I
ALTERNATIVE ELECTRICAL ENERGY SOURCES FOR MAINE
SUMMARY REPORT
W.J. Jones
M. Ruane
MIT Energy Laboratory Report No. MIT-EL 77-010
December 1977
ALTERNATIVE ELECTRICAL ENERGY SOURCES
FOR MAINE
W.J. Jones
M. Ruane
SUMMARY REPORT
This report, prepared for the Central Maine Power Company, presents
a comparative discussion of twelve technologies which were evaluated as
possible alternatives to the construction of a 600 MWe coal-fired generating plant.
The evaluations are published as appendices, each devoted to a specific technology.
Report No. MIT-EL 77-010
MIT Energy Laboratory
December 1977
Acknowledgments
Numerous people shared reports and data with us and provided
comments on the draft material.
We
hope that everyone has been
acknowledged through the references in the technical sections,
but if we missed anyone, thank you!
Ms. Alice Sanderson patiently weathered out many drafts and
prepared the final document with
Merlin.
the assistance of Ms. Dorothy
Appendix
A
Conversion of Biomass - C. Glaser, M. Ruane
Appendix
B
Conservation - P. Carpenter, W.J. Jones, S. Raskin, R. Tabors
Appendix
C
Geothermal Energy Conversion - A. Waterflow
Appendix
D
Ocean Thermal Energy Conversion - M. Ruane
Appendix
E
Fuel Cells - W.J. Jones
Appendix
F
Solar Energy Conversion - J. Geary, W.J. Jones
Appendix
G
Conversion of Solid Wastes - M. Ruane
Appendix
H
Storage of Energy - M. Ruane
Appendix
I
Wave Energy Conversion - J. Mays
Appendix
J
Ocean and Riverine Current Energy Conversion - J. Mays
Appendix
K
Wind Energy Conversion - T. Labuszewski
Appendix
L
Environmental Impacts - J. Gruhl
Initial literature reviews and drafts of the various technical
appendices were prepared by the persons listed.
Preface
The Energy Laboratory of the Mass. Inst. of Tech. was retained by
the Central Maine
Power Company to evaluate several technologies
as possible alternatives to the construction of Sears
Island #1
(a 600 MWe coal fired generating plant scheduled for startup in
1986).
The assessments were made on the basis that a technology
be:
to a base -load
1) an alternative
power generation facility.
defined
as ability
capacity output
2) not restricted
to furnish
electric
Base - load is
up to a rated
for 6570 hours per year.
to
a
single
plant.
It
may be several plants within the state of
Maine.
The
combined output, when
viewed
in isolation, must be a separate, "standalone" source of power.
3) available to deliver energy by
1985.
should
LIST OF TABLES
Table
Page
1.1
Technologies
2.1
Components
2.2
Capacities and Annual Energies from Alternative
Considered
10
of Alternatives
22
Technologies
3.1
25
Summary of Environmental Impacts of Alternative
Technologies
29
4.1
Special
5.1
Levelized Fixed Charge Rate Assumptions
5.2
Optimistic Electricity Costs from Alternative
Requirements
for Alternative
Technologies
Technologies
32
35
37
4
ALTERNATIVE ELECTRICAL ENERGY
SOURCES FOR MAINE
Page
6
Conclusions
1.4
2.0
10
Introduction
1.0
1.1
Scope of the Study
10
1.2
Methodology
11
1.3
Discussion
12
14
Caveats
17
2.1
Principles
of Operation
17
2.2
Components
of Alternatives
21
2.3
Technical
"Quantification"
21
27
Effects
3.0
Environmental
4.0
Applicability to Maine
5.0
Development
Status of Technological
30
31
Requirements
4.1
Special
4.2
Estimates
of Energy
and Capacity
31
33
Economics
Assumptions
5.1
Economic
5.2
Cost of Electricity
3
33
36
LIST OF FIGURES
Figure
Page
1.1
13
Projected Electric Sales for Central Maine Power
5
Conclusions
A)
The alternative technologies to
a
coal-fired
plant considered in this report cannot be relied
upon
steam/electric
expected increase in demand for electricity in Maine
to
by
supply
1986.
the
Tech-
nical, regulatory, and institutional limitations, and the lack of
mercial experience indicate that they could not
reliably
be
com-
expected
to supply the power and energy of the proposed plant.
B)
Several of the alternative
technologies
(biomass,
tion, solar space and hot water heating, solid waste
conserva-
conversion,
sto-
rage, and wind) appear to offer some potential of increased energy
ef-
ficiency and renewable indigenous energy supplies with
re-
duced environmental impacts.
acceptable
These near-term technologies could
to contribute to Maine's energy supply
between
now
and
begin
1986.
They
should be examined further and encouraged to determine if they are
en-
vironmentally and economically desirable.
C)
Other alternative technologies (central
station
solar
mal, central station solar photovoltaic, dispersed solar
waves, and currents), combined with energy-storage
photovoltaic,
systems,
pear to offer potential for renewable indigenous energy
reduced environmental impacts.
Maine should follow their development in other
also
ap-
supplies
These technologies cannot
contribute to Maine's electricity supply until some
ther-
time
locations
and
expected
after
more
to
1986.
favor-
able to their development.
D)
Maine does not have the conditions and resources required
ocean thermal and most forms of geothermal energy conversion.
