> ## Documentation Index
> Fetch the complete documentation index at: https://data.avert.ldeo.columbia.edu/llms.txt
> Use this file to discover all available pages before exploring further.

# Background

> Autonomous power for remote volcano monitoring

All AVERT field stations rely on autonomous power systems to operate in remote, harsh volcanic environments. Reliable power is essential for continuous measurements and real-time data telemetry. Designing these systems is one of the primary challenges of multi-parameter field deployments — the power must last through periods of darkness, storms, and corrosive volcanic gases, often with no opportunity for maintenance for months at a time.

## General design

Most deployments consist of a bank of 12 V deep-cycle batteries charged by an array of solar panels, managed by a solar charge controller. The specific balance of storage (batteries) and recharge (panels) capacity is dictated by the prevailing light and weather conditions at each site. As a general rule, a single 100 Ah battery can provide 1 W for one month with no external input.

<Tabs>
  <Tab title="Alaska (Cleveland & Okmok)">
    The Alaska sites follow the standard AVO template. Each site is housed in a custom-fabricated, plywood-reinforced fibreglass enclosure (hut). Key features:

    * **Batteries**: 24–30 absorbed glass mat (AGM) 12 V, 100 Ah cells, totalling 2,400–3,000 Ah per hut
    * **Solar panels**: Three 90 W panels mounted on the front of each hut
    * **Charge controllers**: Morningstar SunSaver MPPT-15 and SunSaver 10-L, split into two independent systems for redundancy
    * **Wind turbines**: 50 W wind generators at CLCO and CLNE-geophysics to supplement solar during dark Aleutian winters

    At high latitudes, winters are long and dark. The systems must provide continuous power with no charge input for 2–3 months. With an average draw of around 8 W, a fully charged hut can run for approximately 3 months without any solar input.

    <Note>
      Wind turbines carry a risk of generating vibrations that contaminate the
      seismic record. However, the huts and mounting poles are anchored directly
      into the ground, which likely mitigates this effect.
    </Note>
  </Tab>

  <Tab title="Poas (Costa Rica)">
    The Poas sites follow the standard OVSICORI template, with some adaptations:

    * **Batteries**: 2 x 100 Ah batteries per site, mounted on a custom steel frame
    * **Solar panels**: 200–300 W panels affixed to the same steel frame
    * **Li-ion batteries**: Used at the two crater-area sites (VPPC and VPNC) for their lighter weight, given the more challenging access
    * **VPMI hub station**: Equipped with a larger system (2–4 x 100 Ah batteries and a 300 W panel) to power both the node instruments and the Starlink satellite telemetry

    Being close to the equator, day length at Poas does not vary much over the year, and the systems only need to outlast a few days of cloudy conditions.
  </Tab>
</Tabs>

## Telemetry

Data are telemetered in near-real-time via a combination of local radio links and satellite or cellular uplinks deployed at designated hub sites:

* **Alaska**: Sites are networked into a LAN using Intuicom EB-X 900 MHz radio transceivers and linked to the internet via VSAT satellite at Okmok (Fort Glenn) or BGAN satellite and radio relay at Cleveland
* **Poas**: The crater-area sites (VPNC, VPPC, VPMI) use radio links across the short distances (\~1 km) between them, while the outer sites (VPCC, VPRS) use Semtech AirLink RV50X 4G cellular routers. The VPMI hub connects to the internet via a Starlink V2 satellite dish