Novel Electrolyzer Applications: Providing More Than Just Hydrogen

Abstract

Despite the fact that many electrolyzer projects have been installed, there is little operational data available to quantify their response and flexibility. Electrolyzers electrochemically separate water into hydrogen and oxygen using electricity as the feedstock. This work explores the operational flexibility of electrolyzers by performing experimental tests on a proton exchange membrane (PEM) and an alkaline electrolyzer. Many applications value flexibility, particularly with the addition of increased intermittent renewables and new regulations for both stationary and transportation emissions. Test results are compared to the operational requirements for participation in end-user facility energy management, transmission and distribution system support, and wholesale electricity market services.The hydrogen produced from electrolyzers can be used for many different applications and can be integrated into different system architectures. The applications include hydrogen for vehicle fueling, industrial processes, power generation, and injection into the natural gas pipeline. Hydrogen can also be methanized and used for similar applications. Hydrogen production and storage can be combined with power generation equipment including fuel cells, reciprocating engines, combustion turbines, and steam turbines, resulting in a storage device with the ability to time shift delivery of electricity for electric grid applications. In this way, hydrogen can be used to support increased intermittent renewable generation.For the applications considered the following factors are important: (1) the time it takes to respond to a change in power set-point, (2) the time it takes to settle after a power set-point change, (3) the rate at which the device can change power consumption, (4) the lower operation limit or the minimum turndown level, and (5) the time it takes to start up and shut down. The findings are as follows:• Small electrolyzer systems (~40 kW units) begin changing their electricity demand within milliseconds of a set-point change.• The settling time after a set-point change is on the order of seconds.• Electrolyzers can reduce their electrical consumption for an unlimited amount of time.• Electrolyzers exhibit low part-load operation capabilities.• Electrolyzers can start up and shut down in several minutes.In addition, a frequency disturbance correction test was performed to test the ability of an electrolyzer to accelerate the speed at which the grid frequency can be restored. For this test, an isolated grid consisting of a diesel generator, load bank, and electrolyzer was perturbed by changing the load bank's set-point. The time that it takes to restore the frequency was examined for both the case with and without the support of the electrolyzer. In all cases, adjusting the electricity demand for the electrolyzer corresponding to the load bank's change, the system was able to restore the frequency faster with the support of the electrolyzer than without.When comparing the performance metrics for electrolyzers with th...

Nanosized IrOx–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure

“…While alkaline electrolyzers are advantageous with respect to their longevity and costs,t he lack in gas purity,s afety,a nd response time has pushed the research and industrial interests towards proton exchange membrane (PEM) electrolysis in the recent years. [7,8] Forwater splitting in PEM electrolyzers,the choice of the oxygen evolution reaction (OER) catalyst employed at the anode has ap rofound impact on the cost, lifetime,a nd efficiency of the device.Iridium is commonly used as aOER catalyst, but is highly priced ($546 per troy ounce) [9] and one of the rarest elements in the earth crust, with an annual production and consumption value of only about 4t o9 tons. [10][11][12] Several approaches have been proposed to overcome the challenges associated with the precious metal OER catalyst such as reducing the particle size,thereby increasing the surface to mass ratio, [13] using electro-ceramic supports, [14,15] or enhancing the phase structure.…”

Nanosized IrOx–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure

“…While alkaline electrolyzers are advantageous with respect to their longevity and costs,t he lack in gas purity,s afety,a nd response time has pushed the research and industrial interests towards proton exchange membrane (PEM) electrolysis in the recent years. [7,8] Forwater splitting in PEM electrolyzers,the choice of the oxygen evolution reaction (OER) catalyst employed at the anode has ap rofound impact on the cost, lifetime,a nd efficiency of the device.Iridium is commonly used as aOER catalyst, but is highly priced ($546 per troy ounce) [9] and one of the rarest elements in the earth crust, with an annual production and consumption value of only about 4t o9 tons. [10][11][12] Several approaches have been proposed to overcome the challenges associated with the precious metal OER catalyst such as reducing the particle size,thereby increasing the surface to mass ratio, [13] using electro-ceramic supports, [14,15] or enhancing the phase structure.…”

Electrolyzers Enhancing Flexibility in Electric Grids

“…Past research has demonstrated the subsecond response of PEM electrolyzers [24], but this demonstration considered electrolyzers already consuming power at steady state. Electrolyzers starting from a "cold start" (i.e., no power to any balance of plant components) exhibit a longer response time.…”

“…The simulations conducted for DRTS could precisely simulate the real-time dynamics of electric grids and have been solved at a 300 µs time-step. For the fast-loop testing, the simulation comprised a DRTS with a model of the electrolyzer on the basis of characterized data recorded during the stack testing [24]. For these tests, it was expected that the FEC could drive the electrolyzer power consumption such that it would provide support to the voltage and frequency stability.…”