Integrating wind, solar into grid is ‘a solved problem,’ report claims

Source: Elizabeth Harball, E&E reporter • Posted: Friday, August 28, 2015

A new report by a research firm argues that the challenge of integrating wind, solar and other renewables into the U.S. electric system is largely a “solved problem” that won’t be as expensive as critics argue.

Synapse Energy Economics Inc. asserts that by maximizing coordination between regional electric system operators, taking advantage of renewable generation sites across a broader geographic scale, strategically investing in new transmission and seeking demand-side solutions, grid operators are well-equipped to handle more renewables.

And, the report states, it’s likely that the cost of doing so is “relatively small, on the order of $5 per megawatt-hour.”

Under EPA’s final Clean Power Plan, the agency assumed states will incorporate significantly more renewables into their energy mixes by 2030 than in its proposed plan (ClimateWire, Aug. 4). But even under EPA’s proposed rule, overseers of the grid raised concerns that a swift transition to more intermittent emissions-free technology and away from steadier sources like coal plants could affect reliability (Greenwire, April 21).

In response to concerns like these, EPA’s final rule gave states an additional two years to implement their plans, pushing the start date of the initial compliance period to 2022. The agency also introduced a “safety valve” mechanism that will allow states to temporarily exceed their carbon limits under exceptional circumstances.

While these measures so far appear to have placated some regulators, others remain unimpressed. For example, Tony Clark, a commissioner on the Federal Energy Regulatory Commission who has been a frequent critic of the EPA plan, said in a statement after the final rule was released that “though EPA officials are writing these regulations, EPA officials are not responsible for ensuring reliable, affordable power. … Make no mistake, this work is extraordinarily difficult.”

But the Synapse report argues that the challenge of maintaining reliability under the Clean Power Plan is not insurmountable.

“One of the key low-hanging-fruit areas that we found is just increasing cooperation — getting people across the country to talk to each other and better understand how their systems are working and make them work together,” said Patrick Luckow, a senior associate with Synapse and co-author of the report, during a webinar yesterday.

Regional coordination won’t happen ‘seamlessly’

The bigger and more interconnected the system, the report argues, the easier it is to use varying resources when they are needed, taking some of the stress off conventional power plants that must deal with issues related to minimum power output levels and “ramping,” or quickly increasing energy output.

Other ideas outlined in the report include spreading renewable resources out over a wide geographic area to minimize energy production fluctuations related to weather and time of day, as well as demand-side options like charging ratepayers more for energy when it costs more to produce and less when it is abundant.

These strategies shouldn’t seem novel to today’s electric system operators, Synapse said.

“These are things that are already being done today, and people have a good understanding of what needs to be done,” Luckow said.

The report also includes a review of studies on costs specifically related to renewables integration, excluding capital costs for construction and operating costs not resulting from variability or uncertainty. The integration costs varied widely, Synapse reported, although they were generally in the range of $5 per megawatt-hour.

A study by Idaho Power Co. in 2012 did find wind integration costs of up to $19 per MWh. This was because low-cost hydropower would be needed to balance out wind and solar generation, the report explained. Additionally, “while Idaho is well interconnected with the regional electric system, that broader system is not allowed to provide integration services in the model,” the report states.

Tommy Vitolo, a senior associate at Synapse and co-author of the report, said to operators during yesterday’s webinar that because of the uniqueness of each system, “if you are doing actual planning for your actual system, it might be worth time to do an individual study.”

Jürgen Weiss, a senior researcher at the Brattle Group who was not involved in writing Synapse’s report, said “it’s pretty well recognized” that better coordination across regions could help with reliability issues, as the Synapse report suggests. But, he added, “that doesn’t mean that historically that regional coordination has happened easily and seamlessly.”

Weiss also argued that while a cost of about $5 per MWh isn’t prohibitively expensive, even “significant investments” shouldn’t be taken out of the context of the potential cost of climate change-related impacts.

“We ought to put that in the context of the overall energy system, the investment that would be necessary anyway, and any additional cost … should be compared to the risks of not making them,” Weiss said.

The report was internally funded by Synapse, and the webinar introducing the report was backed by the Environment, Economics and Society Institute.

Correction: An earlier version of this article said the webinar introducing the report was backed by the Environmental and Energy Study Institute; it is the Environment, Economics and Society Institute.