Superposition Theorem Used To Solve The Simple Network

Superposition Theorem Example // Using Superposition theorem, find the current through the 2Ω resistor of the network of Figure 1 above. The presence of three sources will result in three different networks to be analyzed. Solution // Considering the effect of the 12-V source (Fig. 2): Considering the effect of the 6V source (Fig. 3): […]

White House Speaker Brings Insights to Final Day of Energy Storage Conference

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Purpose And Applicable Processes Of a SCADA System

What is the SCADA system? SCADA is the technology that enables a user to collect data from one or more distant facilities and to send limited control instructions to those facilities. It is important to note the words “distant” and “limited” in this definition. SCADA has been developed to monitor and control very large process facilities. […]

Features of 3 circuit protection devices (MCB, RCCB and RCBO) you have probably forgotten

Circuit Protection Devices Traditionally, fuses were the main devices chosen for final circuit protection, up until the 1970's when circuit breaker technology started to become dominant. Today, the three principle circuit protection devices are: Miniature Circuit Breakers (MCBs), Residual Current Circuit Breakers (RCCBs) and Residual Current Circuit Breakers with Overcurrent protection (RCBOs) Miniature Circuit Breakers […]

Community Energy Storage Storage for Cleaner, Lower-Cost Electricity

Robin Roy, NRDC

More and more utilities, equipment manufacturers, and others are working to develop energy storage in households and businesses that can help make the electricity grid cleaner and cheaper. And many of these are eager to share their experiences and insights, as shown by the enthusiastic response to the “Community Storage Initiative,” which has already attracted a great group of founding supporters as announced today. More on that, below.

Energy storage can make the electricity system more flexible and ready to use renewable generation that has variable output, like wind and solar. Storage with advanced communication and controls can even offer the prospect of providing the grid with 'ancillary services' like frequency regulation and load following, reducing the need for power plants to quickly ramp up and down as total energy consumption changes during the day. The idea behind community storage is to coordinate the dispatch and optimization of premises-based energy storage resources, often on the customer's side of the energy meter, to achieve electric system wide benefit.

Dedicated batteries and smart charging of electric vehicles are excellent examples of rapidly advancing storage technologies that sit on the customers' side of the electricity meter. Another great example is grid-connected operation of the tens of millions of “hidden batteries” already in our homes in the form of water heaters.

(If you're puzzled by the idea that tens of millions of hidden batteries are already out there, see my previous blogs here and here about how the humble water heater can be turned into effective and low-cost energy storage devices-all while keeping our showers hot. Grid-connected water heaters are electric water heaters with communication and control capability that allow utilities to use them as low-cost thermal batteries, heating the water when power is cheaper and cleaner, and deferring heating when power is expensive.)

NRDC, the National Rural Electric Cooperative Association (NRECA) and the Peak Load Management Alliance (PLMA) have been working together to explore advanced electric water heating technologies, and found enormous opportunities in both high efficiency “heat pump” water heaters and in grid-connected ones. (Heat pump water heaters work something like a refrigerator in reverse, collecting heat from air around the water heater and moving it into the tank.)

There are many energy efficiency policies and programs to help increase the take-up of heat pump water heaters, e.g., building on longstanding and highly successful utility energy efficiency programs, consumer awareness through ENERGY STAR labeling for energy efficient models, tax credits, and appliance efficiency standards. All of those make great sense to keep pushing, and should help increase heat pump water heaters reach their great potential for consumers and the environment.

However, the pathways for increasing all forms of energy storage opportunities in homes and commercial buildings, including using grid-interactive water heaters, are less well developed. Given the great economic and environmental potential for storage, but an absence of obvious venues for information exchange, NRDC joined with NRECA and PLMA in February as founding supporters of the Community Storage Initiative, and were promptly joined by the Edison Electric Institute and the American Public Power Association.

