X. Revolution in Power Engineering
(originally published December 25, 2007)
In my previous post in this series, I discussed the characteristic differences between renewable energy sources and the largely fossil energy that fuels our current societies. A fundamental difference between the fuels for our current energy system and the strongest renewable sources of energy is that the former are natural but non-renewable energy stores that we are in the process of exhausting and the latter are based upon today’s energy flux. There are a number of practical differences that follow from using an energy store versus tapping into natural energy flux as a means of generating electricity.
If the primary energy, the fuel, for the entire electric energy system will be switched from exhaustible energy stores to renewable primary energy, creating one of the foundations for a more sustainable society, there are a number of technical and organizational challenges that face the profession of power engineering.
What is Power Engineering?
Power engineering or power systems engineering is a branch of electrical engineering that concerns itself with technical challenges related to the generation and transmission of electricity as well as power related issues in end-use electrical devices like motors and computers. Power engineers are responsible for the always-on power grid that we have come to rely upon to power our convenience-filled lifestyle. Despite its vital role, power engineering has languished in universities around the world as its cousins, computer engineering and computer science have flourished. Power engineers in the US are now one of the “grayest” of engineering professions, with average age in some specialities in their 50’s.
An argument can be made that Thomas Edison was one of the first power engineers in his role as the inventor of the electric power industry. Early electric grids were built around coal driven heat engines, like Edison’s first plant, the Pearl Street Station in New York, or around hydropower, like the world’s first public electric power plant in Godalming, Surrey, England in 1881. While hydropower is, in terms of power quality and cost of fuel, superior to coal, it has suffered from geographical inflexibility and vulnerability to drought and seasonal variation. Coal’s relative abundance, independence from changes in the weather, and portability made it the choice for most generating stations.
In the contemporary electrical system, for most power engineers, the focus is on electrical reliability: maintaining energy throughput, control of systems, and distribution of electrical energy while minimizing new capital investment. On a daily basis, power plants are scheduled to turn on and off or ramp up and down to meet power demand. Grid operators monitor and regulate voltage levels and the AC frequency of the grid. More voltage sensitive equipment is now plugged into the grid, so tolerance for variations in power quality have been reduced. On a more intermittent basis, infrastructure needs to be overhauled and/or upgraded. Finally, new power plants and infrastructure are designed and sometimes implemented to meet the rising demand for power. In the developing world, electric infrastructure is being built at a quicker pace, commensurate with rapid increases in demand for electricity.
Vested with the mandate to maintain and improve stepwise the world’s largest and most capital-intensive machines, the modern power grids, power engineers focus on options that protect the substantial investment of shareholders and governments in the electrical system while delivering power to users on a largely uninterrupted basis. It is no accident that a number of the primary organizations that run the electric grid in the US have the word “reliability” in their title: The North American Electric Reliability Corporation (NERC), Department of Energy Office of Electric Delivery and Energy Reliability, etc. With a focus on “not failing” in a complex business, power engineers want to eliminate risk and uncertainty whenever possible.
An additional impetus towards conservatism originates in key characteristics of the grid as a massive set of electrical circuits: it is a tightly-coupled system with many interconnections and high degree of complexity. Dodging cascading service interruptions, i.e. blackouts, from often minor causes, is a struggle and increases with growing power demand based upon limited infrastructure growth and change. An awareness of risk helps condition the operational culture of electric utilities and grid operators.
Given this environment, there is a preference among the leaders of electrical utilities for primary energy sources that will maintain reliability and build on the existing knowledge base. Primary energy is the amount of fuel needed as input to produce a given amount of electricity using a particular set of generators. Energy stores such as coal, natural gas, oil, nuclear, and existing hydroelectric dams are favored because of the ability to project within a timescale of months and the next few years, available primary energy and time its release. The existence of established coal, gas, oil, uranium mining and refining, rail and shipping industries allows the electric industry to relegate the work of supplying primary energy to other industries.
Since the days of Samuel Insull, the designer of the modern electric utility, utilities and power engineers have insulated (sorry about the pun) users of power from the workings of the power grid, allowing them to consume electricity without much thought about its origin, availability and, for the most part, its price. As electric grids have become overtaxed and environmental concerns have mounted in the last couple decades, increasingly consumers have been brought into thinking about electricity a little more, though the workings of the electric world are still opaque and far away from most people’s everyday awareness.
The Distributed Energy Rebellion
The first challenge to large utility-based power engineering emerged during the cultural revolutions and energy crisis of the late 1960’s and 70’s. At first more theory than fact, the idea of “un-plugging” from the grid attracted attention among the counter-culture as it would mean becoming independent of the corrupt “system”, against which many would come to define themselves. The resurgent environmental movement fought against pollution that often came from power plants as well as the destruction of natural habitats by damming projects. Peace movements thought of nuclear power as tainted by its association with nuclear weapons.
