The smart network will set up a virtuous cycle for distributed generators and energy storage devices. It will grow the market by opening up more niches where distributed energy is economically competitive. This growth will lead to economies of scale that decrease costs, making distributed energy economical in yet wider applications.
A rule of thumb is that every time production quantities double the cost per unit decreases by around 20%.
Thus the smart energy network will help reduce costs and break down market barriers for generation technologies such as solar photovoltaics, fuel cells and microturbines, and new energy storage technologies such as reversible fuel cells.
The market for upgrades to the power delivery system is one of the largest niches the smart network will open for distributed energy.
By making it easy to connect and coordinate distributed energy resources, the smart network will make it more practical to serve local needs with local generation. This will provide lower-cost alternatives to beefing up substations and power lines in high-growth areas. Large “virtual power plants” composed of many networked small generators could take demands off long-distance transmission lines.
Utilities including Pacific Gas & Electric and Ontario Hydro have uncovered a major savings potential resulting from distributed energy and its ability to avoid traditional grid investments. But turning this innovative concept into standard business practice will require changes in business cultures and regulatory frameworks. A new marketplace for grid upgrades must be created.
Today utilities make long-range plans to upgrade delivery networks and then execute those plans, often with little systematic exploration of potentially cheaper alternatives.
In a smart energy scenario, distribution and transmission system operators publicize upgrade plans and budgets.
They challenge the marketplace to meet those needs through less expensive means. That provides an incentive for aggregators to bid packages of distributed resources, demand management and building efficiency improvements. The smart energy network’s capacity to seamlessly integrate technologies reduces the costs of assembling such packages, making this new marketplace feasible.
Regulatory reforms will provide investor-owned utilities with incentives to promote innovative alternatives to traditional upgrades. Utilities guaranteed a rate of return based on capital investment have less incentive to reduce infrastructure investments or have the need met by third parties. Setting rates of return on the basis of services performed motivates utilities to economize on capital investment.
One cost-cutting incentive for distributed resources is their ability to offer capacity increases that closely track demand growth. Meeting increasing demands by adding central plants and new lines inevitably brings large “lumps” of new capacity on line at once. This system typically moves in boom-and-bust fashion from starvation to surfeit and back to starvation.
Distributed resources come on line in smaller increments and far faster than large plants, so they can match demand curves more accurately.
Because they come in small pieces, distributed resources entail less commitment to technologies that might later be outcompeted in the marketplace. By reducing financial risks of big investments, distributed resources also can lead to big financial paybacks.
Shaving just one percent off average interest rates would reduce the power infrastructure bill $11 billion by 2020.
Figure 1 - By making it easier to interconnect distributed energy resources to the grid, the smart network could cut installation costs and build markets for clean energy technologies such as solar (on photo: Japan's solar city)
Distributed resources also cut costs by allaying siting problems that increasingly plague the electrical industry. Gaining approval for big transmission lines is notoriously difficult.
Moving power generation closer to home reduces or eliminates need for new lines.
Small-scale power plants also require less environmental review and are far less likely to arouse not-in-mybackyard resistance.
The smart energy network could make it easier for owners of distributed generators to sell surplus power. While 36 states have enacted net metering laws that require utilities to take surplus power from small generators, in most cases the amount is capped well below 1 MW.10 Utilities generally are the market for surplus production, and many have set up institutional barriers.
With the smart network in place, small generator operators would have a range of potential buyers for surplus, including neighboring buildings and aggregators.
The
Polymer Electrolyte Membrane (PEM) fuel cells are semi-integrated,
efficient, reliable systems that minimize the use of peripherals.
In 1839, a British Jurist and an amateur physicist named William Grove
first discovered the principle of the fuel cell. Grove utilized four
large cells, each containing hydrogen and oxygen, to produce electricity
and water which was then used to split water in a different container
to produce hydrogen and oxygen. However, it took another 120 years
until NASA demonstrated its use to provide electricity and water for
some early space flights. Today the fuel cell
is the primary source of electricity on the space shuttle. As a result
of these successes, industry slowly began to appreciate the commercial
value of fuel cells. In addition to stationary power generation
applications, there is now a strong push to develop fuel cells for
automotive use. Even though fuel cells provide high performance
characterisitics, reliability, durability, and environmental benefits, a
very high investment cost is still the major barrier against
large-scale deployments.