Hot
rock geothermal energy conversion in Maine might be possible but
6
for
dry
would
not contribute to Maine's
2000.
electricity
supply
Maine should follow its development
after
other,
more
in
until
the
year
favorable
geological locations.
E)
Reliable quantification of the
costs, and environmental impacts of
the
power
and
alternative
not possible without further basic data collection
by specific design studies.
gies in the future,
such data
energy
potential,
technologies
in
Maine
If Maine hopes to utilize these
collection
and
design
is
followed
technolo-
studies
will
be
necessary.
F)
Best case approximations of performance
for
technologies indicate that, regardless of costs,
they
dually supply or eliminate the expected increase in
tricity.
Based on available information, it
to estimate the possible composite
tive technologies were implemented.
the
is
alternative
cannot
demand
for
entirely
performance
if
all
indivielec-
conjectural
the
alterna-
Even the individual best case
proximations are subject to possible errors which
could
lead
ap-
to
se-
rious undercapacity and economic problems if Maine were to rely on
the
alternative technologies.
G)
Many of the alternative technologies (solar space and hot
ter heating, wind, central station solar thermal, central
lar photovoltaic, dispersed solar photovoltaic,
waves,
station
and
Unless extensive
energy
storage
is
these technologies provide on a random basis either peaking
mediate energy, rather than base load power.
7
so-
currents)
are best operated in a fuel-saver mode, in which they supply energy
it becomes available.
wa-
as
included,
or
inter-
On a statistical performance/demand basis these
types
facilities can present a "capacity credit" of "reliable"
a given utility
system.
This "reliable"
power can be
fraction of the rated capability per facility.
vestigations which should result
in
a
of
energy
power
within
expressed
There are
methodology
for
"capacity credit" equivalencies for a number of dispersed
tions.
The studies
H)
as
current
in-
arriving
at
energy
sta-
are not complete.
Best case approximations of performance for the near-term
ternative technologies indicate that their electricity
will be between
50 and 100 mills/KWh.
Actual
costs
costs
will
technologies
fell
in
a
range
al-
in
1986
probably
higher but can only be quantified by actual design studies.
costs for mid-term
a
Estimated
to
200
mills/Kwh in 1986 dollars.
The above are "busbar" costs, that is,
the
costs
the
of
plants.
electricity
at
terminals
of
75
the
generation
Allowance for funds used during construction (see p. 34)
be added to these estimates
I)
to determine
the total busbar
must
costs.
The overall environmental effects of the alternative techno-
logies appear
fects
output
from
be
due
to
to be roughly
equivalent
coal-fired
generation.
to or possibly
The
less than the ef-
absence
experience or even full-scale prototypes makes
of
commercial
quantification
of
the
impacts difficult.
J)
Based on the information in Table 2.1, note that only
conver-
sion of biomass, conservation, distributed solar space
and
heating, solid waste incineration, storage,
and
conversion
potential alternatives for installation
1986.
8
by
wind
Among
hot
this
water
are
group
only conservation, solid waste incineration, and storage have some
es-
tablished commercial experience. The others of this group have the
po-
tential to be commercially developed in time to supply energy for 1986.
It should be recognized that the necessary lead times for
ing and licensing these alternative
availability
available
by
1986
even
though
by then.
9
technologies
the
may
commercial
design-
preclude
technology
their
is
1.0
INTRODUCTION
1.1
Scope of the Study
The Energy Laboratory of the Massachusetts
Institute
of
Techno-
logy (MIT) was retained by the Central Maine Power Company (CMP) to
e-
valuate several technologies (Table 1.1) as
to
the construction of Sears Island #1 (a 600
plant scheduled for startup in 1986).
possible
MWe
This
alternatives
coal-fired
report
generating
presents
the
re-
sults of the study.
Table
1.1
TECHNOLOGIES CONSIDERED
conversion of biomass
increased conservation
geothermal energy conversion
·
ocean thermal energy conversion
fuel cells
solar energy conversion
conversion of solid wastes
storage of energy
wave energy conversion
ocean and riverine current energy conversion
·
wind energy conversion
On a national scale, the technologies of Table 1.1
ted interest because of their
independence
and/or nuclear fuels and because
they
offer
from
the
have
stimula-
conventional
potential
fossil
of
efficient utilization of those supplies or make use of renewable
energy supplies.
10
more
basic
1.2
Methodology
The study of the technologies
views of the available
was based
literature,
primarily
supplemented,
when
discussions with researchers, government agencies,
and architect/engineering firms.
rately.
Each technology
The results of these separate
pendices.
The body of this report
studies
presents
on critical
possible,
equipment
was
re-
vendors,
reviewed
are
included
comparative
by
sepaas
ap-
discussions,
based on the appendices, using four categories:
Status of Technological Development:
description
native approaches in terms of their principles of
of
the
alter-
operation,
ma-
jor components, operating experience, projected development schedule, anticipated technical problems.
the technologies
This was a generic study
of
per se.
Applicability to Maine:
special
requirements
availability of requirements in Maine;
for
potential
utilization;
energy
produc-
tion in Maine; institutional objections to use.
Economics of Operation:
economic assumptions;
capital
and
ope-
rating costs; projected electricity costs.
Environmental Consequences:
conversion technology;
air, water, and land use
impacts
ronmental benefits.
l1
of
ancillary
impacts
operations;
of
envi-
1.3
Discussion
Increased efficiency in the generation and consumption
and the use of renewable
energy
couraged
our
fuels.
in the face of
sources
nation's
should,
in
growing
An exploration
in more
determine those most appropriate for
detail
offer
would
contribution
energy
general,
dependence
Several of the technologies studied by MIT
tial to Maine.
of
be
to
be
on
en-
fossil
this
poten-
necessary
Maine's
to
energy
supply.
