Solar Power

ETS, or 'episodic tremor and slip', is a recently discovered phenomenon in seismic research. Similar to earthquakes but much smaller in magnitude, ETS events are associated with the subduction zone of some convergent plate boundaries. One such region, the Cascadia subduction zone under the Puget Sound, is the focus of an experiment by Ken Creager's group at the University of Washington (UW), called Array of Arrays.

Solar panels are used to produce the power to charge batteries needed to run a station.  The number and size of solar panels needed will depend on the amount of sunlight available at the site and the power draw of the station.  For stations at low to mid latitudes and at least moderate sun we recommend a power ratio of at least 20 to 1.  That is if the station draws 1 watt of power you need at least 20 watts of solar panel.  The Battery Usage Calculator  is helpful in determining power usage for stations.  To get the most power the solar panels need to be oriented to receive the maximum amount of sunlight using solar panel mounts.

EPIC has both 30 and 65 Watt solar panels available.

65 Watt Single OR Dual Solar Panel Ground Mount Setup. Single panel is pictured below; a second panel can be mounted below the first. There is (a limited) angle adjustment range.

10W or 20W of solar power are usually sufficient for summer only experiment depending on a typical seismic station load.

EarthScope EPIC's Polar Group uses both the Suntech STP010 (10W) and the STP020 (20W).  They are both efficient, monocrystalline silicon solar panels and have strong frames.  A mount was designed in house and manufactured specifically for these panels to attached them directly to our  “summer only” enclosures.

This solar panel system uses three Suntech STP020S  (20W) Monocrystalline Silicon solar panels mounted in a triangle to take advantage of the 24 hours a day solar insolation.   With the combination of cold temperature and solar reflection off the snow, this system produces close to 40W worth of solar power all day long in clear conditions.  This is more than adequate for most seismic recorder configurations.

This solar panel system is also very simple and quick to install in snow.  All that is needed is to have the base of the solar system buried in two feet or more of well compacted snow.  No guying is necessary.  Only one solar cable is needed to connect to a junction box located on the post.

The Solar Charge Controller is responsible to properly charge the batteries when solar energy is available.  The GenaSun GV-4 controller, which is used for summer only experiments,  is a very efficient charge controller that uses the MPPT (Maximum Power Point Tracking) to maximize the power available at the solar panel, increasing the efficiency by 10 to 30% over traditional solar regulators.  It also uses very little power in low or no light conditions.