By Nancy W. Stauffer, Massachusetts Institute of Innovation
April 12, 2022
Among Hydro-Quebecs hydroelectric generating stations. Credit: Hydro-Quebec
Power streaming both methods across the Canada– U.S. border offers a pathway to tidy electrical energy in 2050.
The urgent need to cut carbon emissions has actually prompted a growing variety of U.S. states to commit to accomplishing 100 percent tidy electrical energy by 2040 or 2050. However figuring out how to fulfill those commitments and still have a budget friendly and trusted power system is a difficulty. Wind and solar installations will form the backbone of a carbon-free power system, but what technologies can meet electrical energy demand when those intermittent sustainable sources are not sufficient?
In general, the alternatives being gone over consist of nuclear power, natural gas with carbon capture and storage (CCS), and energy storage innovations such as new and better batteries and chemical storage in the form of hydrogen. However in the northeastern United States, there is one more possibility being proposed: electrical energy imported from hydropower plants in the surrounding Canadian province of Quebec.
Those plants can produce as much electricity as about 40 big nuclear power plants, and some power created in Quebec already comes to the Northeast. There could be abundant additional supply to fill any shortfall when New Englands periodic renewables underproduce.
2 years ago, 3 researchers connected with the MIT Center for Energy and Environmental Policy Research (CEEPR)– Emil Dimanchev SM 18, now a PhD candidate at the Norwegian University of Science and Technology; Joshua Hodge, CEEPRs executive director; and John Parsons, a senior lecturer in the MIT Sloan School of Management– started questioning whether viewing Canadian hydro as another source of electrical energy might be too narrow. “Hydropower is a more-than-hundred-year-old technology, and plants are currently developed north,” says Dimanchev. “We may not require to build something new. We may simply need to use those plants differently or to a greater extent.”
The scientists chose to take a look at the prospective function and financial worth of Quebecs hydropower resource in a future low-carbon system in New England. Their goal was to help inform policymakers, utility decision-makers, and others about how finest to include Canadian hydropower into their plans and to figure out how much money and time New England need to spend to integrate more hydropower into its system. What they discovered out was surprising, even to them.
” Hydropower is a more-than-hundred-year-old innovation, and plants are already constructed up north,” states Emil Dimanchev SM 18. “We might not need to develop something new.
The analytical approaches
To check out possible functions for Canadian hydropower to play in New Englands power system, the MIT scientists first needed to forecast how the local power system might search in 2050– both the resources in location and how they would be operated, given any policy restraints. To carry out that analysis, they used GenX, a modeling tool originally established by Jesse Jenkins SM 14, PhD 18 and Nestor Sepulveda SM 16, PhD 20 while they were researchers at the MIT Energy Initiative (MITEI).
The GenX design is developed to support decision-making related to power system financial investment and real-time operation and to examine the effects of possible policy efforts on those decisions. Offered info on future and present technologies– various type of power plants, energy storage innovations, and so on– GenX computes the combination of equipment and operating conditions that can fulfill a defined future need at the most affordable expense. The GenX modeling tool can also incorporate specified policy restraints, such as limits on carbon emissions.
For their research study, Dimanchev, Hodge, and Parsons set specifications in the GenX model using assumptions and data stemmed from a range of sources to construct a representation of the interconnected power systems in New England, New York, and Quebec. (They consisted of New York to account for that states existing need on the Canadian hydro resources.) For data on the readily available hydropower, they turned to Hydro-Québec, the public utility that owns and operates many of the hydropower plants in Quebec.
Its standard in such analyses to consist of real-world engineering restrictions on devices, such as how rapidly particular power plants can be ramped up and down. With aid from Hydro-Québec, the scientists also put hour-to-hour operating restraints on the hydropower resource.
Most of Hydro-Québecs plants are “reservoir hydropower” systems. In them, when power isnt needed, the circulation on a river is limited by a dam downstream of a reservoir, and the tank fills. When power is needed, the dam is opened, and the water in the tank runs through downstream pipelines, producing and turning turbines electricity. Proper management of such a system requires sticking to certain operating restraints. For instance, to prevent flooding, tanks need to not be allowed to overfill– particularly prior to spring snowmelt. And generation cant be increased too quickly because an unexpected flood of water might wear down the river edges or interrupt fishing or water quality.
