Trump’s Impact on Clean-Energy Businesses

Published today at MIT Technology Review:

President-elect Donald Trump is a self-declared climate-change denier who, on the campaign trail, criticized solar power as “very, very expensive” and said wind power was bad for the environment because it was “killing all the eagles.” He also vowed to eliminate all federal action on climate change, including the Clean Power Plan, President Obama’s emissions reduction program for the power sector.

So how will renewable-energy businesses fare under the new regime?

Trump’s rhetoric has had renewable-energy stocks gyrating since the election. But the impact could be far less drastic than many worst-case scenarios. “At the end of the day what Trump says and what is actually implemented are two completely different things,” says Yuan-Sheng Yu, an energy analyst with Lux Research …

For the whole story see “Trump’s Impact on Clean-Energy Businesses

Can Synthetic Inertia from Wind Power Stabilize Grids?

p1110724As renewable power displaces more and more coal, gas, and nuclear generation, electricity grids are losing the conventional power plants whose rotating masses have traditionally helped smooth over glitches in grid voltage and frequency. One solution is to keep old generators spinning in sync with the grid, even as the steam and gas turbines that once drove them are mothballed. Another emerging option will get a hearing next week at the 15th International Workshop on Large-Scale Integration of Wind Power in Vienna: synthetic inertia.

Synthetic inertia is achieved by reprogramming power inverters attached to wind turbines so that they emulate the behavior of synchronized spinning masses.

Montréal-based Hydro-Québec TransÉnergie, which was the first grid operator to mandate this capability from wind farms, will be sharing some of its first data on how Québec’s grid is responding to disruptive events such as powerline and power plant outages. “We have had a couple of events quite recently and have been able to see how much the inertia from the wind power plants was working,” says Noël Aubut, professional engineer for transmission system planning at Hydro-Québec.

The short answer is good, but not good enough to support massive wind power growth. Québec has about 3,300-MW of wind power today, but Canada’s wind industry is calling for 8,000-megawatts more by 2025. Turbine manufacturers are upping their synthetic inertia technology to pave the way.

Synthetic inertia is the latest step in a longstanding technology trend, according to Aubut, that has already transformed renewable generators from potential liabilities to power grid stability into substantial contributors to it. The first step, he says, was equipping renewables to remain solid and thus “not harm the grid” during times of grid instability. Modern wind and solar plants are designed to “ride-through” severe faults, such as short-circuit events that drop grid voltage to zero.

Recent ride-through trouble in Australia appears to be an anomaly. Nine Australian wind farms did shut down during a series of storm-induced faults, that blacked-out the state of South Australia in September, and Australia’s prime minister attacked renewable energy as a threat to energy security. However, an investigation by the Australian Energy Market Operator blamed errant wind farm control settings, and it says some operators have corrected them.

In fact, most wind and solar farms can do much more than just stick around during trouble. For example, most utility-scale installations—and even some residential rooftop solar systems—are designed to combat voltage sags on power grids. Their electronic inverters can detect brownouts and generate reactive power (AC whose current wave leads its voltage wave) to raise the grid voltage.

Synthetic inertia is about responded to crashing AC frequency, usually after the loss of a big power plant. When a big generator goes offline, it leaves the grid under-supplied. That will cause the AC frequency to fall.

Conventional power plants respond naturally and instantly to frequency dips because the momentum of their spinning turbines, synched to the grid, resist deceleration. This slows the frequency drop, buying precious seconds during which power reserves are mobilized to fill the supply gap.

Aubut says Hydro-Québec began setting requirements for synthetic inertia in 2005. Québec’s grid is, electrically speaking, North America’s smallest AC zone, with peak power demand under 40,000 MW. Losing a big power plant causes a steeper frequency drop on smaller grids, and more wind power threatened to limit the Québec operator’s defenses.

In 2005 the utility amended its grid code, requiring wind farms to pull their weight: it mandated that new wind turbines be capable of delivering a power boost equal to 6 percent of their rated capacity during low-frequency events. Manufacturers responded with synthetic inertia designs, and the first were installed in 2011. Today, inertia-compliant turbines from Germany’s Senvion Wind Energy Solutions and ENERCON account for two-thirds of Quebec’s wind capacity.

