And Quebec Hydro can replace 1200+ mWh? Answer seems simple - run the power lines. Unsightly power lines for non-pollutive hydro power or burn more natural gas at higher prices. Pollution in the air is unsightly too.
How much more would it be to bury the lines? Probably a good idea anyway to avoid outage issues.
Burying long-haul high-voltage transmission isn't really a good option.
First, it's frightfully expensive: in round numbers, the cost would be 10x higher.
Second, heat dissipation is a serious issue. They'd have to have oil or similar coolant continually circulating along the route, and there's always a risk that the coolant will leak (causing pollution and taking the line out of services.
Third, putting the line underground can screw around with the system harmonics (in ways I can't explain but that the engineers take seriously). This costs more money to address.
Fourth, if something going wrong, it can take a long time to find and fix the fault.
All that said, it's not impossible to put transmission underground, just expensive and technically challenging. When CL&P did a big upgrade to the Connecticut backbone transmission, short sections were put underground to avoid the worst NIMBY problems.
Public radio this morning reiterated this idea of electric rates going up because the natural gas pipeline is limited. There has been an aggressive buildout of natural gas to residential consumers over the past couple of years here. Is this really poor planning on the part of the natural gas company.
It's not the job of the natural gas distribution companies to build pipelines for power plants to use; the power plants aren't their customers. And, as I discussed above, the power plants have very weak financial incentives to take on long-term commitments for gas supply. New England is missing an institution to coordinate and implement gas pipelines, comparable to how ISO New England plans electric transmission and gets it built.
I downloaded the suggested application and saw the current mix at 6pm was 28% renewable including hydro. A little misleading however when they include refuse in the mix. My layman view of renewable would be more like hydro, wind and solar not landfill gas, wood and refuse.
The definition of "renewable" is determined by your state's laws, not your utility, so it's hard to blame them for using statutory terms. It's
really good to encourage burning of landfill gas. It's arguably the best possible "renewable" option out there. The landfill is going to generate and emit methane in any case. If it's not captured and burned, it will leak into the atmosphere. Methane is a potent GHG, far worse than CO2, so using it to generate electricity not only displaces burning of natural gas elsewhere, but it reduces methane emissions.
The same argument has been advanced re refuse and bio (=wood waste). The stuff is going to decompose and emit various GHGs, so better to burn it, getting some useful work out of it. There have been some studies that suggest this logic doesn't quite pan out unless the refuse/biomass reactor is quite efficient.