A new report from an energy standards setting group adds urgency to the need to upgrade electricity systems in Maine, especially as the state hopes to produce and export more green power. Before any of this work can be fully considered by regulators, however, the important question of how it will be paid for must be answered.

In a report issued last week, North American Electric Reliability Corp., which develops and enforces electricity system standards, said that without upgrades, transmission systems in New England and the rest of the country can’t accommodate power from wind and other renewable sources. In effect, efforts to address climate change and energy independence, which call for producing more power from renewable sources such as wind, are on a collision course with the reliability of the country’s electricity grid, the report concluded.

As electricity generating plants switch from coal to cleaner natural gas, there is concern that coal-fired plants could be closed before the electricity they produce is replaced with that from gas-fired plants. Increasing demand for natural gas could leave some plants without a fuel source, the report warns.

Another concern is the intermittent nature of wind power, which must be built into grid-management plans.

The Maine Public Utilities Commission is currently considering two proposals that would improve the reliability of Maine’s electric system. Central Maine Power Co. proposes to build a new high-voltage transmission line from Orrington to Newington, N.H., to upgrade the backbone of Maine’s power system. The $1.4 billion project would enhance reliability of the 30-year-old system while increasing capacity, which would allow more power to be exported and imported.

The other line, proposed by CMP and Maine Public Service Co., would connect northern Aroostook County with the New England power grid at a cost of $500 million. The County is currently connected only to Canada.

In considering these projects, the PUC’s top concern must be whether the improvements will benefit Maine ratepayers. A large part of that determination rests with how the new lines are paid for.

As part of ISO-New England, which apportions costs for many infrastructure projects based on the percentage of the region’s energy used in each state, Maine pays about 8 percent of the cost of most system upgrades. Maine residents and businesses are expected to pay $300 million over the next five years for system upgrades in southern New England.

Massachusetts is balking at paying 55 percent of the cost of Maine’s upgrades, even though the improvements could increase the supply of electricity, especially wind-generated electricity, to southern New England, which would benefit the area’s residents and help the states meet requirements for renewable energy and reduced carbon emissions.

Part of the opposition stems from concerns that Maine, which has several wind projects on the table, could use up a large share of the region’s renewable energy credits, making wind projects in other states less attractive financially.

Another layer of complication: The Maine PUC must decide by mid-January whether Maine will stay in ISO-New England or begin the process of leaving. This is the result of a push from the Legislature to consider leaving the regional grid over frustration that Maine businesses and consumers are paying for projects that won’t benefit them.

As regulators and lawmakers work through these complex problems, ensuring that Maine ratepayers benefit from the outcome must be their top priority.