Permanent Met. Towers, Part 2: Robust Communications & Power

Earlier this month, I discussed what permanent met tower is and why they matter.  Here’s how WindPole is changing the PMT paradigm.

Instead of erecting an expensive 80-100 meter lattice tower designed to last for 20 years, WindPole leverages existing infrastructure.  All of WindPole’s towers are permanent and already in place, so we use the same towers whether for short-term prospecting or long-term operations.  Every tower in our portfolio has on?site power.  Nearly every site has high bandwidth backhaul facilities, such as fiber optic lines or microwave to the site.  All have copper phone lines that can support DSL.   12,000 are permanent guyed lattice towers above 80 meters; 1,500 are above 120 meters.  (See 12,000 sites at map.windpole.com.  Call if you need us to fill a gap.)

A typical WindPole tower is instrumented at three levels.  That means hub height (80-100 meters) plus two other levels.  Two booms pointing in different directions mitigate the skinny tower’s shadow and hold redundant sensors in case one fails.

On a development tower, we mount two vanes, two temperature sensors, one barometric pressure sensor, and six #40 anemometers.  For the permanent site, we swap out three of the anemometers and the vanes for heated sensors, to prevent data loss due to icing.  Clients like the heated sensors; adventurous ones ask about results from our ultrasonic anemometer tests.   

Power is the next upgrade that enables a tower to meet operational requirements.  At our development sites, solar panels are an adequate source of power. WindPole has always used oversized batteries and bigger-than-needed PV panels.  Though developers need only weekly access to met. data for prospecting, WindPole is building a national real-time forecasting network, so our server polls even development sites every ten minutes.  This needs plenty of power to drive our antennas, modems, and communication.

However, PMTs need uninterrupted power and lots of it to drive energy-hogging heated sensors.  So at a permanent site the power decision flips:  solar is the backup to the on-site utility power.  Our towers are already live broadcast and cell phone sites, so utility power is dependable – but we install solar power and batteries just in case.

Communications also have to be upgraded.  On our development sites, CDMA modems deliver data via wireless connections when our servers ping them every ten minutes.  That far exceeds a developer’s needs.  Using wireless communications and solar power allows us to avoid phone and power links, with their attendant permits, costs, and NIMBY visibility.

However, a permanent tower’s communication needs are different.  Here ‘real time’ means what it says: polling needs to be every two seconds.  For operations or forecasting, ten minute polling does not provide the resolution required to catch fronts and feed a forecast model.  (Aside from the high cost, it is the long polling gap that explains why satellite links are unsuitable for permanent, real-time operations.  The “bird” passes overhead only every ten minutes.)  The existing on site network may allow an operator to avoid installing high-cost fiber lines to a new tower. 

By using existing hub-height towers, WindPole’s permanent met tower offering saves you time, money and hassle.  Heated sensors paired with redundant power and communications produces high data uptime and real-time availability. Check to see if we already have a tower on your site.  Call our tower asset manager at 617-528-9915 or look at our tower asset database at map.windpole.com.