A recent issue of Yale 360 tackles the lies, distortions, and half-truths that surround the question of whether renewable energy can provide a reliable source of electricity at all times or requires thermal generation “base load”capability to be dependable. All of us clearly remember the so-called governor of Texas foaming at the mouth after a severe cold spell knocked that state’s power grid offline in 2021. He blamed the problem on the state having too much renewable energy.
Amory Lovins, a professor of civil and environmental engineering at Stanford University and co-founder of the Rocky Mountain Institute, debunks such misconceptions with a tool that is available free to everyone — data. He uses it to explode 3 myths about renewable energy and the grid.
Myth #1: A Grid Based On Renewable Energy Is Unreliable
Lovins says the indicator most often used to describe grid reliability is the average power outage duration experienced by each customer in a year, a metric known as the System Average Interruption Duration Index or SAIDI, Germany is often cited as an example of a country with an unstable grid. It gets about half of its electricity from renewables. Yet its grid is one of the most reliable with a SAIDI of just 0.25 hours in 2020. The United States, where renewable energy and nuclear power each provide roughly 20% of electricity, had 5 times Germany’s outage rate — 1.28 hours in 2020.
Since 2006, Germany’s renewable share of electricity generation has nearly quadrupled, while its power outage rate was been cut almost in half. Similarly, the Texas grid became more stable as its wind capacity grew six times from 2007 to 2020. Today, Texas generates more wind power — about a fifth of its total electricity — than any other state in the US. The data shows that renewables increase grid reliability, despite what the oil and gas lobby would have us believe.
Myth #2: Fossil Fuels Are Needed To Stabilize The Grid
Once again, the data gives the lie to this popular myth. Between 2010 and 2020, Germany’s generation from fossil fuels declined by 130.9 TWh and nuclear generation declined by 76.3 TWh. These declines were offset by 149.5 TWh of renewable energy. Another 38 TWh were saved due to energy saving strategies. As we saw in above, through all these changes, the grid in Germany became more stable, not less so. By 2020, Germany’s greenhouse gas emissions had declined by 42.3% below its 1990 levels, beating the target of 40% set in 2007. Emissions of carbon dioxide from just the power sector declined from 315 million tons in 2010 to 185 million tons in 2020.
In Japan, following the multiple reactor meltdowns at Fukushima, more than 40 nuclear reactors closed permanently or indefinitely without materially raising fossil-fueled generation or greenhouse gas emissions, Lovins reports. Electricity savings and renewable energy offset virtually the whole loss, despite policies that suppressed renewables.
Myth #3: Renewable Energy Cannot Meet Demand 24/7
This is a favorite topic of the Faux News crowd and a disgraced former president and it’s pure Grade A baloney. Lovins points out that ALL generating sources are offline some of the time either because of weather emergencies or because of routine maintenance. None operate all day, every day, all year long. All sources of electrical power will be unavailable at one time or another.
Grid managers have to deal with that reality, just as they have to deal with fluctuating demand. The influx of larger amounts of renewable energy does not change that reality, even if the ways they deal with variability and uncertainty are changing.
Hydro power fluctuates with the amount of water available. Coal and methane supplies are not 100% reliable. Many of the outages in Texas in 2021 where cause when diesel generators that power pipelines used refused to start. French nuclear facilities were shut down for 96.2 days on average in 2019 due to “planned” or “forced unavailability.” That rose to 115.5 days in 2020. After a blackout in the northeast states in the US in 2003, abrupt nuclear generator shutdowns caused nine reactors to produce almost no power for several day. Many required two weeks to return to full output.
Modern grid operators (except in Texas where grid operations are based on ideology instead of data) emphasize diversity and flexibility rather than nominally steady but less flexible “baseload” generation sources. Diversified renewable portfolios don’t fail as massively, lastingly, or unpredictably as big thermal power stations do. All thermal generating plants are offline 7 to 12% of the time, Lovins says.
The Mission Of A Grid
The purpose of an electric grid is not just to transmit and distribute electricity as demand fluctuates. It also has to manage the intermittency of traditional fossil and nuclear plants. In the same way, the grid can rapidly back up wind and solar variations with other renewables, a task that has become easier thanks to more accurate forecasting of weather and wind speeds. That, in turn, allows better prediction of the output of various renewable energy sources.
Local or onsite renewables are even more resilient because they largely or wholly bypass the grid, where nearly all power failures begin. Modern power electronics have run the billion watt South Australian grid on just sun and wind for days on end, with no coal, no hydro, no nuclear, and just the 4.4% natural gas generation required by the grid regulator.The Hornsdale battery supplied by Tesla has played an important role in making that possible.
Energy storage, whether by batteries, compressed air, hydro, or other means, is a common topic at CleanTechnica. There is a general belief that the transition to renewable energy depends on it. But there are other less expensive carbon-free ways to deal with variable renewables besides giant batteries, Lovins suggests.
The first and foremost is energy efficiency, which reduces demand, especially during periods of peak use. Buildings that are more efficient need less heating or cooling and change their temperature more slowly so they can coast longer on their own thermal capacity and thus sustain comfort with less energy, especially during peak-load periods.
A second option is demand flexibility or demand response, which allows utility companies to compensate customers who lower the amount of electricity they use when asked. This usually is done automatically and imperceptibly. New technology such as smart breaker panels can allow this to happen automatically with little noticeable effect on customers. Many internet EV chargers can also adjust the amount of electricity they deliver or shift charging times to off-peak hours when demand on the grid is low.
One recent study found that the US has 200 gigawatts of cost effective load flexibility potential that could be realized by 2030. In fact, recent power outages in California highlight the need for demand response, which has prompted the California Public Utilities Commission to create the Emergency Load Reduction Program to build on prior demand response efforts.
Another option for stabilizing the grid as renewable energy generation increases is diversity, both geographical and technological — onshore and offshore wind, solar panels, solar thermal power, geothermal, pumped hydro, burning of municipal, industrial, or agricultural wastes. There are even new ideas like vertical bi-facial solar panels and offshore floating solar to fill in renewable energy portfolios. The idea is simple: If one of these sources, at one location, is not generating electricity at a given time, odds are that some others will be.
Vehicle-to-grid technology could become an important part of the grid stabilization process. Ford is already causing a surge in interest in V2G because it has partnered with Sunrun to promote the idea for drivers of its F-150 Lightning electric pickup truck. Simulations show that ice-storage air conditioning in buildings plus smart charging to and from the grid by electric vehicles could make it possible for Texas to use 100% renewable electricity in 2050 without needing any storage batteries at all.
Even Europe, famous for cold dark winters, may only need storage for a few weeks, based on the experience of several German and Belgian utility companies. That’s a much more feasible challenge than many fossil fuel adherents like to believe is possible.
The bottom line is simple, Lovins says. “Electrical grids can deal with much larger fractions of renewable energy at zero or modest cost. Some European countries with little or no hydropower already get about half to three-fourths of their electricity from renewables with grid reliability better than in the U.S. It is time to get past the myths.” Amen to that. Let the data do the talking, not harbingers of doom who are primarily concerned with lining their own pockets, the environment be damned.
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