California Free Press

Off the Top of My Head

Worldwide Greenhouse Gas Emissions Must Decrease 3.33% Per Year To Get To Net-Zero by 2050

by John Lawrence, September 17, 2020

This is just simple mathematics: 30 years times 3.33% = 100%. Instead GHGs have been increasing year over year every year since 1990 with the exception of 1992 (tied with 1991), 1998 (.1 Gt Eq lower than 1997) and 2009. In 2018, the world spewed 51.8 Gt CO₂ eq of carbon dioxide into the atmosphere. Gt is a billion tons. CO₂ eq includes methane and other greenhouse gasses. That means that on average there must be a 1.72 Gt CO₂ reduction every year from now to 2050 to get to net zero by that date. In 2009 there was a reduction of .5 Gt CO₂ from the year before. That was the only year with a substantial reduction and it does not even come close to 1.72. Meanwhile, in the last 10 years GHGs have been increasing not decreasing. Obviously, radical change throughout the world is required if planet earth is to reach net zero by 2050.

Since China and the US are the two largest GHG emitters, they must cooperate to lead the world in reducing GHGs. Particularly in India which is developing rapidly, coal fired electricity generating plants are increasing GHGs. China also has a lot of coal fired electricity generating plants, but is developing renewable energy rapidly. The US is using natural gas more and coal less, but natural gas, which is methane, is responsible for increased emissions of methane so it's no panacea. There are serious concerns about methane leakage in distribution systems and in fracking. At this point the US is producing more GHGs from methane than from coal.

This is from "All-Electric America":

Transforming the United States' current electricity capacity, which is roughly one million megawatts, will require developing approximately 60,000 megawatts of new renewable capacity a year over a thirty-five year time frame to supply all of our energy needs in 2050. In 2015 China planned to install roughly 40,000 megawatts of new renewable power and by 2030 is committed to add a total of 800,000 to one million megawatts, the equivalent of today's total US electrical capacity. There is no doubt that America can do the same if we decide to.

Joe Biden has a plan to develop the electrical recharging infrastructure equivalent to today's network of gas stations so that electric vehicles can be much more prevalent. There will also be incentives for people to purchase electric vehicles. Hydrogen fuel cells are also a technology that can power trucks, ships and even airplanes. Hydrogen is a renewable energy since when it burns, the only by product produced is water. An all electric train system is also possible if the US is determined to do it.

Solar and wind power can serve all of America's needs. Storage of renewable power is also under development. Tesla's Powerwall is available today. It stores energy from solar panels when the sun is shining and delivers the power when the sun isn't. The problem isn't that renewable energy isn't available. The problem is that fossil fuel energy is cheap and plentiful, but if the earth is to remain a habitable planet, 75% of it must remain in the ground. The notion of a carbon budget is that there is an amount of GHGs that can be deposited in the atmosphere between now and 2050 that, if we go beyond that budget, earth's temperature increase will rise above 2 degrees C. As of 2018, the budget for staying below the 2°C threshold has been calculated at approximately 1170 Gt. Calculating approximately 100 Gt added in 2019 and 2020, we have approximately 1079 Gt left. That means we have approximately 20 years at the current rate before earth's temperature rises above 2 degrees C and all hell breaks loose.

As if all hell hasn't broken loose already. 12 million acres burnt in Australia in 2020; 6 million acres burnt in California in 2020. Major hurricanes landing in the Gulf coast faster than people can recover from the last one. Huge chunks of Arctic and Antarctic glaciers breaking off. The Antarctic glaciers have the potential of raising sea levels by 10 feet. What is President Trump doing? Hiding his head in the sand. He has stripped the EPA of environmental regulations and is a global warming denier. Meanwhile, our carbon budget is being exhausted while the US is literally doing nothing about it. That's why it's so important that Joe Biden is elected. He has promised to get us to net zero by 2050.

Rooftop Wind Power Might Take Off By Using Key Principle Of Flight

by Andrea Thompson, April 24, 2020

from WhoWhatWhy blog

An artist’s rendering of AeroMINEs along the edge of a roof and combined with solar arrays. Photo credit: Sandia National Laboratories

This story originally appeared in Scientific American and is republished here as part of Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.

