Project Location: Calif. Polytechnic St. Univ. at San Luis Obispo
Project Director: Dr. Craig V. Baltimore, S.E. – Dept. of Arch. Eng.
The project is to combine solar energy (day time) with natural gas energy (night time) to offset the energy needs of industrial size complexes (point of use) -- create a hybrid power system. The solar energy is in the form of concentrated solar power, where mirrors are used to focus sunlight and heat a fluid (e.g. water). The heated fluid is then used to turn a turbine (generate electricity) and since the project is located on site of the user, the heated fluid can further be used (the heated fluid is called waste heat at this point) to heat water, to go into thermal storage, to heat air, or to run an absorption chiller. During the night, natural gas is used to heat the fluid and the system runs uninterrupted. Below is a rendering of a concentrated solar mirror field and tower.
Source:Industrial Fuel and Power (http://www.ifandp.com/article/002638.html)viewed:06/30/11
In more formal terms the next generation in sustainable alternative energy is the leveraging of renewable energy as supplemental input with clean burning natural gas. The leveraging of Concentrated Solar Power (CSP) and Natural Gas (NG) in point-of-use Combined Cooling, Heat, and Power (CCHP) is a natural adaptation of current technology.
The project uses current proven technologies. The current proven technologies have shown concentrated solar power to be an effective power generating solution for sustainable alternative energy at the large multi-megawatt scale (10 megawatts and greater). To scale down the current large scale technology is not a simple task and the losses in the ratio of input energy to useable output energy (efficiencies) is the major issue for implementation at a smaller intermediate scale. At the smaller intermediate scale (100 kilowatt to 1 megawatt) the efficiencies of the system are greatly reduced and most researchers at first glance do not consider intermediate scale feasible. However, when the reduced efficiencies are combined with point-of-use waste heat, the system may be economically feasible for an industrial size complex.
To investigate the feasibility of intermediate scale concentrated solar power with combined waste heat, California Polytechnic State University at San Luis Obispo has been awarded a grant from the California Energy Commission to build a hybrid concentrated solar power/natural gas system. The initial phase has been funded and this phase is to investigate the issues and quantities of scaling down the proven technology of concentrated solar power.
The current private market is focused on application of concentrated solar power (CSP) at the large scale. These large scale applications are a hot commodity with known risk/rewards for the private market. At this time the private market does not have the incentive to invest in research and development at the intermediate scale application. Plain and simple, intermediate scale point-of-use application is not in the interest of the private market because they are making money at the large scale. There is plenty of large scale business.
The California Energy Commission's 2004 Energy Report Update to the 2003 Integrated Energy Policy Report urged increasing the renewable energy state's electricity mix to a target of 33 percent by 2020. (http://www.energy.ca.gov/renewables/history.html; viewed June 30, 2012). Industrial and Institutional point-of-use intermediate scale concentrated solar power with natural gas hybrid (CSP/NG) offers a great potential for providing a cost effective means for California to meet its 2020 goal and to meet future energy needs. The point of use hybrid system also has the great potential to create a new and large market in construction retrofit and facilities management.
The overall project goal is to study the feasibility and cost performances in scaling down the large scale technology to moderate scale. The project goal is planned to be met in multiple phases. Phase I has been funded and the goal of Phase I is simply to build the intermediate scale facility and turn it on - to study the challenges and issues of deployment.
Phase II is to connect the CSP/NG to an existing facility. The preferred existing facility would make use of electricity, steam, warm air, and cool air. Teaming with an industry partner would provide specifics goals and outcomes during Phase II while providing on-going objectives for future work.