Meeting ambitious clean energy goals is possible, according to a new state report, but some strategies for doing so could be more cost-effective and reliable than others. 

The Governor’s Energy Office drafted a “Pathways to 2040” plan outlining how the state can achieve 100% clean energy by 2040. It outlines a plan to meet that goal based on electrifying two areas with significant greenhouse gas emissions: transportation and heating. The roadmap also tests certain supply and demand variables to see how they would affect costs and reliability.

Similar to the state’s updated climate action plan, key components to meeting the clean energy goal Gov. Janet Mills set in 2023 are electric vehicles and high efficiency heat pumps. But swapping in those technologies will increase the demand for electricity, so the clean energy plan said it is “essential to decarbonize the electricity supply.”

Most of Maine’s clean electricity needs in 2040 can be met with the state’s current and planned renewable energy resources, including the three gigawatts of offshore wind the state is committed to seeing developed in the Gulf of Maine also by 2040. 

The public can provide feedback on the draft plan until Dec. 30. A final version of the report is due to the governor and Legislature by Jan. 15. 

How to get to 100% clean energy by 2040

The main pathway outlined in the plan relies on electrifying much of the transportation and heating needs in the state. 

Such widespread electrification will double power demand with a new winter peak that is three times that of the current summer peak, according to the report. But the plan outlines a way to meet those demands with mostly renewable sources — wind and solar — and a decreased reliance on fossil fuels. 

Transitioning away from oil and gas will take more than just increasing renewable generation, the report explains. It will need support from battery storage, some imported clean energy and infrequent use of combustion-based energy production accounting for less than 5% of total generation in New England. Clean fuels could also replace fossil fuels in hard to electrify sectors like air travel and steel production.

Maine will also need to expand its transmission system and add lines to connect new resources, the plan says. Since Maine is part of the electric grid utilized by the rest of New England, these enhancements will allow for more power to move across the grid and greater exchanges with neighboring states.

The cost of electricity will likely decrease over time with this approach, while greenhouse gas emissions are also projected to be 45% lower than they were in 1990 by 2030 and 80% lower in 2050.

Factors affecting cost, reliability

The plan also explores alternative pathways that are not complete deviations from the baseline proposal, but rather test certain variables of energy supply and demand.

One alternative explores the role of keeping some non-renewable electricity sources in the portfolio. A pathway with 100% renewable electricity generation is possible, but would be more costly because it would require additional infrastructure than currently planned and storage capacity to ensure reliability.

Maine is the most heating oil-dependent state in the country. If the state adopted a more hybrid heating model that maintained some of that fuel usage, rather than complete electrification, there would be lower peak electric loads. While this could save electric system costs, it would be offset by the cost of purchasing and maintaining dual heating systems, as well as the cost of heating fuel. 

Two of the alternative routes probe at the role of flexible load management, or adjusting the timing of electricity usage to periods with less demand to maintain balance with the available supply. The two scenarios show that flexible loads, especially electric vehicle charging, helps system reliability by managing demand. 

Flexible loads also keep distribution peaks lower, which can avoid increased transmission and generation costs. Therefore, the report says these alternatives underscore the need to invest in load flexibility sooner rather than later to maximize long-term savings. 

Comments must be submitted to [email protected] no later than 5 p.m. on Monday, December 30, 2024.