To emulate the inertial behavior of massive rotating equipment, a renewable generator must somehow find extra power quick. Québec’s wind turbines do so through a collaboration between the turbines’ solid-state power electronics and their moving parts. “When the wind turbines see an imbalance between load and generation that causes a frequency deviation on the system they’re able to … extract some kinetic energy that is stored in the rotating masses of the wind turbines,” explains Aubut.

During a December 2015 transformer failure that took more than 1,600-MW of power generation offline, synthetic inertia kicked in 126 MW of extra power to arrest the resulting frequency drop. Quebec’s AC frequency bottomed out at 59.1 hertz – well below its 60-hertz standard – but Aubut and his colleagues estimate that it would have dropped a further 0.1-0.2-hz without the synthetic inertia. And they estimate that this was roughly the same contribution that conventional power plants would have provided.

“If we had had only synchronous generation instead of wind with the same event and operating conditions, we’d have had about the same deviation,” says Aubut.

The trouble, says Aubut, is what happens after the frequency drop. In all but the strongest wind conditions providing synthetic inertia will slow a wind turbine’s rotor. Re-accelerating to optimal speed thereafter absorbs some of the wind power that the turbine can export to the grid. Data from ENERCON shows power reductions of up to 60 percent in some turbines.

This energy recovery phase delays the grid’s frequency recovery. After Québec’s December 2015 transformer event, for example, the system frequency flat-lined for several seconds at 59.4 Hz before additional power reserves could push it back to 60. Under different conditions, says Aubut, that post-inertia recovery could have actually caused a “double-dip” in system frequency, increasing the risk of triggering protective relays at substations and causing blackouts.

Hydro-Québec is revising its synthetic inertia to minimize the risk of a double-dip. It plans to limit power reduction during recovery to no more than 20 percent of a wind turbine’s capacity. Turbine manufacturers are already testing second-generation synthetic inertia systems that comply with the new standard.

ENERCON presented an upgraded synthetic inertia control scheme at last year’s Wind Integration Workshop. Whereas the first generation of ENERCON Inertia Emulation revved rotors back to their optimal speed as quickly as possible, the new scheme uses power estimation and closed-loop control to enable smooth and tunable re-acceleration.

Markus Fischer, ENERCON’s Montreal-based regional manager for grid integration, says the upgraded scheme showed “promising results” in tests on full scale turbines and commercial rollout is “expected to happen in the near future.” Retrofitting its first generation machines, he says, will require no added hardware.

Synthetic inertia requirements, meanwhile, may be spreading. Grid operators in Ontario and Brazil have already joined Hydro-Québec’s lead, and Fischer says the first harmonized grid code for European generators, which entered into force earlier this year, “opens the doors to European system operators to ask for inertial response from wind.”

This post was created for Energywise, IEEE Spectrum’s blog about the future of energy, climate, and the smart grid

Wind Could Provide Over 26% of Chinese Electricity by 2030

Last month I argued that the primary reason Chinese wind farms underperform versus their U.S.-based counterparts is that China’s grid operators deliberately favor operation of coal-fired power plants. Such curtailment of wind power has both economic and technical roots, and it has raised serious questions about whether China can rely on an expanding role for wind energy. New research published today appears to put those concerns to rest, arguing that wind power in China should still grow dramatically.

The report today in the journal Nature Energy projects that wind energy could affordably meet over one-quarter of China’s projected 2030 electricity demand—up from just 3.3 percent of demand last year.

In fact the researchers, from MIT and Tsinghua University, project that modest improvements to the flexibility of China’s grid would enable wind power to grow a further 17 percent. That, they argue, means that China’s non-fossil resources could grow well beyond the 20 percent level that China pledged to achieve under the Paris Climate Agreement. Continue reading

EPA Coal Cuts Light Up Washington

A meeting at the U.S. Federal Energy Regulatory Commission’s (FERC’s) Washington headquarters yesterday lived up to expectations that it would be one of the most exciting sessions in the agency’s history. Buttoned up policy wonks, lobbyists, and power market experts showed up in droves—over 600 registered—to witness a discussion of what President Obama’s coal-cutting Clean Power Plan presaged for the U.S. power grid. The beltway crowd was joined by activists for and against fossil fuels—and extra security.

