It’s been more than two months since Energy Secretary Rick Perry ordered the DOE to conduct a 60-day study on whether wind and solar are undercutting “baseload” coal and nuclear power -- a request that many renewable energy and environmental groups fear will lead to a foregone conclusion against renewable-friendly state subsidies and policies.

In 2015, the lead author of the Energy Department study wrote a security report that concluded renewable energy policies are a greater emerging threat to the U.S. electric power grid than natural disturbances or human attacks, including terrorism. "Current policies are shuttering unprecedented amounts of reliable power sources while simultaneously forcing increasing amounts of intermittent, unreliable power onto the grid," the report states.

But the DOE study’s now-overdue status hasn’t stopped the flood of research highlighting the flaws in Perry’s underlying concept of coal and nuclear power’s primacy in the country’s energy mix. We already covered last week's editorial from David Hochschild of the California Energy Commission and David Olsen of the California Independent System Operator Board of Governors, calling DOE assumptions about grid reliability "nonsense." And they're not the only energy experts saying so.

Last Wednesday, a report from Analysis Group entitled “Electricity Markets, Reliability, and the Evolving U.S. Power System,” laid out further evidence that low-cost natural gas and flat demand for electricity, not state and federal policies supporting renewable energy development, are causing the rising number of retirements of coal and nuclear power plants. The report, funded by the Advanced Energy Economy Institute and the American Wind Energy Association, also finds that “the changing electricity resource mix poses no threat to reliability of the nation’s power system” -- a finding supported by multiple studies that have received a lot of attention in the past two months.

Then on Thursday, the Union of Concerned Scientists published its critique of what it called “Rick Perry’s Unnecessary and Biased Grid Study,” noting that the Trump administration has picked anti-renewables lobbyists to lead the process and appears to be ignoring multiple studies that have shown that more flexible grids can handle much larger shares of wind and solar. It also cites the growing roster of opponents of the study's perceived bias, including U.S. Sen. Chuck Grassley (R-Iowa), who wrote in a letter to Perry last month that “a hastily developed study, which appears to predetermine that variable, renewable sources such as wind have undermined grid reliability, will not be viewed as credible, relevant or worthy of valuable taxpayer resources.”

Monday brought yet another comprehensive report, this one from the Brattle Group and commissioned by the Natural Resources Defense Council (NRDC), declaring that Perry’s idea of coal and nuclear as essential for a stable grid is an outdated concept. The report got the attention of Sen. Maria Cantwell, D-Wash., who wrote in a Monday press release that it “makes it clear that President Trump and Secretary Perry have it wrong: Baseload energy technologies, such as coal, do not make our electric grid more reliable and efficient.”

The Brattle Group study actually goes further by questioning the very concept of “baseload” power -- at least, as far as it’s taken to be synonymous with coal and nuclear power. “Coal and nuclear plants do not provide unique operational services that are specifically identified by or correlated with the term 'baseload' generation,” it wrote. In fact, they can go offline for weeks at a time, and unexpected outages are sometimes the “largest contingencies” that system planners and operators must prepare for, it noted.

Nor do coal and nuclear provide the cost advantages they once enjoyed -- a shift largely due to falling natural gas prices and flattening electricity demand, as opposed to the rise of renewable energy, the report states. In support, it cites a recent study from Columbia University’s Center on Global Energy Policy that estimates that cheap natural gas was responsible for 49 percent of the decline in coal demand, while low electricity demand was responsible for 26 percent, and increased renewable generation was responsible for only 18 percent.

Instead, “as system planning and electricity market design are modernized, it is becoming increasingly clear that the services and attributes most under-recognized by today’s markets are greenhouse gas emissions in some jurisdictions and operational flexibility,” the authors wrote. And despite their intermittency, wind and solar power are compatible with both of these needs, the Brattle/NRDC report finds.

“A resource is considered flexible when it can react to operational signals to ramp its power generation up and down to help meet the needs of the system over multiple hours and minute to minute,” the report notes. “With better understanding of system requirements, flexibility needs can be provided by a wide array of existing resources, and through advances in how those resources are operated.”

Underlying this rethinking of terms like "baseload" and "peaking resources" is the fact that the transformation of the country’s grid power mix is already underway, according to the report. This Brattle Group projection of total U.S. generation additions and retirements between 2010 and 2020 highlights the fall of coal as a central part of many regions’ grid power mix.

Despite these significant retirements, however, “system operators have been able to meet the industry’s high and increasing reliability standards,” according to the report. Mid-Atlantic grid operator PJM, for example, has projected that its expected near-term portfolio of increasing natural gas, wind and solar power and a falling share of coal and nuclear doesn’t threaten grid reliability. Several other studies support this view, including two from the DOE’s National Renewable Energy Laboratory, which found that the U.S. eastern and western grids could support between 30 and 35 percent renewables penetration without significant infrastructure changes.

Even so, grid operators, utilities and regulators still have a lot of work ahead of them to make this optimized, flexible mix of future resources a reality, the report found. This work includes designing markets to properly value both supply and demand-side resources, improving the “dispatchability” of variable resources, and increasing transmission interties between grid systems, to name a few items on its to-do list.

Energy consultant Terry Brinker recently penned an article chronicling some of the challenges and possible negative impacts associated with renewables, including a 2016 blackout in Australia linked to the country's wind generation. But he concludes that renewable energy industry groups, in partnership with lawmakers, energy regulators and the DOE can "work together and create strategic policies that ensure that we all succeed in this new normal."

These are just the kinds of paradigm-changing efforts that Greentech Media will be delving into at this week’s Grid Edge World Forum 2017 conference in San Jose, Calif. The three-day event will feature a who’s-who of utility executives, grid and distributed energy vendors, and regulators seeking answers to the challenges of creating a greener and more reliable grid. Click here to learn more -- or, for our GTM Squared members, check out our livestream of select panels and our Energy Gang live podcast.