The vision of a society of small-scale grids or no grids at all, emerged first from the social imagination rather than from technical feasibility. For some, a retreat from any power use at all was considered preferable to being complicit in pollution and modern society. E.F. Schumacher wrote an influential book, “Small is Beautiful” that identified large size as one of the cultural malaises of industrial society. Solar photovoltaics, stimulated by the space program, and wind energy were thought to be the more environmentally friendly ways to generate electricity even though those technologies remained prohibitively expensive until the last two decades. The hope and eventually the demand by mavericks and political leaders for cleaner solutions to generating power kept inventors and small investors working on these technologies, as did continuing demand for photovoltaic cells by the space industry to power the growing number of communications satellites.
Paradoxically, another impetus towards distributed energy came from the opposite end of the political spectrum, at least in the US. Following the Reagan Revolution of the 1980’s, a movement against regulation of markets spurred some limited organizational de-centralization in the power industry. The idea of deregulating and breaking up the vertically integrated utilities in favor of competition at least in generating electricity opened the electricity market to merchant generators. Though not explicitly supportive of renewable energy, an opening was created by deregulation for commercialization of independent renewable energy generators in addition to utility-owned generators.
The ideal of distributed energy still animates aspects of the renewable energy industry including much of the market for photovoltaic technology, small wind turbines and micro hydroelectric. Distributed energy does not yet compete directly with a professionally run, massively interconnected grid in most locations because as power demand continues to climb, capital costs to electricity self-generators would still be high and distributed electricity storage is still relatively expensive. If electrical storage and various small renewable generators were cheaper and more widely available, one can imagine that a more decentralized grid would result. On the other hand, it is doubtful that power users will want to forego access to the resources of a widely distributed interconnected group of generators or the services of a corps of professionals who insulate them from the vagaries of an electrical system and changes in availability of primary energy. Whether you identify it as a sign of industrial and environmental malaise or a positive social good, the grid will probably live on in some form in an age of distributed and renewable energy.
Revolution in Power Engineering
Whether the grid of the future will fragment into local grids or develop into a more widely interconnected hypergrid with both distributed and centralized generators, the grid(s) of the future will require some form of professional design and management and will most decisively be fueled by renewable energy sources. The efforts to clean up coal and revive nuclear will only delay this fundamental shift to sustainable fuels; they are understandable attempts to re-use the knowledge base of contemporary power engineering in a carbon-constrained world. While sticking with what you know is understandable, a delay in grasping what I am calling a revolution in power engineering only sets us all back as we grapple with the challenges of climate change, increased worldwide demand for energy and oil depletion.
In my previous post in this series, I highlighted how energy stores as opposed to energy flux were central in the organization of the contemporary electric grid: energy stores such as hydroelectric reservoirs, fossil or nuclear fuels allow for an inventory of primary energy supply and the timing and control of energy output. On the other hand energy stores can be depleted by people, while natural energy flux cannot. Natural energy flux is the key element that explains the renewable part of renewable energy. Types of natural energy flux, like solar radiation, wind, or geothermal heat are also the strongest and most widely distributed types of natural renewable energy. On the other hand, on earth’s surface, natural energy flux is not constant nor with the exception of the tides, entirely predictable. Natural energy stores replenished by renewable flux (mostly biomass) are insufficient for our current energy needs without major ecological disruptions or at the moment present technical hurdles to their extraction (geothermal heat in the crust’s basement rock).
Harnessing renewable energy flux, with all the associated challenges, is then one of the core future tasks for the power industry and the basis for a future sustainable energy system. Transferring the primary energy of the power grid from exhaustible energy stores to a primary reliance upon energy flux will then mean a revolution in power engineering, a new way to meet energy demand with many new challenges associated. This is analogous to the scientific revolutions of the Kuhnian type: a paradigm shift that does not throw out existing knowledge and skills but puts them in a new light and context. The existing knowledge base and skills of power engineering remain valuable in a renewable electron economy. The addition of new challenges and a new framework means making a difficult job even harder but also means added prestige, opportunities for enhanced public service, opportunities for financial gain, and intellectual challenge.
Associated with the change in primary fuels for electrical generators are six challenges that will necessitate substantial re-thinking of generator and grid design and operation:
1. New Primary Energy Supply Chain
The first new challenge for power engineering is realizing that the supply chain for primary energy will be radically different and more closely integrated with the delivery of electricity itself. By using renewable flux comes the need to build a whole new set of capture devices (wind turbines, solar panels, geothermal wells) that are positioned to intercept renewable energy where it is strongest. Instead of a separate coal, petroleum products or uranium extraction industries, the capture of renewable energy will most often be integrated directly with the delivery of electricity or its generation. This means changes in investment strategy in equipment (wind turbines, etc.) that replace the function of entire (supplier) industries. As it happened historically, the electrical power industry was able to inherit or share these suppliers with other buyers of coal, uranium, natural gas, and oil. Hydroelectric dams have also had multiple uses beyond power supply that have helped spread out or divert the initial investment costs from the sellers of electrical services themselves. Alliances with new equipment suppliers, merchant generators and/or new sources of investment capital will be required.
