Tag Archives: carbon-free energy

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.

Don’t Buy Oil

The horrible terrorist attack in Paris has drawn a number of responses as to what to do. Both French and US forces have launched bombing raids against ISIS forces in Syria. Many are calling to again put “boots on the ground” – a euphemism for send sending more of our sons and daughters off to die. With irrational fear trumping compassion, many governors want to have nothing to do with refugees from Syria.

Nether war nor fearfulness will solve our problems. It is time for a different perspective. The chaos in the middle east cannot continue without money to pay the fighters and buy the weapons and ammunition. Much of the money to fund the terrorists comes from the sale of oil. A step was taken with the bombing raids recently when over a hundred oil tanker trucks were destroyed. These were tankers that ISIS used to sell oil on the black market. As long as they have access to the oil, ways will be found to sell it. Additionally cash from the Gulf States flows directly to ISIS. It is not the official positions of the governments of the Gulf States, but rather private donors, made rich through the sale of oil, who are contributing to ISIS.

If the terrorists will find a way to sell the oil they control, and the riches of the Gulf States donors will continue to flow to the terrorists, what is to be done? Starve the beast. Stop buying oil. Not just the black market oil or the oil produced by the Emirates, but all oil. If we don’t buy the black market oil, we go somewhere else to buy oil. But someone else will buy the oil. Same for the Gulf States oil. We buy instead from Venezuela or Nigeria. But then someone else buys the Gulf oil. The problem is that oil is a very fungible commodity. Within limits, oil is oil, no matter where it comes from.

The answer is to stop using and therefore stop buying, oil. If we completely withdraw from the market, we will effect a dramatic drop in the price of crude oil. It’s a simple matter of supply and demand. We in the United States constitute a scant 5 percent of the world population, we consume over 20 percent of the world’s resources including oil. The drop in prices means less revenue from the sale of the black market oil and lower revenues for the emirates, hence less money to fuel terror. Transitioning to an electric economy fueled with wind and solar has its costs, but so does waging war.

Transitioning away from the use of oil will happen eventually as oil on the planet runs out, why not start now and help to stabilize geopolitics in the process. Why not start now to reduce pressure on the climate that comes from burning the oil? Why not stop now to help clean the air to reduce health care costs. A final benefit would be that we could become world leaders in sustainable energy technology.

Fuel Cell Vehicles

Auto manufacturers, both here and abroad are scrambling to produce electric vehicles. The most successful out of the gun has been the high end Tesla model S. Others include the Nissan Leaf and BMW i3. Chevrolet will be introducing the Bolt in the near future. All these cars are whisper quite and perform well. They all however suffer the drawback of limited range on a charge and a rather long recharge time at least compared to the time to fill a tank of gasoline.

Notably missing from the cars listed above is the world’s largest car manufacturer – Toyota. They set the standard for hybrid cars with the introduction of the Prius in 2001. It is powered by a internal combustion engine (ICE) which is supported by a electric motor and battery that results in quite high mileage compared to other ICE powered cars.

Although Toyota has yet to produce an all-electric car, they seem to be hedging their bet on the development of an alternative to electric cars with batteries. In development is an electric car that runs off of a fuel cell that is powered by Hydrogen. The chemistry of the fuel cell is just the opposite of the high school CHEM class experiment called electrolysis. If you pass an electric current through water it cause the production of Hydrogen and Oxygen from the water. This process consumes electrical energy.

In a fuel cell powered vehicle, hydrogen gas is stored at high pressure in a tank. When electrical energy is needed, the gas is passed into the fuel cell where it combines with oxygen from the air to produce electrical energy. The principle is simple but in practice fuel cells are complex devices that require unique and often expensive catalysts to make the chemical reaction proceed at a sufficient rate to power a vehicle. The real advantage to this technology is the range of the vehicle between refills. It should be possible to store enough Hydrogen in a vehicle to get a lot more range than can be achieved with charging batteries.

