| 4.7.04 | Wade Troxell, Professor/Director,
Colorado State University Jessica
C. Fisher, Student, Mechanical Engineering, Colorado State
University |
| The Future
of Reliable Power: A Net Energy Case Study at CSU
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The Wake-up Call to an Energy Crisis
From the wake-up call of one of the largest blackouts to date on August 14th 2003, we are reminded how vulnerable the electric grid is to large-scale failures. Blackouts such as this cause widespread damage and destruction to all classes of end-user equipment, as well substantial monetary losses. It is obvious that we need to take actions to prevent such failures in the future.
Providing reliable electric service is an extremely difficult challenge when its operating requirements differ so substantially from any other service. In a power transmission grid, for example, every power station produces and distributes a certain power load. Sudden fluctuations in load (voltage levels or frequency) cause generation to shut down in that area, while load is then forced to redistribute to other plants and immediately drain power from surrounding areas. This produces the same effect over and over again to other areas, resulting in a quickly cascading electric blackout.
This complex network of the distribution lines make it especially vulnerable to power quality problems associated with the provided alternating current (large voltage surges, sags and swells, and pattern-less impulse spikes.) The most common and severe power quality problems are voltage surges; a lightning strike or sudden widespread power demands as seen in the Blackout of 2003, which covered over a third of the country.
The overall consensus is the need for an all-out effort to massively upgrade the existing power production and distribution system nationwide. It seems that there are two choices to improve the current United States power crisis: build and beef up the current power plant and transmission system, or provide customer-specific solutions to ease constraints on transmission and distribution systems. Upgrading and building new transmission lines would be very expensive and somewhat idealistic. Even after time and money have been poured into updating distribution lines to current technology, nothing guarantees that power outages will be completely eliminated.
On the other hand, distributed energy resources create reliable power by bringing the power solutions directly to the location of the user. Reliability is enhanced by proximity to the user, and efficiency is improved by using the heat from the generated power. Hence, on-site generation increases the production and distribution capacities by providing power in high consumption areas and offering substantial load relief and power service reliability. In addition, constructive ecological benefits are achieved by utilizing distributed energy and are seen through the reduction of system inefficiencies, the use of nonrenewable fuels, and environmental emissions.
Distributed Energy and Communication at Colorado State University: A Net
Energy Case Study
Distributed energy is an alternative means of creating reliable power, however, to be most effective distributed energy cannot operate alone. The solution to the power crisis presently facing the United States lies in the merging of distributed energy, and communication and control technology. The Net Energy case study at Colorado State University (CSU) is an example of how to incorporate this idea to model a small-scale environment encompassing residential, commercial, and industrial energy users.
Many benefits would originate from distributed energy at CSU, ranging from increased electric service reliability, saved waste energy with cogeneration, reduced environmental emissions, and an attractive investment payback period. Additionally, communication and control technology provide opportunity to control and monitor power quality. The ability to incorporate intelligent load management can create a more robust and stable system. For the electric power providers, Fort Collins Utilities (FCU), communication and control technology introduce an economic, smart alternative to power plant and line upgrades, saving FCU and their customers both energy and money in the long run.
The basis of distributed energy at CSU is the concept of many remote power generation sites working together for a more robust energy system. To illustrate, two 3.4 MW gas turbines were the optimal configuration for on-site power generation based on historical utility data. On-site electric power generation and CSU’s existing district heating system present an attractive cogeneration opportunity, effectively utilizing waste heat from electricity generation.
Consumers are provided reliable electric service through the use of power quality monitoring and conditioning devices. The appliance industry has microcontrollers that continually monitor the fluctuations of incoming power (large voltage surges, sags and swells, and pattern-less impulse spikes.) Certain perturbations can be identified when the grid is under periods of stress, and within milliseconds, automatically shut down the appliance or non-critical laboratory device to allow for overall system stabilization. Designated non-essential power outlets in dorms, offices, and laboratories can provide for increased power system reliability.
CSU is one of FCU’s largest consumers, using 93.2 GWh in the 2002 fiscal year. Excess power usage is discouraged with a combined utilities surcharge of $8.87 from FCU and its power provider Platte River Power Authority (PRPA). This is merely three times a typical distribution charge. To avoid this penalty, CSU can remain within their contracted electrical demand using a combination of power quality monitoring and on-site power generation to compensate for potential down times of power production.
If this system were implemented at Colorado State University in 2003, the reduced electrical cost and distribution charges would have saved $2.09 million dollars. Incorporating cogeneration, the 30% increase in natural gas usage was offset by overall net energy savings of $1.41 million. This would have generated a payback period of 3.5 years based on equipment costs.
These numbers alone provide proof of the significant benefits of more reliable and economic power through distributed energy at Colorado State University. With increased electric service reliability, saved waste energy with cogeneration, reduced environmental emissions, and an attractive investment payback period, one could imagine the benefits distributed energy could provide for electric power on a much larger scale.