The fuel cell works by processing a hydrogen-rich
fuel – usually natural gas or methanol – into hydrogen, which, when
combined with oxygen, produces electricity and water. This is the
reverse electrolysis process. Rather than burning the fuel, however, the
fuel cell converts the fuel to electricity using a highly efficient
electrochemical process. A fuel cell has few moving parts, and produces
very little waste heat or gas. A fuel cell power plant is
basically made up of three subsystems or sections. In the
fuel-processing section, the natural gas or other hydrocarbon fuel is
converted to a hydrogen-rich fuel. This is normally accomplished through
what is called a steam catalytic reforming process. The fuel is then
fed to the power section, where it reacts with oxygen from the air in a
large number of individual fuel cells to produce direct current (DC) electricity, and by-product heat in the form of usable steam or hot water. For
a power plant, the number of fuel cells can vary from several hundred
(for a 40-kW plant) to several thousand (for a multi-megawatt plant). In
the final, or third stage, the DC electricity is converted in the power
conditioning subsystem to electric utility-grade alternating current
(AC).
Fuel cell - How it works
In
the power section of the fuel cell, which contains the electrodes and
the electrolyte, two separate electrochemical reactions take place: an oxidation
half-reaction occurring at the anode and a reduction half-reaction
occurring at the cathode. The anode and the cathode are separated from
each other by the electrolyte. In the oxidation half-reaction at the
anode, gaseous hydrogen produces hydrogen ions, which travel through the
ionically conducting membrane to the cathode. At the same time,
electrons travel through an external circuit to the cathode. In
the reduction half-reaction at the cathode, oxygen supplied from air
combines with the hydrogen ions and electrons to form water and excess
heat. Thus, the final products of the overall reaction are electricity, water, and excess heat.
The
electrolyte defines the key properties, particularly the operating
temperature, of the fuel cell. Consequently, fuel cells are classified
based on the types of electrolyte used as described below.
Polymer Electrolyte Membrane (PEM)
Alkaline Fuel Cell (AFC)
Phosphoric Acid Fuel Cell (PAFC)
Molten Carbonate Fuel Cell (MCFC)
Solid Oxide Fuel Cell (SOFC)
These
fuel cells operate at different temperatures and each is best suited to
particular applications. The main features of the five types of fuel
cells are summarized in Table 1 below.
TABLE 1 – Comparison of Five Fuel Cell Technologies
A huge swath of northern India was without power
Monday in the worst blackout in a decade. The cause of the failure of
India’s northern grid has yet to be determined. An estimated 400 million
people (about one-third of the population of India) in the states of
Delhi, Haryana, Himachal Pradesh, Punjab, Rajasthan, Uttar Pradesh,
Uttarakhand, and Jammu and Kashmir were affected. At its worst, the
outage made more than 8000 megawatts of electrical capacity unavailable.
As of 7 p.m. Indian local time, officials said 80 percent of the power
had been restored.
As lack of electricity cut power to millions of fans and air
conditioners, people suffered in the sweltering heat of the north Indian
summer. Long distance trains ground to a halt; the Metro underground
system in Delhi, the nation’s capital, was out of service; hospitals and
IT call centers were running on backup power; and drinking water
purification plants across northern India, which require hundreds of
megawatts to operate, were out of service.
Problems started at 2:35 a.m. local time when the northern grid failed
catastrophically somewhere near the city of Agra, home to the Taj Mahal,
according to power officials in New Delhi. Local power authorities
started diverting power from the eastern and western grid and from
places as far away as Bhutan, but there was still a huge shortfall.
Business leaders were furious. The Confederation of Indian Industry
(CII), the nation’s most influential business lobby, called for
immediate reforms in the power sector.
“The increasing gap between the Demand & Supply of Electricity has
been a matter for concern,” said CII director general Chandrajit
Banerjee in a statement. “CII
has consistently been highlighting that urgent steps need to be taken
for addressing key issues ailing the power sector, such as improving the
supply of coal for thermal power plants and reforming the state
distribution utilities. Today’s outage is an urgent reminder for
addressing these issues as a priority.”