Inside proceedings, about the Environmental Protection Agency (EPA) plans’ impact on power grid reliability, protesters against fracking and liquid natural gas exports shouted “NATURAL GAS IS DIRTY” each time a speaker mentioned coal’s fossil fuel nemesis. Outside, the coal industry-backed American Coalition for Clean Coal Electricity distributed both free hand-warmers and dark warnings that dumping coal-fired power would leave Americans “cold in the dark.”

As expected, state regulators and utility executives from coal-reliant states such as Arizona and Michigan hammered home the ‘Cold in the Dark’ message in their exchanges with FERC’s commissioners. Gerry Anderson, Chairman and CEO of Detroit-based utility DTE Energy, called the Clean Power Plan “the most fundamental transformation of our bulk power system that we’ve ever undertaken.”

EPA’s critics argue that the plan’s timing is unrealistic and its compliance options are inadequate. Anderson said Michigan will need to shut down, by 2020, roughly 40 percent of the coal-fired generation that currently provides half of the state’s power. That, he said, “borders on unachievable and would certainly be ill-advised from a reliability perspective.”

EPA’s top air pollution official, Janet McCabe, defended her agency’s record and its respect for the grid. “Over EPA’s long history developing Clean Air Act standards, the agency has consistently treated electric system reliability as absolutely critical. In more than 40 years, at no time has compliance with the Clean Air Act resulted in reliability problems,” said McCabe.

McCabe assured FERC that EPA had carefully crafted its plan to provide flexibility to states and utilities regarding how they cut emissions from coal-fired power generation, and how quickly they contribute to the rule’s overall goal of lowering power sector emissions by 30 percent by 2030 from 2005 levels. (Michigan has state-verified energy conservation and renewable energy options to comply with EPA’s plans according to the Natural Resources Defense Council.)

McCabe said EPA is considering additional flexibility before it finalizes the rule, as early as June. EPA would consider, for example, specific proposals for a “reliability safety valve” to allow a coal plant to run longer than anticipated if delays in critical replacement projects—say, a natural gas pipeline or a transmission line delivering distant wind power—threatened grid security.

As it turned out, language codifying a reliability safety valve was on offer at yesterday’s meeting from Craig Glazer, VP for federal government policy at PJM Interconnection, the independent transmission grid operator for the Mid-Atlantic region. The language represents a consensus reached by regional system operators from across the country—one that is narrowly written and therefore unlikely to give coal interests much relief. “It can’t be a free pass,” said Glazer.

A loosely-constrained valve, explained Glazer, would undermine investment in alternatives to coal-fired power, especially for developers of clean energy technologies. “Nobody’s going to make those investments because they won’t know when the crunch time really comes. It makes it very hard for these new technologies to jump in,” said Glazer.

Clean energy advocates at the meeting, and officials from states that, like California, are on the leading edge of renewable energy development, discounted the idea that additional flexibility would be needed to protect the grid. They pushed back against reports of impending blackouts from some grid operators and the North American Electric Reliability Corporation(NERC). Those reports, they say, ignored or discounted evidence that alternative energy sources can deliver the essential grid services currently provided by conventional power plants.

NERC’s initial assessment, issued in November, foresees rolling blackouts and increased potential for “wide-scale, uncontrolled outages,” and NERC CEO Gerald Cauley says a more detailed study due out in April will identify reliability “hotspots” caused by EPA’s plan. At the FERC meeting, Cauley acknowledged that “the technology is out there allowing solar and wind to be contributors to grid reliability,” but he complained that regulators were not requiring them to do so. Cauley called on FERC to help make that happen.

