A Modern Renaissance of Electrical Power: Microgrid Technology – Part 1

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Figure 1:  The original Edison DC microgrid in New York City, which started operation on September 4, 1882 (1)

A.  Historical Development of Electric Power in the Metropolitan City

The development of electricity for commercial, municipal and industrial use developed at a frantic pace in the mid to late 1800’s and early 1900’s.  The original distribution system consisted of copper wiring laid below the streets of New York’s east side.  The first power plants and distribution systems were small compared to today’s interconnected grids which span nations and continents.  These small “islands” of electrical power were the original microgrids.  In time they grew to become the massive infrastructure which delivers us electrical power we have become dependent upon for the operation of our modern society.

1) Let There Be Light! – Invention of the Light Bulb

When electricity first came on the scene in the 1800’s it was a relatively unknown force. Distribution systems from a central plant were a new concept originally intended to provide electric power for the newly invented incandescent light bulb.  Thomas Edison first developed a DC power electric grid to test out and prove his ideas in New York, at the Manhattan Pearl Street Station in the 1870’s.  This first “microgrid” turned out to be a formidable undertaking.

[…] Edison’s great illumination took far longer to bring about than he expected, and the project was plagued with challenges. “It was massive, all of the problems he had to solve,” says writer Jill Jonnes, author of Empires of Light: Edison, Tesla, Westinghouse, and the Race to Electrify the World, to PBS. For instance, Edison had to do the dirty work of actually convincing city officials to let him use the Lower East Side as a testing ground, which would require digging up long stretches of street to install 80,000 feet insulated copper wiring below the surface.

He also had to design all of the hardware that would go into his first power grid, including switchboards, lamps, and even the actual meters used to charge specific amounts to specific buildings. That included even the six massive steam-powered generators—each weighing 30 tons—which Edison had created to serve this unprecedented new grid, according to IEEE. As PBS explains, Edison was responsible for figuring out all sorts of operational details of the project—including a “bank of 1,000 lamps for testing the system:” (1)

Although Edison was the first to develop a small DC electrical distribution system in a city, there was competition between DC and AC power system schemes in the early years of electrical grid development.  At the same time, there were a hodge-podge of other power sources and distribution methods in the early days of modern city development.

In the 1880s, electricity competed with steam, hydraulics, and especially coal gas. Coal gas was first produced on customer’s premises but later evolved into gasification plants that enjoyed economies of scale. In the industrialized world, cities had networks of piped gas, used for lighting. But gas lamps produced poor light, wasted heat, made rooms hot and smoky, and gave off hydrogen and carbon monoxide. In the 1880s electric lighting soon became advantageous compared to gas lighting. (2)

2) Upward Growth – Elevators and Tall Buildings

Another innovation which had been developing at the same time as electrical production and distribution, was the elevator, a necessity for the development of tall buildings and eventually towers and skyscrapers .  While there are ancient references to elevating devices and lifts, the original electric elevator was first introduced in Germany in 1880 by Werner von Siemens (3).  It was necessary for upward growth in urban centers that a safe and efficient means of moving people and goods was vital for the development of tall buildings.

Later in the 1800s, with the advent of electricity, the electric motor was integrated into elevator technology by German inventor Werner von Siemens. With the motor mounted at the bottom of the cab, this design employed a gearing scheme to climb shaft walls fitted with racks. In 1887, an electric elevator was developed in Baltimore, using a revolving drum to wind the hoisting rope, but these drums could not practically be made large enough to store the long hoisting ropes that would be required by skyscrapers.

Motor technology and control methods evolved rapidly. In 1889 came the direct-connected geared electric elevator, allowing for the building of significantly taller structures. By 1903, this design had evolved into the gearless traction electric elevator, allowing hundred-plus story buildings to become possible and forever changing the urban landscape. Multi-speed motors replaced the original single-speed models to help with landing-leveling and smoother overall operation.