Blackouts are a fact of life in India, which has struggled to meet
demand for electricity in recent years. However, system-wide failures of
the grid are relatively rare. The last major blackout of the northern
grid took place on 2 January 2001, when an estimated 230 million people
were affected for 16 hours. Poor and inadequate transmission equipment
was blamed for the failure in 2001.
India’s Cabinet Minister for Power, Sushil Kumar Shinde, has announced
an inquiry into the cause of today’s power failure. Shinde said at a
news conference that the frequencies at which northern grid typically
operates are between 48.5 and 50.2 hertz. At the time of the grid's
collapse, the frquency was 50.46 Hz, which could have caused or
contributed to the failure.
According to one electricity regulator, who spoke on condition of
anonymity, the cause of the collapse was that the grid became overloaded
as states drew more power than they were allotted.
According to PowerGrid Corporation of India,
power was restored first to railways, airports, and other essential
services by about 8 AM. The utility brought in electricity from both the
eastern and western grids and ramped up hydropower and thermal
generation in the north.
What the little Danish island of Bornholm is showing the world about the future of energy
On Christmas night, Maja Bendtsen and her husband were curled up on the couch watching TV in their cozy house on the Danish island of Bornholm. Suddenly the house lost power. “The lights flickered briefly and then everything went black,” Bendtsen recalls. Peeking out the window, they saw that the whole neighborhood was dark. A
few quick phone calls confirmed that all of Bornholm was without power.
Bendtsen, an engineer with the island’s utility, Østkraft Net,
mentally ruled out the obvious culprits: It wasn’t a particularly busy
night, as Christmas festivities had wrapped up with the midday meal, nor
was the weather particularly cold or stormy.
She thought of one thing, though, and it made her heart sink. She
phoned the Østkraft control room, where the chief engineer confirmed her
suspicion: A ship dragging its anchor in the narrow Baltic Sea channel
between Bornholm and Sweden had severed the 60-kilovolt, 70-megawatt undersea power cable that is the island’s only external source of electricity. It would take a repair crew more than six weeks to pinpoint the damage, haul the cable to the water’s surface, and fix it.
Incredibly, this was the fourth such mishap in 10 years. “We’re getting
accustomed to it, almost,” Bendtsen says. By “accustomed” she doesn’t
mean “resigned.” During the last decade, Østkraft has built up an impressive array of renewable sources
[PDF] like wind, solar, and biomass, which can now supply about
three-quarters of the island’s demand. In the process, Bornholm has
transformed itself into a kind of living laboratory for testing new
energy ideas.
Now it is taking the ultimate step, by deploying one of the world’s most advanced smart grids, called the EcoGrid EU.
It’s a four-year, €21 million (US $27 million) project, funded in part
by the European Union, that aims to demonstrate how electricity will be
produced, distributed, and consumed in the future. While any smart grid
today can track in excruciating detail electricity supply, demand, and
other information, Bornholm’s is one of the first in which individual household consumption can respond to real-time price changes in the electricity market.
By doing that, the grid’s customers are helping to balance the
sometimes big and sudden swings in supply that inevitably accompany the
use of wind and solar power.
Green Grid: The Danish island of Bornholm has only 41
000 full-time residents, but it now boasts one of the world’s most
advanced smart grids, which should help optimize the operation of its
diverse mix of energy sources, including wind, solar, and biomass, as
well as traditional coal and diesel.
And as Bornholm goes, so goes Denmark and the rest of Europe. The European Commission’s 20/20/20 Plan,
for instance, states that by the year 2020, greenhouse gas emissions
will be cut by 20 percent, while renewable energy usage and energy
efficiency will both rise by 20 percent. Last year, the Danish parliament approved an even more ambitious target:
to have renewables supply 35 percent of the country’s total energy
needs—not just electricity but also heating and transportation—by 2020,
and an incredible 100 percent by 2050. Can those targets actually be
reached? Lost at Sea: Bornholm’s only link to the Nordic grid is via a three-phase undersea cable, which has broken four times in the last 10 years.
Photo: Nicky Bonne
That’s what the EcoGrid project aims to find out. The choice of
Bornholm, with its 41 000 full-time residents, to host it was no
accident. Although the island’s beauty draws hundreds of thousands of tourists
every year, it’s not just a vacation destination. Commercial fishing,
dairy farming, and arts and crafts all buttress the economy and give
Østkraft a representative mixture of commercial, industrial, and
residential customers, as well as schools, a hospital, an airport, and
an international seaport.
