A number of important technologies improve the ability or increase the usefulness of other energy technologies. In fact without these technologies, many of the popular renewable or alternative energy technologies would not be useful at all. As alternative energy technologies mature, leveraging the ability of existing technologies to fit into other roles or stitching complex systems together will become increasingly important.
Power electronics are an essential part of any renewable energy or fuel cell power generation unit their purpose is to convert the direct current produced by these technologies into the alternating current we need to power our homes, businesses, and manufacturing facilities. As the component of these facilities that is connected to the rest of the power system, they provide a key role in any strategy of developing these new resources to produce power.
Power electronics also improve the quality of power and protect customer’s equipment from damage. With an increasing level of sophistication, newer power electronics are enabling a host of applications and operations for advance energy management and usage strategies.
The limitation of existing battery technologies is holding back the development of a host of products ranging from hybrid electric vehicles to hand-held consumer electronics. For this reason, a number of advanced battery chemistries are being developed to extend the capabilities of the energy storage component of these products to make them more useful and capable.
Besides developing new energy storage technologies, a significant area of development in battery technology is to incorporate advanced materials into existing and mature battery technologies. This strategy leverages the deep knowledge base surrounding some technologies such as lead acid while advancing its capabilities to survive the harsh environments found in many new applications.
Flywheels have been an essential tool to smooth the power flow in and out of a spinning mechanical device for a very long time. Flywheels store energy by accelerating a rotor up to a very high rate of speed and maintaining the energy in the system as kinetic energy. Energy in not stored in the rotor in proportion to its momentum, but at the square of its surface speed—hence the desire to develop high-speed flywheels with correspondingly higher energy densities to allow for other market applications.
Flywheels are well suited to applications requiring frequent and deep discharges that generally prove too taxing for standard battery installations and are also more compact and require less maintenance. These technologies are used in uninterruptible power supply (UPS) devices, but increasing interest exists for regenerative applications in transportation or industrial settings.
Superconductivity, the absence of electrical resistance under extreme low temperatures—was discovered early in the 20th century. Unfortunately, early superconducting material had to be cooled to an extremely low temperature for the effect to occur, making any practical use of this far too expensive for practical use. During the 1980’s high-temperature superconducting (HTS) ceramic material was discovered, and progress towards improving its effectiveness and manufacturability makes these materials—able to be cooled by cheap liquid nitrogen—very promising for a host of new products.
The first product most often thought of for HTS wires is transmission cables for the electrical power industry. Roughly 10% of all power generated in theUnited Statesis wasted through resistance in the existing power delivery system. Not only will HTS wire save that energy, but the higher carrying capacity of the HTS wires will allow more power to be delivered through existing right-of-ways, instead of having to build new power lines, which is expensive and takes many years to approve. This is a crucial ability, as power blackouts are caused not only by loss of generation, but in bottlenecks in the power delivery system as well. HTS wires can also be made into a host of other electrical power devices such as better transformers, fault limiters and even energy storage devices that promise to transform much of how we use electricity. Most promising is the development of HTS based motors and generators half the size and one third the weight of conventional units.
Ultracapacitors are designed to combine the cycling capabilities of a capacitor with the energy storage capabilities of a battery, filling a niche between these two energy storage technologies. Their inherent capabilities hold out many opportunities for these technologies to make inroads into applications where they are coupled with other storage technologies as a buffer, although many applications exist where they can operate as the primary energy storage device.
Ultracapacitors are made up from two electrodes immersed in an electrolyte and separated by a porous separator. These devices store energy via electrostatic charges on opposite surfaces of the electric double layer, which is formed between each of the electrodes and the electrolyte ions. Because ultracapacitors move electrical charges between solid-state materials rather than through a chemical reaction, they can be cycled tens of thousands of times more rapidly, and are not affected by deep discharges as are chemical batteries. Discharge times range from fractions of seconds to several minutes.
Advanced materials are key components throughout many energy technologies. New materials is a broad category that catches any number of advances in light-weighting, efficiency, production advantages and overall performance improvement of energy technology products. These technologies are wide ranging, including advanced fiber and composites for wind turbine blades, polymer membranes of fuel cell stacks, and nano-scale particles within advanced batteries.
Besides improving efficiency, improvements in the processing of these technologies can improve the cost of these technologies. For instance, solar photovoltaic panels are marching down the cost curve based on material advances in semiconductor compositions and manufacturing methods.
Hydrogen Generation and Storage
Hydrogen is an industrial gas used extensively throughout industry. ‘Discovered’ by Sir William Grove in 1839, a hydrogen/methane mixture called “town gas” was used extensively in the 1900s in theU.S.for lighting and heating. Since then, its use has expanded throughout the chemical industry, but a wide flammability range, difficult detection and low ignition energy means that hydrogen must be respected.
Because of the existing industrial base, the development of the hydrogen economy is a very real option, yet its path may not be the one some envision. The existing network of hydrogen pipelines will likely form the backbone of an expanding network of centrally located hydrogen production with remote facilities supplying smaller and remote demands. Currently, hydrogen production is derived from natural gas—an increasingly expensive commodity. Although this process may continue, additional new technologies are being developed to produce hydrogen at different scales. However, this emerging demand is dependant upon the ability of some fuel cell manufacturers to lower their costs sufficiently.
Hybrid Electric Drivetrains
Significant interest has surrounded hybrid electric vehicles for many years as their promise has begun to be proved out. As the technology improves, fuel economy is expected to increase steadily. The heart of a hybrid vehicle is the drivetrain—a complex setup of mechanical and electrical subsystems governed over by sophisticated electronics that enable the most efficient and optimal means to power the car from one destination to another. As these hybrid drivetrains mature, it may be possible for a modular approach to design may be possible, allowing for a far greater number of companies providing standard parts to firms able to integrate and provide management systems. In a sense, the development of the hybrid electric vehicle is less the creation of a vehicle with improved fuel economy, but rather the evolution of the car into a platform where a number of new technologies can be integrated to address a wider variety of driving requirements than is possible today.