The Community Storage Initiative Vision Statement, and a definition of community storage, is:

Community Storage is an emerging term for utility-sponsored programs that aggregate distributed energy storage resources that are located throughout a community, such as water heaters, electric vehicles, and interconnected storage batteries, to improve the operational efficiency of electric energy services to consumers. The defining characteristic of a community storage program is the coordinated dispatch and optimization of premises-based energy storage resources, often behind a consumer's energy meter, to achieve electric system wide benefit. The Community Storage Initiative (CSI) is focused on collaborative information sharing and coordinated market development efforts in support of wide-scale implementation of energy storage technologies that are commonly located in communities across the country. CSI is dedicated to bringing the economic, environmental and societal benefits of these storage technologies to end-use electric customers throughout the US.

The intent of the Community Storage Initiative is to encourage manufacturers, utilities, and other stakeholders to explore and exchange ideas and experience on energy storage opportunities using customers' equipment. In the few weeks since we first announced the initiative, it has been great to see great enthusiasm and interest in sharing experiences. Today, the Community Storage Initiative is announcing its founding supporters, which represent utilities, technology developers and environmental advocates. We hope to add more supporters and more experience sharing until community storage reaches its full potential in delivering a more flexible, economic, renewables-ready, and cleaner electricity grid.

What's next?

It's clearly early days for delivering on the potential for energy storage at customer premises. We will be doing what we can to promote the exchange of ideas and experience in the full range or key areas, from technology to marketing to consumer incentives and pricing to whatever is needed.

If you'd like to join us, please visit the CSI website and get in touch.

This blog originally appeared on the Natural Resources Defense Council's website. The author, Robin Roy, is the director of  NRDC's Building Energy Efficiency and Clean Energy Strategy, Energy & Transportation Program.

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Electric Circuits? It's All About Nodes, Branches, and Loops

Nodes, Branches, and Loops Since the elements of an electric circuit can be interconnected in several ways, we need to understand some basic concepts of network topology. To differentiate between a circuit and a network, we may regard a network as an interconnection of elements or devices, whereas a circuit is a network providing one […]

What Would Be The Worst Type Of Three Phase Faults (And Why It Happens)

When Three Phase Faults Occur… In a three phase power system, the type of faults that can occur are classified by the combination of conductors or buses that are faulted together. In addition, faults may be classified as either bolted faults or faults that occur through some impedance such as an arc. Each of the basic […]

3 Designs of DC Distribution Systems In Power Substations

DC Distribution Systems The method of connection of the battery, battery charger, and DC distribution systems depends on the duty, the type or load, and whether the system needs to be duplicated or whether duplicate chargers are required. One typical example for a 125 V system is shown in figure 1 below. In this example, an […]

Two Basic Methods Used For Braking a Motor (DC Injection and Dynamic)

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You can use water pipes for grounding purposes, but…

Water Pipes for grounding Water pipes have been used extensively in the past as a grounding electrode. Water pipe connections are not testable and are unreliable due to the use of tar coatings and plastic fittings. City water departments have begun to specifically install plastic insulators in the pipelines to prevent the flow of current […]

Why Do We Care So Much About Power Factor Correction?

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New Study Concludes Getting 50% of NY's Electricity from Renewable Sources by 2030 is a Net Win

A new New York State Department of Public Service study projects New Yorkers can get 50 percent of their electricity from renewable sources for less than four cents a day. Jon Ballard via Flickr

NRDC's Jackson Morris looks at the low cost and high value of procuring 50 percent of New York's electricity from renewable sources.

In December, when New York Governor Andrew Cuomo directed the state's Public Service Commission (PSC) to create a Clean Energy Standard (CES) that ensures New York gets 50 percent of its electricity from renewable sources by 2030, he wrote to PSC Chair Audrey Zibelman, “By mandating a Clean Energy Standard, we ensure that this goal is converted from aspirational to actionable.”

Well, actionability came one step closer late on Friday, when, as part of the regulatory process necessary to enact the CES, the state's Department of Public Service (DPS) released a study that analyzes how much it will cost New Yorkers to meet this ambitious and worthy goal.

