Over the past decade, the United States Army Corps of Engineers undertook a study on modifying the St Lawrence Seaway to transit the largest ships afloat into Lake Ontario. Implementing the plan would have involved substantial dredging of the riverbed. The environmental movement strongly and successfully opposed such plans. However, the cancellation of those plans has opened the door to new discussions about future power generation and maritime transportation along the waterway.
Energy Along the Waterway:
The expansion of wind power generation in several jurisdictions along the waterway plus the excess of off-peak, wintertime thermal generating capacity has produced application for energy storage capability. New York State indicated interest in developing additional grid-scale storage capacity, including interest in compressed air energy storage (CAES) at locations along the St Lawrence River. At the present time and over the past several years, the natural gas industry has stored compressed natural gas in emptied underground salt caverns located south of Buffalo NY.
A company drilling for potable ground water to the southeast of Massena NY, drilled into an underground salt pond. Salt caverns are believed to occur in the deep bedrock along the St Lawrence River, extending as far to the east as the Gulf of St Lawrence where oil and natural gas deposits are believed to exist. The natural gas industry in Quebec experimented with "fracking" in close proximity to the St Lawrence River, in their search for natural gas. That occurrence of that natural gas suggests the possible occurrence of salt caverns in the bedrock near the St Lawrence River.
In terms of grid-scale energy storage capacity, New York State at present has much greater storage capacity than either Ontario or Quebec. Despite the extent and generating capacity of Hydro Quebec's James Bay hydroelectric installations, Quebec has practically zero grid-scale energy storage capacity. The locations of the James Bay reservoirs in relation to each other and also in relation to James Bay, rules out any possible future development of pumped hydroelectric storage in that region. Ontario operates a miniscule capacity pumped hydraulic installation at Niagara Falls, with a small grid-scale chemical-battery storage installation at Toronto.
Future Initiatives - Massena:
Nuclear and CAES: Officials at Massena NY have indicated interest that Massena become home to a future power station that will be located in close proximity to the international power dam. The presence of an underground salt pond near Massena suggests the possible presence of salt caverns in the area, allowing for possible future development of compressed air energy storage (CAES) near Massena.
There will be a need for seismic testing to accurately pinpoint locations of suitable underground salt caverns that may be adapted to future CAES applications. Easy access to river transport allows for barges to carry the displaced rock salt to other locations. The heat of compression of grid-scale CAES may be pumped into geothermal storage, allocated for district heating or applied for industrial heating purposes.
The combination of a nuclear power station and nearby CAES allows for development of steam turbines directly driving turbo air-compressors, saving up to 10% efficiency by bypassing electrical machinery. Such savings may translate to up to 90MW for a 950MW power station. Designers would face the challenge of developing a mechanical power transfer technology whereby the same steam turbine would drive either electrical machinery or a turbo air-compressor at different times of the day.
Pumped Hydraulic: The Riverbank Power Group explored the possibility of pumped underground energy storage near Massena. Such an installation would use a fraction of the water volume flow rate as the power dam at Massena, to generate the equivalent output during peak periods. Both CAES and pumped underground technologies could serve the wind power sector and the nuclear power industry at Massena and in Ontario (excess overnight winter generation).
Seasonal Geothermal: Dr Forsberg's team at MIT undertook extensive research into high-temperature (500ºC) grid-scale seasonal geothermal energy storage, to generate electric power. A competing British group developed a similar geothermal storage system that involves the combination of extensive hot and cold geothermal reservoirs. There may be future scope to introduce such technology near Massena NY, near the proposed nuclear power station.
There may also be potential to develop seasonal low-temperature (80ºC) geothermal energy storage in the same vicinity, and also at the recently discovered underground salt pond. That energy system could store summer time solar thermal energy and provide for home heating in the region, as well as assist in maritime operations during cold weather through the navigation locks near Massena. Seismic testing could pinpoint locations of underground deposits of gravel that may be used for geothermal energy storage.
Hydraulic Turbines: A group of energy researchers have been exploring the potential of 2-stage hydraulic turbines at power dams, including possible retrofits of low-head hydraulic turbines capable of operating at some 70% efficiency, downstream of the outlet runners at existing installations. There is scope to adjust water elevation of the holding reservoirs for the power dams near both Massena and Montreal, courtesy of a control dam located upstream of Massena. A 2-stage hydraulic turbine system could operate with the identical water volume flow-rate as present and raise power output some 4% to 7% (80MW to 140MW) for the entire power dam.