This study,
however,
had
a
narrower
purpose
in
it
was
searching for alternatives which could possibly eliminate or delay
the
need for the coal-fired 600 MWe generation
For this search,
given.
the load forecast
Each technology
1)
of CMP (Figure
was evaluated
to answer
Under what conditions could
serve)
planned
the power and energy
this
at
that
Sears
Island.
.1) was taken
as
a
the following:
technology
to be supplied
by
supply
Sears
(conIsland
#]?
2)
What would be the best
performance
to be expected
from
this
technology?
In some cases,
a successful
commitment
to a single
alternative technologies could conceivably
delay
or a combination
the
generation for a year or two although the energy costs
be higher.
This was not considered
the plant would still be needed
to be
to
needs.
12
supply
a
true
need
for
would
coal
probably
alternative,
Maine's
of
lonq-term
since
energy
Millions of Kilowatts (106)
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1.4
A.
Caveats
The reader should keep in mind several limitations
of
with comparative evaluations performed on the basis
associated
the
available
literature:
Comparison of alternatives is imprecise since
sumptions made by different authors are
irreconcilable, particularly between
nologies, e.g., solar energy conversion
unstated
often
very
as-
critical
tech-
different
and
or
solid
burning
waste.
Published reports tend to be optimistic.
Maine of reported pilot or
and
plant
demonstration
can only indicate gross costs or
design evaluations
Extrapolations
specific
experience
More
benefits.
engineering
to
detailed
are
studies
required before a firm commitment to any of the
alternative
technologies can be made.
B.
Uncertainty surrounds almost every facet of the analysis
formed in choosing alternative generation technologies to meet
electrical
demand
in 1986 and beyond.
sible in this situation.
Usually,
No
absolute
the wisest
veral courses of action simultaneously.
policy
answers
is to
per-
Maine's
pos-
are
se-
pursue
What should be avoided is
the
the
uncer-
on one or more of the alternative
tech-
closing off of options which may become very important
in
tain future.
C.
To concentrate
solely
nologies could conceivably leave Maine in a serious
tuation by 1986.
undercapacity
si-
This might happen if, for any number of technical and
institutional reasons, one or more alternatives failed to produce
14
their hoped-for energy.
The adverse consequences
undercapacity would be principally economic.
for
Maine
However, both
of
such
the
Fede-
ral Power Commission (FPC, 1976, p. 5) and the National Electric
Reli-
ability Council (NERC, 1976, p. 3) have warned of
widespread capacity deficiencies by
the
the
possibility
could lead to brownouts and blackouts.
mid-1980's.
Utilities
Such
would
of
shortages
probably
in-
stall short procurement time generation in the form of gas turbines
the extent
possible.
The present
capacity
turbines is sized to meet normal
would require several years to
growth
requirements.
design,
machinery required to increase gas
installations would adversely
of the manufacturers
manufacture
turbine
affect
the
load.
would contain too
peaking
little base
much
intermediate
load capacity.
More
and
light distillate
industry
Gas
generation
mix
The
gas
install
production.
matching generation characteristics to the
of
The
and
the
turbine
by
poorly
resulting
capacity
oil would
to
mix
and
too
have to
be
burned, if allowed by national energy policy.
Undercapacity has the effect of reducing reserve margins
associated carrying costs
for
capacity.
Although
there
and
may
be
trade-off between the carrying costs for reserve margins and the
of reduced reliability levels, this issue is best
addressed
rather than "backed into" by a poor choice of technologies
the
a
costs
directly,
for
opera-
tion.
D.
Adverse environmental effects could also result
dercapacity situation.
might
an
The urgency of bringing capacity on line
create pressures for bypassing
time.
from
environmental
Older, less efficient, and
have to be kept in service
less
longer.
15
hearings
environmentally
which
sound
un-
might
require
plants
E.
What happens if Maine concentrates only
of Sears Island #1?
does not altogether
on
the
A commitment to the conventional coal
eliminate
the possibility
of action could conceivably
vironmental drawbacks.
later
alternative
However,
as
and,
employment
encour-
the
in
en-
might
technologies
Several of the alternative
and increasing
this
and
have its own economic
offer unique economic benefits which would be missed, such
aging new industries
sit-
of an undercapacity
uation, although it reduces its chances of occurrence.
course
construction
case
Re-
conservation, reduced cost-of-living and doing business in Maine.
liance on indigenous renewable energy sources would
In some
Maine's out-of-state energy payments.
help
also
ra-
even
re-
Most of the renewable sources
sult in lower consumer energy costs.
appear
to
be
reduce
(e.g.,
situations
pidly rising coal costs), the alternative technologies might
energy
of
environmentally
to
comparable
of
coal.
burning
Choosing only the coal option could deny Maine the opportunity for
in-
troducing new, possibly less environmentally harmful energy supplies.
F.
some set of alternative
technologies
also
The alternative technologies are more risky
plant, so someone
cessary
capital.
has
pay the risk
premium.
If the alternatives
sorb the losses.
by the utility
in-
stockholders
or are
not
technologies.
