RECENT SOLAR THERMAL DEVELOPMENTS | Everything about solar energy

Luz International Corp., developer of solar energy generating stations on the mainland, has been contracted by the state government to conduct a feasibility study for the islands. Site visits have been made and discussions held with local utilities. Luz will examine facility sizes from a 1-30 MW range, and possibly up to 200 MW capacity. Land availability (80 MW require 400 acres), utility interface, energy storage, and other factors are conditions Luz will consider in this project.

In addition, inter-island electrical connections will be addressed if the systems are proposed away from population centers. A final report is due in late 1991 (M. Sloan, personal communication, 1991).

Bechtel Corporation, in response to a USDOE initiative, is leading a group of solar Stirling dish manufacturers in the advancement of this system. A proposal will be submitted to USDOE requesting about $14 million to conduct Phase I of this program. The installation, to be conducted probably on Maui, is intended to consist of first generation prototype systems for each qualifying team. One unit will be interconnected with the utility. The Phase П installations are intended to consist of 10 solar/fossil hybrid dish systems per qualifying team (and must have at least 1000 hours of on-sun testing at an approved site).

Hawaiian Electric Company, Maui Electric Company, and the Pacific International Center for High Technology Research will lead the project effort. A sum of $250,000 has been requested from the Hawaii Legislature for site preparation, foundation work, data acquisition system procurement, and engineering and construction management services. Hawaii and Maui Electric cost-sharing in Phase I will be about one full-time person during the installation and two-year operational periods. In addition, Hawaiian Electric and Maui Electric will assist in site location, permitting, and other activities. The technical experience gained from this project will be beneficial to the state and utilities in considering future commercial solar thermal systems for the islands (Bechtel Corp., 1990). The state government is planning to install solar (global and diffuse) insolation monitoring stations around the islands. The information obtained from these stations will add to the database of solar insolation (D. Rezachek, personal communication, 1991).

CONCLUSIONS

Historically, Hawaii has accumulated considerable solar data, but most of it has been for global insolation. New solar monitoring equipment will be installed by the end of this year to enable calculation of the direct component of solar radiation at various sites. The best sites for solar thermal concentrating systems are: (1) Kona Coast of the Big Island, especially at the Natural. Energy Laboratory of Hawaii; (2) western and southern areas of Kauai; (3) Maui plains; (4) southcentral Molokai; and (5) western coast of Oahu. These sites are all located on the leeward or dry side of the island; thus, cloud cover would only be a problem during stormy periods and Kona weather conditions (southerly winds about 10% of the time). The preliminary direct insolation measurements made from a few of these sites indicate good potential. Land costs will have to be addressed in depth on a site-specific basis. Finally, electrical generation could be used at all sites; however, transmission capability will need to be examined.

REFERENCES

Amfac Energy, Inc. (November, 1983). Preliminary design for solar repowering at Pioneer Mill Co., Ltd., final report to U. S. Department of Energy (Contract DE-FC03-82SF11676).

Bechtel Corporation (December 12,1990). Dish-sprling technology cooperative development program, preliminary proposal to U. S. Department of Energy.

Falicoff, W., G. Koide, and P. Takahashi (1979). Solar/wind handbook for Hawaii: technical applications for Hawaii, the Pacific Basin and sites worldwide with similar climatic conditions. University of Hawaii.

How, K. (1978). Solar radiation in Hawaii: 1932 – 1975, Hawaiian Sugar Planters’ Association Experimental Station Report R57, Honolulu, Hawaii.

Law, H. K. (December, 1976). Characteristics of solar radiation in Hawaii, senior honors thesis, College of Engineering, University of Hawaii.

Yoshihara, T., and P. Ekem (1977). Solar radiation measurements in Hawaii, Hawaii Natural Energy Institute, University of Hawaii.

Yoshihara, T., and P. Ekem (1978). Assessment of the potential of solar energy in Hawaii, final report, Hawaii Natural Energy Institute, University of Hawaii.

Yuen, P„ A. Seki, and G. Curtis (1983). Operation and maintenance of Wilcox Hospital solar photovoltaic energy system on Kauai, May 1,1982 to February 28,1983, final report, University of Hawaii.

TABLE 1 Energy generation, bv Source: U. S. and Hawaii (1988)

Petroleum Nat. Gas Coal Nuclear Hydro Biomass Other Hawaii 91.25 7.55 1.2

U. S. 42.69 23.07 23.51 7.09 3.3___________ 0.35

TABLE 2 Energy Use, bv Sector: U. S. and Hawaii (1988)

Electricity Prod. Transportation Other Hawaii 31.6 56.7 11.7

U. S._____________ 271)_________ 37.1 35.9

TABLE 3 Electricity Generation, bv Source: Counties of Hawaii (1988)