Transmission Lines: Long-distance transmission lines radiate from the power dams near Massena and Montreal connect to major cities across New York State as well as in Ontario and in Quebec. There is potential to upgrade the transmission capacity along these existing corridors, to accommodate future power generation capacity that may become possible at Massena. Several complimentary power generation and energy storage installations may be located in close proximity to each other at Massena.
Geological Concerns: During the early-mid 20th century, buildings around Massena suffered major damage during an earthquake that had an epicenter located in the Catskill Mountain region. The majority of these buildings were built above strata of Leda clay that loses compressive strength when subjected to certain low-frequency vibrations, including the vibration frequency of earthquake tremors. Seismic testing can pinpoint the strata of Leda clay in the region around Massena, to allow a future nuclear power station to be built on a solid geological base.
Future Initiatives - Quebec:
Unlike other regions that experience peak demand for electric power during summer, the peak demand in Quebec occurs during winter and as a direct result of cheap electric power and abundant use of electric heaters. Quebec is increasing wind power generation and with little overnight and seasonal energy storage capacity. Like Massena, there may be future potential to develop either or both of compressed air energy storage (CAES) and/or pumped underground hydraulic storage at or near the power dam located to the southwest of Montreal.
There may also be potential to develop seasonal low-temperature (80ºC) geothermal energy storage near that location, using concentrated summer solar thermal energy. A possible future introduction of CAES at this location would allow the heat-of-compression to be transferred into geothermal storage, or allocated to district heating. Nearby access to river transport allows barges to carry displaced rock salt to other location.
Seasonal CAES: The occurrence of oil and natural gas deposits in Eastern (Atlantic) Canada has renewed interest in developing the natural gas deposits that are believed to occur in the region around the Gulf of St Lawrence, including into Quebec. The possible presence of natural gas in this region also suggests the possible occurrence of salt caverns in the earth's bedrock, caverns that may be fully or partially flushed of rock salt. It may be possible to develop seawater-displacement CAES in this region of Quebec, that is, use seawater to displace compressed air from the underground storage cavern to develop seasonal grid-scale storage capacity (EG: 3-months of 2,000-MW).
Future Initiatives - Maritime:
There may be scope to extend the length of existing navigation locks along the St Lawrence Seaway, between the Gulf of St Lawrence and Lake Ontario and possibly into the Upper Great Lakes to transit extended length maritime technology such as barge trains. Borrowing from precedent along the enlarged Panama Canal, the installation of side reservoirs can reduce water consumption by up to 66% to transit a pair of ships sailing in opposite directions. While extended length watercraft may carry greater payload while consuming less fuel, such technology may greatly assist the future development of the energy sector along the St Lawrence Seaway.
The development of grid-scale overnight and seasonal CAES, as well as pumped underground hydraulic storage would require the relocation of a massive tonnage of rock salt and of rock. In such application, maritime bulk transport far exceeds the capability of railways and/or truck transport in terms of competitive cost per ton, per BTU of energy consumed and per person involved in transportation. The possible future introduction of CAES at power dams near Montreal and Massena could extend the shipping season upstream of Montreal.
Regular short bursts of compressed air under the water at the navigation locks can break up the surface ice cover, to transit ships through the locks. The use of side reservoirs at extended length navigation locks would compliment seasonal low-grade geothermal energy storage. A small portion of stored heat could assist in the winter operation of the navigation locks. In terms of moving massive volume and massive tonnage, the maritime transportation mode consumes less energy per ton of payload that either railway or road transport.
The presence of power generation and energy storage at the navigation locks and canals leading to/from those locks, would allow for the use of grid-scale battery power aboard hybrid or all-electric tug boats. The technology may involve flow batteries, lithium batteries or sodium-sulfur batteries. At port as well as on the approach to, departure from and time at the navigation locks, there would be scope to recharge the battery systems. Such recharge capability would be available immediately to the southwest of Montreal, at Massena NY and through the locks at Niagara.
There is much potential to develop future power generation and future grid-scale energy storage along the St Lawrence River, with related potential for future energy developments to enhance future maritime transportation operations along sections of that river. Easy access to maritime transport would allow for easy movement of displaced rock salt and displaced rocks that result from the development of energy installations.
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