“We’re like a microcosm of Danish society,” Bendtsen says. “We are in
many senses a picture of the future power system in Denmark.” And by
studying how a high-tech grid can help this little island cope with the
challenges of renewable energy, EcoGrid’s organizers hope to discover
larger lessons for the wider world.
Bornholm has long held a special place in the Danish
psyche. According to local legend, when God got to the end of his
creation he still had bits of paradise left over, and so he threw them
all down in the Baltic Sea and created Bornholm.
In medieval times, another tale goes, Danish kings hid their mistresses
away in the island’s large forest. Today, Europeans flock to Bornholm
in the summer for its beautiful sandy beaches, sunny (for Denmark)
weather, and, yes, that forest.
Island Oversight: Researchers at the Technical University of Denmark, outside Copenhagen, can monitor Bornholm’s power grid in real time.
For Jacob Østergaard,
though, the most attractive thing about Bornholm isn’t the beaches or
the sun: It’s that pesky undersea cable, or, more important, what that
cable allows him as a power engineer to do. Østergaard, a professor of
electrical engineering at the Technical University of Denmark (DTU),
in Lyngby, is involved in a number of electricity projects on Bornholm,
including EcoGrid. The cable can be switched off at will, he explains,
putting the Bornholm grid into what’s known in electricity circles as
“island” mode. And that’s interesting, he says, because the wealth of
wind power makes the Bornholm grid challenging to operate and
fascinating to study. Last year, he and his colleagues even built a
duplicate of the Østkraft control room on the DTU campus to monitor the
Bornholm grid in real time.
On a windy day, Bornholm’s turbines can supply up to 30 MW of power,
or more than half of the island’s peak load of 55 MW. But the wind
blows as it will, and that variability and unpredictability can wreak
havoc on the grid’s stability. If the wind abruptly dies, for instance,
electricity supply could dip way below demand, causing the grid’s
nominal 50-hertz frequency to likewise plummet. A dip or a spike of just
over a tenth of a hertz is cause for alarm, Østergaard says, and if it
drifts out of kilter even further—to, say, 47 Hz—it can trigger a
blackout.
Something close to that happened on 17 September 2009
[PDF], when the sea cable was shut down for maintenance. To keep the
grid balanced, the wind turbines were also initially shut down. At 11:25
a.m., all was calm, with the grid frequency steadily hovering just
north of 50 Hz. Then, at 11:26 a.m., six of the turbines were turned on,
and over the next several minutes their share of the island’s power
supply rose to 15 percent.
But as the wind output grew erratic, so did the grid frequency, spiking
more than a tenth of a hertz several times and dropping sharply to 49.8
Hz just before noon. Østkraft engineers and DTU researchers were
closely monitoring the situation and quickly stepped in, ramping up the
output of the island’s conventional generators and dialing back the
proportion of wind to 10 percent, at which point the frequency returned
to normal.
Fueling the Future: The main power plant on Bornholm burns wood chips in addition to coal and diesel.
Dozens of experiments before and since have confirmed that there’s an
upper limit of about 15 percent on the amount of wind power that
Bornholm’s grid can absorb when in island mode. And to greater or lesser
degrees, all power grids that have a substantial amount of wind and
solar do the same thing, falling back on traditional “peak” generators to compensate for gaps in renewable output. Some grid operators also store electricity in pumped hydro or compressed-air installations or in industrial-grade batteries, but the latter aren’t yet economical, and the former can be used only in certain locations.
But what if, instead of boosting generation when demand is high, you
just cut back demand? Answering that basic question is at the heart of
the EcoGrid.
The goal of the smart grid isn’t to demonstrate that
Bornholm can be energy independent, notes Bendtsen, sitting in one of
the light-filled offices at Østkraft’s sleek headquarters just outside
the main town of Rønne. The island is independent already: At present it
has about 50 MW of domestic capacity, from a mix of conventional coal
and diesel generators, three dozen wind turbines that dot the
countryside like giant pinwheels, rooftop photovoltaics, a biogas plant,
and several wood-chip- and straw-fired plants. As a result, the
Christmas night blackout lasted only a few hours, the time it took to
bring the domestic plants online.
