Coming Full Circle at Redwood National and State Parks

Espa Lagoon PV system

Interns Erin McDonald and Matthew Smith (lower right) pose with RNSP employees after successful installation of Espa Lagoon’s new PV system. (Photo Credit SERC)

In the spring of 2000, SERC initiated a collaboration with the University-National Park Energy Partnership Program (UNPEPP). This past summer, the SERC-UNPEPP relationship reached a new milestone with the completion of a renewable energy project six years in the making.

UNPEPP links national parks with university energy programs all over the United States. Students work as summer interns in the parks, identifying opportunities to improve energy efficiency or use renewable energy. Since the collaboration began, SERC and nearby Redwood National and State Parks (RNSP) have successfully completed five renewable energy-related projects, including design and installation of solar electric and solar hot water systems and energy efficiency analyses at various park facilities.

UNPEPP intern Matt Smith welding

Intern Matthew Smith welds parts for the PV rack. (Photo Credit SERC)

SERC’s first UNPEPP project was a site analysis and the design of a renewable energy system to power an off-grid ranger residence located at Espa Lagoon in Prairie Creek Redwoods State Park, a unit of RNSP. UNPEPP interns Lonny Grafman and Angelique Sorensen designed a solar photovoltaic and fuel cell system for the site in the summer of 2000, but the plan was not implemented due to a funding shortfall at the Park.

In 2006 RNSP proposed reviving the project. The Park had finally overcome the funding problem by salvaging solar equipment (used but still in fine condition) from another decommissioned facility. The site analysis performed in 2000 laid the foundation for the 2006 project. 2006 UNPEPP interns Erin McDonald and Matthew Smith, both undergraduate environmental resources engineering students at Humboldt State University, began their internship with a renewable energy training led by SERC engineers. The training provided basic information on a variety of renewable power systems, including system sizing, design and installation. The power system being replaced included two antiquated, oversized diesel generators located adjacent to an otherwise beautiful and serene lagoon ecosystem. Overall system efficiency was less than 7%. In addition to their technical shortcomings, the noise, air, and groundwater pollution issues associated with these generators called for a renewable energy replacement more in line with the residence’s natural setting. The hybrid system replacing the generators is a solar PV array with a quieter, cleaner, and appropriately sized propane generator as an alternate generation source. The propane generator will operate in winter or during consecutive cloudy days when the PV system cannot meet the total load. Given the limited solar resource at this often foggy Northern California coastal site, Matthew and Erin estimate that the PV portion of the system will meet 38% of the year-round residential electric load.

Although the design from 2000 recommended the purchase of new equipment, the 2006 project obtained all major components from previous RNSP installations; a successful strategy that offset the need to spend additional money on equipment. After revisiting the UNPEPP 2000 interns’ site recommendation, load calculations and solar resource data, and then testing the performance of the old equipment, the interns determined where to place system components for best performance. Working closely with SERC machinist Ray Glover, Erin and Matthew designed and constructed a custom steel rack to hold the PV modules. The interns then transported the rack and equipment to the project site and installed them with the assistance of Park employees.

For the past six years, UNPEPP interns have had rewarding educational experiences while helping our national parks become more sustainable. Interestingly for SERC, what may be our final UNPEPP collaboration turned out to be the completion of our first; the UNPEPP 2006 interns installed a solar electric system based on design recommendations made by the UNPEPP 2000 interns, and the renewable energy system for the Espa Lagoon ranger residence has come full circle.