Solar panels perched on the roofs of houses and other buildings are an increasingly common sight in the US, but rooftop wind systems have never caught on. Past efforts to scale down the towering turbines that generate wind power to something that might sit on a home have been plagued by too many technical problems to make such devices practical. Now, however, a new design could circumvent those issues by harnessing the same principle that creates lift for airplane wings.

Overall, electricity generated by renewable sources has grown in the US in recent years, and wind power has been a major driver of that trend. It accounts for more than 40 percent of electricity from renewables in the US (though only 7 percent of all electricity production). Unlike solar energy cells, which are limited to collecting energy during daylight hours, wind turbines can run all night in any place with the right conditions — namely, in open plains or gentle hills with consistently sufficient wind speeds. But in addition to those requirements, large turbines need open space, which is not always available near towns and sprawling cities. Installing rooftop wind systems on homes and city buildings could help harness more of this resource.

When it comes to wind power, size matters. The amount of energy an individual turbine can generate is proportional to the area its blades sweep — so devices that are small enough to fit on a roof are less powerful. “What’s kept distributed wind from being successful is that most of the systems are basically miniaturized wind turbines,” says Brent Houchens, a mechanical engineer at Sandia National Laboratories. The smaller devices do not produce enough energy to be cost-effective. Plus, their quickly spinning blades create noisy vibrations, and their many moving parts are more prone to breakage. Compared with passive rooftop solar panels, wind turbines have the potential to be quite high-maintenance.

Houchens and his colleagues think they have engineered a solution that overcomes these obstacles by borrowing from a fundamental principle of air flight. The curved shape of an airplane wing — called an airfoil — alters the air pressure on either side of it and ultimately produces lift. Houchens’ colleague Carsten Westergaard, president of Westergaard Solutions and a mechanical engineer at Texas Tech University, says he hitched two airfoils together so that “the flow from one airfoil will amplify the other airfoil, and they become more powerful.” Oriented like two airplane wings standing upright on their side, the pair of airfoils directly face the wind. As the wind moves through, low pressure builds up between the foils and sucks air in through slits in their partly hollow bodies. That movement of air turns a small turbine housed in a tube and generates electricity.

Thanks to this design, the device — which the researchers call an AeroMINE (“MINE” stands for Motionless, Integrated Extraction) — can pull wind energy from a larger area (essentially, the AeroMINE’s rectangular face) than its turbine blades could on their own in a traditional setup. Houchens likens such standard turbines to cookie cutters that leave wasted dough behind. The new device makes use of all the available wind, allowing it to extract more energy.

AeroMINEs also do not generate the same vibrations and noise as regular turbines; they are “less noisy than a ventilation fan,” Westergaard says. The relative simplicity of their design means there are fewer moving parts to malfunction. The turbine, which is housed inside a building, would be easier to access if it does need repairs. This arrangement also keeps the blades isolated from any contact with people or wildlife. The team is designing the system so that it could be used in conjunction with rooftop solar panels, plugging into the existing infrastructure to harvest the energy they generate.

“I do think this technology could be groundbreaking” for areas with good wind conditions, says Luciano Castillo, a mechanical engineer at Purdue University, who is not involved in the project but has worked with Westergaard in the past. He also thinks the simplicity of AeroMINEs could make them a good option for developing countries, because the new devices do not require specialized parts or tools and are relatively easy to fix. Castillo and Westergaard both see the potential to use the design underwater to harness tidal energy as well.

Jay Apt, co-director of the Carnegie Mellon Electricity Industry Center, who is also not involved in the project, agrees that the simplicity of the design is attractive. But he is unsure whether the system can be scaled up to efficiently generate energy at a low enough cost in a real-world setting. Houchens says that with suitable wind conditions, he and his colleagues think AeroMINEs can be competitive with the current cost of rooftop solar power.

