams provides valuable information for homes of

the future.

Wonderland Custom Builders

has completed construction of

its 3,500 sq.ft. house at its

Broadlands development, which

was featured in the 1999

Denver Parade of Homes. This

prototype home includes several

energy-efficient features: low-e

windows; radiant floor heating;

highly efficient furnace and

water heater; and engineered

wood wall framing. The house

uses significantly fewer building resources to achieve energy

savings of 20% to 50% over

similar houses built to meet

conventional standards. 

This home in

Golden has

eight solar

panels on its

south-facing

roof that provide heat for

an 80-gallon

domestic hot

water tank

and 400 gallons of water

for home

heating.

Dave Parsons, PIX - 05479

17
Solar Hot Water System Production Per Unit 

of Collector Rating

This map shows the thermal output of a solar hot water system in metric units based on a perunit rating of the capacity of the solar panels (per thousand British thermal units per day

[kBtu/d]). You can compare this output with that of a conventional electric water heater. 

18

Solar water-heating systems have solar collectors that face the sun. The systems

either heat the water directly or heat a working fluid that, in turn, heats the water.

The solar-heated water moves by pumping (active) or by convection (passive)

through a system of pipes that supply hot water and heat to a home. In most

cases, your solar system will have a conventional gas or electric back-up system.

Using the sun to heat your water saves you money on your monthly utility bill.

Because Colorado has a warm, sunny climate, we can tap the power of the sun to

meet most of our hot water needs. Once the higher initial costs ($1,500-$3,000) of

your solar water-heating system are recovered through lower utility bills, you’ll save

money for the remainder of the system’s lifetime. When cost is included as part of

a mortgage on a new home, solar water-heating systems can often increase a

homeowner’s monthly cash flow from the first day of ownership. 

Take, for example, a solar hot water heater consisting of two solar panels with a combined system rating of 30 kBtu/day located in Pueblo.

The panels are mounted on a roof facing south and tilted toward the sky at the

angle of the latitude. In Colorado’s sunny climate, this would be sufficient to supply

about 70% of the hot water needs of a family of four. The savings are:

System Rating Yearly Output Annual Savings Simple Payback 

30 kBtu/day 3,600 kWh thermal $266 6 - 12 years 
Geothermal

Heat Pumps

Many parts of Colorado often

experience seasonal weather

extremes, from scorching heat

in the summer to sub-zero

temperatures in the winter. Yet

a few feet below the Earth’s

surface, the ground remains at

a relatively constant temperature. Because of these seasonal

temperature extremes,

Colorado is an excellent place

for use of geothermal or

ground-source heat pumps

(GHPs).

A GHP system works by moving the heat from the earth (or

a groundwater source) into

your home in the winter,

pulling the heat from the house

and discharging it into the

ground in the summer. Like a

cave, the ground temperature

is warmer than the air above it

during the winter and cooler

than the air in the summer.

Heat pumps use underground

piping loops, installed vertically or in horizontal trenches

100 to 400 feet below the

surface. 

While the initial purchase

price of a heat pump is often

higher than that of a comparable gas-fired furnace and central air-conditioning system, it

consumes 25% to 75% less

energy. 

This is because heat pumps

deliver three times more energy in the form of heating and

cooling to the home as they

consume in electricity. 

For example, a geothermal

heat pump system costs roughly $7,500 for a 3-ton unit, a

typical residential size. In

comparison, conventional

heating and cooling systems

with a similar capacity would

cost about $4,000 to $5,000.

When included in the mortgage, however, the homeowner

has a positive cash flow from

the beginning because of the

monthly savings on energy. 

For more information:

The Geothermal Heat

Pump Consortium

www.ghpc.org,

1.800.255.4436

Provids extensive information

on heat pumps.

19
Small solar and wind electric

systems often make sense for

Colorado farmers and ranchers. They are often the cheapest and most reliable way to

provide water for irrigation

and animals, power outbuildings, or secure fences. With

the cost of conventional power

line installation at as much as

$10,000 per mile from a utility, an investment of $200 to

$5,000 in a solar or wind

power generator makes more

sense. 

Portable PV Well Pump

Eastern Colorado ranchers,

like John Buol, are always

looking for better ways to get

water to their thirsty livestock

herds. When Buol wanted to

lease a pasture near the Bonny

Reservoir, he talked to a driller

about using photovoltaics (PV)

to pump water from an old

well next to a fallen windmill.

The driller, Wayne Parrish, had

been working with PV-powered pumping systems for a

while. Parrish put together a

simple portable system with a

340-watt PV panel and a

direct-current motor attached

to a pump-jack all mounted on

a trailer. The system’s total

cost was $5,000. According to

Buol, "You just pull the trailer

up to the well, tie it up to the

pump rod, and pump the water. 

