for alternative energy technologies is rapidly changing. More and more
consumers and businesses are turning to alternative energy sources and
technologies. Developments in the field are proliferating at an
ever-increasing rate, raising new questions about safety and
These new applications
are introducing different challenges for fire protection professionals
that require a higher level of attention. New approaches are emerging
for handling society’s energy supplies such as distributed energy
resources and power isolation/shutdown requirements. These are causing a
reevaluation of the relevant codes and standards.
applications are manifesting themselves in all types of settings. For
example, within the built infrastructure these include multiple types of
occupancies (e.g., commercial, industrial, residential) and include
non-building applications such as transportation, as well as
combinations thereof, such as an electric vehicle connected to a
charging station in a commercial parking structure.
UNDERSTANDING ALTERNATIVE ENERGY AND ALTERNATIVE FUELS
energy is a relatively broad concept whose precise definition is partly
dependent on the specific context in which it is used. This includes
recognition of baseline energy sources from which "alternatives” are
measured. The predominant use of fossil fuels for many applications
provides the de facto baseline from which today’s alternatives are
definitions of alternative energy magazine.sfpe.org/careers 13 in
mainstream literature are often rooted in renewable energy sources. For
example, the concept of alternative energy includes: "energy that is
derived from sources that do not use up natural resources or harm the
environment”, or "energy sources that have no undesired consequences”
(such as fossil fuels or nuclear energy), are renewable, and considered
to be ‘free’ energy sources. The sources of energy that are normally
considered to be "alternative,” and which are the most commonly found
among information sources addressing this topic, include the following:
biopower, geothermal, hydropower, wind and solar.
Sometimes specific alternatives are precisely defined in various public policy programs. This may contribute to the perceived confusion on the use of the term "alternative” when talking about alternative energy.
An example of the use of legislative requirements to define "alternative fuels” is the classification system used for motor vehicles that utilize gasoline or diesel fuel. This is set by the U.S. Environmental Protection Agency through the Clean Air Act Amendment of 1990 and Energy Policy Act of 1992, which recognizes the following 10 classes of alternative fuels: (1) electricity; (2) hydrogen; (3) natural gas; (4) propane; (5) methanol; (6) ethanol; (7) reformulated gasoline; (8) clean diesel; (9) coalderived liquids; and (10) biological materials.
In this case, some of the alternatives are fossil-based fuels that are not recognized as renewable sources.
TRADITIONAL SOURCES OF ALTERNATIVE ENERGY
today’s society, alternative energy sources are most often considered
to include: biopower, geothermal, hydropower, wind and solar.
is the derivation of energy from bio-products. This approach is not
new, and historically includes the use of wood, peat and other
bio-materials. In modern society, biomass includes pulp and paper,
municipal solid waste, landfill gas, corn-based ethanol and similar
fuels. The latest technological focus with biomass is on feedstock
logistics, fuel sustainability, flue gas clean-up, and integration with
other biomass applications such as integrated bio-refineries.
involves bio-based materials that might stand alone or be blended with
conventional fuels, such as ethanol-blended gasoline used with today’s
motor vehicles. Different fuels have different physical characteristics
and present different fire protection challenges. For example, the water
solubility of some liquid biomass fuels requires modified protection
methods such as specialized firefighting foams.
Geothermal is an alternative energy source that utilizes natural heat within the Earth for power generation. This is typically accomplished through the use of injection and production wells set into and out of the Earth as a closed circuit steam generation loop.
typical geothermal power plant involves capturing steam (or other
media) from beneath the surface of the Earth and channeling it through
turbines or other machinery for the generation of power, such as
electricity. These plants would have hazards similar to conventional
electrical power generating plants (e.g., lube oil system), but without
the combustion process and its related hazards.
is an alternative energy source with noteworthy historical roots. The
great industrial mills of the industrial era, for example, were
typically built on rivers and other natural waterways to capitalize on
mechanical and electrical power generation. Today, hydroelectricity is a
direct contributor to the overall energy supply.
is expanding beyond conventional applications of river ways, and
involves tidal flows and other marine and hydrokinetic applications.
Like geothermal, the fire protection challenges of hydropower tend to be
less than that with other power generation facilities that require a
combustion component as part of their power generation process.
provides a clean and renewable power generation source that has been
increasing in use through the proliferation of localized wind turbines.
In their simplest form, these are electrical generators mounted on top
of a tall structural support tower and equipped with large wind
propellers. Larger wind turbines can exceed 2 MW per unit, and they are
found both in separate installations and in groups within a wind farm
The wind turbine unit
itself presents the same fire protection challenges as an electrical
generator in other installations, albeit at an elevated and less
accessible location. Wind turbines do, however, present appreciable
structural load considerations when installed on or near a building.
Structural integrity is a serious consideration, among other factors,
during building design or retrofit. These wind turbines are typically
located on top of a tall structural tower and well removed from
exposures if a serious fire occurs—though outdoor fires and similar
exposure concerns are a possibility during a serious fire involving a
Solar power is another
technology that has proliferated in recent years, in part because of
improved manufacturing methods that are making this approach
realistically affordable and readily available. The three basic means of
capturing the sun’s energy are: passive solar (i.e., capturing the
sun’s energy in building design and construction); solar thermal (i.e.,
sunlight converted to heat); and photovoltaic (sunlight converted to
Of particular interest
from a fire protection engineering perspective are solar thermal and
photovoltaic systems. Solar thermal systems involve the heating of
fluids in a circulating loop system, and they can add appreciable weight
load to a structure. They can also introduce possible hazards to
emergency responders such as rooftop tripping and scalds from hot
On the other hand,
photovoltaic systems that convert sunlight into electrical energy
present certain inherent hazards beyond the concerns with solar thermal
systems. A critical consideration for emergency responders and others is
that photovoltaic panels are electrically "on” when exposed to sunshine
and other light. Power isolation is a technical challenge during an
emergency, and complete power shutdown is normally not an option when
exposed to sunshine.