Here's the very good news from that report: Hitting the 50-percent target is projected to add less than a dollar to the monthly electric bill of the average New Yorker-that is, add less than 1 percent to the cost of the typical residential electric bill- while creating benefits totaling $1.8 billion by 2023.while creating benefits totaling $1.8 billion by 2023. And those benefits don't even include the sizeable public health gains that result from when we replace dirty fossil fuel power with clean, renewable energy. In fact, state renewable energy standards in 2013 alone provided a wide range of benefits, according a recent study from Lawrence Berkeley National Laboratory:

• $5.2 billion in reduced air pollution;


• 200,000 renewable energy jobs; and,


• $1.3-$3.7 billion in reduced natural gas prices.

In other words, the cleaner the power, the better the benefits for New Yorkers overall.

In addition to the DPS study's striking topline conclusion-$1.8 billion benefits for less than a dollar on the average electric bill-below are three key initial takeaways. (Recognize that we're still sifting through all 297 slides of the report and will inevitably have additional reactions going forward in the formal comment process).

The role of energy efficiency in minimizing CES costs is pivotal. But will it materialize?

Importantly, the study emphasizes the pivotal role energy efficiency must play in keeping clean energy costs down. After all, when New Yorkers swap out inefficient lighting and appliances for energy-saving models, they don't just cut their own electric costs; they also reduce energy demand overall, thereby lowering electric costs for everyone across the Empire State. In addition to reducing wholesale electricity and capacity prices, energy efficiency also directly reduces the cost of meeting the CES: When the pie is smaller over all, you need fewer supplies to bake it. (Conversely, if New York drops the ball on efficiency, it'll cost a whole lot more to get to 50 percent.)

Learn more about NY REV by attending “NY and Beyond: Advancing Microgrids Nationally with Lessons Learned in New York“, May 19.

That's why, even as New York tests out new utility business models (pdf), market designs, technologies, and scales up innovative distributed energy resources under Governor Cuomo's groundbreaking Reforming the Energy Vision initiative, it's essential we rely on some tried-and-true models that can guarantee energy efficiency savings across New York. As we continue to ramp up renewables (which the CES will deliver), we need comparable regulatory certainty for energy efficiency: New York needs a clear energy-efficiency standard, even as the means of delivering that efficiency will continue to evolve under the REV. Once this standard is put in place, it can ensure New York accomplishes what other leading states already have-year-over-year electricity savings of 2 percent a year or more.

Projected gas prices are a key variable. But 50x'30 delivers savings in various scenarios.

Another key takeaway from the new cost study relates to projected natural gas prices. They're a key variable in any analysis of this kind, particularly given that New York currently relies heavily on that fossil fuel for electricity generation. Some argue that cheap gas poses a major barrier to the deployment of renewable energy. And while that does alter the calculus somewhat, the good news is that even if the “premium” paid for renewables increases if gas prices plunge further, that increased per megawatt-hour premium to meet the CES is largely offset by cheaper wholesale electricity prices overall. And if in the future gas prices are higher than anticipated, renewables become even more cost-effective and reduce our exposure to those volatile fossil fuel price spikes going forward.

(For those interested, check out Figure 9.1 from slide 98 of the report, below, which illustrates this relationship. From the report: “Figure 9.1 illustrates projected CES gross program costs relative to total historic and projected statewide wholesale electricity spend. As an example, in the base case the maximum cost impact of the CES until 2023 on typical monthly residential electricity bills is estimated to be less than $1 in real terms(1). While CES program costs would be higher under low energy prices, this would be outweighed by customers' savings on their overall energy bills due to lower energy prices.“)

A new New York State Department of Public Service study projects New Yorkers can get 50 percent of their electricity from renewable sources for less than four cents a day. Jon Ballard via Flickr

From the report, Figure 9.1

The cost study gets it right on the societal value of carbon reductions.

In this study, it's important that the state factored in the benefits that come from cutting carbon pollution under the CES. To do these calculations, the PSC rightfully used the EPA's well-vetted social cost of carbon. That metric details the costs carbon pollution impose on us all, on a per ton basis. (Here's how the EPA explains it: “The SC-CO2 is an estimate of the economic damages associated with a small increase in carbon dioxide (CO2) emissions, conventionally one metric ton, in a given year. This dollar figure also represents the value of damages avoided for a small emission reduction (i.e., the benefit of a CO2 reduction.”) Included here are the climate-change-related costs of extreme weather events such as Hurricanes Irene (which resulted in damages totaling $20 billion) and Sandy ($65 billion), along with the costs we incur from increasingly dangerous floods, wildfires, and heat waves that are fueled by global warming.