Electromagnet technology replaced manual rope-driven switching and braking. Push-button controls and various complex signal systems modernized the elevator even further. Safety improvements have been continual, including a notable development by Charles Otis, son of original “safety” inventor Elisha, that engaged the “safety” at any excessive speed, even if the hoisting rope remained intact. (4)

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Figure 2:  The Woolworth Building at 233 Broadway, Manhattan, New York City – The World’s Tallest Building, 1926 (5)

3) Hydroelectric A/C Power – Tesla, Westinghouse and Niagara Falls

Although Niagara Falls was not the first hydroelectric project it was by far the largest and from the massive power production capacity spawned a second Industrial Revolution.

“On September 30, 1882, the world’s first hydroelectric power plant began operation on the Fox River in Appleton, Wisconsin. […] Unlike Edison’s New York plant which used steam power to drive its generators, the Appleton plant used the natural energy of the Fox River. When the plant opened, it produced enough electricity to light Rogers’s home, the plant itself, and a nearby building. Hydroelectric power plants of today generate a lot more electricity. By the early 20th century, these plants produced a significant portion of the country’s electric energy. The cheap electricity provided by the plants spurred industrial growth in many regions of the country. To get even more power out of the flowing water, the government started building dams.” (6)

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Figure 3:  The interior of Power House No. 1 of the Niagara Falls Power Company (1895-1899) (7)

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Figure 4:  Adam’s power station with three Tesla AC generators at Niagara Falls, November 16, 1896. (7)

Electrical Transmission, Tesla and the Polyphase Motor

The problem of the best means of transmission, though, would be worked out not by the commission but in the natural course of things, which included great strides in the development of AC. In addition, the natural course of things included some special intervention from on high (that is, from Edison himself).

But above all, it involved Tesla, probably the only inventor ever who could be put in a class with Edison’s in terms of the number and significance of his innovations. The Croatian-born scientific mystic–he spoke of his insight into the mechanical principles of the motor as a kind of religious vision–had once worked for Edison. He had started out with the Edison Company in Paris, where his remarkable abilities were noticed by Edison’s business cohort and close friend Charles Batchelor, who encouraged Tesla to transfer to the Edison office in New York City, which he did in 1884. There Edison, too, became impressed with him after he successfully performed a number of challenging assignments. But when Tesla asked Edison to let him undertake research on AC–in particular on his concept for an AC motor–Edison rejected the idea. Not only wasn’t Edison interested in motors, he refused to have anything to do with the rival current.

So for the time being Tesla threw himself into work on DC. He told Edison he thought he could substantially improve the DC dynamo. Edison told him if he could, it would earn him a $50,000 bonus. This would have enabled Tesla to set up a laboratory of his own where he could have pursued his AC interests. By dint of extremely long hours and diligent effort, he came up with a set of some 24 designs for new equipment, which would eventually be used to replace Edison’s present equipment.

But he never found the promised $50,000 in his pay envelope. When he asked Edison about this matter, Edison told him he had been joking. “You don’t understand American humor,” he said. Deeply disappointed, Tesla quit his position with the Edison company, and with financial backers, started his own company, which enabled him to work on his AC ideas, among other obligations.

The motor Tesla patented in 1888 is known as the induction motor. It not only provided a serviceable motor for AC, but the induction motor had a distinct advantage over the DC motor. (About two-thirds of the motors in use today are induction motors.)

The idea of the induction motor is simplicity itself, based on the Faraday principle. And its simplicity is its advantage over the DC motor.

An electrical motor–whether DC or AC–is a generator in reverse. The generator operates by causing a conductor (armature) to move (rotate) in a magnetic field, producing a current in the armature. The motor operates by causing a current to flow in an armature in a magnetic field, producing rotation of the armature. A generator uses motion to produce electricity. A motor uses electricity to produce motion.

The DC motor uses commutators and brushes (a contact switching mechanism that opens and closes circuits) to change the direction of the current in the rotating armature, and thus sustain the direction of rotation and direction of current.

