Power, Communications, and Weather Station Systems
Electricity - Generated with four solar panels and two wind turbine generators and stored in a bank of 24 volt batteries. The Trace inverter "inverts" the DC stored power to 115 volts AC for consumption throughout the Island. The computer built into the Inverter detects battery voltage and if voltage drops too low, will automatically start the propane back-up generator.
Communications - The eight camera's, seven of which are on the website, as well as the Davis weather station feed data into the Island computer that transmits via micro-wave dish the information to a second computer on the mainland. This system will also accommodate telephone and plug-in laptop computers for internet connection while staying on the island.
Weather Station - The Weatherhawk weather station is mounted atop the Bell Tower with a wireless signal to a receiver in the Lighthouse quarters which is then transmitted to the mainland.
Propane Gas - Runs the back-up generator as well as the heating and cooking units in the Lighthouse Quarters. Keepers early on used Kerosene lamps for light and wood, followed later by coal fired stoves, to cook and keep warm. All fuel was carried onto the island as there were and are no trees.
Click an item in the list to see a photo and description on the right
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University of Nebraska Weather Station
All of the above data is averaged to hourly and daily averages, stored on the compact flash cards, and downloaded to a server at the University of Nebraska. Most of the data is also stored as 10-minute averages, and daily maximum and minimum values are also recorded.
- Propeller anemometer - Measures wind speed and wind direction every 10 seconds.
- Air temperature & relative humidity sensor - Measures air temperature and relative humidity every 10 seconds; Used in
conjunction with the sonic anemometer and krypton hygrometer.
- Sonic anemometer - Measures wind speed and wind direction every 1/10th of a second (i.e., 10 Hz); Used in conjunction with 2) and 4)
to calculate lake evaporation.
- Krypton hygrometer - Measures fluctuations in atmospheric humidity every 1/10th of a second (i.e., 10 Hz); Used in conjunction with 2)
and 3) to calculate lake evaporation.
- Ventilated pyrgeometer - Measures infrared radiation coming from
the sky (i.e., the "greenhouse effect") every 10 seconds.
- Ventilated pyranometer - Measures incoming solar radiation every 10
- Air temperature & relative humidity sensor - Measures air
temperature and relative humidity every 10 seconds; Used as a back-up
to 2) and for calculating quantities such as dewpoint, specific
humidity, vapor pressure, etc.
- Infrared radiometer - Aimed at the water to measure lake surface
temperature every 10 seconds.
- Krypton hygrometer signal processor - Processes data from 4) to
pass into the datalogger.
- Tipping bucket rain gage - Measures rainfall every 10 seconds
(with a precision of 0.1 mm).
- Sonic anemometer signal processor - Processes data from 3) to pass
into the datalogger.
- Enclosure, barometer, dataloggers, compact flash modules, voltage
regulator, and ethernet connections - Encloses the two dataloggers to
record all the information, and records barometric pressure every 10
seconds. Also includes a voltage regulator to control the power supply
from the batteries and solar panels, two 2-Gb compact flash data
storage modules for the dataloggers, and two direct ethernet
Use the following link to view weather data from Granite Island:
Granite Island Weather Data
The Detroit Free Press published an article on the technology of Granite Island on November 4, 2001. It is located online in the Free Press archives at this link: