DeBlasio is the director of the Distributed Energy Resources
Center at the National Renewable Energy Laboratory
in Golden, Co. He also chairs a committee of the Institute of Electrical and
Electronics Engineers (IEEE), which is developing national interconnection
standards. The standards could be ready as early as the end of 2001.
What is Distributed Generation (also referred to as "Distributed Power" and
Distributed power provides power to your home at your home. Distributed
generation refers to small electric generating units close to the load centers
(e.g., residential, commercial or industrial). It encompasses onsite
generation, self-generation, co-generation (also called "combined heat and
power"), and any small-scale power generation that is not provided by a central
There are many benefits to distributed generation. Most power outages are due
to problems in transmission. Distributed systems are onsite, so they are more
reliable. They also take less time and money to build than a large central
power plant. And because "waste" heat from electric generation can be captured
and used for heating, water heating or, through thermal absorption, cooling,
efficiencies can reach 70% to 80%. By contrast, most coal plants are only 33%
efficient and the best gas plants are about 60% efficient.
Distributed generation projects are undertaken by end-use customers, utility
companies (Consolidated Edison is installing 400MW around New York City to
avert power shortages this summer) and power marketers.
Distributed power technologies are applicable to almost any situation.
Systems can operate either interconnected or independent of the grid using
today's system interconnection technologies.
How much power can Distributed Generation provide?
If properly implemented, Distributed Generation could produce up to 20% of the
electricity on the grid through interconnection. But less if systems are not
hooked, though there is still a reduction to grid load.
Distributed power can play a major role improving the reliability of the US
electric power system by 1) adding power to the grid 2) reducing
the load on the grid and 3) by providing "high 9s" premium power to businesses
that require that level of service.
What technologies are used in Distributed Generation?
- Reciprocating Engines (small portable units up to 60MW base load units )
- Turbines (500kW up to 100MW)
- Micro-Turbines (25kW up to 300KW)
- Fuel Cells -(25KW up to 1000 kW)
- Solar Electric (a few watts up to large applications ranging in the kW's)
- Wind (a few kW to MW application ranges)
- Storage - battery, flywheel, hydrogen, superconductivity, thermal,
mechanical, air, pump-water, etc.
What are the issues involved with interconnection?
Tying in distributed generators to the electric grid is not a simple matter.
The electric power system as we know it is designed for one-way power flow
(radial grid). Power travels from a central plant to the consumer. The set up
becomes more complicated when you add power from thousands--potentially
millions--of distributed systems flowing onto the grid. Since distributed
suppliers can also be consumers, it's becomes a two-way set up. The Institute
of Electrical and Electronics Engineers (IEEE) has been aggressively working on
a national interconnection standard that can be used by over 3000 utilities. A
universal standard would minimize redundant efforts to address a multitude of
requirements, thus minimizing the time and cost to hook-up a system.
Many states, including Texas, California and New York, have already developed
guidelines that address both the technical as well as non-technical issues
(regulatory hurdles) to interconnection. These efforts have been done in
coordination with IEEE's work.
What is net metering?
Net metering means that customers with distributed systems can sell excess
power they generate back to the local utility. In other words, they can make
the meter "run backwards." For example, electricity generated by home rooftop
solar panels during the middle of the day--which coincides with "peak" power
demand--can be sold back to the grid. But at night, when solar panels can't
generate power, the homeowner will buy power from the utility. Since net
metering helps "pay back" the cost of investing in the distributed equipment,
it's great incentive. However, only 33 states so far have adopted some form of
net metering, as have Germany, Japan and Switzerland.
Clark is the chief scientist at BP Solarex, a division of energy giant BP. With offices and manufacturing
facilities in 30 countries, 20% of market share and revenues expected to exceed
$200 million this year, BP Solarex among the biggest players in the industry.
How does a solar cell work?
A solar cell is made of a semi-conductive material (most commonly silicon, such
as in computer chips) that turns light into electricity. The energy particles
in light are called photons and the energy particles used for electricity are
electrons. When photons from sunlight strike the semi-conductive material,
some are transformed into electrons. The solar cell is designed to harness
those new electrons and channels them to tiny wires at the end of each solar
panel where they are then fed into the general electrical supply of a house or
building. Photovolatic (PV) technology was first developed at Bell Labs in
Improvements in the efficiency of silicon solar cells has been obtained by a
number of techniques: forming improved contacts, using very pure silicon with
few defects, developing high quality anti-reflection layers (such as silicon
How much does solar power cost?