Cleantech supporters, however, are calling on the government to ensure that NERC recognizes and incorporates renewable energy’s full capabilities when it issues projections of future grid operations. They got a boost from FERC Commissioner Norman Bay. The former chief of enforcement at FERC and Obama’s designee to become FERC’s next chairman in April, Bay pressed Cauley on the issue yesterday.

Bay asked Cauley how he was going to ensure that NERC is more transparent, and wondered whether NERC would make public the underlying assumptions and models it will use to craft future reports. Cauley responded by acknowledging that NERC relied on forecasts provided by utilities, and worked with utility experts to “get ideas on trends and conclusions” when crafting its reliability studies.

Cauley also acknowledged that they were not “entirely open and consensus based” the way NERC’s standards-development process was. And he demurred on how much more open the process could be, telling Bay, “I’ll have to get back to you on that.”

The challenge from Bay follows criticism leveled at NERC in a report issued last week by the Brattle Group, an energy analytics firm based in Boston. Brattle found that compliance with EPA’s plan was “unlikely to materially affect reliability.”

Brattle’s report concurred with renewables advocates who have argued that NERC got it wrong by focusing too much on the loss of coal-fired generation and too little on that which would replace it: “The changes required to comply with the CPP will not occur in a vacuum—rather, they will be met with careful consideration and a measured response by market regulators, operators, and participants. We find that in its review NERC fails to adequately account for the extent to which the potential reliability issues it raises are already being addressed or can be addressed through planning and operations processes as well as through technical advancements.”

This post was created for Energywise, IEEE Spectrum’s blog on green power, cars and climate

Will Shuttering Coal Plants Really Threaten the Grid?

Does President Obama’s plan to squelch carbon emissions from coal-fired power plants really threaten the stability of the grid? That politically-charged question is scheduled for a high-profile airing today at a meeting in Washington to be telecast live starting at 9 am ET from the Federal Energy Regulatory Commission (FERC).

Such “technical meetings” at FERC are usually pretty dry affairs. But this one could be unusually colorful, presenting starkly conflicting views of lower-carbon living, judging from written remarks submitted by panelists.

On one side are some state officials opposed to the EPA Clean Power Plan, which aims to cut U.S. power sector emissions 30 percent by 2030 from 2005 levels. Susan Bitter Smith, Arizona’s top public utilities regulator, argues that EPA’s plan is “seriously jeopardizing grid reliability.” Complying with it would, she writes, cause “irreparable disruption” to Arizona’s (coal-dependent) power system.

Environmental advocates and renewable energy interests will be hitting back, challenging the credibility of worrisome grid studies wielded by Bitter Smith and other EPA critics. Some come from organizations that are supposed to be neutral arbiters of grid operation, such as the standards-setting North American Electric Reliability Corporation (NERC). Clean energy advocates see evidence of bias and fear-mongering in these studies, and they are asking FERC to step in to assure the transparency and neutrality of future analyses. Continue reading

Germany’s Grid: Renewables-Rich and Rock-Solid

Grid graph German Energy TransitionLast Friday Germany’s grid regulator released the 2013 data for grid reliability, and the figures have renewable energy advocates crowing. The latest numbers (released in German) reveal no sign of growing instability despite record levels of renewable energy on the grid — 28.5 percent of the power supplied in the first half of 2014. In fact, Germany’s grid is one of the world’s most reliable. Continue reading

Floating Wind Turbines Headed for Offshore Farms

PrinciplePower.WindFloatFloating wind power is no longer science fiction. Promising results from five test platforms operating worldwide—including three in Japan—are turning into project plans for a first generation of floating wind farms. Industry analyst Annette Bossler, who runs Bremen, Maine-based Main(e) International Consulting, predicts that the number of test platforms will nearly double over the next two years and that commercialization is within site. “By 2018-2019 you will start to see the first really large-scale commercial use of floating platforms,” predicts Bossler.

Putting wind turbines on offshore platforms akin to those developed for the petroleum industry provides a means of exploiting high-quality offshore winds—which are stronger and more consistent than onshore winds—in waters too deep for today’s bottom-fixed foundations. Continue reading