16
eco-
must
ab-
best interests
to
someone
pursue the construction of Sears Island #1 while continuing to
some of the alternative
coal
ne-
fail
to be in Maine's
Even so, it seems
a
than
the
utility
nomically competitive with conventional generation,
and
problems.
attract
to
are developed
If the alternatives
dustry, either electricity consumers or electric
would
associated
investments
will have to pay a risk premium
Island
Sears
Choosing to develop both the coal plant at
explore
2.0
STATUS OF TECHNOLOGICAL DEVELOPMENT*
2.1
Principles of Operation
Our evaluation searched for technologies which could
substituted for Sears Island #1.
be
have
be
Such technologies would
possibly
capable of producing or conserving
600
MW
roughly 4 billion KWh of energy per year.
of
In
large centralized facilities (e.g., biomass
electrical
general
to
power
either
combustion
and
power
a
few
plants)
or numerous small decentralized facilities (e.g., wind turbines)
the best use of the characteristics
of alternative
offer
technologies.
In the following discussions only the most promising form of
technology will be considered.
each
Thus, while it may be technically
sible to erect a 1 KW wind turbine for every
household,
this
pos-
discus-
sion would only consider the more likely design of several hundred
1-3
MW units.
1-3
Furthermore, only the most promising of
MW wind turbine designs will be presented.
ternatives
tural.
becomes
unwieldy
and
the
the
candidate
Otherwise the list
comparisons
of
entirely
The various appendices give more justification for
al-
conjec-
the
choice
of the following as the best prospective designs.
CONVERSION OF BIOMASS:
Multiple harvesting
with commercial logging and pulp operations would
the presently noncommercial portions of the forest
The fuel wood would be chipped in the forest
small, centrally located conversion plants.
and
be
in
for
used
conjunction
to
use
trucked
as
remove
to
fuel.
several
These plants would burn
*Note: The technologies were first examined for the intrinsic
characteristics (capabilities, status of development and/or commercialization, environmental impact, and anticipated cost of generated
electricity). In Section 4.0, the applicability of each technology to
Maine is discussed.
17
the chips to produce steam for the generation of electricity.
of about 50 MWe size appears
CONSERVATION:
A
to be optimal.
Utilities,
industries,
lishments, and residential users would
take
commercial
to
action
Heroic
changes
in
lifestyle
are
not
estab-
reduce
tricity consumption by foregoing demands and increasing the
of end use.
plant
elec-
efficiency
Con-
considered.
servation produces no electricity but might reduce
the
need
for
new
generation in 1986.
GEOTHERMAL ENERGY CONVERSION:
In
the
absence
of
natural
wet or dry steam reservoirs, hot dry rock technology is needed
any geothermal resources.
to
tap
Deep wells must be drilled, after which
the
through
hot rocks would be fractured and water pumped
transfer heat to the surface.
the
cracks
Depending on the temperatures
involved,
the hot water would be used to vaporize water or another working
Plant sizes on
to drive a turbine, generating electricity.
to
fluid
the
order
ocean
water
of 100 MWe are considered.
OCEAN THERMAL ENERGY CONVERSION:
Warm surface
would be used to vaporize a low boiling point working fluid to drive
Cool ocean water, taken
turbine, generating electricity.
from
depths
Floating
below 1500 ft, is used to condense the turbine exhaust.
a
con-
crete hulls with 100 MWe capacity are considered.
FUEL CELLS:
with air (oxygen),
electricity.
Hydrocarbon fuels would be chemically
without
combustion,
to
generate
Power conditioning equipment would
electricity for public use.
then
direct
MWe)
are
possible
small (20 MWe) capacity plants is more likely.
18
current
produce
Because modular design is
technology, larger plants (600
combined
but
basic
60
to
Hz
dispersal
this
of
SOLAR ENERGY CONVERSION:
considered.
At central station
Several
solar
mirror systems would focus sunlight on
develop steam.
solar
thermal
a
technologies
plants
central
for use when the sun was not available.
of 100 MWe are considered.
electricity
energy
Central
area-extensive
receiver-boiler
The steam would be used to generate
diately or the steam or generated electrical
would
plants
be
stored
the
order
plants
would
on
Central station photovoltaic
This would then be converted to
city for public use.
Central plants of 100 MWe are considered.
direct
current electricity.
60
Hz
electriSolar
space and water heating involves dispersed single-residence or
Either air or water would be
to
imme-
utilize arrays of photovoltaic cells to instantaneously produce
structure technologies.
are
single-
circulated
the solar collectors to the living area or hot water system.
tricity would be produced, but electricity used for space
from
No
elec-
conditioning
might be replaced by solar-derived energy, resulting in reduced
demand
from conventional sources at those times when collectible sunshine
available.
Dispersed
solar
photovoltaic
systems
for
(single-structure) use would operate on the principles of
systems.
small-scale
the
central
Direct current from photovoltaic cells would be converted
60 Hz electrical
power to satisfy
the demands
Storage technology is critical to
energy.
was
most
to
of the user.
economic
The increased size of collection facilities
uses
to
of
solar
"charge"
the
storage also places an economic burden on solar energy technologies.