The cost of solar panels themselves has dropped precipitously in the last few
years, from $100 per watt in the early 1970s to around $3 per watt today. The
total installed cost for a solar system with the electrical inverter (solar
panels produce AC current and houses use DC current, so the electricity must go
through an inverter to be usable for lights, computers, whatever), wiring,
mounting brackets and labor costs for the installation is about $7 to $10 per
watt depending on the size of the system, where it is located, what type panels
are used, etc.
A typical house can be completely energy independent with a 5 KW (5000 watts)
solar system. At $7 per watt installed cost, a typical house can provide all
of its own electricity for about $35,000 and would never have to pay for
electricity again - insulating against future increases in power costs. Of
course there are many ways to further reduce that cost. If you're building a
new home and build your solar system into the original construction, as opposed
to retro-fitting an existing structure, you off-set some of the labor costs as
well as substituting for an existing building material you would have otherwise
used. Additionally, New York, New Jersey, California, Illinois, Hawaii and
others have instituted incentive programs to stimulate the solar market in
those states and make solar more affordable for more people. In fact, right
now in New York or California, if you build solar into the construction of a
new home, and make it part of your mortgage, the savings on your utilities will
be equal to or greater than the additional cost of the mortgage.
In fact, enough energy falls from the sun every single day to provide all the
world's energy needs for 27 years - but obviously we use only a tiny fraction
While in developed countries solar is crossing the threshold of being
economically sensible--aside from the non-polluting environmental
benefits--solar has long made economic sense in developing countries and places
where the power grid doesn't reach. Solar energy's traditional markets have
been in remote, isolated locations such as mountaintop telecommunications
switching stations, coastal buoys, off shore oil rigs, etc. where it is
impossible to run power lines and difficult to take fuel for generators.
What is "architectural PV"?
Architectural PV is actually building-integrated PV where the PV systems are
part of the building structure - i.e. the roof, outside walls or cladding and
windows. Ultimately, PV will be incorporated into buildings so that it will be
transparent or not evident to the public, but will add to the aesthetic
appearance of the building. Thin film PV materials are attractive since they
can deposited on conventional building materials such as glass and steel, and
they can be made semi-transparent for windows or sky-lighting. This will be an
enormous market for PV, but it will take a decade or more to develop since the
infrastructure for manufacturing, distributing, installing, maintaining and
financing architectural PV will require the coordinated efforts of PV
manufacturers, building material companies (e.g. glass companies), construction
firms, banks, and government agencies.
What role does government funded research and development play?
The National Renewable Energy Laboratory (NREL) has played an important role
as a facilitator, bringing together teams of scientists and engineers from
universities, industry and the government laboratories to work on advancing
state of the art PV technologies in general. Government funding has been a
significant help to the US PV industry, allowing US companies to leverage
government funds to increase their research, development and engineering
efforts through cost-shared programs.
Worldwide, what countries are the leaders in solar use?
The two largest users of solar energy are Germany and Japan. Those two
countries alone constitute around 60% of the global market for PV. The
Netherlands is also a large and growing market for solar energy. Other
countries in Western Europe - Spain, Italy, UK, and France have all instituted
incentive programs that will expand the size of the solar market in those
countries significantly in the next few years.
The US constitutes about 15% of the global market for solar and much of that
is for industrial, off-grid applications. BP expects the US to be one of the
fastest growing markets for solar over the next 10 years as solar becomes more.
Currently, in the US, solar is growing fastest in states with incentive
programs such as New York, New Jersey, California and Illinois.
James Dehlsen and Geoffrey Dean
Dehlsen is Chairman and CEO of Clipper Windpower. Dehlsen first made his name in the wind business as the
founder of Zond (now Enron Wind), which
developed several large wind farms, starting in the 1980s in California. The
early projects were a "beta test" in the field. But the trial-by-error
experience helped Dehlsen develop his own turbine designs. Dr. Geoffrey Dean, the Director of
Technology for Clipper Windpower, also contributed to these answers. Dehlsen and Dean's latest
project involves harnessing "wind" underwater by capturing the power of sea
How do windmills work?
Wind turbines work by translating energy carried in the wind into rotational
motion of the turbine blades, and then by using this motion to power a
generator, which feeds electricity into the transmission grid. The blades are
airfoils that, like an airplane wing, provide lift. This lift force turns the
Right now wind provides less than 1% of US electric generation. How do you
see that changing in the next 10 to 20 years?
Over the next 10 to 20 years windpower will grow dramatically. Growth will be
driven by the need for cost competitive, clean power, as the available natural
gas supplies diminish and the effects of global warming become more pronounced.
