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Reliable Power Goes Hybrid
Northern Power Systems combines conventional and renewable fuel sources to create systems that generate high quality electric power for computer-intensive industries and remote installations
By Tom Gibson
Driving on
Route 100 through Waitsfield, population 300, you find a typical bucolic
Vermont town, complete with an abundance of arts and crafts businesses
and a covered bridge off the main thoroughfare. You would hardly expect
to find a thriving, high-tech business like Northern Power Systems here.
But turning into Mad River Park, I begin to see how such an outfit weaves
into the fabric of the Green Mountain State. Evergreen-covered mountains
loom in the distance. The slopes of Mad River Glen and Sugarbush ski resorts
fan out over nearby mountains. It's late March, and patchy snow still
covers the ground. Cars in the parking lot sport bike and ski racks on
their roofs, indicating the locals are ready for any season.
You also notice something else. The parking lot was full to the brim, forcing me to park in the outer reaches. As I meet with Trevor Atkinson for a tour, he remarks, "We're going through a big growth phase right now." Indeed, the company has grown from 20 to 100 people in the last five years (some 50 engineers staff the company). Temporary trailers next to the plant accommodate the overflow of employees. And the company has seen tremendous growth in revenue -- over a 300 percent increase since 1997.
Northern Power Systems (Northern) designs, builds, and installs ultra-reliable electric power systems for industrial, commercial, military, and government customers worldwide, having installed systems in 40 countries on all seven continents. These systems convert wind, sunlight, oil, and natural gas to electricity using established power generation technologies integrated with state-of-the-art electronic controls. Northern has pioneered hybrid systems that combine fossil and renewable fuel sources and allow multiple generation sources to deliver cleaner electric power with redundant components, eliminating any potential single point of failure.
A wind turbine stands in front of the plant and makes a whipping and humming noise as gusts of wind turn its rotor. This symbolizes the roots of Northern, as Donald Mayer and David Sellers, both from Vermont, originally founded the firm as North Wind Power Company in 1974, when they collected some old wind turbines from the Midwest intending to resell them. Wind mills hadn't been built for 20 to 30 years, and solar collectors were still expensive. Focusing on a couple different brands and models, they rebuilt the units and sold them for use at remote telecommunications sites. They ran out of units in the late 1970s, prompting them to begin building their own wind turbines.
Clint (Jito) Coleman, now Northern's president,
started consulting with the company in 1975, and he came on board in 1980
as chief engineer and vice president of engineering. He has a master's
degree in mechanical engineering and did his thesis on wind turbines.
When asked what motivated him, he replies, "In the 60s and 70s, I
became concerned about the nuclear industry as an answer to the world's
energy needs. I was troubled by the fallacy of that approach and realized
we couldn't change directions unless we had viable alternatives. Renewable
energy became the viable alternative."
The fledgling company reached a turning point when it designed a wind turbine that could operate reliably in the most demanding environments. Turbines were built in Vermont, tested during a rugged winter, and installed at a communication relay station in Antarctica. The system has provided continuous energy for over 15 years through temperatures of -70 degrees F and wind speeds approaching 200 mph.
By 1980, North Wind Power had to expand from wind turbines for the telecom industry. "The customer wanted a power system, not a windmill," Coleman explains. "When it comes to renewable energy, you've got to go hybrid. The renewable part isn't going to be there all the time." The company developed its first hybrid systems in the 1980s and later won U.S. Navy contracts for offshore hybrid power installations.
Still a Fondness for Wind Turbines
But even with the diversification into different forms of energy,
wind remains the heart and soul of Northern. Atkinson showed me a windmill
blade they fabricate in their shop. "It's a birch laminate with an
epoxy finish," he reveals. "It's made with the same technology
wooden boats are built with." A veteran of 18 years with the company,
Atkinson has an associate's degree in mechanical engineering but works
in the industrial infrastructure group as an electrical designer. He explains
that they manufacture some of their windmills -- many of which Coleman
helped design -- and buy others.
