Primary power

Next, we note that world primary power today is slightly over 10 TW, so we can write ... 

This is the energy source for hydraulic systems. It converts electrical energy into dynamic, hydraulic pressure. In almost all cases, hydraulic systems utilize positive displacement pumps as their primary power source. These are broken down into two primary sub-classifications constant-volume or variable-volume. In the former, the pumps are designed to deliver a fixed output (i.e. both volume and pressure) of hydraulic fluid. In the later, the pump delivers only the volume or pressure required for specific functions of the system or its components. 

Stray-current effects are basically associated with primary power supply... 

Polymer electrolyte fuel cells (PEFCs) have attracted great interest as a primary power source for electric vehicles or residential co-generation systems. However, both the anode and cathode of PEFCs usually require platinum or its alloys as the catalyst, which have high activity at low operating temperatures (<100 °C). For large-scale commercialization, it is very important to reduce the amount of Pt used in fuel cells for reasons of cost and limited supply. 

The fuel cell station provides primary power for the facility as well as half of the hot water needed for heating. Excess electricity from the system flows back to the grid for use by other customers. 

Electric power should be available from two highly reliable sources. The usual arrangement is an alternating current (AC) power supply, with trickle charger supplying an emergency battery system. Batteries should be sized for loss of primary power for a period of no less than 8 hours, and for at least 12 hours if the supply is not reasonably reliable. An exception is power for alarm bells or horns, which require only 1 hour of emergency power. The power supply should be monitored by a power-on lamp on the control panel and a main power failure alarm. 

On October 30, 1998, a flammable gas release led to gas migration to a non-electrically classified Electrical and Instrumentation (E l) Room. The flammable gas was ingested into the exterior heating and ventilation inlet duct. When the 480 volt primary power switch, within the E l room was remotely shut off, an explosion resulted. The E l module explosion led to a subsequent fire in adjacent production buildings. There were no injuries to personnel. The root cause of the incident was determined to be the failure of management systems... 

According to the international regulations the energy independence of a country is calculated as the total primary power resources (E own) and total power supplied to the national economy ratio (E sup), i.e. 

KBr03 has been recently introduced as a convenient source for strongly electrophilic bromine, which is particularly useful for bromination of electron-poor systems. Although it can effectively be utilized in simple aromatic brominations (e.g. benzene822), its primary power is in the bromination of deactivated aromatics such as benzoic acids823,824, nitrobenzene825, nitrochlorobenzene826 and benzophenone (equation 1 15)827. 

Figure 5.3. Layout of a decentralised, building-integrated hydrogen and fuel cell system based on intermittent primary power sources (such as wind or solar energy), reversible fuel cells and local stores, including stationary and maybe vehicle-based stores, and possibly capable of interchanging hydrogen with users in other buildings through pipelines (Sorensen, 2002a).

Thinking Critically Present an argument supporting or opposing nuclear power as your state s primary power source. Assume that the primary source of power currently is the burning of fossil fuels. 

Secondary or backup power is often worth far more than primary power. For example, the value of grid electric capacity is roughly 1000 per kW. That is, if one takes the depreciated cost of an average generating plant, a transmission... 

The value of backup power is as much as three to four times the value of primary power on a kilowatt basis. For example, the lifecycle cost of the backup power systems found at the base of a cell tower, which now consists of a bank of lead acid batteries and a diesel or natural gas fired combustion engine, is between 3000 and 4000 per kW. Critical power facilities for data processing centers and the like are also in this cost range. The simple fact is that customers need electricity and will pay a considerable insurance premium to obtain assurance of uninterruptible power. In the case of cellular phone service providers, their federal FCC license may be at risk if they are unable to demonstrate adequate operating capability in the event of grid outages. 

Looking to the future, it may be possible to make some predictions regarding primary power demands and the expected environmental impact over the next 50... 

Based on these projections, total primary power consumption is expected to rise from 12 TW in 1990 up to 28 TW by 2050. The overriding question is from where this 28 TW of power will be derived. 

Obviously, this is not an insignificant amount of power. Ten terawatts was the entire global power production from all sources in 1990. In addition, if atmospheric carbon dioxide emissions are to be stabilized, there will be an even greater need for renewable energy. For example, if man-made releases of carbon dioxide are to be stabilized at 550 ppm—twice the preindustrial level of carbon dioxide in the atmosphere—20 to 30 TW of carbon-neutral primary power would be needed.4... 

The five most common renewable sources of primary power are hydroelectric, geothermal, wind, biomass, and solar. Hydroelectric power is considered by many to be a model energy source. It is clean, relatively benign environmentally, nonpolluting, and relatively inexpensive. However, the global theoretical potential of the hydrology of all the world s precipitation and all of the energy... 

Solar power is still another option for noncarbon primary power. Theoretically there is 1.2 x 10s TW of solar energy potential. However, if solar cells are assumed to be 10 percent efficient, realistic land estimates lead to a practical value of 600 TW of available incident solar power, leading to 60 TW of generated power with 10 percent conversion efficiency. 

To generate 20 TW of power using solar cells with 10 percent efficiency requires approximately 0.16 percent of the world s landmass, including 8.8 percent of the landmass of the United States. To generate 12 TW of primary power by this method would require 0.1 percent of the Earth s landmass, including 5.5 percent of the United States. 

To meet the increased demands for primary power in the 21st century, normal economic driving forces appear to indicate that the demand for 28 TW of power without unacceptable environmental consequences could result from a combination of wind, solar, biomass, and nuclear power. However, sources such as wind and solar require new technologies to effectively store and transport power with little loss. 

---