In the AC induction motor, the current supply to the armature is by induction from the magnetic field produced by the field current.  The induction motor thus does away with the troublesome commutators and brushes (or any other contact switching mechanism). However, in the induction motor the armature wouldn’t turn except as a result of rotation of the magnetic field, which is achieved through the use of polyphase current. The different current phases function in tandem (analogous to pedals on a bicycle) to create differently oriented magnetic fields to propel the armature.  

Westinghouse bought up the patents on the Tesla motors almost immediately and set to work trying to adapt them to the single-phase system then in use. This didn’t work. So he started developing a two-phase system. But in December 1890, because of the company’s financial straits–the company had incurred large liabilities through the purchase of a number of smaller companies, and had to temporarily cut back on research and development projects–Westinghouse stopped the work on polyphase. (8)

4) The Modern Centralized Electric Power System

After the innovative technologies which allowed expansion and growth within metropolitan centers were developed there was a race to establish large power plants and distribution systems from power sources to users.  Alternating Current aka AC power was found to the preferred method of power transmission over copper wires from distant sources.  Direct Current power transmission proved problematic over distances, generated resistance heat resulting in line power losses. (9)

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Figure 5:  New York City streets in 1890. Besides telegraph lines, multiple electric lines were required for each class of device requiring different voltages (11)

AC has a major advantage in that it is possible to transmit AC power as high voltage and convert it to low voltage to serve individual users.

From the late 1800s onward, a patchwork of AC and DC grids cropped up across the country, in direct competition with one another. Small systems were consolidated throughout the early 1900s, and local and state governments began cobbling together regulations and regulatory groups. However, even with regulations, some businessmen found ways to create elaborate and powerful monopolies. Public outrage at the subsequent costs came to a head during the Great Depression and sparked Federal regulations, as well as projects to provide electricity to rural areas, through the Tennessee Valley Authority and others.

By the 1930s regulated electric utilities became well-established, providing all three major aspects of electricity, the power plants, transmission lines, and distribution. This type of electricity system, a regulated monopoly, is called a vertically-integrated utility. Bigger transmission lines and more remote power plants were built, and transmission systems became significantly larger, crossing many miles of land and even state lines.

As electricity became more widespread, larger plants were constructed to provide more electricity, and bigger transmission lines were used to transmit electricity from farther away. In 1978 the Public Utilities Regulatory Policies Act was passed, making it possible for power plants owned by non-utilities to sell electricity too, opening the door to privatization.

By the 1990s, the Federal government was completely in support of opening access to the electricity grid to everyone, not only the vertically-integrated utilities. The vertically-integrated utilities didn’t want competition and found ways to prevent outsiders from using their transmission lines, so the government stepped in and created rules to force open access to the lines, and set the stage for Independent System Operators, not-for-profit entities that managed the transmission of electricity in different regions.

Today’s electricity grid – actually three separate grids – is extraordinarily complex as a result. From the very beginning of electricity in America, systems were varied and regionally-adapted, and it is no different today. Some states have their own independent electricity grid operators, like California and Texas. Other states are part of regional operators, like the Midwest Independent System Operator or the New England Independent System Operator. Not all regions use a system operator, and there are still municipalities that provide all aspects of electricity. (10)

 

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Figure 6:  Diagram of a modern electric power system (11)

A Brief History of Electrical Transmission Development

The first transmission of three-phase alternating current using high voltage took place in 1891 during the international electricity exhibition in Frankfurt. A 15,000 V transmission line, approximately 175 km long, connected Lauffen on the Neckar and Frankfurt.[6][12]

Voltages used for electric power transmission increased throughout the 20th century. By 1914, fifty-five transmission systems each operating at more than 70,000 V were in service. The highest voltage then used was 150,000 V.[13] By allowing multiple generating plants to be interconnected over a wide area, electricity production cost was reduced. The most efficient available plants could be used to supply the varying loads during the day. Reliability was improved and capital investment cost was reduced, since stand-by generating capacity could be shared over many more customers and a wider geographic area. Remote and low-cost sources of energy, such as hydroelectric power or mine-mouth coal, could be exploited to lower energy production cost.[3][6]

