SPIRIT RIDGE INN DEMONSTRATION PROJECT

Installed in 1999

The north-end of Camano Island has an unexpected yet important NW feature: The Spirit Ridge Inn SOLAR Demonstration Project. Since it is generally not recognized that our rainy northwest climate really has substantial solar energy, this system was designed to prove the feasibility of solar photovoltaic electric power generation in the Puget Sound region. While there are an increasing number of other solar photovoltaic systems in the Puget Sound area, many cannot provide power when outages occur. This system is one that can provide power when the utility is inoperative, even if the utility failed permanently. The project is on the property of Kurt and Leslie Asplund, owners of Spirit Ridge Inn. Since the facility is on private property, an appointment is necessary to see this system.

FEATURES

The property's two full-time residences are on the East End of the fifteen-acre retreat. Both of these residences are connected to the solar power system. In addition, the new inn and library has its back-up power system connected to the solar photovoltaic system. A unique and restful attraction at the Inn are the many evergreen trees on the property --a feature that the Asplund’s value highly. The trees preserve the natural setting for the Asplunds and the visitors of Spirit Ridge Inn. Sun/Wind Concepts (on Camano Island) was assigned the design task for this system. The project was a major challenge, inasmuch as the trees -- while esthetically pleasing -- created a major obstacle to the penetration of the suns rays, which are essential for an effective solar system. However, Sun/Wind Concepts viewed the project as an opportunity to demonstrate that in many situations solar obstacles such as trees can be effectively dealt with without sacrificing the beauty of the surrounding forest. The site was surveyed and a location was found on the then south property line where the sun was not obstructed for most of the day. It necessitated running longer and heavier electrical feed lines to the PV power system from the garden shed, which proved to be an ideal structure to house the power conversion equipment. Since there is an early morning sun due to a low eastern horizon and only a few evening hours that the sun is not visible due to tree shadows, it was decided to utilize state of the art ‘sun trackers’  to allow the photovoltaic  panels to track the sun for maximum array efficiency. These fully automatic trackers can provide up to 25% to 40% greater output than stationary arrays, particularly in summer, since the trackers are always nearly perpendicular to the sun. The trackers follow the sun in much the same way that an observatory telescope follows the stars. This allows the system to produce much more energy over the daylight period.

Three solar trackers have been installed. Each tracker has twelve 75 Watt PV panels for a total of thirty-six PV panels with a peak output of 2,700 Watts of peak photovoltaic power or 2.7 kilowatts in full sun. There are certain line losses which are inherent, but most of the power is transferred to the power shed -- where the power created charges up a large deep cycle battery bank. The batteries are heavy duty deep cycle type and were manufactured by a company in Nova Scotia that makes diesel-electric railroad batteries. The power shed is also equipped with two high tech Xantrex/Trace inverters, capable of converting battery power to 240 Volts. Higher than utility grade household power provides uninterrupted power. This power is grid-interactive and has several automatic modes of operation. If the utility power fails,  power to the two residences critical circuits and emergency power for the inn is maintained by the 11-kilowatt system. If the power outage lasts more than a day, a propane generator can manually or automatically start and assist in charging the batteries. It can also supplement power to the loads. As long as there is sun the Asplunds will have power! The automatic feature works so well that computer operations at the facilities are not interrupted. And, the inverters and gen-set can be controlled and monitored from any computer in either residence or in the inn/library. A unique feature is the automatic generator start function. The inverters can be programmed to start the generator during daylight hours when everyone is awake so residents’ sleep won't be disturbed. In addition, the generator was deliberately placed on the far side of the power shed to keep unwanted noise far away from the residence – generator noise is not noticeable from the residence itself. Additionally, the PV and inverter system is designed to back-feed the utility grid, reducing the electrical load on the utility, thus, reducing the electric bill. It is even capable of running the power meter backwards when the loads in the residences are minimum and the sun is shining.