You and Your Solar Panel NADP Training Webinar: Wednesday July 22nd 2:00 – 3:00 PM (CDT) go.illinois.edu/NADPTraining

Overview Solar Powered NADP Equipment Sizing panels and battery banks Wiring Diagrams Equipment Installation Equipment Maintenance Equipment Troubleshooting

NADP Equipment for DC Operation ACM Collector NCON Collector

NADP Equipment for DC Operation YES – Can operate on 12-V DC (battery) or 120-V AC (line power) NO – Can only operate on 120-V AC (line power), except under some circumstances* ACM Collector NCON Collector *requires either a DC-AC inverter. DC-voltage collector in development!

NADP Equipment for DC Operation ACM Collector The ACM collector motorbox is designed for either 120-V AC or 12-V DC power. DC power can operate collector in backup mode.

NADP Equipment for DC Operation ETI NOAH-IV raingage YES – Can operate on 12-V DC (battery) or 120-V AC (line power) Hach Ott-Pluvio2 raingage

Requirements for Good (and Safe) DC Power System Design Proper system grounding, power-disconnect, and fuses/circuit breakers Sufficient solar power generation capacity Properly-oriented solar panels Adequately-sized power cables and proper wiring connections Sufficient battery capacity Properly-maintained batteries

Typical NADP Equipment Power Consumption Current Draw, Amps (at 12-V DC) ACM Collector Dry state (above ~40 deg. F) 0.05 Dry state (below ~40 deg. F, sensor heater) 0.55 Activated wet (during event, above ~40 deg. F) 0.60 Activated wet (during event, below ~40 deg. F) 1.15 Electronic Raingage (constant) 0.1

Typical NADP DC Power System Equipment Estimated Cost Solar Panel (140 W, qty. 2) $550 Solar Charge Controller and Breakers $230 Solar Panel Mount $220 Wiring $25 Batteries, Deep Cycle Marine, ~90 Amp-Hr (qty. 2)

Battery Configurations For outdoor installations, Adsorbed Glass Mat (AGM). “No maintenance” and resistant to freezing. “Deep Cycle” and/or “Marine” recommended (e.g. Optima “yellow” deep-cycle, or EverStart Maxx) Recommended configuration: Two to three ~ 90 Amp-hr

Battery Configurations If an insulated field-shelter is available, “flooded lead acid” batteries offer more capacity at lower cost. Must be protected from freezing. Must have water levels maintained Configurations Multiple 12-v batteries in parallel Multiple 6-v batteries in series/parallel (always even number); e.g., Trojan T-105 6V

Battery Configurations Deep Cycle Battery Bank, three 12V batteries wired in parallel. Boxwell, Solar Electricity Handbook, 2014

Battery Configurations Deep Cycle Battery Bank, two sets of 105 amp hour 6V batteries in series, wired in parallel for a total of 210 Amp hours at 12V Boxwell, Solar Electricity Handbook, 2014

AC/DC + - + - Breaker Box ACM Motor Box AC Outlet with GFI or TVSS DC Battery

DC ONLY + - + -

Overall View: DC Solar INPUT External Regulator with blocking diode + _ INPUT External Regulator with blocking diode OUTPUT + _ Solar panel + _ 12 volt Deep cycle battery system sized for climate requirements and solar insolation + _ + _ _ + In-line fuse holder and 5A fuse (+ leg) Precipitation Collector

Solar Charge Controller Solar panel Battery (install fuse on positive lead) Collector Suggest grounding of negative leads (Follow manufacturer’s instructions.)

Cell/Regulator/Battery At full sun, panels can produce > 22 volts DC External Regulator has 2 jobs I N P U T SOLAR PANEL 1. Keep charge voltage less than ~ 16-18. O U + - + + If greater, this can damage battery. 2. Keep system from discharging when dark. T P U T - - Blocking diode lets power go only one way (to battery). + -

External Regulator Check Blocking Diode Check Disconnect the solar panel wires from external regulator. Test with Volt Ohm Meter (VOM) at regulator INPUT position. •If greater than 5V DC; regulator is bad, allowing panel to discharge battery through the regulator. •If less than 5V DC; regulator is OK Reconnect wires from the solar panel to the regulator. Charge Control Check Note: requires full sun Disconnect solar panel wires from external regulator INPUT and measure DC coming from panel. Should be from 18-22V DC. Reconnect wires from solar panel to regulator and disconnect OUTPUT side wires from regulator to battery. Measure DC going to batteries. Should be less than 17V DC. Reconnect wires from regulator to battery.

Troubleshooting: Common Issues Insufficient solar power generation Old/worn-out batteries Insufficient battery capacity Damaged/Poor Wiring or equipment issues

E-Gage Voltage Plots http://nadp.isws.illinois.edu/siteOps/ppt/

DC Power System Maintenance Seasonally Check battery water levels (if required) Check condition of battery box (insect/rodent infestations) Annually Disconnect and load test all batteries Clean/tighten wiring connections “Balance” battery bank (depending on equipment)

DC Power System Maintenance Weekly (with sample change) Verify equipment operation (lid opening/sensor heating) Remove snow Monthly Clean solar panels with water / window cleaner Verify solar controller operation

Load Testing Batteries Separate batteries. Test each battery independently with load tester as instructed. If OK; reassemble. If bad or marginal ; battery should be removed from site, hard charged and then load tested by battery shop. Portable load testers can be purchased for ~ $50.00. These are recommended as standard equipment for sites routinely using backup batteries.

Load Testing Batteries

Other Issues and Review

Other Issues and Review

Other Issues and Review

System Design - Resources Boxwell, M., Solar Electricity Handbook, Greenstream Publishing, solarelectricityhandbook.com Northern Arizona Wind and Sun, https://www.solar-electric.com/

Or E-mail ntn@isws.illinois.edu Thank You! Questions or Comments? Call: 1-800-952-7353 Fax: 217-333-0249 Or E-mail ntn@isws.illinois.edu