A problem with the use of Hydrogen is one of thermodynamics. It takes more energy to produce Hydrogen than you can get back when used. Basically any time you do work, energy will be wasted. Thermodynamically work is the use of energy to drive a process, be it chemical , electrical or mechanical. In the case of Hydrogen energy losses occur when it is created from water by electrolysis, when it is compressed for transportation, when it is decompressed for use, and when it is used in a fuel cell. Each of these processes constitute an inefficiency where energy is lost.

Another problem is that Hydrogen is a gas and somewhat difficult to handle. Hydrogen stored in metal containers, or piped in metal pipes causes embrittlement. The metals become more fragile and likely to fail under pressure on exposure to Hydrogen. It is also problematic in that it has a low energy density by volume. It takes a lot of space to store a given weight of Hydrogen.

Toyota is betting that these difficulties with the production, storage and utilization of Hydrogen can be overcome.

Arkansas and the HVDC Power Line

Plains and Eastern Clean Line has proposed and are planning the construction of a 700 mile High Voltage Direct Current Power line stretching from the Oklahoma Panhandle to Memphis. The 600 kilovolt line will have the capacity to move 3.5 GigaWatts of power, equivalent to the output of 5 or 6 coal fired power plants. This represents a major move to deliver excess clean, wind-generated electricity out of the midwest to markets to the east.

wind turbine blade

wind turbine blade

Similar projects are in progress to our north, the Grain Belt Express Line will be passing through Missouri on the way to St. Louis and points east and the Rock Island Clean Line which will pass through Iowa and tie into several eastern states.

These projects are not so much about the here and now, but rather the there and then. Multimillion dollar projects take long lead times between inception and completion, usually several years, so they have to be planned with the future needs in mind. The recent requirement by the EPA to reduce our nations carbon emissions only hastens our need for clean renewable electrical energy to replace obsolescent coal fired power plants.

The lines have both supporters and detractors. Environmental groups usually favor the projects as a way to reduce carbon emissions and thus reduce the risk of the damaging effects of global warming. On the other side are land owners who see the power lines marching across their land as more big government intrusion into their lifestyles and even interfering with their livelihoods. Additional arguments against construction of the lines are possible health effects, and the fact that the entities proposing the construction are private companies.

It seems strange that an argument against private industry would be made. The United States to a very large degree operates that way, it’s capitalism, right? Rights of way (ROW) must be secured for these power line projects private or otherwise, just as any project in the public interest such as water lines or a railway. Fair market price must be paid for any property taken for the ROW.

Because these are direct current lines they have a relatively small footprint, at most about 200 feet wide.

Monopole_structure

Monopole_structure

The total area utilized by the Plains and Eastern Clean Line is about 8000 acres spread over the total roughly 300 miles in Arkansas. The actual land area taken out of service is much less than that as grazing land and hay fields are essentially undisturbed even within the ROW.

Health effects of the power lines relate to several phenomena – Induced magnetic fields, possible corona discharge, and ion production. There is no convincing evidence based on years of experience with power lines that any of the aforementioned causes have health effects.

The magnetic field induced by the proposed line is about the same as the earth’s magnetic field. A few meters from the edge of the right of way won’t even deflect a compass. Power transmission line operators design equipment to avoid corona discharge as it wastes power. With respect to the ions generated, if you worry about power lines, stay away from beaches and waterfalls as they produce even greater numbers of ions.

In the interest in full disclosure I am a member of the Arkansas Chapter of the Sierra Club which has endorsed the proposed power line.

Ivanpah tower

Solar Thermal Electricity Generation

After spending a near cloudless weekend on the Buffalo National River, my thoughts turned the considerable power of heat from the sun. When concentrated the sun’s heat can be used to do work, specifically generate electricity.

A new facility has begun operation near the Nevada border in the California desert. Ivanpah, CA in the Mojave desert is home to a solar thermal power plant covering a little over five square miles. The plant produces enough energy to power 140,000 homes (377 megaWatts.)

The plant consists of three towers each surrounded by thousands of mirrors.

Ivanpah plant

Ivanpah plant

Computers control where the mirrors are pointed such that they are always pointed at the top of the tower. There boiler tubes convert water to steam to at very high temperature and pressure. This is used to turn turbines for the generation of electricity. It works just like a conventional coal or nuclear power plant, but without the carbon emissions or radioactive waste. Clean sustainable energy.