Another engineer who has found a home in
the wind turbine environment is Dan Costin, who has a Ph.D. in engineering
mechanics with a background in mechanical engineering. He started his
career at General Dynamics designing fighter aircraft structures and later
designed transmission structures for Borg Warner in the automotive industry.
Working on wind turbines involves transferring many of his skills from
this experience. "I got to a point in my career where I really wanted
to do something different and something in line with my personal beliefs,"
he recalls. "I realized I could make a difference in the environment
and the economy of this country by focusing on wind turbines. I had the
experience of the aerodynamics from the aircraft industry and the experience
of the transmission from the automotive industry that I could apply to
this product. So far it has worked out very well."
Costin's specialty: designing structures for wind turbines, which Northern custom builds. His work covers from the root of the blade to the top of the tower, as blades and towers are commodity items in the wind energy industry. "Everything between those is our area of competence, and we're looking at each component to see what we need in terms of performance of the part and the manufacturing processes to get the cost down for the volumes we're projecting," he says, indicating they want to standardize designs and shift more to mass production. Components in his bailiwick include the structure for holding the generator, generator housing, shafts, and breaking system.
From the beginning, much of Northern's market has come in the form of power systems required in remote, harsh environments where grid power can be unreliable, if available at all. Because of their critical nature, these applications require high-quality, unmanned, continuous power with little or no maintenance. In the telecommunications field, for example, networks for cellular phones, government emergency radios, microwave voice and data, and television and radio transmitters spread over vast expanses of diverse terrain.
In the same vein, many isolated power systems serve remote villages as well as military and scientific applications. Traditionally, villages have relied on fossil-fuel generators for their electrical generation, but the high cost of maintaining these, along with delivering and storing fuel, has led many communities to look for alternative solutions such as renewable and hybrid on-site power systems. For unattended sites, mainly communications installations, scientists and military engineers rely on renewable energy sources due to their local availability, high reliability, and low cost.
Power systems for such applications typically consist of a photovoltaic solar array, wind turbines, and a fossil-fuel-powered generator, with system controls and a battery bank rounding out the system. Power conditioners rectify alternating current power from a generator to direct current to charge batteries and then discharge the batteries through an inverter back to AC, if necessary. If the load consumes less energy than produced, the excess is stored in the batteries, and when the load consumes more energy, the batteries provide additional power.
Spurred by the Computer Revolution
In recent years, a new market for Northern's power systems has evolved
as businesses have become increasingly dependent on computers, the Internet,
and 24/7 operations and require reliable, clean power for vast communication
and data networks. These include Internet service providers, data management
service providers, call centers, customer service facilities, and online
retailers as well as office buildings, hotels, college campuses, and hospitals.
This trend, combined with the effects of
deregulation in the electric power industry, has created an emerging on-site
generation market, fueling much of Northern's current revenue growth.
By generating some or all of its own power, a facility can gain greater
control of its power needs, reduce energy costs, improve power quality
and reliability, increase efficiency, and reduce the environmental impact
of power generation. In normal operation, an on-site power systems runs
in tandem with the utility grid to supply power to the plant for its baseline
electricity needs, allowing the utility to handle peak demands. In the
event of an outage, the control system seamlessly transfers the plant's
critical operations from the utility to the on-site generation system.
For its on-site power systems, also known as distributed generation, Northern has developed designs that use a single fuel source as well as combinations of various sources. Reciprocating internal combustion engines connected to an electric generator are most common due to their relatively low cost and proven track record. Small gas turbines known as microturbines can generate electricity from a variety of fuels, including natural gas, digester gas, and landfill gas and offer some of the lowest emissions of any conventional fossil-fuel technology. Fuel cells generate power in a chemical process that combines hydrogen and oxygen to make water. Renewable energy sources such as wind power or solar photovoltaics can be used alone or combined with fossil-fuel sources into a hybrid system.
