Tag Archives: wind power

World Wide Wind

We will at some point cease to produce electrical energy by burning fossil fuels, either (sooner) because we realize the harmful effects of using the atmosphere as a toilet, or (later) because we simply use them all up. These fuels can be replaced with sustainable sources, principally wind and solar. Where are we now and where are we going?

In the United States we currently get 13 per cent of our electrical power from renewables. The majority of that from hydropower, followed by wind biomass and solar power as a distant fourth. There seems to be limited potential for growth in hydropower or biomass but the sky the limit for wind and solar, assuming that the issue of intermittency can be overcome.

Although we have no national policy for the country, president Obama has mandated that the federal government get 20% of its electrical energy from renewables by 2020. Various states have renewable portfolios that range from trivial to ambitious: The old south, a couple of coal states in the Appalachians, a few midwest to rocky mountain states have none. Hawaii has the most ambitious, with a target of 40% by 2030.

Internationally, it’s a mixed bag. Mountainous Costa Rica, with a population of about 5 million, gets from 90 to 100% of its electrical energy from renewables, mainly hydro and geothermal. Similarly Norway with twice the population of Costa Rica produces very close to 100% of their electric power from hydropower plants.

Because of availability of cheap electric power they have developed energy intensive industries such as the production high grade Silicon for solar cells. Interestingly a focus of World War II was on Norway. Germany invaded Norway to gain access to energy intensive production of heavy water for their experimental nuclear reactor program.

The real potential for expansion of renewable power is in the wind, especially in countries with lots of coastline. At one point last week, Denmark was producing 140 % of its electrical energy, exporting the excess to Sweden and Germany. Their current average wind produced electricity is approaching 40%, and they are still building out.

Germany is an interesting study. They have a vigorous low carbon energy transition plan (Energiewende.) Their target is an astounding 80% renewable by 2050! They are currently installing wind and solar PV faster than anybody on the planet. Currently they are around 27% with very little hydropower, twice the US average.

The biggest player of course is China. They are the current world leader in carbon emissions, having surpassed the US a few years ago. China’s air pollution problems are legendary. Smog from from eastern China can be tracked across the pacific to our west coast. They recognize they have a problem and are aggressively addressing it by moving away from fossil fuels and toward efficiency and renewables. In 2014 they installed three quarters of the new solar capacity on the planet.

tesla battery

Batteries for the Future – Now

A recent Op-Ed in the New York Times (about food) gave a hat tip to the Sierra Club and their Beyond Coal campaign – an effort to close all coal fired power plants by 2030. The point of the piece was the necessity of activism and organizing around a particular issue.

Since the inception of the program in 2010, no new coal plants have been built and 188 closed or planned to close in the near term. Currently just of under 40% of the electric generation capacity in the United States comes from burning coal, but the number is falling – replaced by natural gas plants and a mix of wind and solar.

As long as intermittent energy, wind and solar, constitute a small fraction of the total electric supply, grid operators can balance the load as needed by reducing power from the coal plants. But what about when the coal plants are gone? What do we do when the sun isn’t shining or the wind isn’t blowing?

There is no doubt that there is enough solar in the Southwestern US or wind the Midwest to power the nation, but storage and transmission is a controlling factor to the use of these clean sources of energy. Tea party types are resisting transmission lines on the basis of property rights and governments in conservative states are making small scale renewable energy less attractive to protect their power companies’ turf.

When one thinks of energy storage, explicitly electrical energy, batteries are it. Enter Elon Musk, billionaire entrepreneur and builder of the Tesla Electric car. More important than the electric car are the batteries that power them, at least that is what Mr. Musk thinks. He has recently gone into the battery market, not only for his cars, but for stationary applications. He introduced a 10 kWh battery that can be used for a myriad of applications.

For a home owner this means “behind the meter” storage. Obviously off the grid folks rely on batteries but even grid-tied homes can utilize storage for weathering storms when the grid goes down. Folks with grid-tied renewable energy systems can utilize storage. Some power companies have time of use metering, that is the cost of power varies as to when it is used. If a home owner has a storage capacity, S/he can chose to sell power back to the grid when the price is higher. Even without a renewable energy supply, home owners with storage can charge batteries during the night when rates are lower, then sell power back to the grid during the day, making a profit in the exchange.