Based on projections from the National Renewable Energy Laboratory and in other places, the researchers defined electrical power need for every hour of the year 2050, and the design calculated the cost-optimal mix of technologies and system operating routine that would satisfy that per hour demand, including the dispatch of the Hydro-Québec hydropower system. In addition, the model figured out how electrical power would be traded among New England, New York, and Quebec.
Effects of decarbonization limitations on technology mix and electrical energy trading
To take a look at the impact of the emissions-reduction mandates in the New England states, the scientists ran the model assuming decreases in carbon emissions between 80 percent and 100 percent relative to 1990 levels. The results of those runs show that, as emissions limits get more strict, New England utilizes more wind and solar and extends the lifetime of its existing nuclear plants. To stabilize the intermittency of the renewables, the region uses natural gas plants, demand-side management, battery storage (modeled as lithium-ion batteries), and trading with Quebecs hydropower-based system. On the other hand, the optimum mix in Quebec is mostly composed of existing hydro generation. Some solar is added, however brand-new reservoirs are constructed only if sustainable costs are presumed to be very high.
The most substantial– and possibly unexpected– result is that in all the circumstances, the hydropower-based system of Quebec is not only an exporter however also an importer of electricity, with the instructions of circulation on the Quebec-New England transmission lines changing with time.
Historically, energy has actually always flowed from Quebec to New England. The design results for 2018 show electrical power streaming from north to south, with the amount capped by the current bandwidth limit of 2,225 megawatts (MW).
An analysis for 2050, presuming that New England decarbonizes 90 percent and the capacity of the transmission lines stays the very same, finds electricity streams going both ways. Flows from north to south still control. For nearly 3,500 of the 8,760 hours of the year, electrical power flows in the opposite instructions– from New England to Quebec. And for more than 2,200 of those hours, the circulation going north is at the optimum the transmission lines can bring.
The instructions of flow is motivated by economics. When sustainable generation is abundant in New England, rates are low, and its less expensive for Quebec to import electrical energy from New England and save water in its tanks. Conversely, when New Englands renewables are scarce and costs are high, New England imports hydro-generated electricity from Quebec.
Rather than delivering electrical energy, Canadian hydro provides a means of saving the electrical power produced by the periodic renewables in New England.
” We see this in our modeling due to the fact that when we tell the design to fulfill electricity need using these resources, the model decides that it is cost-optimal to utilize the tanks to keep energy instead of anything else,” states Dimanchev. “We ought to be sending the energy backward and forward, so the reservoirs in Quebec remain in essence a battery that we use to keep a few of the electricity produced by our periodic renewables and discharge it when we require it.”
Provided that result, the researchers chose to check out the impact of expanding the bandwidth in between New England and Quebec. Building transmission lines is always contentious, however what would be the impact if it could be done?
Their model results programs that when bandwidth is increased from 2,225 MW to 6,225 MW, streams in both directions are higher, and in both cases the flow is at the new optimum for more than 1,000 hours.
Results of the analysis thus confirm that the economic action to expanded bandwidth is more two-way trading. To continue the battery analogy, more transmission capability to and from Quebec successfully increases the rate at which the battery can be charged and discharged.
Impacts of two-way trading on the energy mix
What effect would the arrival of two-way trading have on the mix of energy-generating sources in New England and Quebec in 2050?
Assuming existing transmission capacity, in New England, the modification from one-way to two-way trading increases both wind and solar power generation and to a lower extent nuclear; it likewise decreases the usage of natural gas with CCS. In Quebec, two-way trading lowers solar power generation, and the use of wind disappears. Hence, two-way trading reallocates renewables from Quebec to New England, where its more affordable to set up and run solar and wind systems.
Another analysis examined the impact on the energy mix of assuming two-way trading plus expanded bandwidth. For New England, greater bandwidth permits wind, solar, and nuclear to expand further; natural gas with CCS all but disappears; and both exports and imports increase substantially. In Quebec, solar declines still further, and both exports and imports of electrical energy increase.