2. New Technical Understanding of Energy Capture Devices/New Generator Technologies
The second new challenge is that the capture devices for renewable flux (wind turbines, solar collectors, wave power generators, etc.) are a diverse set of technologies, some of them new to the world and many of them new or unknown to many power engineers. Whole new technical and business competencies will need to be developed to be able to interact with the makers of these new devices or to participate in inventing and or refining new renewable flux capture devices/generators.
3. Integration with Meteorology and Geophysics
One of the features of renewable energy flux that complicates harnessing it for power production is that it is not constant or entirely predictable. The third new challenge for power engineering is forming a much deeper disciplinary alliance with meteorology and geophysics that would allow grid operators a wider operational window to plan the deployment of generators. Currently grid operators rely on weather reports to predict power demand but in the renewable grid of the future, power supply will be critically affected by weather and, in the case of geothermal, subsurface events. The renewable grid will motivate the already rapidly advancing science of weather prediction to make more accurate forecasts days and weeks in advance to help power engineers manage power output.
4. New Energy Storage
The fourth new challenge for power engineers is building adequate energy storage to further bridge renewable energy supply with demand, replacing the controlled timing of energy release from the natural-supplied energy stores of fossil and nuclear fuels by constructing artificial stores. While hydroelectric dams are a notable early and, from the point of view of the power generated, successful example of a successful artificial energy storage, most of the major rivers in the developed world that offer hydroelectric potential have already been exploited. In addition to any environmental problems associated with dam building, growth in hydroelectric capacity has a natural ceiling that is below that of world-wide energy demand. I have discussed existing alternatives in energy storage in an earlier post in this series. The growth and implementation of these types of storage will take increased research and development on the storage technologies themselves, as well as willingness to invest and apply existing storage technologies that have both some technical or financial advantage and are carbon neutral.
5. New Transmission Infrastructure
A fifth challenge for power engineering is the modification of transmission infrastructure to allow for access to the strongest renewable energy flux in remote and/or hostile environments. Some all-renewable energy proposals suggest that distances of 5000 miles (8000 km) or more from source to load are conceivable, if the variability in time and space of renewable energy flux is to be balanced to meet energy demand. Conventional high voltage DC, the long distance electricity carrier of choice, may need to be further developed with new conductor technology to be able to more efficiently transport electrical energy long distances. Research into cheaper and more efficient underground cabling technology may help speed regulatory approval of transmission projects, saving time and thereby money. Building transmission facilities in hostile marine conditions far from shore or in the middle of frozen lakes represent new engineering challenges. Proposals to tap into high altitude wind would require strong but light conductors to reach high into the atmosphere. Furthermore, renewable energy generators generally have lower capacity factors (produce power only a portion of the time) than conventional power plants, leading to challenges related to designing transmission to be used most efficiently by renewable energy; combined planning of transmission and generation capacity might need to take place on a regional or national level to insure the most efficient design of transmission lines.
6. New Grid Management and Information Systems
Finally, the sixth challenge, as implied above, integrating renewable generators require a higher level of coordination and information about micro and macro-events on the grid that will require new communication and information technologies. Already on the agenda of power engineers is the building of the “smart grid” which will bring the use of current information technology, two-way communication between power users and power generators, a system of addressable nodes not unlike the Internet. Beyond smart grid proposals, an all-renewable grid will need to have the ability to communicate with and manage a multiplicity of generators with different capacities and power output profiles, factoring in weather data on both supply and demand sides. In constructing such a grid, planning for energy flows and fuel availability will include consideration of an extraordinary number of factors, also requiring the capacity to develop massively multi-factor models of natural energy flux, generator capacity, existing and future generators, security concerns and back-up generators.
Political Will and Market Demand
Power engineers may be able to help move us towards the renewable future within their profession and industry but ultimately some of the conditions for this eminently do-able transformation reside outside engineering in the centers of political and economic power. Motivated by a public concerned about sustainability and climate change, political leaders would need to add and re-frame regulations that a transition from fossil and exhaustible fuels to renewable ones were national and international priorities. Cap and trade or carbon tax proposals are one form such expressions of political will can take. Feed in tariffs, a way to explicitly promote renewable energy through offering guaranteed premium pricing to renewable energy generators, have boosted the renewable energy industry in a number of European countries and have received support most recently from the California Energy Commission.
Despite the importance of better policy, individuals and individual firms can get out ahead of policy and the market by investing now in renewable, transmission, and grid management technologies that can meet the requirements of power engineers and electricity consumers. Over the last several years, venture capitalists have been anticipating the shape of future electricity markets in their cleantech investment strategies, focused largely on new technology. Google’s RE<C announcement appears to be a similar effort. Large diversified electric equipment suppliers like General Electric and Siemens, with a diversity of commitments to many different types of generation, may increase investment in these areas if market and political leaders show resolve in steering us towards a renewable future.