Utility scale storage can be beneficial right now. Battery storage can be added incrementally to defer transmission and distribution line upgrades as demand grows. Batteries can be used to back up temporary shortages due to short term power plant outages. Not to get too far down in the weeds on these issues, suffice it to say the Batteries will play a huge part in the future of clean energy supplies.

This something we should all strive for. We will get away from burning stuff for power, and batteries will make this more practical.

earth

A Positive Potpourri

So much news about global warming and climate change is negative. The planet’s hotter, the weather weirder, and the future dimmer. Whereas over half of Americans believe in global warming, less than half care. But there is some hope for the future out there.

Little is coming out of congress but the state of California is leading the way to a sustainable future. The land of “fruits and nuts,” the land where the leader is referred to as “Governor Moonbeam,” will be breaking ground for a new high speed rail to run from San Jose to Los Angeles. The nation’s largest infrastructure project will cost billions but take scads of cars off the highways and planes from the sky. It will produce jobs that can’t be sent overseas, and most importantly reduce the carbon footprint for the people of California.

And speaking of a carbon footprint, Governor Jerry Brown has set an ambitious goal of 50 % of the energy to come from clean sustainable sources such as wind, solar and geothermal by 2030. Nowhere else in the country is there such an ambitious standard.

The Journal of Environmental Studies and Sciences show that the cost of onshore wind and solar PV are cheaper than coal for generating electricity, when the cost of climate forcing is factored into the use of fossil fuels, either gas or coal. The cost of solar panels alone has dropped by 50% between 2008 and 2009. Although Solar PV generated electricity only accounts of a scant 0.7 % of installed capacity, it recently has become the the most rapidly installed new generation in the country.

The oil and gas boom due to technological advances like shale fracking have accounted for a 10% reduction in oil imports (equivalent). That’s good but automotive efficiency due to gas mileage standards coupled with increase utilization of mass transit has resulted in nearly twice the savings, some 18% reduction. Reductions due to efficiency are far too often overlooked when considering reducing our reliance on fossil fuels.

An important aspect of sustainable energy is the fact that it creates jobs, more than any of the fossil fuel industries. The US Bureau of Labor Statistics estimates that there are about 80,000 jobs in the coal mining industry, but over a 142,00 jobs in solar industries.

Several HVDC transmissions are moving through regulatory approval, including the Plains and Clean Line which will pass through Pope county. When approved and constructed, they will allow the utilization of much otherwise stranded electric generating capacity from abundant midwestern wind.

Also here in Arkansas, a 12 megawatt (MW) solar photovoltaic installation will be built on a one hundred acre site in an industrial park in East Camden. Arkansas Electric Cooperative Corporation (AECC) will sell power to their members across Arkansas. AECC has also agreed to purchase an additional 150 MW for a total of 201 MW of wind power from producers in Oklahoma. An 80 MW wind turbine farm has been proposed for a site near Springdale. It will use a novel shrouded turbine design which is claimed to completely eliminate bird and bat mortality.

Global Warming 2014 Edition

This year has seen several international, national, and local issues relating to global warming.

Organizationally, the IPCC or the Intergovernmental Panel on Climate Change might be considered the lead agency on issues of global warming. The IPCC is a group of thousands of climate scientists from around the world. The fifth pentennial assessment report states: “to avoid dangerous interference with the climate system, we need to move away from business as usual. Simply to hold the temperature rise to 2 degrees [Celsius] will require reductions of green house gases from 40 to 70 per cent compared with 2010 by mid-century, and to near-zero by the end of this century.”

Whereas the IPCC is the scientific wing of the UN, the UNFCCC or the United Nations Framework on Climate Change is more of a political policy wing. In their meeting in Lima Peru this year they concluded that it is increasingly difficult to prevent the temperature of the planet’s atmosphere from rising by 3.6 degrees Fahrenheit. According to a large body of scientific research, that is the tipping point at which the world will be locked into a near-term future of drought, food and water shortages, melting ice sheets, shrinking glaciers, rising sea levels and widespread flooding—events that could harm the world’s population and economy.

After months of negotiations, President Obama and President Xi Jinping in November affirmed the importance of strengthening bilateral cooperation on climate change and will work together to adopt a protocol on climate change. They are committed to reaching an ambitious 2015 agreement that reflects the principle of common but differentiated responsibilities and respective capabilities, in light of different national circumstances.