But producing electricity that way is expensive, and so the cable to
Sweden lets the island buy electricity from the Nordic grid when it’s
cheap and sell when the price is high. Ordinarily, trading in
electricity markets is done at the level of utilities and the like.
EcoGrid is letting individual households and smaller businesses also
become market players.
The idea is to shift the consumption of electricity to periods of the
day and night when electricity demand and prices are low, Bendtsen
explains. You could do that by simply sending people a text message
whenever prices change. But that would quickly get tiresome.
Photo: Nicky BonneFrom Waste to Watts: Bornholm’s 2-megawatt biogas plant [right] converts manure and other organic waste into electricity and heat.
“And if we let people interact directly with the market, their behavior
will, of course, change,” says Østergaard. “Everyone will want to charge their electric vehicles when the price is low, for example. If too many people do that, you create congestion in the weakest parts of the grid.”
Instead, EcoGrid’s people have installed smart grid controllers
[PDF] in about 1200 households and a hundred businesses, and since
April the controllers have been receiving a continuous stream of data
based on the 5-minute price for electricity in the Nordic electricity market,
which covers Denmark, Finland, Norway, and Sweden. The controllers
wirelessly communicate with designated appliances, and algorithms
determine whether to turn each one on or off, based on factors like the
time of day, the weather, and current, past, and future market prices.
At first, the project’s organizers envisioned regulating a whole suite
of household machines—dishwashers, washing machines, refrigerators, TVs,
lights. It turns out, though, that although such smart appliances have
been on the market for years, there’s still no standard protocol for
automating them. So your dishwasher might speak ZigBee while your freezer converses in KNX, and they can’t easily understand each other.
Standards clearly would help, says Bendtsen. “Imagine that you go to a
white goods store to buy a new dishwasher,” she says. “You have to
consider not just what size and what color and how much energy and water
does it use but which language does it speak. Fine if you’re an
engineer, but we need some sort of standard so that ordinary people
don’t have to think about all these things themselves.”
In the meantime, the EcoGrid is keeping things simple and dealing
primarily with households that have electric heating systems and heat
pumps. In 700 of those households, the heating system is directly
controlled using algorithms developed at IBM’s research lab in Zurich.
A thermal model of each household has been created, based on factors
like electricity usage patterns and the size of the windows and walls,
explains Dieter Gantenbein, smart grid project leader at IBM Research–Zurich.
“If you leave the window open a lot to let your cat in and out, then
your parameters will be different from somebody who keeps the windows
closed,” he says. From the thermal model, he adds, “we can determine the
electrical flexibility of this house—we have a planned strategy on how
to throttle the heat pump up or down. The goal is that the owners do not
see any reduction in their quality of life.” About 100 businesses on
Bornholm are being similarly equipped.
Showing the Way: A demonstration house on Borholm is
equipped with rooftop photovoltaics and smart-grid devices to let people
see how these technologies work.
Another 500 or so households are being treated as a single electricity- consuming unit; Siemens’s Denmark subsidiary
is coordinating that part of the smart grid. The remainder of the 1900
households enrolled in the project—about a tenth of the island—are just
getting smart meters, which provide them with fine-grained information
about their electricity consumption and market prices but don’t control
their usage in any way.
Interestingly, EcoGrid participants aren’t being told to expect a drop
in their electricity bills. That’s partly a way to manage expectations,
but it’s also just being realistic: Numerous studies in Denmark and
other countries have shown that the incremental savings people get from being more energy efficient usually aren’t enough to change their behavior. That said, Gantenbein notes, there’s been no lack of volunteers on Bornholm.
“Danes take preservation of the environment close to their hearts,” he
says. “It’s like a sport. They heat carefully, they close doors, they
use different technologies, and by being engaged, they are very
enthusiastic to participate in such an ambitious pilot.”
Photo: Nicky Bonne Environmental Enthusiast: Martin
Kok-Hansen [left] was one of the first homeowners to sign up for the
EcoGrid smart grid. He’s already decided to swap his halogen lights for
more efficient bulbs.