CONVERSION OF SOLID WASTES:
Municipal
solid
be collected at a series of transfer stations and then
truck to several central energy conversion plants.
wastes
would
transported
There,
the
solid
wastes would either be incinerated to produce steam for electricity
19
by
generation or processed into another form to be used
tary fuel for coal- or oil-fired utility boilers.
sized at about
as
a
supplemen-
Incineration
50 MWe are considered.
STORAGE OF ENERGY:
lected or converted
Storage devices would allow energy
in one time period
to
be
used
in
and
conventional
would be associated
could
utilize
energy.
sources.
generation
with
thermal,
a
technologies.
single
pumped
System storage would
hydro,
store
electricity
Storage facilities could be
any
storage
technology.
mechanical,
or
from
size
Storage
electrical
a
since
and
alterna-
Dedicated
conversion
col-
another,
would result in more reliable and efficient operation of both
tive
units
variety
their
of
modular
units could be combined to form larger capacities.
WAVE ENERGY CONVERSION:
Buoy-type systems or floating
could convert the kinetic energy of waves
into
mechanical
compress air or pump water for eventual electricity
cams
energy
production.
to
Wave
energy systems would have to be moored off the coast with undersea
bles for transmission of electricity to shore.
The size
tems would be limited by mooring and transmission
of
ca-
the
sys-
considerations,
and
would probably be on the order of 1-5 MW capacity.
OCEAN AND RIVERINE CURRENT ENERGY
rents could be used to turn
turbines
manner similar to waterwheels.
CONVERSION:
for electricity
production
River current turbines
be moored in the river and
would
transmission to the shore.
Unit sizes would be
require
cable
flows but will be on the order of 1 MW capacity.
20
River
a
in
would
systems
have
for
function
cur-
of
a
to
energy
river
WIND ENERGY CONVERSION:
A
tower-mounted,
turbine could convert the kinetic energy of the
wind
energy to turn a generator to produce electricity.
storage would be critical to sustained,
tion.
Unit
2.2
reliable
sizes from 1.5 MWe to 3 MWe are being
into
which are needed for
are
other
successful
components
off-the-shelf technologies.
rotational
Proper
siting
electricity
of the availability
produc-
are
critical
commercial
which
new
operation.
are
components
In
essentially
addition
established,
These are summarized in Table
2.1,
and
along
estimates
of the technologies.
Technical "Quantification"
For most
of the technologies
sic data about the available
there
primary
is a shortage
energy
of
sources.
adequate
The
data
and, as a result,
are
example, wind speed data have
incomplete
typically
or
been
would be found at an optimal wind
turbine
collected
wind
site.
and solid waste production
specific basis.
data
improve
are
future
also
A particularly weak point
speeds).
speed
Such
data
which
efforts
currents,
assessments.
on
existing
a
lack of time-dependent information on a daily time scale.
21
ground
Collection
needed
in
For
near
for data on energy generation potential of wind, waves,
solar insolation in Maine would
energy
inappropriate.
level at airports (which are chosen for their low wind
data do not completely represent the elevated
bawhich
are available have often been collected for purposes other than
assessments
and
considered.
with a list of the major anticipated technical problems
2.3
axis
Components of Alternatives
For most of the technologies there
there
horizontal
more
data
and
Biomass
siteis
the
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For several of the technologies, there is a trade-off between
cost and design complexity and the energy
logy.
The added cost and complexity
production
result
lecting and storing energy for those
is
generation and storage is in general a
and is best done as part of specific
when
not
the
and central
station
solar
and
For
der to facilitate their comparison as base load
operated in a fuel saver mode.
more
In general,
col-
energy
Matching
critical
studies.
photovoltaic
Costs for these technologies would be
of
basic
problem
this
an attempt has been made to consider storage with central
lar thermal
techno-
available.
complex
design
the
from the necessity
periods
source (e.g., sunlight, wind, or waves)
of
report
station
generation,
adding
if
so-
in
technologies.
attractive
the
or-
Energy
they
storage
were
increases
energy costs while making capacity ratings more reliable.
Capacity and energy estimates were prepared
city estimates were made for the
rated
(Table
(maximum)
2.2).
operating
for the likely unit design of each alternative technology.
timates are based upon the rated capacity
tors.
and
Capa-
typical
Also given is the approximate number of units
capacity
Energy
capacity
es-
of
each
fac-
techno-
logy which would be needed to replace the contribution of Sears
Island
#1.
The figures in Table 2.2 are annual averages
scale data are generally unavailable.
Annual
and seasonal problems such as reduced
tions, and so forth.
To
guarantee
since
averaging
insolation,
adequate
wind
shorter
time
masks
daily
speed
year-long
capacity
energy production would require oversizing several alternative
logies (solar, waves, currents, and wind).
The
and impact of storage
determined
options
can only
design study.
24
be
degree
varia-
of
in
and
techno-
oversizing
a
specific
Table 2.2
CAPACITIES AND ANNUAL ENERGIES FROM ALTERNATIVE TECHNOLOGIES
Technology
Unit
Energy
Unitsa
Unitsa
Rated
of Rated
to Provide
to Provide
Capacity
Unit
600 MWe at
3.7 x 109 KWh
(MWe)
(109 KWh)
Rated
Capacity
·__
__ _
50
.307
12
12
Ocean Thermal
100
.614
6
6
Geothermal
100
.614
6
6
Fuel Cells
20
0.131
30
29
.614
6
6
.614
6
6
2.9x10- 5
NAC
130,000
.006
3.1xlO-5
See note d
117,000
50
.360
12
10
1.5
.005-.026f
600-120
7 1 0 -1 4 0 f
Biomass
Conservation b
Solar
Central Station Thermal
100
Central Station Photovoltaic
100
Space & Water Heating
NAC
Photovoltaice
Dispersed
Solid Wastes
Storageb
Waves
f
Currents
1
.001
600
3700f
Wind
1.5-3.0
.005-.010f
400-200
740-370f
aIgnores daily and seasonal variation.
bDoes not produce any energy; replaces need for capacity
CProvides thermal not electrical energy; may be substituted for electrical
energy
dCapacity depends strongly on assumptions about storage.
eBased on study for Arizona.
fStorage not included.
