HPWREN Solar Power Relay Station (Optional Design)

This document describes the requirements and design for a solar system required to support an HPWREN relay station. Though this design was originally established for the Rincon Native American Reservation, it is currently not being used.


Step 1: Power Requirements

We prototyped one system for this installation. The power requirement for the system is detailed down below. It is important to not only understand the power consumption, but also the various voltage breakdowns and their associated power requirements. Additionally, it is important to acknowledge the fact that we want 24x365 uptime.

Implementation 1: Low Power
QuantityPartVoltageCurrentPower
2Lucent 802.11 RORs5v3A15 watts
4Hyperlink 1 watt Amplifiers12v0.42A5 watts
Total Power:5v at 6A
12v at 1.68A
50 watts
Adjusted Total Power:
(after 80% dc-dc converter efficency)
5v at 7.5A
12v at 2.1A
62.5 watts

Step 2. System Diagram

Below is a basic schematic diagram for a solar power system. In reality the load should have a DC-DC convetor on it to adjust and regulate the voltage coming from the batteries. However, if you know the tolerance range of the equipment you could always set LVD (low voltage disconnect) and HVD (high voltage disconnect) to the applicable limits. It is also important to remember this is a simple diagram and the battery array should have some blocking diodes so if one battery dies it doesn't kill all of the batteries. It is also very important to think about the voltage of the solar array and batteries as higher voltages tend to lose less power due to wire resistance. HVD is to protect the equipment should the batteries be disconnected accidentally. LVD is to protect the batteries so they will not be completely drained (it then reconnects when the batteries get recharge to a high enough level). In this system we will be using 24 volts instead of 12 so some of the values in the diagram will be different.

Step 3. Components

Below is a list of components we selected for our setup. A lot of solar companies have programs to calculate how many solar panels / batteries you need. They need a couple of specifics:

  • Location (lat/long, elevation): N33.35065 W116.98072, Elevation: 3263 ft. (GPS)
  • Continous Power Drain: 62.5 watts
  • Prefered final output voltage(s): 24v
  • Physical Issues (pole-mount, roof-top, etc.): Ground-mount on rack

Additionally, we choose to go with a combined charge controller and load controller as opposed to aquiring each part individually.

Implementation 1: Equipment List
QuantityDescriptionManufacturerDistributorPrice
8BY/CD-DCS-100 AGM 12v 100AH Deep Cycle BatteriesCDSolar Depot, Inc.
61 Paul Drive
San Rafael, CA 94903
(800) 822-4041
Shawn Moshfeghi
shawnm(at)solardepot.com
132.75 EA
8PV/SX-80U 80 watt 12v 4.75A Solar PanelsSolarexSolar Depot, Inc.
61 Paul Drive
San Rafael, CA 94903
(800) 822-4041
Shawn Moshfeghi
shawnm(at)solardepot.com
374.25 EA
2MH/SX-OM-4X Omnimount Kit M40-M120 - Rack for solar panel mounting (may go to pole mount instead)???Solar Depot, Inc.
61 Paul Drive
San Rafael, CA 94903
(800) 822-4041
Shawn Moshfeghi
shawnm(at)solardepot.com
129.75 EA
2BE/AM-L16BB-8 Case for battery storage (weather resistant but vented)???Solar Depot, Inc.
61 Paul Drive
San Rafael, CA 94903
(800) 822-4041
Shawn Moshfeghi
shawnm(at)solardepot.com
305.00 EA
1PR/MS-PS30MC Pro Star 30A Charge Controller /w meter and coating (12/24 volts)Morning StarSolar Depot178.20 EA
1WR/SX-ATK Add on terminal kitSolarexSolar Depot Inc.32.70 EA
7WR/SX-IM15 Inter Mod WireKit Flex 15"SolarexSolar Depot Inc.6.00 EA
1WR/SD-IP120 Output Cable 6 ga 10'???Solar Depot Inc.35.00 EA
1WR/SX-IP72 Inter Panel WireKit FlexSolarexSolar Depot Inc.16.00 EA
8WR/SD-12-00T Battery Cable 12" 2/0 ga.???Solar Depot Inc.6.00 EA
2WR/SD-36-00 Inverter Cable 36", 2/0 ga.???Solar Depot Inc.10.50 EA
1SG/DL-LA100V DC Lightning Arrestor???Solar Depot Inc.29.25 EA
1DCB-202 - 25 watt series, 24 volt input, 12 volt out at 2.1 A (86% efficent)International Power SourcesInternational Power Sources, Inc.
200 Butterfield Dr.
Ashland, MA
01721
Tel: (800) 226-2100
Fax: (508) 879-8669
$109
1DCC-201 - 50 watt, 24 volt input, 5 volt ouput @ 10A (%86 efficent)International Power SourcesInternational Power Sources, Inc.
200 Butterfield Dr.
Ashland, MA
01721
Tel: (508) 881-7434
Fax: (508) 879-8669
$129
Total Cost:$5565.65

Step 4. Final Design Diagrams

Implementation 1: Low Power

The work on this project was completed by Todd Hansen for NLANR. This work is funded in part by NSF Cooperative Agreement No. ANI-9807479

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