Remote - Spring 2015 - (Page 10)

Feature Article Small Power, Big Benefits - Fuel Cells for Remote and Off-Grid Applications Joe Blanchard, GM Stationary Power Plug Power, Inc. Hydrogen fuel cells offer a highly reliable, cost-effective and emissionfree power solution for the challenges of remote and off-grid applications. This technology has been used with commercial customers for more than a decade and can be a successful component to the power architecture of many small to moderate-sized applications including the railway signaling, microwave communications and public safety network examples detailed in this article. What is a Fuel Cell? Simply put, a fuel cell is an appliance that converts the chemical energy of a fuel (hydrogen, methanol, propane) and an oxidant (air or oxygen) into water, with the by-product being electricity that can be used to power equipment. There are several types of fuel cells and different manufacturers have developed products based on different types. Each has somewhat different fuels and properties and a few are suited to remote and off-grid applications. Plug Power's ReliOn products are a Proton Exchange Membrane (PEM) fuel cell and use hydrogen as the fuel. A fuel cell is dimensioned for power, so a customer orders a product based on how many continuous Watts of power are needed by the equipment being powered. Hydrogen The runtime for a fuel cell is determined by the amount of fuel - in this case, hydrogen - stored at the customer location. Fuel cells with lower power output use proportionately less fuel than those with higher power output, so a small fuel cell will run longer on a defined quantity of hydrogen than a larger one will. For remote and off-grid applications, this can be an important consideration. If the customer location is difficult to reach due to its distance from town or the climate in which it is located (northern mountains with snowy winters, for instance), the ability to store enough hydrogen on-site to accommodate the needed amount of runtime until the location can be refueled is critical to the success of the site. Hydrogen is generally stored in cylinders made either from steel or a composite material. Cylinders can be swapped or refueled on site, depending on the location of the customer equipment. Hydrogen is available from a number of sources including Plug Power's GenFuel suite of fueling solutions. Fuel Cells in Networks The fuel cell connects to a customer's network DC bus and runs parallel to the site's batteries and rectifier. The fuel cell is load following, so it puts out the amount of power required by the customer's equipment, up to the fuel cell's rated power. Hybrid Off-Grid Solution It may be installed either indoors in an environmentally controlled customer shelter or outdoors in an environmentally-hardened cabinet. These products generally are used to replace an internal combustion generator. They may be used in conjunction with other power sources including solar panels, wind and batteries to augment or replace utility grid power. Fuel cells may be used both for on-grid and off-grid applications. 10 www.RemoteMagazine.com In an on-grid application, the grid provides primary power and the fuel cell provides backup power. The fuel cell may either be set to begin providing power in the absence of AC power or when the site's battery voltage has dropped to a certain point. In either condition, the fuel cell provides power to the customer's equipment until such time as either the AC power is restored or the battery voltage comes back up to a customer-defined point. Case Study: Sunrail Sunrail is a Floridabased commuter rail network. As such, they have traffic control signals and other safety signaling equipment located throughout their service territory. This particular site is an off-grid location where the customer had determined that the necessary 3,000-foot grid extension was cost-prohibitive. Because of the critical nature of the safety signaling equipment, it was imperative to find an alternate power solution. The low equipment power load of 200 W allowed the customer to purchase a hybrid solution comprised of hydrogen fuel cells, a solar array and batteries. Due to product availability, Phase 1 of the solution involved a four month long fuel cell-battery hybrid charge-discharge model. The signaling equipment was powered by the batteries at the site. When the batteries discharged to a customer-defined level, the fuel cells powered up and recharged the batteries while providing power to the communications equipment until the batteries reached a charged state, at which point, the fuel cells went back to standby mode until the batteries needed to be recharged again. In Phase 2, the solar array was delivered and installed. The solar array became the primary power source, charging the batteries and powering the signaling equipment. The fuel cells are used as backup power. This hybrid power solution provides value to Sunrail in three important areas. Reliability, cost effectiveness and clean energy. Reliability: The nature of a hybrid power solution is its increased reliability over just one power source. Because this site is critical and off-grid, the reliability of the hybrid solution is key. Cost-Effectiveness: The customer was able to avoid a costly 3,000 foot grid extension by selecting the fuel cell/solar/battery solution. This solution is also enabled with remote monitoring, which decreases the number of site maintenance visits over a traditional internal combustion generator solution, thus saving operations expense. Clean Energy: The hybrid fuel cell/solar/battery solution is cleaner than a traditional internal combustion generator. It has no carbon footprint at the point of use. The only emissions are warm, moist air and a bit of water from the fuel cell and there are no particulate emissions from any of the solution components. The use of hydrogen fuel negates the need for fuel spill containment or cleanup. The Sunrail site has been operational since mid-2013. Case Study: Communication Infrastructure Corporation (CIC) This project involves a hydrogen fuel cell power solution being used by a network operator who built a microwave network spanning 39 towers and more than 700 miles. Communication Infrastructure Corporation (CIC), a single source provider for microwave point-to-point and point-to-multipoint radio networks, was retained to design and build the network. CIC has installed more than 30,000 microwave sites since 1999. CIC has been work- http://www.RemoteMagazine.com

Table of Contents for the Digital Edition of Remote - Spring 2015

Editor's Choice
The Impact of OPC UA and Information Modeling on Monitoring Solutions
Protecting Critical Infrastructure: Understanding the Threat to SCADA Networks
Small Power, Big Benefits – Fuel Cells for Remote and Off-Grid Applications
What to Expect in the Equipment Industry in 2015
Wireless Well Pad Retrofit
IT-OT Convergence: The Importance of Aligning Historically Disparate Technologies
Internet of Things North Americs Preview
SCADA
Networking
Security
Onsite Power
Industry News

Remote - Spring 2015