Driving Distributed Energy with Smart Networks

Smart power delivery system

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.

Source : Internet

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Fuel cells in power section

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.

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Basic Principles

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.

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Types of Fuel Cells

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.

1. Polymer Electrolyte Membrane (PEM)
2. Alkaline Fuel Cell (AFC)
3. Phosphoric Acid Fuel Cell (PAFC)
4. Molten Carbonate Fuel Cell (MCFC)
5. 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

Type	Electrolyte	Temperature C	Applications	Advantages
Polymer Electrolyte Membrane (PEM)	Solid organic polymer poly-perflourosulfonic acid	60–100	Electric utility, transportation, portable power	Solid electrolyte reduces corrosion, low temperature, quick start-up
Alkaline (AFC)	Aqueous solution of potassium hydroxide soaked in a matrix	90–100	Military, space	Cathode reaction faster in alkaline electrolyte; therefore high performance
Phosphoric Acid (PAFC)	Liquid phosphoric acid soaked in a matrix	175–200	Electric utility, transportation, and heat	Up to 85% efficiency in cogeneration of electricity
Molten Carbonate (MCFC)	Liquid solution of lithium, sodium, and/or potassium carbonates soaked in a matrix	600–1000	Electric utility	Higher efficiency, fuel flexibility, inexpensive catalysts
Solid Oxide (SOFC)	Solid zirconium oxide to which a small amount of yttria is added	600–1000	Electric utility	Higher efficiency, fuel flexibility, inexpensive catalysts. Solid electrolyte advantages like PEM

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Northern India Recovering from Huge Blackout

         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.

          India has been struggling with electricity supply issues for some time. Harry Goldstein reported on attempts by Mumbai (part of India's western grid) to make itself blackout-proof in 2006. In 2010, contributing editor Seema Singh reported on how electricity policy was imperiling India's agricultural future.

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