Session: 4.1.4 - Renewable Energy Systems

Paper Number: 108709

108709 - Design and Analysis of a Csp Plant and Pumped Hydro Storage Facility 

One of the main challenges facing the renewable energy industry today is the issue of energy storage. Solar power experiences a peak production capacity in the middle of the day, during peak sun hours. This, however, poses a unique problem in that the daily peak energy demand does not coincide with the peak production hours for renewable energy sources. This paper demonstrates the design and analysis of a facility that pairs a concentrating solar power system with a pumped-storage project. The facility described herein will consist of a concentrating solar thermal collector array driving a Rankine cycle power plant, which will then be used to operate a reversible pump-turbine. This system will use power generated in the day to pump water from a lower reservoir to an upper reservoir; this water will then be allowed to flow in reverse through the pump, generating energy for use in the evening hours from 4-9 PM, when energy demand reaches its peak. The facility proposed here consists of a redesign of Hoover Dam’s powerhouse utilizing brand new GE pump-turbines which can operate as both pumps and turbines depending on the direction of rotation. This redesign also rests on the uprating of Hoover dam from around 2,000 MW of capacity to 2,500 MW of capacity. The second phase of this proposal focuses on the development of a concentrating solar power facility relying on solar troughs to generate a nameplate capacity of 2,500 MW with a capacity factor of 2. This capacity factor allows the facility to produce excess thermal energy for use in thermal energy storage banks that will allow for plant operations at night and in the early morning hours. The thermal energy storage considered in the design of this plant will assist in starting the plant during the early morning hours and will allow the plant to be operated at full capacity throughout the day even when a cloud passes over or in the evening when the sun begins to set. An added bonus of the large thermal storage capacity is that in the summer, when insolation is higher, the plant can be run at full capacity all the way up to 11 PM. This will allow the pumped storage-CSP facility to produce a net power output of about 5 MW during the summer’s peak power usage period lasting from 4 - 9 PM. The total cost of the CSP aspect of this plant is estimated at roughly 14 billion USD with each of the 5 CSP modules costing about 2.76 billion USD. The estimated LCOE for the CSP project is 12.63 ¢/kWh. The only unknown cost factor in this proposal is the cost of the modifications to Hoover Dam. This dam is an 85-year-old structure, and any major modifications pose a significant challenge that will require in depth studies to produce any serious proposal and cost estimate. As such, no estimate will be provided on the cost of Hoover Dam modifications. With annual inflows from the Colorado river falling and outflows from Hoover Dam falling year over year, the power production capacity and utilization of Hoover Dam is diminished. By using Hoover Dam as a pumped storage project, more water will be available for circulation through the turbines since that water will be pumped right back upstream for use the next day. This would revitalize Hoover dam’s ability to produce large amounts of completely renewable energy and serve to solve some of the energy crises facing the renewable energy driven future.

Presenting Author: Kevin R. Anderson California State Polytechnic University

Presenting Author Biography: Dr. Kevin R. Anderson is Professor of Mechanical Engineering at Calif. State Polytechnic Univ. Pomona.