The team, which has received funding from Sandia and the Department of Energy, has tested scaled-down models in wind tunnels to fine-tune the design. In June the researchers have plans to test a four-meter-tall version of the device on a single-story mock building at the Scaled Wind Farm Technology (SWiFT) facility, part of Texas Tech’s National Wind Institute.

Related front page panorama photo credit: Adapted by WhoWhatWhy from Sandia National Laboratories.

'A Breath of Fresh Air': Offshore Wind Power Could Produce More Electricity Than World Uses

Published on Friday, October 25, 2019

by Common Dreams

"Let's get going!"

by Eoin Higgins, staff writer

 

53 Comments

Shanghai Donghai Bridge's 100mw offshore wind power project is China's first national offshore wind power demonstration project in the early morning light of morning in Shanghai, Oct. 4, 2019. (Photo: Costfoto/Barcroft Media/Barcroft Media/Getty Images)

A new report from the International Energy Agency released Friday claims that wind power could be a $1 trillion business by 2040 and that the power provided by the green technology has the potential to outstrip global energy needs. 

"Talk about a breath of fresh air," tweeted writer Steven E. de Souza.

Talk about a breath of fresh air https://t.co/r2a0bvMXBc

— Steven E. de Souza (@StevenEdeSouza) October 25, 2019

The IEA report looks at the business of wind power and opines that as investment increases and the technology becomes cheaper, the sector could explode. 

The IEA finds that global offshore wind capacity may increase 15-fold and attract around $1 trillion of cumulative investment by 2040. This is driven by falling costs, supportive government policies and some remarkable technological progress, such as larger turbines and floating foundations. That's just the start—the IEA report finds that offshore wind technology has the potential to grow far more strongly with stepped-up support from policy makers.

"Offshore wind currently provides just 0.3% of global power generation, but its potential is vast," said IEA executive director Fatih Birol.

It would take a major infrastructural commitment to develop wind power to the point that the renewable energy resource could take over the majority of global energy needs, but it's not impossible. As The Guardian pointed out Friday, "if windfarms were built across all useable sites which are no further than 60km (37 miles) off the coast, and where coastal waters are no deeper than 60 metres, they could generate 36,000 terawatt hours of renewable electricity a year."

"This would easily meeting the current global demand for electricity of 23,000 terawatt hours," added The Guardian.

Such a change in worldwide energy demand would require a massive investment of "public pressure, business leadership, and political leadership," green group Friends of the Earth said on Twitter. 

350 Action founder Bill McKibben saw no need to wait. 

"Wind turbines in the shallow parts of the planet's oceans can provide more electricity than the planet uses," McKibben tweeted. "So let's get going!"

Our work is licensed under a Creative Commons Attribution-Share Alike 3.0 License. Feel free to republish and share widely.

 

Off the Top of My Head

California to Require All New Homes to be Built with Solar

by John Lawrence, May 11, 2018

California is serious about fighting global warming even if the US under Trump isn't. All new homes will have to be built with solar panels within two years. That is a remarkable achievement and a spit in the face to Trump and his fossil fuel loving boys. While the US Federal government is doing everything it can to sell more gas and oil and pollute the atmosphere even more, California is becoming the leader in the effort to stop global warming. Trump has even threatened to sue California over its strict standards on tailpipe emissions. The car manufacturers don't want to have to build more electric cars. California is demanding that they do just that if they want to sell them in California.

In homes and cars California is leading the way in solarization and electrification. You see more hybrid and plug-in hybrid cars on the road today. It's almost mandatory for taxis, Lyft and Uber drivers to drive hybrids or spend a fortune on gas with conventional gas powered vehicles. There are even a fair number of Teslas on the road which consume no gas and emit no carbon dioxide or other pollutants from their tail pipes. These are very promising developments. They show the rest of the world that, even though the US at the Federal level is going backward and retrogressing, some states within the US are moving forward and are more in sync with progressive forces, goals and ideals in the rest of the world.