The rapid industrialization in the 20th century made electrical transmission lines and grids a critical infrastructure item in most industrialized nations. The interconnection of local generation plants and small distribution networks was greatly spurred by the requirements of World War I, with large electrical generating plants built by governments to provide power to munitions factories. Later these generating plants were connected to supply civil loads through long-distance transmission. (11)

 

To be continued in Part 2:  Distributed Generation and The Microgrid Revolution

 

References:

  1. The Forgotten Story Of NYC’s First Power Grid  by Kelsey Campbell-Dollaghan
  2. The Electrical Grid – Wikipedia
  3. The History of the Elevator – Wikipedia
  4. Elevator History – Columbia Elevator
  5. The History of Elevators and Escalators – The Wonder Book Of Knowledge | by Henry Chase (1921)
  6. The World’s First Hydroelectric Power Station
  7. Tesla Memorial Society of New York Website 
  8. The Day They Turned The Falls On: The Invention Of The Universal Electrical Power System by Jack Foran
  9. How electricity grew up? A brief history of the electrical grid
  10. The electricity grid: A history
  11. Electric power transmission

DOE Energy Review Report Recommends Grid Modernization and Transmission System Upgrades

The Department of Energy (DOE) recently released its first installment of its Quadrennial Energy Review (QER) – a comprehensive report examining how the United States can modernize energy infrastructure to promote economic competitiveness, energy security, and environmental responsibility. This installment…

Source: switchboard.nrdc.org

>” […]  Electric grid reform is timely due to a confluence of factors. First, our grid infrastructure is old and in dire need of upgrade. We could just patch up the existing system by replacing old poles and wires with new ones and call it a day. But given evolving customer preferences for more control over energy usage and newly available efficiency-enabling technologies, doing that would be like replacing an old rotary phone with a newer one instead of upgrading to a smart phone. Grid reform should also consider the changing environment, as grid reliability is increasingly threatened by severe weather. The continuing shift in the energy generation mix to include the benefits of more roof-top solar and remote wind generation will also require changes to our transmission grid.

QER electric grid modernization findings and recommendations

Here are some QER highlights relevant to FERC and what it can do to support a clean electricity grid. (Our Sustainable FERC Project coalition submitted comments to DOE on some of these items before the QER was finalized.)

The necessary transmission build-out for a low-carbon future is likely consistent with historic investment 

To access wind and solar renewable resources far from populated cities, we need long-distance transmission infrastructure. But how much is enough? The QER studied a variety of clean energy future cases, including scenarios with high penetrations of wind and solar power, a cap on climate-warming carbon dioxide emissions to achieve a 40 percent reduction in 2030, and increased natural gas prices. The scenarios produced a range of new transmission requirements, all consistent with our historic investment in transmission infrastructure. In other words, the needed transmission infrastructure build-out to get to a low-carbon future is reasonable. So it boils down to this: the nation will continue to invest billions of dollars in grid infrastructure updates whether we build for a clean energy future or ignore the potential for it – which will it be? We’d argue for the clean pathway to clean our air and stave off the worst effects of climate change

We can more efficiently use existing infrastructure to avoid unnecessary and costly transmission construction 

Just as the highways clog at rush hour, the electric grid gets congested when customer power demand is at its peak. The QER emphasizes that there are a number of ways to alleviate congestion on transmission wires without building costly new infrastructure. These include managing energy use through energy efficiency (smarter use of energy) and demand response (customer reduction in electricity use during high congestion times in exchange for compensation), locally supplying energy through distributed generation (such as rooftop solar), or using stored energy when the transmission lines are constrained. These alternatives not only reduce new transmission construction requirements, but come with the added bonus of improving electric service reliability and reducing pollution from electricity generation. Indeed, three important DOE-funded planning studies show that scenarios combining high levels of these resources can reduce the expected costs of new transmission investment (see a description of the Eastern Interconnection study here).