Taking the distributed generation concept a step further, Northern has developed cogeneration systems, which capture the thermal energy lost during electrical power generation and use it for heating buildings and systems. Also known as combined heat and power (CHP), this lowers energy demand by raising fuel efficiency to 70 or 80 percent, compared to typical efficiencies of 30 to 35 percent from utility-produced power. In particular, manufacturing industries that need hot water or steam or have processes involving dehumidification, drying, curing, and other heat applications benefit from this. Heat can also go to an absorption chiller, which uses a refrigerant phase-change cycle to produce cooling.
Erin Carroll, a mechanical engineer at Northern who works with distributed generation and cogeneration, appreciates the benefits of her work to companies that use such systems: "You've got them so they're not at the mercy of the utility. If there's a power outage, they don't go down. They can keep working. It's a good feeling."
As a small company, Northern configures systems in its shop by purchasing big-ticket items like microturbines and diesel generators and then assembling them into packages using components they fabricate such as electronic controls and housings. As Atkinson says on our tour of the shop, "We take a standard product and add value." As a small example, he points to a standard diesel generator with a diesel-powered heater they designed and added to keep the engine block warm for easy starting in cold environments.
In touring the plant, you can't help occasionally glimpsing a new building under construction behind Northern's present facility. Jito Coleman beams with excitement when he tells how it will have 28,000 square feet and double the company's building size. Northern plans to grow to 150 or 160 people as it expands into the new digs. Of course, they'll need a bigger parking lot -- a small price to pay for the success created by two Vermonters who started by salvaging used wind turbines destined for a scrap heap.
Typical Northern Power Systems Designs in Operation Around the World
Satellite Communications from Antarctica
To provide satellite communications with the outside world for the
U.S. McMurdo Station in Antarctica, the National Science Foundation needed
a highly reliable, stand-alone system to power its Black Island satellite
earth station. Accessible only by helicopter or a dangerous two-day traverse,
the Black Island location demanded an alternative to a typical high-maintenance
diesel-only power system. Northern's original solution: a hybrid system
with a wind turbine coupled to a diesel-powered closed-cycle vapor turbine
generator. Both power sources charged a 24-volt battery bank with the
entire system managed by a controller. The site now also supports a NASA
tracking station and includes satellite earth station terminals, terrestrial
links, and fixed and mobile HF radio receiving equipment. The final power
system consists of four wind turbines, three diesel generators, and a
photovoltaic array.
Power and Hot Water for Bottling Operations
Northern devised a power system at the Marin County, California facility
of Pokka USA, a contract bottler of soft drinks and other beverages, to
produce basic and standby electricity to run its bottling lines as well
as hot water for its pasteurization process. The system consists of a
natural-gas-fired generator and sophisticated heat recovery process that
converts waste heat from electricity generation to hot water. Working
in parallel with the electrical utility grid, the system delivers about
70 percent of Pokka's electricity and 30 percent of its hot water. The
system has reduced Pokka's annual energy bill by an estimated $800,000
and eliminated the effects of utility power outages and disruptions.
A Long Pipeline
In 1999, the Caspian Pipeline Consortium, consisting of eight major
oil companies and the governments of Russia, Kazakhstan, and Oman, built
the Caspian Pipeline. This extends 1500 km from the Tenzig Oil Fields
of Kazakhstan on the eastern side of the Caspian Sea to a new Black Sea
port near Novorossiysk, Russia and will have an eventual capacity of 1.34
million barrels per day. Northern supplied 113 power shelters for remote
locations along the pipeline, which traverses deserts, semi-arid plains,
and forested mountains. Designed for unmanned operation, each shelter
connects to AC transmission lines extending along the pipeline and feeds
a 48-volt-battery bank for backup. The system includes electrical hardware
that connects monitoring and control devices to the pipeline computer
network, allowing a remote operator to monitor and control pipeline subsystems
such as valve actuation and shelter parameters such as battery temperature
and voltage and HVAC functions.
Progressive
Engineer
Editor: Tom Gibson
2049 Crossroads Drive, Lewisburg, PA 17837
570-568-8444 * progress@jdweb.com
©2004 Progressive Engineer