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Polar Pod  

Contact
Tracy Dahl
Polar Field Services
Partner in CH2M Hill Polar Services
+1-303-518-8713

http://www.polar.ch2m.com/		 Polar Pod
 Polar Pod being tested in Colorado. Lid is normally closed in operation.
(Click on images to see a bigger version)
System Solar icon Battery icon Photovoltaic with battery back-up.
Location This is a portable system that can meet a variety of applications.
Description The Polar Pod is designed to provide polar researchers with a reliable source of AC and DC electricity – without the noise, fumes, fueling and maintenance requirements of an engine generator. It can be configured for various types of research, from supplying an AC power source for running laptop computers, to providing a highly efficient DC power supply for running sampling and data collection equipment.

Consisting of only two major components, the Polar Pod can be quickly set up and taken down with no tools required. The solar panel has an integrated aluminum frame with an adjustable tilt angle to follow the quickly changing angle of the polar sun over the course of the summer. The battery box also contains the DC/AC inverter, solar charge controller, circuit protection, with AC and DC receptacles accessible without opening the lid. The box fits within the framework of the solar panel, providing the ballast necessary to prevent it overturning in high winds.

The Polar Pod has been optimized for summer use in polar environments, and is not intended for year-round deployments. Year-round power stations for data acquisition and/or data transmission are also available.

Specifications:
  • Insulated, weather resistant enclosure
  • 80 watt Kyocera, KC80 PV panel
  • 84 Amp Hour (at 20 hr rate) gel type battery (suitable for air transportation): Concorde “Sun Xtender”, PVX-840T
  • 15 Amp solar charge controller with integral DC load control: Morningstar “Prostar”, PS15M
  • 250 watt, true sine wave inverter: Exeltech XP250
  • GFCI 115VAC outlet for the highest level of safety
  • Marine type DC inlet and outlet for all-weather operation: Marinco “Connect Pro” trolling motor receptacle, Marinco 12VBPS DC plug
  • Circuit protection for safety and reliability:
    • - Square D, QOU type breakers
    • - Blue Sea Systems ST fuse block, for ATO/ATC blade type fuses

The system is capable of producing a maximum of 250 watts of 120VAC power for up to four hours in full sun conditions. The system is also capable of supplying 12VDC power, for direct charging of most laptop computers (adaptor required) and other 12 volt equipment.

Polar Pod interior view The interior of the Polar Pod’s insulated enclosure. The space on the left is for containing the operator’s manual, extension cord, and spare fuses.

Set-Up:

Setting up the Polar Pod for operation is quite simple, and can be done by two people in less than 30 minutes. It is possible for one person to set the unit up in the field, but due to the weight of the battery box it is recommended to have two people on hand.
  1. Unfold the frame by removing the two pins (one on each side) which hold the frame in the closed position.
  2. Fold out the legs and secure with the pins in a high angle (steep pitch) position. This will facilitate placement of the box.
  3. Orient the PV panel facing south.
  4. Set the box in place within the bottom frame.
  5. Plug the cord from the PV (solar) panel into the lower right plug. This plug is identified on the box as “PV IN”, and has a yellow retaining bracket.
  6. Open the lid.
  7. Turn on the breaker in the lower right side of the box labeled “PV”.
  8. Insert one of the 15 amp fuses into the #2 position on the fuse block. This is the top row, second from left. See photo below.
Polar Pod fuse block Fuses in the “ON”, operational position. The #2 position takes a 30 amp fuse for the DC/AC inverter (115 volt power). The #4 position takes a 15 amp fuse, and enables battery charging. The two fuses in the lower row are spares. Note that several individual circuits are available for instruments should the Researcher require them.
  1. If 115 volt AC power is required, turn on the inverter with the small, shielded switch on the left side of the unit. The LED will light and a low hum may be discernable. The GFCI protected AC outlet is now live.
  2. If 12 volt DC power is required, turn on the second breaker in the lower right side of the box. This is typically used for DC instrumentation. If the Researcher requires DC power, he/she should alert VPR to the specific cabling needed.
  3. Close and secure the lid.
  4. Set the angle on the PV panel to be as perpendicular to the angle of the sun as possible. This is called the “angle of incidence”. The more perpendicular to the sun, the higher the power output of the panel.
  5. Check the voltage on the charge controller’s LCD display daily. If battery voltage appears to be falling below 12VDC, it is possible to manually “track” the sun by rotating the unit over the course of the day. 

Polar Pod rear view Polar Pod set up for operation.

Maintenance:

Unlike an engine generator, there is really very little maintenance to be done. There is no fuel to add, no oil to change, no spark plugs, no concerns about inclement weather. Just turn it on and point it at the sun.

If the glass gets obscured, it will reduce output from the PV panel, so keep debris and snow off of it.

If the unit is set up on snow cover, it will ultimately end up sitting on a snow pedestal, as the snow all around it melts away. The solution is simply to move it to a new spot before it falls over.

As mentioned above, the battery voltage should be checked periodically to ensure that it is charging adequately. With no load (nothing but the PV panel plugged in) and in full sun, voltages of 13.5VDC and higher are normal. Long periods of reduced sunlight (days of overcast) can lead to lower battery voltage. If voltage drops below 11.8VDC, it may be necessary to reduce loads or make efforts to track the sun over the course of the day. If voltage falls too low, the inverter will turn itself off until voltage recovers. The charge controller has a similar feature for turning off DC loads. Once voltage returns to normal, power once again becomes available.
Data Power system supports camp infrastructure only. No system performance or scientific data are logged or communicated on a continuous basis.
Comms System powers camp laptops and Iridium communications. E-mail and data transfers accomplished by researchers while on site.