NA:
not applicable.
25
-
Estimates of the impact of conservation on electricity demand
are
highly unreliable; in addition, some conservation measures tend to
re-
duce only peaking and intermediate capacity requirements, rather than
base load requirements.
We estimate that an all-out
conservation
ef-
fort could theoretically eliminate 325 MW of capacity requirements
and
2 billion KWh/yr of energy demand by 1986.
This is what could be saved only if
the
complete
and
conservation effort were implemented by the government
basis.
slowly
(Electricity customers in
in the near dark while
Maine
cannot
be
the rest of the nation
on
sustained
a
national
asked
to
lives
the
freeze
"good
life.")
If a utility system has excess base-load energy,
storage
can
employed at the system level to reduce or postpone new peaking and
in-
termediate capacity requirements by making better use of existing
load generation.
System level storage
in
serve system energy demands although it can
city.
itself
provide
Since system level storage depends on excess
to provide
intermediate
and peaking
energy
does
not
and capacity,
load
it is
alternative to the construction of new base load capacity.
26
base
directly
additional
base
be
capaenergy
not
an
3.0
ENVIRONMENTAL EFFECTS
Appendix L (Environmental Impacts)
presents
the
results
special literature review on the comparative environmental
of
total
im-
Some authors have found
the
pacts of technologies such as
burning
burning
wastes,
and geothermal
energy
conversion
wastes,
to be comparable
a
impacts
the alternative technologies.
solid
of
to
forest
the
im-
are
not
pacts of coal-burning plants.
The alternative technologies for electricity production
environmental panaceas.
Several have as yet
unresolved
problems which could have a serious impact on Maine.
environmental
Others,
when
in
operation, have minimal environmental impact.
Many of the alternative
sources
newable primary energy sources and
air, water,
and land pollution
gas generation.
considered
avoid
impacts
most
do
of
rely
the
of conventional
With adequate planning and
good
upon
environmental
coal,
design,
oil,
it
that most of these renewable primary energy resources can
be
utilization.
of the facilities requires
and
materials
The
manufactured
utilized
products
There are
economic costs associated with even some of the
least
27
for
substantial
environmentally
Maine must decide if the benefits
additional costs.
the
construction
which environmental impacts must be considered.
damaging technologies.
and
appears
indefinitely with no long-term environmental effects comparable to
potential problems of coal mining and
re-
warrant
the
The major impacts of the alternative technologies
this
report
are given
in Table
3.1.
Conservation
has
considered
the
pact, closely followed by the dispersed solar energy-derived
least
in
im-
technolo-
gies, (thermal, photovoltaic) wind, current and wave conversion.
Cen-
tral solar facilities and ocean thermal facilities may be in about
the
middle.
and
At the high impact end are the burning
biomass and geothermal energy conversion.
28
of
solid
waste,
Table
3.1
SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVE TECHNOLOGIES
cr~~(
:E
C)
U)
0 0_.,
(b
uD
SOLAR
01
c. -1
CD
n
c)
I
CD
La CD
00
o
U)
(D
,)
-_.
O
=r
0
301
0 C-)
0 0
o
CD
fD
0CD
ID
U)
01
__J..
1-I rt
3 0
C-c')
:0
0c-
G)
C
1)
-S
1
U)
U)
-.
01
ml
Energy Resource Depletion
Conversion Area
Transmission Area
Water Consumption
Use of Air Space
Air Pollution - Particulate
Air Pollution - Gaseous
Water Pollution
Construction Activity
Heavy Metals/Toxic
Thermal Discharge
Solid Waste
1
1
1
1
2
1
1
1
1
4
3
2
1
2
3
3
4
3
3
3
3
4
4
2
3
4
1
4
3
3
3
2
3
1
1
3
3
2
3
3
1
3
1
1
1
1
4
1
1
1
2
2
)3
1
3
3
1
1
1
1
1
1
3
3
1
)l
1
1
1
1
1
1
4
1
1
1
1
1
1
4
1
1
1
1
3
1
1
1
1
1
1
3
1
1
1
1
3
1
1
1
1
1
3
2
1
3
3
4
4
3
3
2
2
3
3
3
4
3
1
3
1
1
1
1
3
1
1
1
1
1
2
1
1
2
1
1
1
1
4
1
1
2
3
2
2
1
4
1
1
1
1
2
1
1
1
1
1
2
1
1
2
4
4
2
3
2
2
3
3
2
3
1
1
3
1
3
1
Visual Intrusion
Noise
Public Health
Transportation
3
1
1
1
1
1
3
1
1
1
1
1
1
1
1
2
1
1
1
1
1
2
2
1
1
2
2
1
1
1
1
1
1
1
2
1
27 28 22
TOTALS
Impact Rating:
O
3
1 - negligible
3 - moderate
2 - slight
4 - severe
)
)
C
20 20 28 30
26 C4
30 16
indicates ratings for which the more optimistic value of a
spread was chosen.
