Here’s an energy idea so simple it fits in one sentence: Connect already drilled but currently unused gas wells to small generators to produce electricity on the spot.
Dave Weddle and his team at Wellhead Energy Systems LLC in Somerset believe this new approach can help upgrade the nation’s power grid. Their self-contained system, called GridFox, makes use of a previously overlooked energy resource: capped natural gas wells.
Nonproducing gas wells happen when oil-well drillers hit pockets of natural gas that are too small to make it worthwhile to connect them to major pipelines. These wells are capped and abandoned. In the lingo of energy explorers, they become “stranded” assets. They’ve been sitting idle ever since, earning nothing for their owners, all the energy inside locked away and unused.
Wellhead Energy Systems’ GridFox technology can change that.
Small and simple
For many years, engineers have been drawing complex new energy schemes on paper, dreaming about a more diverse power grid that doesn’t depend so heavily on coal. However, rows of enormous wind turbines and solar collectors sprawled over hundreds of acres take a long time to build and install. The energy they produce is intermittent, varying through the day and night. And often the places with the most sunshine or the most wind are in locations far away from electricity consumers.
What’s different about Wellhead Energy Systems’ approach is its simplicity. Instead of building gigantic new generating facilities and hundreds of miles of new transmission lines for remote renewable power sources, each GridFox unit is small and can be used within existing local power systems.
Each GridFox system fits in a standard 40-foot-long international shipping container that can be easily transported to the site of an unused gas well. A GridFox unit sits on a small concrete pad not much bigger than the foundation for a multicar garage. Short connecting lines bring the gas from the wellhead into the GridFox container, where devices prepare and compress the raw gas to be used as the fuel for a reciprocating engine that produces electricity. In a typical situation, standard power lines provide a path for the electricity to flow out from the container and into the local power grid. Computers and other sophisticated electronics monitor all steps of the process.
Unlike solar or wind facilities, a GridFox unit operates every minute of every day and every night, except for about two weeks a year of downtime for basic maintenance. It provides the same steady, high-quality power as conventional generating plants. Such “distributed generation,” where the source of electricity is much closer to consumers instead of traveling great distances from a central power plant, adds diversity to the power grid and is very efficient.
The engine inside a GridFox unit needs only a small amount of gas flow (typically about 200,000 cubic feet in a 24-hour period) to generate up to 1 megawatt of electricity. That’s enough energy to provide power to a rural hospital, a small manufacturing site, or more than 800 rural homes. Being able to add dependable electricity to the existing local power grid quickly and easily could be an important tool for rural economic development.
Lots of wells
Stranded gas wells are surprisingly common. In Kentucky, there may be as many as 7,000 small natural gas wells sitting idle. No one knows yet their full potential as energy-producing sites, but electric utilities are eager to find out. Since Wellhead Energy’s first working model began producing electricity in June for a Jackson Energy substation in McKee, Weddle and his business partners have received inquiries from a dozen other electric cooperatives in Kentucky and Tennessee.
Weddle says, “We are also talking with electric co-ops and a couple of public power companies in Indiana, West Virginia, Ohio, and Illinois.” These states, like Kentucky, have plenty of stranded natural gas wells.
But there’s another option for the GridFox system that makes it useful in even more places, like producing green power from landfill gas. In any community with the right size landfill, a GridFox unit can be brought in by tractor-trailer and set up onsite to use these gases as the fuel for the generator. In a case like this, a GridFox unit might be more practical than building a permanent structure. When all usable gas has been withdrawn at a landfill, the GridFox unit can be trucked to a new location and started again.
Don Schaefer, president and CEO of Jackson Energy, a rural electric cooperative serving more than 50,000 members in 15 southeastern Kentucky counties, says, “Our mission as an electric cooperative has always been to provide reliable electricity at the lowest possible cost. The GridFox system is attractive to us because the cost of this electricity is very affordable, much less than from solar or wind. And the more generating sources you add to your system, the more reliable your system can be.”