A 5-acre solar array next to the Belfast Public Works Department . Credit: Abigail Curtis / BDN

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It didn’t take catastrophic power failures like those that have hit Texas this week to show that Maine’s power grid may not be ready for the promised clean energy future. To be clear, the recent massive power outages in Texas were not caused by renewable energy, as some officials have erroneously claimed. Rather, millions of Texans were without power during an unusually long stretch of freezing temperatures because of problems with natural gas supply, cost-saving measures and a power grid that is purposely disconnected from the nation’s electricity system.

In Maine, possible deficiencies in the state’s power delivery system came to light earlier this month after Central Maine Power Co. said it can’t accommodate dozens of solar projects without expensive upgrades. CMP told the solar power generators that they likely would be charged far more than the company had previously said to pay for improvements to its systems to handle the power they would add to the state’s electric network. The power company said it may need to upgrade 100 substations to accommodate the new, dispersed energy sources. CMP has since said it believes it has found lower cost alternatives, but further study is required.

The reports that CMP would charge up to 10 times more than what was included in preliminary agreements with more than a dozen solar energy projects set off a firestorm of criticism and questions, and worry that some of these projects could be abandoned.

Three investigations related to the situation have been launched by the Maine Public Utilities Commission. The PUC announced Thursday that it would examine the need for modernizing the state’s electricity system to meet clean energy goals.

“To address climate change in the years ahead, we will be placing new demands on our electric distribution system, and we must assess how to modernize the grid at the lowest cost for Maine people,” PUC Chairman Philip L. Bartlett II said in a press release Thursday. “Recent issues related to interconnection of distributed resources highlight both the challenges we face and the urgency of the need for effective planning. We are at the beginning of a period of significant transition, and we must seize the opportunity to modernize our grid to support beneficial electrification, integrate more renewable resources, and improve reliability.”

It appears that several things are at play here. One is the state’s push to rapidly increase renewable power generation to meet climate change goals. As a result, many new solar and wind projects are coming online or are planned for the future. Many are in rural areas where electricity infrastructure is scarce.

According to CMP, more than 600 projects have asked to connect to the company’s system, although not all of these projects will come to fruition. The projects represent 2,000 megawatts of new power, which exceeds the utility’s current peak load demand of 1,700 megawatts.

Many of these projects are small, often called distributed power generation. Instead of, for example, a natural gas-fired power plant or a large cluster of wind turbines producing a lot of electricity that is carried by transmission lines to substations, these distributed power projects produce small amounts of electricity that is sent through distribution lines, the smaller lines that run along our roads and connect to our homes. The flow of electricity on these lines is bidirectional — to and from the generation source — and often intermittent. This raised concerns about voltage problems at substations, the company said.

CMP and other utilities have built new and upgraded transmission lines to carry large power loads, but they and electricity generators haven’t invested as much in the smaller distribution lines and the substations that will handle the new electricity. Transmission line projects are paid for by ratepayers while interconnections to distribution lines are paid by the electricity generator.

In 2015, Central Maine Power Co. completed the Maine Power Reliability Project. The $1.4 billion power line and substation project, the largest construction endeavor in Maine at that time, was necessary, the company said, to improve Maine’s power system and to prepare it for the growing renewable energy industry.

“The improvements were designed to keep the system operating reliably over the coming decades and to provide the infrastructure for the state’s emerging wind, hydro, biomass, and tidal energy industries,” CMP said in a website posting about the project.

So, it is disconcerting that about five years later the company is now saying that its infrastructure can’t accommodate the influx of power expected to come from solar and wind projects in Maine.

This raises questions about why CMP is only now identifying deficiencies in the system and why the PUC apparently wasn’t aware of these potential concerns as the state moved to encourage significant growth in renewable energy production. The situation is further confused by CMP’s delayed and poorly explained change in cost estimates.

The demand for clean electricity in Maine is growing. The focus now should be on ensuring that the state’s energy grid is — and remains — capable of handling that electricity without excessive fees that stifle renewable energy production.

The Bangor Daily News editorial board members are Publisher Richard J. Warren, Opinion Editor Susan Young, Deputy Opinion Editor Matt Junker and BDN President Todd Benoit. Young has worked for the BDN...