The new requirement will add cost to the purchase of a new home, but the home buyers will save enormously on their energy bills. California energy companies such as San Diego Gas and Electric, Pacific Gas and Electric and Southern California Edison are not happy. Their revenues will decline. Revenues for Shell, Exxon and Chevron will also decline, but gas and electric companies will continue to make big bucks in the red states where they glorify the internal combustion engine and would not be caught dead driving a Prius.

The New York Times reported:

The new requirement, to take effect in two years, brings solar power into the mainstream in a way it has never been until now. It will add thousands of dollars to the cost of home when a shortage of affordable housing is one of California’s most pressing issues.

That made the relative ease of its approval — in a unanimous vote by the five-member California Energy Commission before a standing-room crowd, with little debate — all the more remarkable.

“This adoption of these standards represents a quantum leap,” Bob Raymer, senior engineer for the California Building Industry Association, said during the public comments before the vote. “You can bet every state will be watching to see what happens.”

Several California cities have required that some new buildings include solar power, or have made commitments to 100 percent clean energy through various sources. New Jersey, Massachusetts and Washington, D.C., have also considered legislation to require that new buildings be solar-ready, according to the National Conference of State Legislatures. And Hawaii is among the states that have mandated other energy-efficiency measures, like solar water heaters.

But California’s move is by far the boldest and most consequential of any.

California law requires at least 50 percent of the state’s electricity to come from noncarbon-producing sources by 2030. Solar power has increasingly become a driver in the growth of the state’s alternative energy production.

And a new rate structure coming next year will charge California customers based on the time of day they use electricity. So homeowners with energy-efficiency features — a battery in particular, allowing energy to be stored for when it is most efficiently used — will avoid higher costs.

“Any additional amount in the mortgage is more than offset,” said Andrew McAllister, an Energy Commission member who led a building-code review that produced the proposal. “It’s good for the customer.”

Three cheers for California, the most progressive state in the union. I'm glad and proud that I'm a resident here. California is not perfect by any means, but we are going in the right direction. God bless California. With all the negative news in the world today, California is a bright light showing that there is still hope for civilization. Now if the US as a nation and especially at the Federal level could get on board with California and get rid of their regressive mentality, there might still be hope for the US as a nation.

 

As Trump & Pruitt Unleash Climate Demons, Scientists Dream of Atlantic Wind Farm

Published on Wednesday, October 11, 2017

by Informed Comment

"Why would someone deliberately sabotage our air, water and climate?"

by Juan Cole

 

7 Comments

A Scott Pruitt puppet seen at the Peoples Climate March in Washington, D.C. in April 2017. (Photo: Marcie Meditch/Peoples Climate March/flickr)

The debate over whether Donald Trump or Rex Tillerson has the higher IQ, provoked by a Trump tweet that he now says was a joke, actually raises a serious question.

Why would someone deliberately sabotage our air, water and climate? The science needed for understanding that some gases are heat-trapping isn’t very complicated and I’m confident that schoolchildren can grasp it easily and even do some basic confirmatory experiments. So if Trump and EPA head Scott Pruitt are unable to understand the evil they are doing, is it because they lack basic intelligence? Or is the problem moral? Or is it just groupthink?

I mean, this is the year when hurricanes wrecked the Caribbean because of increased water temperature.

Even as Pruitt moved to abolish Obama-era regulations on coal plants–the most polluting of all energy sources– and argued for an end to tax breaks for wind and solar installations, scientists were reporting that putting floating wind farms in the north Atlantic could power the entire earth.

The authors of the new paper point out that on land, if you put a lot of wind turbines in one place, they begin interfering with one another and limiting the amount energy that can be extracted.

But they found that if you made floating wind farms in the north Atlantic, the winds are so high and constant that you would not run into the problem.

As Informed Comment pointed out last year, Scotland has set up several floating wind turbines some 25 miles offshore. Putting them out in the middle of the north Atlantic would be far more difficult, of course.

Here is a BBC update on the Scotland project:

World’s first floating offshore wind farm in Scotland.- BBC News

Every day there are technical breakthroughs in wind and solar power at the level of basic science. It will take some years to turn them into practical technology. In the meantime the terra-sabotage of Trump and his oil-drenched cronies will worsen the quality of life for millions of human beings, perhaps billions if we project out.