We can also avoid costly transmission construction by using existing transmission more efficiently through improved operations. Without getting into the wonky details, this means grid operators can adopt smart network technologies and better network management practices to minimize electricity transmission bottlenecks.

We need to appropriately value and compensate energy efficiency, demand response, energy storage, and other resources providing cleaner, cheaper grid services 

Unlike traditional power plants, energy efficiency, demand response, energy storage and other resources can nimbly respond to unanticipated grid events or meet energy demand without requiring extra transmission capacity at peak times. But these resources often offer more to the grid than they receive in compensation. Accurately valuing the services these resources provide would allow regulators and utilities to incent their participation in grid markets. The QER therefore recommends that DOE help develop frameworks to value and compensate grid services that promote a reliable, affordable, and environmentally sustainable grid. […]”<

See on Scoop.itGreen & Sustainable News

US Utilities #1 Priority is to Replace and Modernize Old Grid Infrastructure

The State of the Electric Utility 2015 survey revealed that aging infrastructure is what troubles industry players most.

Source: www.utilitydive.com

>” Utility executives identified aging infrastructure as the number one challenge facing the electric industry, […] easily topping an aging workforce, regulatory models and stagnant load growth. In response, the industry is spending hundreds of billions to replace and upgrade infrastructure, rushing to meet consumer demand for higher quality power enabled by construction of a more modern grid.

“The last few years there’s been more of an emphasis on transmission and distribution, and the driver there has been the advent of all these new technologies that are trying to connect with the grid,” said Richard McMahon, Jr., vice president of energy supply and finance for the Edison Electric Institute, the electric utility trade organization. “There are also a lot of customer-driven desires utilities are trying to facilitate. There’s a lot of spending on metering automation, as well as at the distribution level, distribution transformers to accommodate distributed generation.”

Today’s grid may not be up to the task of reliably integrating high levels of renewables, distributed energy resources, and smart grid technologies, Utility Dive found. The American Society of Civil Engineers (ASCE) gave U.S. energy infrastructure a barely passing grade of D+ in 2013, at stark odds with the sophisticated grid management required by the rapid acceleration of utility-scale renewables, distributed resources and two-way devices.

“Distributed energy cannot be a profit center without the modernized grid infrastructure that’s needed for grid integration,” Utility Dive concluded in the report. […]

Outages on the rise

The American Society of Civil Engineers report that gave U.S. infrastructure a barely-passing grade pointed out that aging equipment “has resulted in an increasing number of intermittent power disruptions, as well as vulnerability to cyber attacks.”

Significant power outages rose to more than 300 in 2011, up from about 75 in 2007, and the report found many transmission and distribution outages have been attributed to system operations failures, though from 2007 to 2012 water was the primary cause of major outages.

“While 2011 had more weather-related events that disrupted power, overall there was a slightly improved performance from the previous years,” the report said. “Reliability issues are also emerging due to the complex process of rotating in new energy sources and ‘retiring’ older infrastructure.

ASCE said that for now, the United States has sufficient capacity to meet demands, but from 2011 through 2020 demand for electricity in all regions is expected to increase 8% or 9%. The report forecasts that the U.S. will add 108 GW of generation by 2016.

“After 2020, capacity expansion is forecast to be a greater problem, particularly with regard to generation, regardless of the energy resource mix,” the report said. “Excess capacity, known as planning reserve margin, is expected to decline in a majority of regions, and generation supply could dip below resource requirements by 2040 in every area except the Southwest without prudent investments.” […]”<

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California’s PG&E Takes Grid Energy Storage to the Distribution Substation

California’s utilities are building a 1.3-gigawatt energy storage system, one piece at a time.

Source: www.greentechmedia.com

>” […] PG&E’s solicitation (PDF) is one of the first rounds from the 74 megawatts of storage projects the utility is set to announce by December. That, in turn, is part of the first procurement round for the state’s 1.3-gigawatt mandate for storage by 2021, which is requiring PG&E, Southern California Edison, and San Diego Gas & Electric to sign up about 200 megawatts of cost-effective grid storage by year’s end.