Achieving the proposed New York State Clean Energy Standard has so many benefits to offer: less global warming pollution, cleaner air for our kids to breathe, new, good-paying jobs in fields like wind and solar power and (hopefully, ultimately!) energy efficiency. Pretty impressive: All these benefits could move from inspirational to actionable for less than four pennies a day.

This article orginated on the Natural Resources Defense Council blog. Author Jackson Morris is the NRDC director, eastern energy project. 

5 anomalies in AC power that can damage your home devices

AC Power Fluctuations In addition to lightning, there are a number of other disturbances that can come in on the AC power lines and damage equipment. Some surge protectors can reduce or eliminate damage from some of these perturbations. There is considerable confusion about the overlap between damage from AC power disturbances and from lightning. […]

What Would Be The Best Conductor Material for Electrical Cables

Al or Cu conductor… The conductivity of copper is 65% higher than that of aluminium which means that the conductor size of similarly rated cables is proportionately smaller. Correspondingly less expense is then incurred in providing for insulation, shielding and armouring the cables themselves. Transport of the less-bulky cables is easier and so is installation. […]

What Is The Energy, But For Real?

The basics of energy Energy is best defined as “the capacity for doing work”. Electricity is but one of many forms of energy. Other familiar forms of or descriptions of energy are thermal or heat, light, mechanical, and so on. Energy is also described as kinetic, that energy associated with a moving body, and potential […]

Why Energy Storage May Be The Most Important Technology In The World Right Now

In 1882, Thomas Edison built the Pearl Street Station, the world's first steam powered electrical distribution plant. In the years that followed, intense competition broke out between he and George Westinghouse, which became known as the War of the Currents, and the technology improved markedly in the coming decades.

As Robert Gordon pointed out in The Rise and Fall of American Growth, by 1940 life had been fully transformed. Even middle class homes had most of the modern conveniences we enjoy today, including refrigerators, air conditioners, telephones and radios. Soon, they would have TV's as well.

Power Measurement On Four-Wire System Using Wattmeter Methods

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The basics of selectivity (discrimination) between circuit breakers

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Greensmith Energy Secures Market Leader Position-Reaches 70 Megawatts of Energy Storage

HERNDON, Va.--(BUSINESS WIRE)--Greensmith Energy, one of the largest providers of energy storage software and turn-key solutions, announced 70 megawatts of energy storage deployments – all powered by the company's proven GEMS software platform. While most of the capacity was integrated and installed by the company over the past two years, Greensmith is also reporting growth in software licensing as punctuated by the 53MWh software-as-a-service contract awarded earlier this year by Deltro Energy. 

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Testing of the earthing system Commissioning of new earthing system is essential as a validation step for the design and installation process and for the design inputs. In most cases commissioning should measure the outputs of the earthing system in terms of produced voltages and current distributions rather than solely resistance. The commissioning should consider […]

Greensmith Energy Secures Market Leader Position-Reaches 70 Megawatts of Energy Storage

HERNDON, Va.--(BUSINESS WIRE)--Greensmith Energy, one of the largest providers of energy storage software and turn-key solutions, announced 70 megawatts of energy storage deployments – all powered by the company's proven GEMS software platform. While most of the capacity was integrated and installed by the company over the past two years, Greensmith is also reporting growth in software licensing as punctuated by the 53MWh software-as-a-service contract awarded earlier this year by Deltro Energy. 

Six core activities in the commissioning of the earthing system

Testing of the earthing system Commissioning of new earthing system is essential as a validation step for the design and installation process and for the design inputs. In most cases commissioning should measure the outputs of the earthing system in terms of produced voltages and current distributions rather than solely resistance. The commissioning should consider […]