In June President Obama, through the Environmental Protection Agency, has promulgated rules for power plants to reduce carbon emissions by 30 per cent by 2030. This is the first time that the EPA has taken steps to regulate Carbon Dioxide as a pollutant, an action begun in 2007 by President Bush, but delayed by court battles meant to block the regulations.

Construction of the Keystone XL pipeline remains stalled. This pipeline, if completed, will move oil produced by strip mining the Athabasca tar sands in Alberta Canada. The line will terminate after traversing almost 1200 miles at refineries on the Gulf coast. It’s approval is questionable as this will exacerbate global warming by providing an international market for more carbon emissions.

The draft Environmental Impact Statement for the proposed Plains and Clean Line has been released. Basically the EIS determined that there are no adverse environmental or socioeconomic effects of the transmission line. The power line will move 3,500 MegaWatts of wind generated electricity from the panhandle of Oklahoma, across Arkansas to Memphis.

Entergy has recently purchased a gas turbine fired electrical power plant near El Dorado. With a capacity of 1980 MegaWatts, this may signal the intention to close the older less efficient coal fired White bluff plant.

plains-and-eastern-clean-line-project

Health Effects of Power Lines

The proposal of a couple of high voltage electric power lines in northwest Arkansas has some concerned about health effects of those who may be living nearby. The larger of the two is a 750 kilovolt DC transmission line which will move excess electricity generated from wind turbines in Oklahoma and Kansas across Arkansas to connect with the Tennessee Valley Authority network in Memphis.

The health concern is all about exposure to electromagnetic fields (EMF) emanating from the power lines. Are there health effects? What are they? How close do you have to be? There is no question that those giant pylons with the looping wires are unsightly, and in the minds of some unnecessary, but are they a health risk? The short answer is more than likely not, but it will take some discussion.

First and foremost we are bathed in electromagnetic radiation from birth to death. The sun provides many forms; visible radiation (sunlight) by which we see. Infrared radiation from the sun warms us. Ultraviolet radiation tans us.

In addition to these natural forms of radiation we are exposed to man made electromagnetic radiation from radio, television, and cell phone transmissions. Electrical wiring and all electrical devices in the home create electromagnetic fields.

The evidence of harm from Power lines is scant and contradictory. It all started with a study in Denver in 1979. Researchers found a correlation between living near power lines and childhood leukemia, even though it is not biologically plausible. Basically what the researchers proved again that income correlates with cancer, and those who live near power lines are in a lower socioeconomic bracket.

Since that time there have been literally tens of thousands of peer reviewed studies which show no clear indication of harm. An important principle of toxicology, the science of poisons, is the dose response relationship. The greater the dose – the the greater the harm. Any of the studies which did suggest harm did not correlate with exposure.

Magnetic fields are measured in units of Gauss (G). For example the magnetic field in a medical diagnostic device called a MRI is huge, of the order of 70,000 G . There is no evidence of harm from MRI scans.

Other magnetic fields that we are exposed to include those from small electric devices in the home. A hair dryer in use produces a field strength thousands of times smaller, 20 G with a similar values for an electric razor. A refrigerator produces a field of about .02 G.

So what about a power line? The field strength drops off rapidly with distance from the source so the actual field strength under or near a power line is quite small. At a distance of 30 meters the field strength is a fraction of a thousandth of a Gauss (.004 G.) This is hundreds to thousands of times lower than exposures in average homes.

At the expense of repeating myself there is essentially no proof of either toxic or carcinogenic risks associated with living near power lines. Argue if you will that they are ugly, or that you don’t want them on your land, or that they aren’t necessary. Arguments about health effects however will fall on deaf ears.

Energy Storage

The success of transitioning to sustainable energy supplies in the United States relies to a large degree on our ability to store energy produced by intermittent energy sources such as solar, wind and biomass. We have plenty sunlight and wind to go around. Conversion of biomass to a liquid or gaseous fuel is a convenient method for storing energy, but photosynthesis is quite inefficient compared to other ways of capturing solar energy. Also any biomass to energy scheme will involve burning something which always has some negative health consequences.

The future could be powered by electricity from solar and wind exclusively but how will we store the electricity for use when the sun isn’t shining or the wind isn’t blowing? Batteries are an obvious way of storing energy but are impractical for storing energy on the scale of an electric utility.

grid scale batteries

grid scale batteries

Batteries for powering transportation are in use now and will expand greatly in the future.