[…]

Some of these projects will be aggregating distributed, behind-the-meter batteries to help solve local grid needs. But PG&E’s substation RFO is aimed strictly at utility-owned and -operated battery systems — which makes sense, because PG&E is justifying its cost by showing how much it saves by not building or upgrading new substations.

[…]

PG&E’s cost-benefit calculation for these projects is fairly straightforward — subtract the cost of upgrading the substation from the cost of the battery system. Still, the duty cycle being asked of these energy storage systems (ESS) is pretty severe, according to the RFO:

“[T]his is defined as discharging the ESS from 100% state of charge (SOC) at guaranteed maximum power for the guaranteed discharge duration, then charging it to back to 100% SOC and subsequently discharging it at guaranteed maximum power for half of the guaranteed discharge duration, and finally charging it back to 100% SOC during the course of a single day. The ESS shall be capable of performing the guaranteed site specific duty cycle for up to 365 days per year excluding time for planned maintenance and/or forced outages.”

[…]

Asset or investment deferral of this kind is actually a significant route to market for existing battery-based grid storage systems, with projects around the world allowing stressed-out substations to keep operating for years longer by cushioning the peaks with stored battery power. In fact, PG&E has a 2-megawatt project in Vacaville that’s serving that purpose for a transmission substation.

But the new projects are some of the first targeting the medium- and low-voltage distribution grid, where the rules for batteries are different. California regulators are asking the state’s big utilities to come up with ways to value distributed energy assets — solar panels, batteries, plug-in vehicles, smart thermostats and other grid-edge systems — in their multi-billion-dollar, multi-year distribution grid investment plans.

PG&E didn’t disclose how much investment it’s hoping to defer with these new projects, or how much it planned to pay for them. But the numbers could be significant. In New York City, utility Consolidated Edison is proposing a plan to replace $1 billion in substation upgrades with a mix of energy efficiency, demand response, and distributed energy resources like rooftop solar and energy storage.”<

See on Scoop.itGreen Energy Technologies & Development

Energy Storage Solutions for the Smart Grid

In order to ramp up clean energy production, we have to figure out how to store and transmit it effectively. Companies are experimenting with new tech to figure out the best way to progress.

Source: www.techrepublic.com

>”The smart grid energy storage sector is expected to grow to $50 billion by 2020, with an annual compound growth rate of 8%, according to a recent report from Lux Research. In 2013, renewable energy accounted for only 10% of total US energy usage and 13% of electricity generation, according to the US Energy and Information Administration.

But as renewable energy generation rises, transmission and storage advancements will be necessary. Curtailment, the act of spilling renewable energy because there’s more than enough, is one issue to tackle. By changing grid transmission lines in 2010, Texas saw the curtailment in their grid drop from 9% to 4% in 2012, according to a report by the National Renewable Energy Laboratory.

The tipping point with energy storage depends on the grid and the technology used, said Sam Jaffe, an analyst at Navigant Research. Some places in the world that have extremely high penetration rates of renewable energy don’t have major problems with wasted renewables. Denmark sends its extra wind power to Sweden and Norway, while importing hydro power from those two countries when the wind isn’t blowing. Denmark’s wind penetration is now at almost 40%.

“That’s because they are interconnected to other grids that have a lot of flexibility to offtake renewable energy,” he said.”<

 

See on Scoop.itGreen Energy Technologies & Development

Coal opposes Senate Energy Commission Nomination

See on Scoop.itGreen & Sustainable News

Ronald J. Binz, nominated to lead the Federal Energy Regulatory Commission, is opposed by the coal industry because of his efforts to promote renewable energy.

Duane Tilden‘s insight:

>At the Electricity Consumers Resource Council, which represents large industrial customers, Marc Yacker, a vice president, said that the coal industry had some reason to be worried. The industry believes, he said, that “the whole idea of socializing the cost of new transmission necessary to get wind to population centers is anti-coal.”<

See on www.nytimes.com