Those results assume that the New England power system decarbonizes by 99 percent in 2050 relative to 1990 levels. At 90 percent and even 80 percent decarbonization levels, the model concludes that natural gas capability reduces with the addition of brand-new transmission relative to the existing transmission circumstance. Existing plants are retired, and brand-new plants are not developed as they are no longer economically justified. Given that natural gas plants are the only source of carbon emissions in the 2050 energy system, the scientists conclude that the greater access to hydro tanks made possible by expanded transmission would speed up the decarbonization of the electrical power system.
Results of transmission changes on costs
The scientists likewise checked out how two-way trading with broadened transmission capability would impact costs in New England and Quebec, assuming 99 percent decarbonization in New England. New Englands savings on repaired expenses (financial investments in new devices) are mostly due to a decreased requirement to invest in more natural gas with CCS, and its savings on variable expenses (operating expenses) are due to a lowered requirement to run those plants.
Hence, the analysis reveals that everyone wins as transmission capability boosts– and the benefit grows as the decarbonization target tightens up. At 99 percent decarbonization, the general New England-Quebec area pays about $21 per megawatt-hour (MWh) of electrical power with todays bandwidth however just $18/MWh with expanded transmission. Assuming 100 percent reduction in carbon emissions, the region pays $29/MWh with existing transmission capacity and only $22/MWh with broadened transmission.
This figure shows the level of electricity flow from north to south (positive numbers) and from south to north (negative numbers) versus the number of hours per year. The flows in 2018 (blue) are always from Quebec to New England and are capped by the transmission capacity limit of 2,225 megawatts.
Addressing misconceptions
These outcomes clarified several misconceptions that policymakers, fans of sustainable energy, and others tend to have.
The first mistaken belief is that the New England renewables and Canadian hydropower are rivals. The modeling results rather reveal that theyre complementary. When the power systems in New England and Quebec collaborate as an integrated system, the Canadian tanks are used part of the time to keep the eco-friendly electrical energy. And with more access to hydropower storage in Quebec, theres generally more sustainable financial investment in New England.
The second mistaken belief occurs when policymakers refer to Canadian hydro as a “baseload resource,” which suggests a reputable source of electrical power– particularly one that provides power all the time. “Our research study shows that by seeing Canadian hydropower as a baseload source of electrical energy– or indeed a source of electrical power at all– youre not taking full benefit of what that resource can offer,” says Dimanchev.
While the MIT analysis focuses on New England and Quebec, the scientists believe that their results may have wider ramifications. Taking advantage of that capability can decrease the cost of deep decarbonization and aid move some regions towards a decarbonized supply of electricity.
References:
” The role of hydropower reservoirs in deep decarbonization policy” by Emil G. Dimanchev, Joshua L. Hodge and John E. Parsons, 5 May 2021, Energy Policy.DOI: 10.1016/ j.enpol.2021.112369.
” Two-Way Trade in Green Electrons: Deep Decarbonization of the Northeastern U.S. and the Role of Canadian Hydropower” by Emil G. Dimanchev, Joshua L. Hodge and John E. Parsons.
This research was moneyed by the MIT Center for Energy and Environmental Policy Research, which is supported in part by a consortium of market and government associates.This article appears in the Autumn 2021 problem of Energy Futures, the publication of the MIT Energy Initiative.
For their research study, Dimanchev, Hodge, and Parsons set specifications in the GenX model using data and assumptions obtained from a variety of sources to construct a representation of the interconnected power systems in New England, New York, and Quebec. When sustainable generation is plentiful in New England, prices are low, and its cheaper for Quebec to import electricity from New England and save water in its reservoirs. Alternatively, when New Englands renewables are scarce and prices are high, New England imports hydro-generated electrical power from Quebec.
The scientists likewise checked out how two-way trading with expanded transmission capacity would affect expenses in New England and Quebec, assuming 99 percent decarbonization in New England. New Englands cost savings on fixed costs (investments in brand-new devices) are mostly due to a reduced need to invest in more natural gas with CCS, and its savings on variable costs (operating costs) are due to a decreased requirement to run those plants.