The field camera is a Raspberry Pi HD Camera using Raspistill software on a Raspberry Pi 2 connected via wi-fi to the PCC wireless network which is linked to the internet via a small dish provided by Coastside.net. The data is stored in an ftp server at www.flypcc.org. This html web page is also stored there in www.flypcc.org/camera/index.html. Using Linux Cronjob the camera takes and uploads a picture every 5 minutes from 4AM to 12 Midnight. The weather station is a Wireless Vantage Pro2™ Plus including UV & Solar Radiation Sensors 6162 weather station: barometer, anemometer, wind vane, temperature and humidity and rain gauge with wireless connection to a base station which is connected to a Weatherbridge (connected to the router) which collects the data and sends it to Weather Underground.
The solar power system consists of 4 solar panels totaling 320 watts, 8 235ah 6 volt golf cart batteries in series/parallel for 12 volts (940ah), an IOTA charger and a gas 110VAC generator. The solar panels can produce 1600 watt hours per typical Bay Area day which is equivalent to 5 hours of full, overhead sun (maybe less in HMB). That varies by season due to the angle of the sun and panels (now set for spring-fall). A 30 amp PWM solar charge controller controls the charging of the battery bank applying maximum available voltage when the batteries are low on charge. The charge controller limits the voltage to 14.5 volts during bulk charging to avoid damage to the batteries from gassing. When the charge level of the batteries builds up the controller backs off from the 14.5 maximum to 13.4 "float" voltage to maintain a high state of charge. Some variation in the state of charge plot will demonstrate "protection" mode when the controller turns off the panels on sunny days. The battery bank voltage stays high after recent charging and low after recent heavy discharging due to the relaxation time of the battery chemistry. So the best time to measure is 6:30AM before the daily charging/discharging starts. Hence the above plot. The indicated voltage during daily solar charging doesn't give much information about state of charge except that 13 volts is good and 12 volts means the state of charge is low.
The IOTA charger runs on 110VAC from the generator. It produces 13.4 volts DC MAXIMUM. Its mainly useful if the batteries
are heavily discharged and the voltage is in the low 12's. Running the generator when the voltage from solar
already reads 13.4 volts will add ZERO current. It's just burning gas.
- Steve Williams
PCC Weather Underground Station
|Canada Cove Weather Station
(trailer park 1 mile north)
|Battery Bank Voltage||Sam's Chowder House Webcams
Field is at far end of top photo