PV Electric Fences

Don Curry believes electric

fences are the best way to keep

his cattle where he wants them.

They are more efficient, cheaper, and safer than the 5-wire

barbed fence commonly used

by ranchers. But, they weren’t

always practical. 

SELF

20

GENERATION

FOR RANCHERS

AND FARMERS

These ranch hands assembled John Buol s PV-powered

water pump in just 20 minutes. When Buol moves his

herd to another pasture, he takes his pump with him.

Rick Hinricks, Boulder, Colorado
Tying the fences into the power

grid was cost-prohibitive, and

battery-operated fences don’t

last long enough on a large

ranch. PV chargers seemed to

be the way to go for Curry. "It

just doesn’t pay to keep changing batteries up there every

other day or so," said Curry.

"These solar chargers last all

summer and longer. I’ve had

three of them here for three

years—same systems, same batteries." The 3-watt PV panels

charge the 6-volt rechargeable

gel-cell batteries for up to 21

days, and installation of the

charger takes about three

minutes, according to Curry.

Rural Electric Co-ops

Profit from PV

After winter storms broke 645 poles on its

electricity lines in 1988, K.C. Electric

Cooperative in Hugo was looking for alternatives. K.C.’s 90 miles of lines to stock

wells were costing them more in maintenance than they could recover from fees.

The co-op decided it was time to consider

using PV. 

K.C. installed solar-electric systems that

operate reliably and pump water for livestock the day after a winter storm or during the hot, calm days of summer. The coop owns and maintains the systems, and

charges customers a flat monthly fee,

depending on the size of the system.

Ranchers like the PV pumping systems

because they can be located where they

are needed, no matter how remote. They

operate consistently.

This portable PV system pumps 1.75 gallons per

minute from a 60-foot well to fill a remote stock tank.

For more information:

National Renewable

Energy Laboratory

www.nrel.gov/pv

call 303.275.4363.

To obtain a copy of

Electricity When and

Where You Need It: From

the Sun—Photovoltaics for

Farms and Ranches ,

January 1997,

NREL/BR-412/21732. 

Colorado Solar Energy

Industries Association

www.coseia.org

1.800.633.9764

Provides information about

equipment suppliers.

K.C. Electric Cooperative, PIX - 03396

21
Small Wind

Turbines

Colorado settlers in the 19th

century used water-pumping

windmills to bring water to

thirsty farms and ranches.

Today, windmills still serve

this function. However, due to

advances in technology, the

wind is now being used to

generate electricity as well. 

Small wind turbines are relatively simple and hardy pieces

of machinery. They consist of

a turbine, blades, a tower,

wiring, and associated electrical equipment. For remote

homes and stand-alone operations, small wind turbines

might use a battery for energy

storage. Or for grid-tied systems, they will come with an

inverter to interconnect with

the utility. 

Tower height is very important

for wind turbines because

wind speeds increase with

height, and the available wind

power increases exponentially

with wind speed. 

You can estimate what a small

wind system will produce at a

certain location if you know

the average wind speed. A

manufacturer will be able to

tell you the output to expect

from a particular turbine. 

For more information:

DOE’s Wind Energy

Program

www.eren.doe.gov/wind/

homeowner.html 

Provides information on small

wind energy systems for

homeowners and ranchers,

including sections on economics and wind energy basics. 

Call DOE s Energy

Efficiency and Renewable

Energy Clearinghouse

(EREC) at 1.800.363.3732 for

a free short brochure on small

wind systems.

American Wind Energy

Association (AWEA)

www.awea.org/smallwind.html

202.383.2500

For industry standards on

equipment and a list of hardware suppliers. AWEA, also

has numerous publications

available, such as Wind

Power for Home and

Business , and an instructive

titled, An Introduction to

Residential Wind Systems .

22

This home in Boulder County obtains most of its

electricity from a small wind rated at 3-kW and a PV

system rated at 8.6 kW. The home has all electric

appliances, including a geothermal heat pump for

heating and cooling, a range, a washer and dryer,

and even an electric car.

Jim Green, NREL, PIX - 09074
The map presents output for a 1-kW system;

for systems of different sizes multiply the

result by the rated capacity of the turbine.

The following assumptions were used to estimate small wind turbine productivity: wind turbine tower height is assumed to be 82 feet

(25 m). Wind turbine sites are assumed to be

flat with good exposure to prevailing winds

Example

For a 10-kW wind turbine in Sterling, using the

average retail cost of electricity in the state for

residential customers of $0.074 per kWh: This 10-kilowatt wind turbine designed to

supply most of the electricity for an

average electric home in areas with an

average wind speed of 12 mph.

