Tag Archives: wind power

Pipelines and Electric Lines

Over the coming months two major public service transmission lines will be installed across Pope county. One is a high voltage direct current (HVDC) electric transmission line from the panhandle of Oklahoma to Memphis, Tennessee. The other is a pipeline to move oil from Cushing, Oklahoma to Memphis. One will contribute to a clean energy future, the other will contribute to global warming. Both will, to the point of law suits, incense landowners along the rights of way.

Cushing Oklahoma, because of location and historical precedent, is the major hub for oil pipelines in the United States. It also happens to have the largest oil storage tank farm in the world. The Diamond pipeline will move 200 thousand barrels of light sweet crude per day to a Valero refinery in Memphis. To get a sense of just how much oil that is, if the pipeline were diverted it could fill the Dallas Cowboys stadium in less than a day. If the oil were all converted to gasoline, it could fill the tanks of half a million cars a day.

Opposition to this 900 million dollar project comes from landowners who would rather not have a 25 to 150 foot wide strip of land which must be maintained as an open space – no forestation or permanent structures in the right of way. The pipeline is also opposed by environmental groups who would rather not have more crude oil turned in to fuel which ultimately contributes to global warming.

The panhandle region of both Texas and Oklahoma have some of the best wind resources in the country. Wind speeds average near 20 miles per hour. It is a problem however as there is no market for all the potential wind energy in the area, hence the need for transmission lines to take what energy could be generated elsewhere. Most practical is transmission to the east across Arkansas to a distribution hub in Memphis. This will allow for clean renewable energy to replace energy from coal fired power plants across the Tennessee Valley Authority power grid. It also will require a 150 or so foot right of way.

The HVDC transmission line will carry 4,000 Megawatts of direct current electricity about 700 miles start to finish. Power poles are 150 feet tall and spaced 5 to the mile. This power line is like a super highway for electrons with very limited access. The only “drop-off” point planned currently is an off ramp near Atkins. This will allow 500 Megawatts of power to flow into the local grid.

Like the oil pipeline, land owners are opposing the HVDC line. The nation’s preeminent environmental group, the Sierra Club, is supporting it.

Both project require regulatory oversight which allows the use of eminent domain to secure the rights of way. The process is different for the projects. The oil pipeline has been approved by the Arkansas Public Service Commission (APSC) even though the Pipeline will provide no direct benefit to Arkansas. Apparently pipelines get a legal pass, not afforded to the electric transmission lines.

Because the initial HVDC line had no direct benefit to Arkansas, it was denied legal status by the APSC and therefore is seeking federal oversight. By partnering with the Department of Energy Clean line will gain federal right of eminent domain.

Wind Power Transmission Line

A federal decision on the Plains and Eastern Clean Line High Voltage Direct Current line is imminent. This proposed 700 plus mile long transmission line will extend from the panhandle of Oklahoma, through Pope County, and on to Memphis. If approved and built it will allow for the movement of large amounts of wind generated power from the midwest to parts east where it can be used to replace coal fired generating plants.

The route already approved by the National Environmental Policy Act (NEPA) will pass through central Pope county. A substation just north of Atkins will allow Arkansans a piece of the power from the line. For perspective the line will cross Big Piney Creek near where it crosses Highway 164.

The line and others like it are necessary to reduce our need for coal which fouls the atmosphere in multiple ways. There is a superabundance of clean, relatively inexpensive energy waiting to be tapped in the midwest, the only need being transmission.

The Line is not without its detractors however, especially those in the path of the powerline right-of-way (ROW.) It will require a couple of hundred foot wide ROW with 150 foot towers spaced about 5 to the mile. The land within the ROW can be used safely for any purpose with the exception of forestry – crops, hay fields, and pastures are acceptable uses for the area. Landowners will be compensated for the ROW but they complain that compensation is insufficient.

It really boils down to “Not In My Backyard” (NIMBY.) This is not surprising, nobody wants their view of a skyline marred by powerlines. But powerlines are a fact of modern life. Anyone who is connected to the electrical grid benefits from numerous folks having yielded a ROW to get that power to their home or business.

One suggestion to remove the negative visual impact would be to bury the line underground. It has been done locally on a very small scale. In some newer subdivisions the distribution lines are buried but not for far, as it is quite expensive compared to overhead lines.

The relative cost of burying high voltage transmission lines is assumed to be prohibitive as it is just not done with the exception of lines that cross large bodies of water where it is the only possible alternative.

To bury a transmission line requires serious disruption, trenching then back filling, not just pastures and hay fields but sidewalks, roadways, and even rivers and wet lands. For forest land, a clear cut ROW would be necessary to be able to bring in the heavy equipment necessary to excavate and lay the line.

One of the benefits of buried lines is that they are less susceptible to weather related outages. The other side of the coin is when an outage occurs in an underground line it is harder to locate and harder to access, changing repair times from hours for overhead lines to weeks for underground lines.