Solar thermal power technology is not really all that new. A solar thermal power system was demonstrated at the the 1878 World’s Fair in Paris. A 20 square meter parabolic reflector, basically a light concentrating mirror, was used to make steam to run a printing press. Other solar thermal plants employing power towers have been built but the Ivanpah plant is by far the world’s largest and most efficient.

It is very efficient in multiple ways. Solar photovoltaic plants, usually seen on rooftops, are also configured in large numbers in fields to produce power for the grid and operate at about 15 per cent efficiency. The Ivanpah facility captures upwards of 20 per cent or more of the sun’s energy.

A unique feature of this solar thermal plant compared to other sustainable but intermittent power sources such as wind and solar PV is the ability to generate power around the clock. Some of the day time heat energy from the plant can be stored in special insulated reservoirs containing molten salt solutions. At night, generators can be run off of steam produced by water circulated through the heat storage reservoirs.

Another important variable in any thermal power plant is water use. This is especially important in the desert. When water is heated to make steam, it can only be used to do work if and when it is cooled back to water. Cooling the steam can use lots and lots of water. That’s why you see thermal plants like coal or nuclear fired plants located near large bodies of water – rivers, lakes, even sea coasts. The Ivanpah plant uses an air cooled system to condense the steam so it is particularly frugal when it comes to water use.

To complete the discussion I should mention downsides, two come to mind. First is land use, solar thermal plants of this type require relatively large areas in sunny climates. Luckily we have much desert land that with proper oversight to protect natural habitat can provide a significant amount of electricity production.

Finally there is the issue of bird kills. Some species of birds, especially fly catchers are being killed by flying into the heated air near the towers. Estimates are that about 30,000 birds are killed per year. That may sound like a lot but compare that with the number of birds killed annually by collisions with man made objects. A billion, yes that is a billion with a capital B, birds die from running into windows, and towers and what not.

CO2

Clean Air, Stable Climate

Section 202 of the Clean Air Act requires the EPA to regulate any pollutant which in their judgment may reasonably be anticipated to endanger public health or welfare. Previously this had been applied to acute respiratory toxins such as sulfur and nitrogen oxides or substances which contribute to their formation.

After an extended court battle the United States Supreme Court ruled in 2007 in favor of the EPA that regulating green house gases (GHG) is a requisite part of the EPA’s mandate. Greenhouse gases, principally Carbon Dioxide trap heat in the atmosphere and because of the threat of global warming endanger the public health and welfare.

Rule making took several more years but now the regulations have begun to roll. The first to feel regulation was new power plants which had to meet stringent emissions standards. Likewise emissions standards for new cars continue to rise.

auto_smog

auto_smog

The most recent regulations require a national average reduction of Carbon Dioxide Emissions of 30 % by 2030. The rule is actually 50 different rules, one for each state. And the mandate is not for any particular method to reduce emissions, just that they must be reduced.

Because Arkansas has above average reliance on coal fired power which emits the lion’s share of carbon, our required reduction amounts to 44 %. This may sound like a lot but remember we have 15 years to achieve this level of reduction.

Almost half this reduction can be achieved at little to no cost to the consumer. A study by the American Council for an Energy Efficient Economy found that nearly half that emission reduction can come about by increased energy efficiency. Whereas the reduced demand for power will mean a small loss of jobs as coal fired power plants close, many more jobs will be created for the necessary technology improvements to greater efficiency.

Wyoming coal

Wyoming coal

Generally the public is in agreement with the scientific community about threat of global warming. So how about the “ruling class?” Both the Republican and the Democrat, Asa Hutchinson and Mike Ross have spoken against the rule. Similarly an interim legislative committee, Insurance and Commerce, hase passed a resolution condemning the EPA rule as illegitimate. Cries of violation of “states rights” rang through the halls.

In reality the only serious argument is that clean air and a stable environment for the future MAY cost somewhat. Let it be noted that every regulatory action to clean our air and water has been met with cries that to do so will crash our economy. It hasn’t happened yet, not with removing lead from gasoline, nor with preventing acid rain, and now not with mitigating the risk of global warming.