For all types
of solar systems, consideration needs to be given to maintaining full
access by firefighters on rooftops and on other sections of a building
where firefighters operate during an emergency situation. Advancing
solar technologies now include devices beyond traditional panels, such
as photovoltaic fabrics and films that can be installed in any
orientation (e.g., on a vertical surface) and can introduce questions
concerning flame spread. New products also include building components
such as photovoltaic roofing shingles and tiles, which present hazards
to firefighters and others that are not readily obvious.
THE BIG PICTURE
societal advantages of alternative energy sources such as biopower,
geothermal, hydropower, wind and solar are appreciable, and any inherent
hazards of these technologies can be readily managed. The use of these
technologies follows two general tracks: smaller individual applications
and large-scale power generation facilities.
and solar are the predominant technologies that are proliferating with
smaller individual applications on separate buildings. This is creating
challenges on the electrical grid as a result of distributed power
supplies. Some systems, such as photovoltaic installations on the roofs
of large mercantile stores, can create significant power generation
equal to a small power generating facility. These require special
attention by fire protection engineers and emergency responders alike.
alternative energy approaches are used in a centralized manner for
large-scale power generation, they present fire protection challenges
that are similar to conventional largescale power plants for engineers
and emergency responders. For example, emergency responders might
approach a wind farm or concentrated solar installation with significant
pre-planning and in close coordination with the site owner and/ or
utility—similar to how they would approach a conventional power plant in
certain alternative energy applications are the power source of choice
for some emergency management and emergency response applications. For
instance, the use of solar power for emergency preparedness and disaster
planning is an obvious application of alternative energy independent of
the electrical power grid. An intriguing approach used in California is
the installation of fire-apparatus, roof-top photovoltaic systems to
accommodate deployment over long periods of time (e.g., a wildfire
event), providing a dependable electrical power supply for radio
operation and other critical electrical equipment.
NEW APPROACHES AND THEIR CHALLENGES
approaches that modify or work in conjunction with primary sources of
energy are a natural part of any discussion of alternative energy. This
includes technology and programs that address the following: new power
systems (e.g., fuel cells); energy storage (e.g., batteries); power
supply enhancements (e.g., concentrated solar power); energy management
(e.g., Smartgrid) and energy conservation (e.g., LEED).
new type of power system that is satisfying today’s energy needs is
fuel cell technology. These units create electrical energy through
membrane interaction and have no moving components. They often use
hydrogen as an energy carrier in a process that leaves no adverse
byproducts or residue, and they can use other carbon-based fuels,
including bio fuels.
Fuel cells show
great promise for the future, and the upfront higher equipment costs
can be offset by minimal maintenance and clean and quiet operation.
Hydrogen fuel cells have become the power source of choice for certain
emergency power supply applications, such as remote telephone
communication sites. One recent noteworthy application is a set of 12
fuel cells providing 4.8 megawatts of power for the new Freedom Tower
and related towers at the World Trade Tower site in lower Manhattan.
storage is not a new concept, as exemplified by Article 480 of the
National Electrical Code® on battery storage, which first appeared in
the 1897 edition. Today, battery systems are being taken to new
dimensions, including large battery storage systems that are intended to
boost access to distributed alternative energy sources such as wind and
solar power supplementing the electrical grid. One example is a new
storage cell unit used by a New England utility to coordinate peak
energy loads, composed of a collection of 82,000 individual lithium-ion
battery cells housed in a shipping container.
supply enhancements are also appearing more often in the built
infrastructure. One example is an approach referred to as "concentrated
solar power,” with large-scale photovoltaic systems that utilize
additional features such as moveable panels that follow the sunshine or
mirrors to enhance the energy yield of the panels. Some of these systems
are not standalone facilities, but are appearing on the rooftops of
large commercial or mercantile buildings.
management is another concept that has far-reaching consequences for
how electrical power is used in today’s world. Perhaps the most
noteworthy example of an emerging concept with sweeping implications is
the "smart grid” concept. This is a complete revision of how the
electrical power supply is managed. Instead of a continual one-way feed
of electrical power from generation sites to the consumer, smart grid
enables bidirectional flows of energy and two-way communication and
control capabilities through the use of digital computing and
communication technologies within the power delivery infrastructure.
conservation is an important partner to alternative energy approaches,
despite its relative passive nature. This discussion would not be
complete without mention of energy conservation approaches that are
sweeping the built infrastructure. Fire protection professionals are
continually facing new and unusual characteristics, as they balance
safety with green building design concepts such as Leadership in Energy
and Environmental Design (LEED).
HORIZONS OF TOMORROW
all new alternative energy applications, fire protection engineers and
other safety professionals are working diligently to maintain expected
levels of safety for consumers, emergency responders, operators,
maintainers, regulators and others. The technological advances of
tomorrow are making possible a wide spectrum of alternative energy
sources. Some emerging technologies such as fuel cells are already
showing great advantages, while others such as nanotechnology for
enhanced battery design suggest significant promise for the future. The
alternative energy applications of today and tomorrow are making the
world a better place, and mitigating any hazards they pose is an
important part of assuring their successful implementation.
Casey Grant is with the Fire Protection Research Foundation.