Yearly Electricity Production from a 1-kW Wind

System in Colorado

Colorado Renewable Resource Database Colorado Renewable Resource Database, PIX - 02102

23

10 kW 23,700- 28,500 kWh $1,754-2,109 18-22 years

Rating Expected Yearly Output Yearly Savings Typical Payback 
One of the most important

environmental decisions we

make as consumers is how we

transport ourselves from place

to place. Exhaust from cars

and trucks on Colorado roadways is one of the leading

sources of regional air pollution

and the buildup of greenhouse

gases in the atmosphere.

Vehicle exhaust has grown

steadily cleaner over the last 20

years, but the fact is, there are

more vehicles on the road, and

those vehicles drive more miles

than ever before.

As individuals, we can lessen

the environmental impact of

our transportation choices

through two approaches: reducing the miles we travel in our

own vehicles, and making the

miles we do travel as clean and

efficient as possible. 

How do we reduce our miles

traveled when we need to get to

work, run errands, or take our

children to school and soccer? 

We can take mass transit,

walk, bike, carpool, move

closer to work, or telecommute. These are familiar alternatives, but they’re as important as ever before.

Clean Cities

It takes cooperation among

many organizations to help

clean up the air. The U.S.

Department of Energy s Clean

Cities program is bringing

broad coalitions of state and

local governments, car manufacturers, fuel suppliers, and

nonprofit organizations to

address the transportation sector s contribution to pollution.

Clean Cities encourages the

use of Alternative Fuel

Vehicles (AFVs) that run on

cleaner fuels. These fuels

include natural gas, ethanol,

methanol, liquified natural gas,

and even electricity.

In Colorado, Clean Cities has

three coalitions working for

cleaner air located in:

Denver

Colorado Springs

Weld and Larimer Counties

and Rocky Mountain

National Park

These coalitions are proving

that AFVs are not concept cars

of the future, they are available

today and are being used by

thousands of Coloradans.

NEWTRANSPORTATION

OPTIONS

24
AFVs need special fueling

stations, and there are many

already in service in Colorado

and across the country. In

Colorado alone, there are nearly 150 alternative fuel stations.

Your local gas station may

even sell alternative fuels.

Most of the stations in

Colorado provide compressed

natural gas and propane, but

there are a few ethanol and liquid natural gas stations as

well. AFVs are the right environmental and economic

choice for fleets and general

consumers. 

Denver’s 16th Street Mall

The 16th Street Mall in downtown Denver operates hybrid

electric buses to transport business professionals, shoppers,

and tourists from one side of

the mall to the other. These

fuel-efficient buses have been

operational since mid-1999

and have proven so effective

that another 36 are on order.

They are fueled with gasoline, 

Colorado s Clean Corridor

The Clean Cities participants in Colorado (Colorado Springs, Denver, Weld and Larimer

Counties, and Rocky Mountain National Park) have teamed together to develop a 170-mile

Clean Fuels Corridor that ensures ample alternative fuel stations from Colorado Springs to the

Wyoming border. The goal is to give AFV drivers plenty of refueling options to make their trips

as worry-free as they would be driving a gasoline-powered vehicle. There are 10 other Clean

Cities corridors across the country where consumers with AFVs can drive with confidence. 

Compressed Natural Gas Fueling Stations

25
but use a battery pack that

helps with acceleration. 

Rocky Mountain National Park

Poor air quality is not just a

city issue. It also affects

national parks and other rural

areas. Rocky Mountain

National Park is dedicated to

using AFVs to help reduce air

pollution and noise in certain

areas. The park, a Clean

Cities participant, currently

has several compressed natural

gas vehicles and electric pickup trucks in operation. In

addition, the park is trying to

replace gas guzzling, polluting,

and noisy snowmobile engines

with those that can run on

alternative fuels. 

Renewable

Fuels

To ensure there is no air in

their beer, Coors Brewing

Company overfills each can it

produces at its facility in

Golden. This results in 22 million gallons per year of wasted

7%-alcohol condensate. Coors

has joined forces with Merrick

& Company and Total

Petroleum to recycle the condensate to produce more than

1.5 million gallons of 100%

fuel-grade ethanol. 

Total Petroleum uses the

ethanol as an oxygenate to

make cleaner-burning gasoline,

which is distributed along

Colorado s Front Range.

Colorado law requires gasoline

stations to sell oxygenated fuel

during the winter to combat

carbon monoxide pollution.

Ethanol oxygenates are the second largest use of renewable

energy in the state. Ethanol is

a cleaner fuel than gasoline

and does not cause problems

to car engines.