While wind plays a relatively small role in the US presently, it is the fastest
growing power industry in the world, growing by over 40% per year for the past
five years. Some areas of Europe receive over 10% of their power from wind,
with goals of having half of their power come from this renewable resource by
While still representing a small fraction of the nation's capacity, American
windpower has multiplied nearly fourfold over the past five years, and the
American Wind Energy Association projects an 80 percent growth in wind
generating capacity before the end of 2001. Recent projects in Colorado, Iowa,
Minnesota, Oregon, Pennsylvania, Texas and Wyoming have raised the presently
installed US wind capacity to 2,500 megawatts (MW). (One MW is enough to power
1,000 homes). More than 2,000 MW of new capacity are expected this year,
including the world's largest wind farm, 300 MW under construction on the
Oregon/Washington border. The Bonneville Power Authority is seeking to buy
1,000 to 2,500 MW of new windpower before the end of 2002. Clipper Windpower
is presently assembling a 3,000 MW wind project in the Dakotas called "Rolling
Thunder". This project will not only be ten times larger than the
Oregon/Washington project, but will be one of the largest energy projects in
the world today.
Three principal reasons are driving this industry growth: (1) rising fossil
fuel energy costs, (2) mounting concern over environmental effects of
fossil-fuel derived energy, and (3) decreasing costs of wind-generated
Wind energy is emerging as a power generation source of choice based on
economics. The US wind resource is enormous--the Midwest has been called the
Saudi Arabia of wind. As fossil fuel prices rise, wind power is spreading to
new areas and will only become more attractive economically and environmentally
in the future.
Critics point out that wind is an intermittent power source, generating
power only about 30% of the time. How is the wind industry addressing this
Wind projects typically produce "capacity factors" of 30 to 40%, meaning that
because winds are not constant, wind turbines produce a fraction of what they
could under sustained high winds. Most wind sites produce some power
more than 90% of the time, but at the same time only reach their peak power
around 10% of the time. The turbines are designed and sized to deliver power
at the lowest cost of energy possible, taking into account the intermittency of
the wind. However, while energy production is directly tied to wind
availability, technology advancements have raised reliability, making most
turbines available for production 90-95% of the time.
With thermal generating systems, the "throttle" is set to operate at 75 to 90%
of peak power. With wind power generating plants, the energy source -- the
wind -- is intermittent and, for commercial generating facilities, will usually
drive the wind turbine generator at between 30 to 40% of peak power.
The initial cost of windpower plants continue to fall and are nearing those of
thermal plants. However, with thermal plants there are fuel costs and other
costs or "externalities" (waste streams) that are not present with windpower.
Because wind energy is not dependent on fuel prices, wind energy prices are
stable, remaining constant for decades ahead. Fuel supply interruptions, along
with unpredictable and rising fuel prices for thermal plants have highlighted
wind's cost-stability, making it that much more attractive.
Critics also point out that wind farms in remote locations require long
transmission lines, which adds to the expense.
Any generating resource has transmission requirements. If the cost of
transmission cannot be covered in the economics of the project, then it simply
does not get financed and built. Wind is no different.
What is the role of government-funded R&D?
The Department of Energy and the National Renewable Energy Laboratory (NREL)
have been stalwart supporters of wind energy in the US over the past 10 years.
Researchers in these organizations provide enormous support for the American
wind industry, in areas from turbine technology development and assessment to
resource quantification to transmission studies. Funding provided by the DOE
has resulted in great gains in wind turbine performance and reliability, and
continues to result in reductions in system costs that make the technology more
competitive with fossil fueled power plants.
The new National Energy Policy report recommends an extension of the 1.5
cent per kWh wind production tax credit. Can you explain how this tax credit
works? Also, I understand that wind is now in the 4 cent range, and new
turbines in development will produce power even more cheaply. Does the industry
still need a tax credit?
The production tax credit (PTC) is designed to encourage turbine productivity.
The more energy a turbine can produce, the larger the tax benefit based on 1.5
cents per kilowatt hour generated. The PTC lasts for 10 years from the time of
For a commercially windy area (16-18 mph average winds), the cost of wind
energy is around 4 to 5.5 cents per kilowatt-hour and is headed towards 3.5
cents per kilowatt-hour in the not-too-distant future. While the wind industry
would prefer to not have to rely on the tax credit, it is in direct competition
with fossil fuel burning sources that (a) receive substantial federal support,
and (b) do not incorporate the cost of environmental damage into their energy
pricing. The PTC is needed because it simply works towards leveling the
What's the "C" Plane?
The Current Plane, or C-PlaneTM, is the next generation of renewable
energy development, using wind turbine-like technology to generate power from
swiftly moving ocean currents. These flows hold the potential to power
significant portions of numerous population centers worldwide. The technology
needed to capture this energy is emerging from broad-reaching partnerships
between government, academia and industry.
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