This article which was published in the ECN journal in March, 2011 briefly describe existing centralized electric generation technologies that have been in operation for over a century. Smart Grids use advanced computer controls at distributed customer nodes of these centralized systems to optimize the supply/demand dynamics with increased efficiency and cost effectiveness. Smart Grids also aim at addressing the ever increasing constraints of environmental emission policies and the growing competition from the rapidly growing renewable energy based generation. Renewable energy technologies such as solar and wind are challenged by their inherent non-steady state power injection into the existing grid. Smart Grids must also evolve to address the integration and management of efficient storage technologies such as flywheels to potentially deal with such fluctuating power generators at the source. This article will describe a vision where the individual home owner generator, using renewable energy, will be able to use the Smart Grid to buy and sell electricity to others using similar protocols to those employed in the IT and social media networks of today.
Thomas Edison designed and built the first electricity generating plant in the United States. His Pearl Street plant in Manhattan started operating in September 1882. It initially supplied electricity to nearly 500 lamps to about 50 customers connected in what would be labeled today as an island model of distributed generation using Edison’s coal-powered dynamo.
At the turn of the century most large businesses generated their own electricity. This vertical electric generation gave way to more convenient and lower cost electricity once the utilities invested in building centralized power plants with large scale distribution infra-structure. Centralized electric generating utilities expanded over the following decades dramatically to meet the ever increasing demand for electricity. While such utilities offered efficient power generating plants, reliable transmission network, and lowest costs, the concern that they were a monopoly attracted the public’s attention. This ushered in the rate base regulation which continued for decades until production costs began to increase while demand started to decrease.
The well established buy-sell relationship between the utilities and their customers changed by the passage of the Energy Policy Act in 1992 (EPACT 1992). Basically this policy ushered in customer choices and options to purchase electricity albeit in very complex and challenging structures. EPACT 1992 mandated that wholesale customers have open access to the transmission system. The policy also provided such access to wholesale generators that were in direct competition to the utilities. Retail open access was denied by EPACT 1992 but provisions were made for States for such open access. By the year 2000, deregulation of electricity became the norm for most commercial and industrial consumers. By this time residential markets were realizing a modicum of deregulation as well. While Policy makers moved on to produce EPACT 2005, the complexity of this market sector remains. However, in August of 2003 the Northeast massive blackouts brought sudden awareness to each citizen that electricity is the lifeline of our modern society and that its generation, environmental impact, and sustainability is of paramount importance.
Today, over fifty percent of the electricity is generated from burning coal, while generation from natural gas and nuclear energy is in the mid to lower twenty percent respectively. The proliferation of nuclear energy for electricity generation is constrained by nuclear fuel waste disposal and management, limited skilled human resources, and homeland security. Whereas fossil fuel based generation is associated with increased emission of the combustion products: Water vapor, carbon, sulfur, and nitrogen oxides.
The outcry against “acid rain” in the beginning of the seventies yielded stringent nitrogen and sulfur oxide emissions reduction mandates by policy and cap-and-trade. As a result new, abatement technologies emerged and the levels of these emission continue a downward trend ever since.
Carbon dioxide is considered a green house gas because it has specific molecular characteristics of absorption and emission in the thermal infrared electromagnetic spectrum range. Greenhouse gases affect the temperature of the Earth and its atmosphere. Carbon dioxide levels have increased substantially primarily due the increased consumption of fossil fuels. The past decade has seen rapid increase in public policy debate to reduce its emission and indeed many States legislated Renewable Portfolio Standards (RPS) that require utilities to use a certain percent of its generation from renewable sources such as solar, wind, biomass and geothermal . Such RPS policies and goals vary widely amongst the States and countries Wordwide. Feed-in-tariffs, which pay directly for any electric generation from renewable, are also employed as a direct incentive for reduction of green gas emission. Public policy debates on such RPS, feed-in-tariffs, and cap-and-trade policies are currently very active on various governmental and public forums and such emerging of such policies usually take a long time especially in democratic societies. In the mean time, some countries have managed to invest heavily in modernizing the electric grid, producing a Smart Grid that aims at managing and optimizing the generation and use of electricity for the purpose of higher efficiency of resource management and environmental responsibility.
Power plants generate the electricity and transmit it across the extensive nationwide electric grid network. The demand for electricity is determined by the specific behavior of its consumer: Industrial demand is much larger than the residential consumer but with a much different demand duty cycle. The direct storage of electricity is today very costly and inefficient and therefore is not considered as viable forS large commercial scale to smooth out and balance such varying duty cycles. The utilities work diligently and constantly on balancing and optimizing such complex supply/demand dynamics to produce high reliability power to all their customers.
The Smart Grid as it has emerged over the past couple of decades aims to achieve such supply/demand balance using advanced digital computer controls. Two-way digital sensors and communication modules are distributed within nodes of the electric network. A Smart Meter is an example of a simple two-way residential metering technology. Utilities that use Smart Grid management systems imbed much more sophisticated two-way systems that both interrogate and control the power flow through each grid network node. Such Smart Grid sensors help dynamically assess local demand and optimize supply routing with increased efficiency, reliability, and safety.
Renewable energy sources such as wind and solar power have unique power generation duty cycles because of the variable nature of wind energy, sun light variations, and local weather. The Smart Grid could integrate such renewable energy sources with the existing base-load fossil and nuclear power generators. However, utilities have historically not invested heavily in research and development and successful Smart Grid implementation would depend on the availability of advanced sensors and control software products. Capital investment in this sector would usher the emergence of the most economical sensor and software technologies. With such technologies, the Smart Grid could deliver it envisioned reality of efficient integration of renewable energy with fossil and nuclear electric generation at higher reliability, efficiency, security, and significant reduction of carbon dioxide emissions.
The information age, with its recent expansion into social networks, has evolved the individual into a communication node. Such individual nodes, what I call an information iNode, needs to encompass its energy consumption and generation as well. The current Smart Grid vision needs to be enlarged to include this modern day individual iNode. Federal and State incentives together with some feed-in tariffs encourage the individual to install renewable energy sources technologies such as solar and wind at the residential level. Such policies are on the increase both domestically and overseas and they also incentivize the individual to use the emerging electric vehicles with the objective of reducing the dependency on imported oil
An expanded Smart Grid vision that includes the individual iNode is schematically shown in Figure 1. Two representative homes are shown with roof top mounted photovoltaic solar panel and each with one single pole-mounted small wind turbine. These renewable energy technologies combined reduce the individual resident’s electric energy consumption form the grid. The electric utility grid network is depicted by the two giant towers shown on either side. The grid network is shown connected to each home via Smart Meter with two-way communications to the Smart Grid that is fully integrated with the World Wide Web servers. Each of these individual resident iNodes would be able to buy and sell electricity to and from other iNodes or utilities via downloaded software applications that the iNode can be managed using a lap top, a smart phone, or a tablet. This Smart Grid vision places the mobile individual iNode at the center of power generation, supply, and demand management. The individual as an information and energy iNode is the ultimate goal of individual freedom, responsibility, and economic growth.