Me, I don’t think it has anything to do with IQ, which is a suspicious measure to begin with (there are lots of kinds of intelligence and individuals don’t typically excel in more than one or two.

I think it is just greed, pure and simple.

© 2017 Juan Cole

Juan Cole teaches Middle Eastern and South Asian history at the University of Michigan. His new book, The New Arabs: How the Millennial Generation Is Changing the Middle East (Simon and Schuster), will officially be published July 1st. He is also the author of Engaging the Muslim World and Napoleon's Egypt: Invading the Middle East (both Palgrave Macmillan). He has appeared widely on television, radio and on op-ed pages as a commentator on Middle East affairs, and has a regular column at Salon.com. He has written, edited, or translated 14 books and has authored 60 journal articles. His weblog on the contemporary Middle East is Informed Comment.

West Coast’s First Offshore Wind Turbine Gets Green Light for Development

Brandon Baker

EcoWatch/ News Report

Published: Friday 7 February 2014

 

“The WindFloat Pacific project is the latest in a series of lease initiatives BOEM has undertaken to move forward offshore wind energy development.”

The development of what should be the U.S.’ first offshore wind farm on the West Coast received a boost this week, earning approval to begin building. 

The approval of a five-turbine, 30-megawatt (MW) pilot project off Coos Bay in Oregon was announced Wednesday by Gov. John Kitzhaber, U.S. Secretary of the Interior Sally Jewell and Bureau of Ocean Energy Management (BOEM) Director Tommy Beaudreau. The farm would be about 15 miles from shore in about 1,400 feet of water, according to The Associated Press.

Seattle-based Principle Power will use a floating wind turbine technology that has not been deployed in U.S. waters but has been used in Europe and Asia. Belinda Batten, director of the Northwest National Marine Renewable Energy Center at Oregon State University, told The Associated Press that plans for offshore farms on the West Coast had yet to surface because of different technological needs to deal with the Pacific Ocean getting deeper more quickly than the Atlantic or other areas. Turbines off the Atlantic coast will be anchored to the seabed.

 The Coos Bay project will use electrical cables and a single power cable to transmit electricity back to the mainland. “We’re not as anxious to commercialize it, but it’s still worth getting the projects into the water and testing them,” Batten said. “As we learn how to deploy and maintain them, the price will come down.”

Using statistics from the National Renewable Energy Laboratory, the U.S. Department of Interior estimates that the West Coast is capable of producing more than 800 gigawatts (GW) of wind energy—which equals more than three-quarters of the nation’s entire power generation capacity, according to North American Wind Power. The estimate for the whole country is nearly 2,000 GW.

“The WindFloat Pacific project is the latest in a series of lease initiatives BOEM has undertaken to move forward offshore wind energy development,” Beaudreau said. “On the Atlantic Coast, the five commercial project leases we’ve issued, if fully developed, could generate enough renewable energy to power 1.4 million homes.”

Atlantic coast projects include a pilot project in Maine that developers hope will give way to a 500-MW farm, as well as a wind farm to be constructed off the shores of Cape Cod, MA that has been stymied by lawsuits from opposers.

Global Warming: How to Kick the Fossil Fuel Habit - Part 2

by John Lawrence from the San Diego Free Press

This series of articles is based on an excellent book by Tom Rand: "Kick the Fossil Fuel Habit - 10 Clean Technologies to Save Our World." In Part 1 we dealt with all the possibilities for solar power generation. In this article we will consider wind. For centuries wind powered ships and windmills drew water out of the ground. We are now in a position to reconnect with this form of energy and convert it into electricity. How it works is very simple. As the wind blows, enough force is created to spin a turbine which in turn generates electrical energy. These days a single wind turbine can power a decent sized town.

The US Department of Energy has calculated that wind could generate 15 times the total world energy use. That's 15 times all the energy generated by oil, coal and nuclear at the present time. Even oil magnate T. Boone Pickens has called the US the "Saudi Arabia of wind."

