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

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

3. NADP Equipment for DC Operation
ACM Collector
NCON Collector

4. 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!

5. 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.

6. 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

7. 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

8. 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

9. 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)

10. 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

11. 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

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

13. 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

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

15. DC ONLY
+ - + -

16. 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

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

18. 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 ~
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). + -

19. 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.

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

21. E-Gage Voltage Plots

22. 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)

23. 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

24. 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 ~ $ These are recommended as standard equipment for sites routinely using backup batteries.

25. Load Testing Batteries

26. Other Issues and Review

27. Other Issues and Review

28. Other Issues and Review

29. System Design - Resources
Boxwell, M., Solar Electricity Handbook, Greenstream Publishing, solarelectricityhandbook.com
Northern Arizona Wind and Sun,

30. Or E-mail ntn@isws.illinois.edu
Thank You!
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