Is Gridless Electricity Via Fuel Cells Practical?

Will fuel cells ever be viable and practical enough to make a rural residence, or even a small commercial business, grid-independent?

A demonstration project in New York state is in the early stages of answering this question by proving a fuel cell’s practicality and feasibility in a rural residential setting. Even more important to the propane industry is that the project, if successful, will validate propane fuel cells for “edge-of-grid residences.”

The year-long project, launched last August, is a cooperative effort among several sponsors, including the Propane Education & Research Council (PERC), the Department of Energy, and the New York State Energy Research and Development Authority (NYSERDA). Delaware County Electric Cooperative (DCEC) is heading up the project and is working with Mirabito Fuel Group (Sydney, N.Y.), which is providing the propane; fuel cell provider Plug Power Inc. (Latham, N.Y.); energy storage provider Gaia Power Technologies (Peekskill, N.Y.); and others.

In addition to providing the fuel, Mirabito is also supplying technical assistance and fuel sampling services. No special propane grade was requested.

A $300,000 federal Congressional grant provided in 2003 has allowed DCEC to procure, install, test, and demonstrate the fuel cell capability at a residence in the Town of Tompkins, southwest of Albany in Delaware County. New York Congressman Maurice Hinchey was instrumental in securing the funding. Another $175,000 was given by the Department of Energy and NYSERDA as part of the Energy Storage Initiative for an integrated power electronics and energy storage system.

Among the chief considerations for demonstrating the viability of off-the-grid energy production is that rural electric co-ops are often requested by new member customers to provide electric service to extremely remote areas. With the cost of extending distribution approximately $50,000/mile plus the associated maintenance costs of keeping the lines clear of vegetation and in-service, co-ops are investigating alternatives to running wires to homes in remote areas. Fuel cells offer the opportunity to generate power quietly and efficiently, says Mark Schneider, manager of engineering at DCEC, and fuel cells can one day offer local generation with on-site energy storage as an attractive alternative.

Propane’s role in the project can be summed up in a statement by the co-op on the demonstration: DCEC is using propane as its method of chemical energy storage due to propane’s availability in all areas, particularly areas where off-grid energy storage is important, and because it complies with our safety goals and aesthetic standards for the project.

The DCEC project features a 5-kw Plug Power fuel cell that is integrated through an 11-kw power electronics and battery storage system provided by Gaia Power Technologies. Known as the PowerTower, Gaia’s unit manages the electrical load, provides the peak energy needs, controls the fuel cell’s output, and continually charges the fuel cell during off-peak times. The system is being subjected to varying load and environmental conditions, and the electrical usage, fuel cell, and power system are being monitored constantly.

A 1000-gal, propane tank was installed underground last spring and connected to the Plug Power unit, which uses proton exchange membrane technology to process the propane into hydrogen. The unit is expected to consume 850 gal. of propane during the one-year test.

Described by DCEC as a typical New York home that represents a challenging real-world application, the 2300-sq-ft. 12-year-old. well-insulated home has no gas appliances. A young family is living in the home during the testing period. The home uses an average of 47.6 kwh of electricity per day. while its maximum energy usage for one day has been estimated at 67 kwh. The average power draw is 1 .98 kwh and its maximum power draw is 15.2 kwh. A hot tub is the biggest single electric load of the house, reports Mark Hilson Schneider, the DCEC engineer

(A 5-kw Plug Power fuel cell is being tested at a 2300-sq-ft residence, occupied by a young family, in upstate New York to demonstrate the unit’s practicality and feasibility in a rural residential setting.)

overseeing the project. The hot tub “has given us the most challenge,” Schneider told BPN, “because of the high demand (approximately 6.5 kwh) and the fact that it cycles on and off frequently, especially in the winter.”

A thermal recovery loop pulls waste heat out of the fuel cell to heat water and for the home's baseboard heaters. The water is constantly heated through this process.

In its initial announcement, DCEC noted that there are a few challenges to overcome, including the potential incompatibility between propane tank dehydration additives and the fuel reformer/scrubber. Additionally, the co-op cited possible issues with the integration of controls with the energy storage controller, and that distributed generation products are not designed to efficiently and easily integrate with battery storage (regulated direct current output is not available). The coop also noted that there can be a 10% to 20% voltage dip, which will be noticeable, associated with large startup surge currents from the hot tub heater.

—Ann Rey