29
4.0
APPLICABILITY TO MAINE
Each of the technologies
was examined
quirements for its satisfactory
(for example, wind
speed
production
regimes,
solar
to
identify
of
electricity
insolation
When possible, the ability of Maine to provide these
special
in
and energy.
This
approach
gies is highly site-dependent.
Specific
to
the
and
was
electri-
subject
of
siting
etc.).
requirements
is necessarily
possibility of large errors because the performance
Maine
levels,
quantified and estimates were made of the resulting available
cal capacity
re-
the
technolo-
design
studies
were beyond the scope of this evaluation.
In an attempt to draw reliable
conclusions
about
tives to construction of the Sears Island 600 MWe plant,
the
a
alternabest
case
approach was used to evaluate the uncertain performance information
the alternative technologies.
The maximum electrical
technology under best case assumptions
was
output
determined.
of
of
This
each
number
could then be compared with the minimum requirements for replacing
Sears Island
plant.
In
some
cases
(e.g.,
ocean
thermal
the
energy)
Maine's total resources were clearly too limited to allow operation
of
the alternative technology.
In other cases (e.g., wind energy) it is conjectural to say
Maine's resources are, but statements can
be
made
like,
"Over
one-MWe wind turbines would be needed to produce 95% reliable
capacity."
The reader is cautioned to note that whether
wind turbines can actually be sited, licensed, and
only partly a technical question.
built
what
2000
by
Considerable institutional
600
2000
one-MWe
1986
and
vironmental barriers might have to be overcome before such a system
30
MWe
is
en-
the
fol-
possible
per-
which
might
not
tech-
nological requirements, such as the development of manufacturing
meth-
of wind turbines
would
lowing two sections
our estimates
represent
formance, without regard to
of the best
barriers
non-technical
the
in
given
numbers
The
be possible.
exist or arise.
4.1
Special Requirements
The special
ods for the mass
requirements
production
discussed
turbine
of wind
lowing special requirements encompass the
Rather,
blades.
energy
basic
and
the
raw
fol-
ma-
(Table 4.1).
technologies
needs of the alternative
terial
are
section
in this
could
With two exceptions, all of the technologies
clearly
con-
tribute to the electrical energy supply in Maine.
A.
Ocean thermal systems will not operate in the relatively cold
and shallow waters off the Maine coast.
B.
Geothermal systems must rely upon hot dry rock technology be-
cause Maine has no known hydrothermal or
No data
are
available
on
the
extent
geopressured
and
resources.
characteristics
of
theoretically
be
More
im-
Maine's hot dry rock resources.
4.2
Estimates of Energy and Capacity
The fact
that the
remaining
can
technologies
academic.
operated in Maine is interesting but may be only
portant
is the question
of how much energy
duced or saved by the technologies.
31
and
capacity
can
be
pro-
Table 4.1
SPECIAL REQUIREMENTS FOR ALTERNATIVE TECHNOLOGIES
Technology
Requirements
Availability in Maine
Biomass
Biomass supply
90% forested; collection
could be a problem; competition from pulp industry.
Conservation
Mandatorv Measures
--
and Public Support
Ocean Thermal
Thermal gradient
totaling 150 C
None
Geothermal
Hot dry rocks
Unknown
Fuel Cells
Clean gaseous
None
or liquid fuels
from coal
Solar Energy
Solar insolation
Low insolation levels; a(Iverse weather
Solid Wastes
Solid waste
Small, rural population;
supply
collection problems
Storage
Suitable sites
Limited
Waves
Coastal Access
300-400 miles of open walter
coastline; fishing inter*
ference
Currents
River Sites
Numerous; icing and ship
interference
Wind
Coastal reoions and moun tains
High Wind
Speeds
32
5.0
ECONOMICS
Because there is, in general, little or no
commercial
experience
with the alternative technologies
studied
here,
estimates
cost are necessarily approximate.
In many
cases
there
of
are
their
no
data
whatsoever on the costs of certain components or operations.
The cost data which exist are very sensitive
made in their derivation.
not reported
to
the
assumptions
Unfortunately many of those assumptions
in the literature,
making
it necessary
for
pret the available data in order to draw even rough
us
to
are
inter-
technical appendices have noted these assumptions
comparisons.
and
include
The
inter-
pretations when appropriate.
5.1
Economic Assumptions
In order
to allow at least an order
of
magnitude
the economics of the various alternative technologies,
nomic methodology was applied.
comparison
a
common
but
should
sentative of the relative costs of the alternatives.
Only
and environmental impact minimization could provide
units that
are still
are
in the experimental
Our basis of cost
comparison
still
in
based
A
chosen.
converted
All reported costs have been
using an escalation rate of 5% per year.
ded.
33
comparison
to
absolute
on
avail-
prototype
designs.
produced
mills/KWh,
terminals of the generation plant, .
specific
the
stages or "paper"
various technologies has been the cost
repre-
accurate
of the electricity
has
transmission,
Even then, costs will be no more reliable than
which
be
a
design study including issues such as siting, licensing,
able performance data, most of
eco-
The numbers which this methodology
produced are probably low in an absolute sense
cost data.
of
at
the
by
output
year,
1986,
1986
dollars
Escalation was
not
the
was
by
compoun-
No attempt was made to determine a lifetime
cost
for
operating
is
Costs after 1986 were not compared as it
the various technologies.
considered to be too far into the future for
to
numbers
make
sense.