Another country with large wind resources is Denmark. Back in the 1970s Denmark decided to become energy independent by developing their wind resources big time. Today a substantial share of the wind turbines in use throughout the world were manufactured in Denmark. Today wind supplies about 30% of Denmark's energy needs, and they intend to increase that to 50% by 2020. As far as storage goes, Denmark has encouraged the use of electric vehicles which are charged primarily by wind power. That power stored in car batteries can be fed back onto the grid at times when wind is not sufficient to generate all the power that is needed. The Danes have thus come up with a clever way to store energy that is wind generated.

Large scale wind power is the fastest growing energy source in the world. Just in 2007, 94 gigawatts of capacity was installed - enough to replace 90 coal-fired plants or power almost 90 million homes. Germany, which is also huge on solar power, leads the world in wind power with over 20,000 turbines up and running which generate more than 7% of the country's electricity.

Clipper, a California company, developed a turbine rated at around 10 megawatts which is enough to supply a decent-sized town. It has a rotor diameter twice the wing span of a jumbo jet. Like a lot of other companies mentioned in Rand's book, Clipper developed financial problems, was acquired by another company which subsequently divested itself. The company is now located in Cedar Rapids, Iowa, is still in business, but limits itself to manufacturing replacement parts. The material in the book is somewhat dated. Although it was copyrighted in 2010, much of the research was done in 2007. Today the largest wind turbine manufacturer is Denmark followed by China, Spain and Germany. GE is the sixth largest and the only US company in the top ten.

Many of the largest operational onshore wind farms are located in the United States and China. For example, the Gansu Wind Farm in China has a capacity of over 5,000 MW of power with a goal of 20,000 MW by 2020. The Alta Wind Energy Center in California is the largest onshore wind farm outside of China, with a capacity of 1,020 MW. As of April 2013, the 1,000 MW London Array in the UK is the largest offshore wind farm in the world. It started producing electricity at the end of October 2012.

This offshore wind farm will reduce annual CO₂ emissions by approximately 900,000 tons, which equals the emissions of 300,000 passenger cars. The second phase of the array has been scaled back after concerns were raised by the Royal Society for the Protection of Birds about its effect on a local population of red-throated divers.

Also in the UK is the 504 MW Greater Gabbard wind farm. In the shallow harbor outside Copenhagen sits the Middelgrunden project which is generating enough power for 30,000 homes with turbines standing more than 330 feet tall.

T. Boone Pickens views the American Great Plains as a resource which is ready to exploit, and he's putting his money there to build wind farms all the way from the Texas panhandle to North Dakota. He figures we could generate one-fifth of US electrical production for $1 trillion.

There are also projects being considered for the deep sea where the wind is much more powerful. This is important because almost 80% of the power consumption in the US is by people living along the coasts of the Atlantic, the Pacific and the Great Lakes. Deep sea projects are underway in Norway, Denmark and France and a full scale wind farm is planned for 2013 in the North Sea.

There are also micro wind turbines designed in such a way as to resemble a work of art. Helix Wind located in Poway, CA makes a visually stunning turbine that looks like a pulsating piece of modern art which produces enough energy for several homes. It could fit right into a neighborhood without attracting adverse attention. Helix Wind turbines are completely safe for wildlife because they spin at much lower speeds than horizontal turbines and appear as a solid mass rather than a sharp blurring blade that a bird or bat cannot see or detect.

Wind power systems are also being devised to mine the high altitudes such as the jet stream where the winds are really strong and steady. Sky Windpower has developed giant "spinning kites" designed to fly in the jet stream and send energy back to earth through a tether cable. Sky Windpower reckons that they could generate power at two cents a kilowatt hour - way less than coal. Time magazine named the company's invention as one of the top 50 inventions of 2008.

So what are the problems and pitfalls with wind power? One is the intermittency of the wind. The other is the storage problem. There are various means of storage. One is, as mentioned previously, storage in car batteries connected to the energy internet. Another is using excess wind power to pump water uphill, releasing it to generate hydroelectric power when the wind isn't blowing. Another is a really large interconnected grid so that when the wind isn't blowing in one area, chances are it's blowing in another.

