I found this item in the AGU newsroom today, I don’t quite know what to make of it.
by Margaret Donelick
BiMBy Power Company, LLC will present a poster at the AGU Meeting on December 15 in San Francisco’s Moscone Center that describes an innovative device designed to provide grid-scale, renewable energy storage capacity and constructed using overburden from strip coal mines or waste rock from open-pit metal mines.
Called a Big Mass Battery or BiMBy, the device lowers the carbon footprint of burned coal by repurposing the overburden moved during mining to enable construction of an on-demand renewable energy power plant. A carbon footprint for coal similar to that of natural gas may be achieved by using the BiMBy to store compressed air. A carbon footprint for coal much lower than that for natural gas may be achieved by using the BiMBy to store compressed hydrogen, potentially making coal the go-to fossil fuel as fossil fuels are replaced by renewable energy sources.
Up to 30% of the volume of a typical pile of mine overburden/waste rock is pore space filled with air and/or water. Encapsulating the pore space deep within the pile to form a pressure vessel allows compressed gas to be stored within that pore space at a pressure determined by the load of mine overburden/waste rock overlying the encapsulated pore space. In the US, 3-4 giga-tonnes of mine overburden associated with coal mining and 1-2 giga-tonnes associated with metals mining are moved annually.
The worldwide totals are perhaps 5-10 times the US amounts. Widescale repurposing of mine overburden/waste rock for several decades in the US would provide enough energy storage capacity to replace a significant fraction of the fossil fuels currently burned to generate electricity; 10-20% replaced for BiMBys storing compressed air, and 100% replaced with capacity to spare for BiMBys storing hydrogen.
Using mine overburden/waste rock to build renewable energy storage creates the notions of ‘green coal’ and ‘clean gold’. The BiMBy concept offers skilled power plant jobs at active mine sites and a new strategy for converting inactive mine brown-field sites into on-grid or off-grid renewable energy power plants, as per EPA’s RE Powering America.
At a currently operating coal mine, a predictable BiMBy construction timeline can be the basis for a predictable longterm plan to operate and ultimately shutdown the mine. At an inactive and polluting metal mine, the BiMBy pressure vessel at such a polluting site is encapsulated and operated dry and with a positive air pressure, offering a potentially transformative way to satisfy environmental regulatory compliance at the site.
The 50 mega-tonnes of overburden moved annually as the Rosebud Mine near Colstrip, MT could be used to build compressed-air-based renewable energy storage capacity sufficient to convert 10,000 or more US homes to 100% renewable energy, or 200,000 or more homes over 20 years of mining. The 300 mega-tonnes of waste rock at the inactive Anaconda Mine near Yerington, NV could be used to convert 200,000 US homes to 100% renewable energy.