Most electric cars today use Lithium ion batteries. They have the best energy to volume and energy to weight ratios referred to as energy density. The problem is that even the best batteries pale in comparison to the energy density of gasoline. Liquid fossil fuels like diesel and gasoline are very energy dense and can produce 50 times as much energy as a Lithium ion battery of equal weight or volume. With current technology the Nissan Leaf, an all electric vehicle, has a range of under one hundred miles. Batteries being developed now can increase the energy density by five to ten fold, giving electric cars a range of several hundred miles.

Storing energy for the electrical grid can accommodate a wider range of methods. One of the simplest ways of storing energy is to pump water up a hill.

Pumped storage

Pumped storage

All you need are two reservoirs, one higher than the other. When energy is available it is used to pump the water to the upper reservoir. When energy is needed, the water is released, causing the turbines to reverse direction and generate rather than consume energy. The only limitation is space and geographic relief.

Another utility scale energy storage method being examined is compressed air. Just as pumping water up a hill stores energy, so does compressing a gas. In the latter part of the nineteenth century, several European cities used compressed air for energy storage. Rather than convert the energy in the compressed air to electricity, it was piped and metered to do mechanical work. Everything from motors for heavy industry to sewing machines ran on the compressed air. The major limitation of compressed air storage is the necessity of a large underground reservoir to hold the compressed air. Wind turbines in the midwest will in the future store energy with compressed air.

compressed air

compressed air

Flywheels are another method to store energy. An electric motor spins up the flywheel, later when energy is needed the motion is used to power a generator. The big advantage of flywheel storage is that it can be done anywhere. No need for a big hole in the ground or pairs of reservoirs at different altitudes.

One of the best methods to pair production and storage of energy is solar thermal. Simply heat a fluid with sunlight. When electrical energy is needed use the heat to power a generator. Power towers have a collection of mirrors pointed at the top of a tower. A fluid is circulated through the heated zone, then sent to a storage site for later extraction of energy.

All these techniques involve converting one form of energy to another, but can ultimately be used to generate electricity even when the wind isn’t blowing and sun isn’t shining.

High Voltage Direct Current Power Transmission

Wind generated electricity is about the cheapest and certainly the fastest growing source of energy in the United States, maybe the world. Currently there is an excess of wind power to our west but few consumers in the area. The capacity to move the clean sustainable wind generated electricity from the plains where it is abundant to other areas where the people are limits it utilization.

Both the Federal Energy Regulatory Commission and Plains and Eastern Clean Line have held meetings in Arkansas and Oklahoma to introduce the public to a proposed 750 mile electric transmission line which may be constructed over the next few years. This power line will move wind generated electricity from the plains to southeastern states. Of the several proposed corridors, all pass through Pope county somewhere between just north of Russellville to north of Dover. The transmission line terminates at Memphis. Wherever possible they will follow established rights-of-way to minimize disturbance to land owners.

The transmission line was approved by the Federal Energy Regulatory Commission (FERC) last year to move electric power from the plains- Northwest Texas, Northwest Oklahoma, and Southwest Kansas to consumers in the southeastern United States, basically the Tennessee Valley Authority.

One interesting feature of this power line is the employment of direct current transmission. One usually thinks of direct current (DC) as the type of electricity utilized in devices with batteries such as cell phones or flashlights. On the other hand alternating current (AC) is the stuff of home wiring. Virtually all transmission lines in the country are AC, but technological advances now make DC line transmission more cost effective. High voltage power moved over three hundred miles is now better done with direct current.

The high voltage direct current (HVDC) line which when complete can move 3.5 Gigawatts electric at 500 kilovolts. To put this in perspective this is enough transmission capacity to deliver the energy equivalent of about four nuclear reactors or enough electricity to power over one million homes. Little to none of this power will be “dropped off” in Arkansas for a couple of reasons, not the least of which is we don’t need it, at least right now. The other is the expense to step down and transform the HVDC to lower voltage AC so that it is compatible with our grid.

The transmission line is all about the future of electricity in the United States. A big issue of our energy future is the need to convert to cleaner sustainable energy sources but transmission and storage are impediments.

Midwestern wind power is a big part of our energy future. Theoretically electricity generated from wind farms from the Canadian border to Texas could power the whole country. It won’t because there is wind elsewhere such as the coastal areas, and of course there are other sustainable energy sources. The point is we have an abundance of clean energy potential. The future is bright and will be lit with wind, solar and other types of sustainable energy.