Wind has the potential of supplying 40% of the US energy needs. How fast could we get there? We'd need to install around 1.5 million two-megawatt turbines over the next ten years or so. That's a big job but Lester Brown of the Earth Policy Institute says: "We build 65 million cars every year, so it's not a big deal. We could produce these wind turbines for the entire world simply by opening the closed automobile assembly plants in the United States."

The final question Rand always asks of any technology is: "So what do you get for $1 trillion." You could replace 20% of the US electrical supply (that's almost half of coal-based production), with maybe another $200 billion to get that energy to where it's needed.

Next time: Geothermal

Wind, Solar Power Paired With Storage Could Be Cost-Effective Way To Power Grid

From University of Delaware Website

Dec. 10, 2012--Renewable energy could fully power a large electric grid 99.9 percent of the time by 2030 at costs comparable to today’s electricity expenses, according to new research by the University of Delaware and Delaware Technical Community College.

A well-designed combination of wind power, solar power and storage in batteries and fuel cells would nearly always exceed electricity demands while keeping costs low, the scientists found.

“These results break the conventional wisdom that renewable energy is too unreliable and expensive,” said co-author Willett Kempton, professor in the School of Marine Science and Policy in UD’s College of Earth, Ocean, and Environment. “The key is to get the right combination of electricity sources and storage — which we did by an exhaustive search — and to calculate costs correctly.”

The authors developed a computer model to consider 28 billion combinations of renewable energy sources and storage mechanisms, each tested over four years of historical hourly weather data and electricity demands. The model incorporated data from within a large regional grid called PJM Interconnection, which includes 13 states from New Jersey to Illinois and represents one-fifth of the United States’ total electric grid.

Unlike other studies, the model focused on minimizing costs instead of the traditional approach of matching generation to electricity use. The researchers found that generating more electricity than needed during average hours — in order to meet needs on high-demand but low-wind power hours — would be cheaper than storing excess power for later high demand.

Storage is relatively costly because the storage medium, batteries or hydrogen tanks, must be larger for each additional hour stored.

One of several new findings is that a very large electric system can be run almost entirely on renewable energy.

“For example, using hydrogen for storage, we can run an electric system that today would meeting a need of 72 GW, 99.9 percent of the time, using 17 GW of solar, 68 GW of offshore wind, and 115 GW of inland wind,” said co-author Cory Budischak, instructor in the Energy Management Department at Delaware Technical Community College and former UD student.

A GW (“gigawatt”) is a measure of electricity generation capability. One GW is the capacity of 200 large wind turbines or of 250,000 rooftop solar systems. Renewable electricity generators must have higher GW capacity than traditional generators, since wind and solar do not generate at maximum all the time.

The study sheds light on what an electric system might look like with heavy reliance on renewable energy sources. Wind speeds and sun exposure vary with weather and seasons, requiring ways to improve reliability. In this study, reliability was achieved by: expanding the geographic area of renewable generation, using diverse sources, employing storage systems, and for the last few percent of the time, burning fossil fuels as a backup. 

During the hours when there was not enough renewable electricity to meet power needs, the model drew from storage and, on the rare hours with neither renewable electricity or stored power, then fossil fuel. When there was more renewable energy generated than needed, the model would first fill storage, use the remaining to replace natural gas for heating homes and businesses and only after those, let the excess go to waste.

The study used estimates of technology costs in 2030 without government subsidies, comparing them to costs of fossil fuel generation in wide use today. The cost of fossil fuels includes both the fuel cost itself and the documented external costs such as human health effects caused by power plant air pollution. The projected capital costs for wind and solar in 2030 are about half of today’s wind and solar costs, whereas maintenance costs are projected to be approximately the same.

“Aiming for 90 percent or more renewable energy in 2030, in order to achieve climate change targets of 80 to 90 percent reduction of the greenhouse gas carbon dioxide from the power sector, leads to economic savings,” the authors observe. 

The research was published online last month in the Journal of Power Sources.

Article by Teresa Messmore