New Cars

In early 2000, Honda’s Insight

became the first hybrid electric

vehicle (HEV) available in

Colorado. Toyota will soon follow suit when it introduces its

Prius HEV. An HEV runs on

both fuel and electricity. It

uses a small internal combustion engine or fuel cell in combination with a small battery

pack to assist with acceleration

and hill climbing. With this

setup, HEVs can achieve 70 to

80 miles per gallon of gasoline.

In the near future,

Daimler/Chrysler, Ford,

General Motors, and others

Hybrid electric

buses transport

hundreds of

people each day

in Denver’s

downtown mall.

Denver currently

operates two

hybrid electric

busses running

on compressed

natural gas and

has plans to

purchase an

additional 34 in

the future.

26 Warren Gretz, NREL, PIX - 06125
will introduce hybrids of their own.

These cars are harbingers of a leap

in automobile technology on its way

that will provide many clean transportation options to Colorado consumers.

Denver officials are following

Boulder’s example by using electric

vehicles for city business. Boulder

incorporated electric vehicles (EVs)

into its city fleet in 1998. Denver

developed the "Take Charge" program in 1999 to include three EV’s

in its automobile fleet. These small

neighborhood EVs look like bubbleshaped golf-carts. 

"The city has a commitment to lead

by example as it relates to alternative

fuels," said Denver Mayor

Wellington Webb. "This demonstration project will help us to determine

the feasibility of EVs and also educate the public about this exciting

technology." The neighborhood

EVs carry two people, reach top

speeds of 25 miles-per-hour, and are

equipped with global positioning

systems. They have a 40-mile

capacity between charges and will be

limited to traveling the streets in

downtown Denver.

For more information: 

DOE Alternative Fuel Vehicles

Buyers Guide

www.fleets.doe.gov

For information on Colorado incentives and laws, select "incentives,"

then "laws," and then search for

"Colorado."

DOE’s Alternative Fuels

Data Center

www.afdc.doe.gov

Lists the locations of fuel stations on

maps with real-time data. You can

search for a fuel type based on your

zip code, city, or state. You can also

zoom-in for more detail and find the

address, phone, and other information about the fuel station.

DOE’s Clean Cities Program

www.ccities.doe.gov

1.800.C.CITIES (334.8437)

For information on market-based

approaches to adopting alternative

fuels and vehicles. 

The owner of this

car, and one of the

first individuals in

Colorado to buy a

hybrid-electric

vehicle, Kevin

Eber, shows off his

new Honda Insight

to coworkers at

the National

Renewable Energy

Laboratory in

Spring 2000. Eric Manuel

27
CHOOSINGWISELY

At the beginning of the new

millennium, Coloradans have

the opportunity to create a

place for clean energy in our

future. "Colorado has one of

the best renewable energy

resource bases in the nation,"

said Kristin Shewfelt of

McStain Enterprises, a

Boulder-based home builder

and partner in DOE’s Building

America Program. "Our

state’s leadership in these cutting-edge technologies of the

future will help maintain both

economic prosperity and environmental quality." 

McStain is a member of the

newly formed Colorado

Coalition for New Energy

Technologies, consisting of 15

businesses and non-profit

organizations supporting environmentally responsible economic growth through the

efficient use of Colorado’s

abundant and clean sources of

energy. Shewfelt applauds the

formation in of a nonpartisan

Renewable Energy and

Energy Efficiency Caucus in

the state legislature in

March 2000. 

As citizens, we can support

these businesses and organizations, incorporate clean energy practices and products into

our lives, and make clean

energy our energy of choice.

For more information:

Energy Efficiency and

Renewable Energy

Clearinghouse (EREC)

1.800.363.3732

P.O. Box 3048

Merrifield, VA 22116

EREC is the U.S. Department

of Energy’s (DOE’s) source

for information and publications on renewable energy and

energy efficiency.

Energy Efficiency and

Renewable Energy Network

(EREN)

www.eren.doe.gov

EREN is the primary Web site

of the DOE’s Office of Energy

Efficiency and Renewable

Energy. Through this site you

can access the Consumer

Energy Information site,

www.eren.doe.gov/

consumerinfo/

for how to put renewable

energy to work in your

daily life. 

The Governor’s Office of

Energy Management and

Conservation (OEMC)

www.state.co.us/oemc

1.800.632.6662 

OEMC is the lead agency on

energy efficiency issues in

the state. 

28
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employees, makes any warranty, express or

implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or

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and opinions of authors expressed herein do not

necessarily state or reflect those of the United

States government or any agency thereof.

Available for a processing fee to U.S.

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and its contractors, in paper, from:

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e-mail: reports@adonis.osti.gov

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29