Cost estimates are in the range of 2 to 10 times more expensive than overhead lines. Power companies across the land, whether private like Entergy or public like the Arkansas Electric Coops, have made the decision to stay with overhead lines, wherever possible.

pv2

Alternative Energy Alternatives

So you want to be green, or at least greener, when it comes to your electricity use. There are a welter of options available. Here in Arkansas we are not blessed with sufficient wind resources to make homeowner wind very cost effective, so going green means solar photovoltaic systems (solar PV) are the best game going. But with this restriction there are still several different approaches to decarbonize your electricity.

In remote areas without grid connections, the only reasonable green electricity is with a solar PV system and batteries. The batteries are necessary not only to tide you over for when the sun doesn’t shine but also to stabilize the power to your home or cabin. Imagine on an otherwise sunny day a solar array is providing nicely for the home, but a cloud passes over. This would temporarily reduce the current, possibly to the point of damaging electronics, Hence batteries are essential. Just how many batteries needed is a function of how long will the sun not keep up with demand. On occasion in this area we can go for a week or two without much sun due to rain and clouds. The point is that this is the most expensive option due to the costs associated with the batteries.

Much more practical are so called “grid tied” solar arrays which essentially use the electrical grid as a battery. If you buy electricity from Entergy, SWEPCO, or AVEC for example, and you add solar panels to your home, the power company is your battery. When the sun shines your meter will slow down or actually run backwards sending power to the grid. At night or on rainy or cloudy days power is drawn back from the grid. Because Arkansas is a net metering state, when producing you are paid the same price as when you buy. Depending on how many panels you have you can replace some or all of your electrical needs. Currently costs are such that the payback period is about half the rated lifetime of the panels. You will recoup your initial investment in about a dozen years, and the panels will continue to produce for at least that many years to come.

All homes don’t have access to the southern sky on their property due to shading from trees or the terrain. That said you can still participate via community solar farms. The first community solar farm has begun near Little Rock. A developer is constructing a solar farm tied to Entergy’s grid. Any Entergy customer can basically buy a piece of the solar production. The buyer has their own meter which is aggregated with their home meter, just as if the solar panels were on their roof. Entergy deducts any power costs produced by the solar panels from the power costs at the home. The cost for this approach is somewhat higher as because of the costs for site development and land acquisition.

Yet one more option exists to green up your electricity. The green power costs for the aforementioned approaches all require some significant start up costs. Another alternative is to buy “green tickets” or participate in the purchase of Renewable Energy Credits. There are companies that will for a nominal charge on top of your actual electric bill, buy green energy. The additional charge is used to buy power from green sources and send that electricity to the grid, which offsets electricity from fossil fueled sources. Basically you are subsidizing clean energy. You don’t own any equipment but your dollars go to green the environment.

Private Sector must be the Answer

In Al Gore’s award winning movie “An Inconvenient Truth” he used the old saw to depict a real problem with global warming. If you put a frog in hot water it will immediately jump out. Put a frog in cold water but very slowly warm it up and the frog will stay until it is too late and be boiled alive.

That is a nice analogy for the dilemma we face with with global warming. The process is slow. Another analogy would be to call it glacially slow, but glaciers are moving, and melting, at a fairly rapid pace these days. Humans and a number of animals evolved to react to rapidly occurring threats – the snap of a twig in the brush, the glint of light from an eye, and we are ready to fight or flee.

Global warming is a decades to centuries change that threatens us now, and many just don’t see the threat, a threat not to us individually, but to our future. Some are so insensitive to the risk that even if they believe it to be true, won’t react because it doesn’t matter to them personally. If the majority of us hold this opinion, we are doomed as a species.

Some governments are beginning to react with policies that favor carbon free energy strategies, but the steps are often small and can be more costly than simple business as usual burning of fossil fuels. Hey, it’s on face value cheaper and we know how it works.

On a more hopeful note is the fact that technology got us into this problem, but technology and the private sector, hold the potential to get us out. Obviously we need to stop burning fossil fuels, especially coal and oil. Natural Gas, essentially methane, is does not produce as much pollution as the others, but ultimately its use must be curtailed also.

There two ways to replace the fossil fuels, use less through efficiency and replace energy production with non-carbon sources such as wind, solar and geothermal. Of the three, wind is the most developed. We currently get about 4 % of our electric energy production from wind, entirely land based. The potential for off shore wind, especially on the east coast affords considerable potential but currently is more expensive to exploit than wind resources in the midwest. Currently the cost of wind generated power is as cheap as that from a modern coal fired plant. And the costs continue to decline, the opposite of the cost for producing power from coal.

Solar Photovoltaic systems (solar panels) are sprouting up everywhere, especially since the price has dropped by half in just the last few years. Not only are homeowners adding panels to their roofs but utility scale systems are being installed. Entergy recently announced that they intend to build a 500 acre solar farm near Stuttgart. For perspective, a square mile covers 640 acres.

Until the intermittent energy sources of wind and solar penetrate to about 30% of total production, no additional back up power is needed. Essentially there is enough existing reserve power to keep the lights on after dark when the wind isn’t blowing. Beyond that, battery backup will be needed. Development and deployment of utility scale battery production will surely follow the demand.

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.