Martin Kok-Hansen is just such an enthusiast. He and
his family live in a one-story brick house on the northern edge of
Rønne, and he was among the first on Bornholm to sign up for the smart
grid. The real estate agent says he decided to participate for the same
reason he traded in his Jeep Grand Cherokee for a Volkswagen Golf a few
years back. “In the future, we won’t have that much power,” he says.
“And my son is probably going to have kids as well. Where are they going
to get all the power from?”
There’s now a Landis+Gyr smart meter on the wall of Kok-Hansen’s
garage, a small relay and reader in the laundry room that turns the
electric heater on and off, and a digital thermostat in the living room;
all three of these units communicate wirelessly with a “gateway”
controller and router that in turn connect via the Internet to the
utility company. The gateway and most of the other hardware, as well as
the household communication and end-user Web services, were designed by a
company called GreenWave Reality, based in Irvine, Calif.
Like other participants, Kok-Hansen can set limits on how warm or cool
his house gets. “If it’s 21 °C in here and they need the power, they can
switch off the heat and let it fall to 18 °C,” he says. That’s two or
three degrees cooler than normal, but he thinks he can cope. “Maybe you
put on a sweater for a while.”
Photo: Nicky Bonne Smart Beer: Bornholm
has about 200 experimental bottle coolers outfitted with special
controllers so that they can respond to changes in grid frequency by
automatically turning off or on.
Standing in his recently remodeled kitchen, laptop perched on the black
granite countertop, he logs into his account on the Østkraft website.
He can see, in near real time, how much electricity he’s using. It’s
been illuminating, to say the least.
“Right now I’m using 1200 watts,” he says, pointing to a graph
onscreen. “But when you turn this one on”—he walks over to a wall switch
and flicks on the recessed halo gen lights overhead—“you see that the
usage goes way up.” Sure enough, within a few seconds, the graphed value
nearly doubles. That’s because each halogen bulb is 50 watts, and the
kitchen has 16 of them. At current rates, 1 kilowatt-hour runs about 2
Danish kroner, or 35 cents. So keeping those lights on just 4 hours a
day is costing him $500 a year, he figures. He plans to swap them out
soon for compact fluorescents or LEDs.
“I definitely will change those,” he says. “This is a whole new lifestyle.”
The SuperBest supermarket just off the main square in
Rønne is packed on a Saturday afternoon. A young man stops at a
refrigerator, pulls out a few bottles of beer, and puts them in his
cart. He doesn’t bother to read the explanatory sticker plastered across
the refrigerator’s glass front, nor does he glance up at the
shoebox-size device sitting atop the cooler. And so he may have no
inkling that this refrigerator, and about 200 other units like it on
Bornholm, is special: Like the EcoGrid’s heat pumps, the bottle coolers are helping to balance the grid [PDF].
Two years ago, researchers at DTU modified each cooler so that it
directly monitors grid frequency, explains Østergaard. In a series of
experiments, his group has shown that the coolers can be programmed to
turn themselves off when the frequency drops by more than a tenth, and
then automatically turn back on when the frequency stabilizes. “If it’s
just a small frequency variation, then you just have a small number of
coolers respond,” he explains. “But if there’s a large variation, then
all of them will react.”
The concept of using coolers, pumps, and other appliances in this way
has been kicking around for a while, Østergaard says, but only in the
last decade or so has it become economically feasible. “These days,
every cooler has a thermostat with a microcontroller and processor, so
you can just program it to do this,” he notes. Whereas the heating
systems hooked up to the EcoGrid are reacting to market prices, which
are an indirect measure of power supply and demand, the Bornholm bottle
coolers are detecting conditions on the grid itself.
Østergaard says both approaches are useful: “It’s important to balance
the grid on all time scales, from seconds and minutes to days and
years.” And by using information technology to strategically roll back
demand, rather than ramping up supply, the smart grid can create a more
efficient network. “Moving bits and bytes is less expensive than moving
amperes,” he says.
As to whether Denmark and the rest of Europe will meet their lofty
energy goals, Østergaard’s not saying. “It’s good to have goals,” he
allows. “I don’t know if we will succeed. But without projects like
this, there is no chance at all.”
Lost at Sea: Bornholm’s only link to the Nordic grid is via a three-phase undersea cable, which has broken four times in the last 10 years.