The quality of the economic and operating data simply does not
adding another set of assumptions to
costs.
lifetime
develop
a
such
specific design study were undertaken, then
justify
a
If
year-by-year
an-
alysis should be performed.
total
the
Electricity costs were found by dividing
annual
Matura-
pital and operating costs by the energy produced in one year.
tion problems, which might
first few
years
of
low
cause
plant
were
operation,
sumptions were necessary, optimistic but
used, so the resulting
energy
ignored.
reasonable
are probably
costs
during
the
Whenever
as-
production
energy
as
low
In most cases, it was impossible to quantify the effects of
duction of equipment and services on the 1986 prices,
is not included.
No attempt was made to determine
effects (increased employment, sales of goods and
etc.) of the alternative technologies
as
a
were
assumptions
as
possible.
pro-
so
mass
this
effect
economic
secondary
in
services
possible
ca-
Maine,
credit
against
the
capital
their costs.
Annual capital costs were determined by
burning
plant,
A levelized fixed charge rate
(LFCR)
investment for an alternative technology, say
into an annual levelized charge.
converting
a
wood
of 18% was used for all the alternatives and reflects the
of owning a capital investment.
annual
Debt service, equity return,
ation, state and local income taxes, investment tax credit,
and property
taxes
are included
in the LFCR;
during construction (AFUDC) is not.
34
allowance
for
cost
depreciinsurance,
funds
used
Service life strongly affects the calculation of LFCR,
portant implications for the evaluation of
gies.
the
with
alternative
technolo-
Because they are new technologies, their service life
be estimated and will certainly vary from one
technology
im-
can
to
only
another.
da-
Given this uncertainty and the uncertainties of the basic economic
ta, there seemed to be little justification for adding
of individually calculated LFCR's.
Over a range of
the
refinement
posssible
service
lives (10-30 years), and using the assumptions of Table 5.1, the
value
of the LFCR changed between roughly 15% and 19%.
Table 5.1
LEVELIZED FIXED CHARGE RATE ASSUMPTIONS
Bond Interest
Bond Fraction
Common Stock Interest
Common Stock Fraction
Preferred Stock Interest
Preferred Stock Fraction
State Income Tax
Federal Income Tax
Investment Tax Credit
Investment Tax Credit Fraction
Property Tax, Insurance
Service Life - N
9.75%
52.00%
14.50%
34.00%
10.00%
14.00%
7.00%
48.00%
10.00%
75.00%
1.50%
10-33 years
Allowance for funds used during construction (AFUDC) was
cluded in the costs calculated for the technologies.
length of the construction period
charges by as much as 30%.
these
could
not
in-
Depending on
the
increase
the
If this increase were included
the LFCR, LFCR would range between 19% and 24%.
An
LFCR
instead
of
arbitrarily chosen as an optimistic but representative LFCR.
35
capital
18%
in
was
Operating costs were taken directly from
lated from known components of
plant
the
operation,
literature,
or
calcu-
estimated
as
a
fraction of plant investment.
Energy generated was based on the rated
native technologies and their
estimated
capacity
capacity
of
the
factors.
alterIn
cases there is no commercial experience on which to base forced
most
outage
and maintenance estimates.
5.2
Cost of Electricity
Based on the optimistic approach outlined
costs of electricity from each of
derived (Table 5.2).
the
in
Section
1986
technologies
were
alternative
5.1,
These costs should be
considered
numbers, (i.e., "most optimistic"), in the sense that
as
that commercially installed units will not
provide
it
expected
and
below
manufactu-
Actual commercial costs may turn out to be
ring breakthroughs.
higher
of two or more.
Conservation is one method that can
their investment.
measures
is
case
electricity
these costs, even with reasonably likely technological
by a factor
best
taken
actually
pay
consumers
for
The economics of conservation vary according to
the
and the cost of the electricity.
Storage costs
have
two
components:
the
cost
energy, which depends on its generating source, and
storage equipment.
The incremental storage
of
the
Base load
generation
equipment
is
36
the
are
the
costs
needed
energy taken from storage can be economically competitive
mediate and peaking generation.
of
cost
same for all generating units, so the determining factor
of the stored energy.
stored
the
is
the
cost
so
that
the
with
inter-
Table 5.2
OPTIMISTIC ELECTRICITY COSTS FROM ALTERNATIVE TECHNOLOGIES
Technology
Range of Busbar Electricity Costs
Mills/KWha in 1986 dollars
Conversion of Biomass
50 - 70
Conservationb
Ocean Thermal Energy Conversion
70 - 90
Geothermal Energy Conversion
25 - 80
Fuel Cells
55 - 70
Solar Energy Conversion
Central Station Thermal
600 - 800
Central Station Photovoltaic
346 - 3000C
Space Heating and Coolingd
Dispersed Photovoltaice
Conversion of Solid Wastes
40 - 90
Storage of Energyb
Wave Energy Conversionf
25 - 116
Ocean and Riverine Current Energy Conversion 200 - 260
Wind Energy Conversion
65 - 100
aThese figures do not include AFUDC.
Depending upon fuel costs, if AFUDC
is included, the busbar cost of electricity can increase up to 30%
bCosts
depend
on the cost of the energy
conserved
or stored.
CCost depends on assumptions made about projected reductions in photovoltaic cell costs.
dMay be economic for average homeowner (depending upon his alternatives).
eMay be economic if photovoltaic cell costs fall drastically, but utility
backup supply still needed.
flow by as much as a factor of 3 due to missing costs.
37