So why the dire warnings from politicians? A 2014 study conducted by the Sierra Club and Oil Change International found that for every dollar the fossil fuel industry contributes to candidates, it reaps 59 dollars in subsidies. Follow the money.

Global Warming, Fossil Fuels, Air Quality, and Health

Everybody wants to be healthy, and we go to considerable lengths to achieve the same. Preventive care, diet and exercise all contribute to good health. There are factors however which are beyond our individual capacity to control. Global warming is one of those things that we have to address collectively. It comes about due to the release of certain air pollutants. Reducing these pollutants will not only help mitigate the direct environmental damage but also improve our health.

Air pollution has been linked to several of the leading causes of death in the United States. Asthma, chronic bronchitis, emphysema, lung cancer, myocardial infarction, congestive heart failure, and stroke have all been shown to be linked in multiple peer reviewed articles in major medical journals. Even conditions as diverse as Type II diabetes and Alzheimer’s’ disease have shown correlations with air pollution levels.

Chronic exposure to gasses such as ozone and nitrogen oxides and fine particulate matter

particulate matter

particulate matter

cause an inflammatory reaction in sensitive tissues and contribute to poor health. The source of the pollutants is a result of our quest for the cheapest possible energy sources to power our lives. There is a deal with the devil in cheap energy sources, mostly fossil fuels. Burning coal and oil and to a lesser extent natural gas result in the production of these unhealthy pollutants.

That good news is that the USEPA through the Clean Air Act regulates these pollutants and constantly reviews the scientific data supporting limitations of pollutant release. The act was passed in 1963 and has been significantly amended several times to tighten air quality standards. Enforcement of the act has led to considerable improvement of air quality, but currently something like one third of Americans live in counties which are out of containment.OzoneFormationDiagram

In 1990 Congress directed the EPA to conduct occasional scientific reviews as to the costs and benefits of air quality regulations. A 2009 study by the National Research Council finds that the cost for health care from one coal fired power plant is 156 million dollars per year. Collectively 62 billion dollars a year is spent as a result of burning coal to make electricity. This is due to the health effects of pollutants at currently allowed levels. Another study showed that over 20 years of clean air act regulations, one dollar spent on air quality protection resulted in a savings of 44 dollars in health care costs. The EPA estimates that the investment of 65 billion dollars in 2020 will save a total of 2 trillion dollars in health care.

One argument to revitalize the economy is to cut regulations, thus lowering the cost of doing business. Lowering air quality standards may save business and the consumer money on energy production but will greatly increase health care costs- out of proportion with the savings on energy costs. This is not the time to try to save money limiting the actions of the EPA, regardless of the budget cutting fervor in congress. We can pay a little for air quality but overall save a lot by supporting strict air quality standards, even if it means abandoning coal fired electricity production.

There is no question that somewhere in the future we will stop burning fossil fuels to produce energy, whether it is due to depletion of the resources or our recognition of the harmful effects to health and the environment. Any and all programs which get us away from fossil fuel consumption will benefit society. Ultimately we need clean sustainable energy sources such as wind and solar which release no air pollutants.

Geothermal Energy

The term geothermal has come to be associated with two technologies which are only tangentially related; first, power can be produced by drilling into the ground to a depth where the rock is hot enough to boil water. The other use of the term geothermal is associated with ground source heat pumps which need only drill down a few feet to a temperature of fifty to sixty degrees Fahrenheit.
 
Utility scale power can be produced by drilling into the ground to a depth where the rock is hot enough to boil water to produce steam. The steam is then used to drive a turbine to generate electricity just as a nuclear reactor or a coal fired power plant produces steam to turn turbines. Electricity production from geothermal heat requires drilling several kilometers into the earth and is consequently very expensive, but in certain locations heat is near enough to the surface to make its utilization practical.
 
Heat at the core of the earth is approximately 6000 degrees Celsius, hence a temperature gradient exists: twenty five degrees C per kilometer. The heat is due to at least two factors, residual heat from the accretion of the planet over four billion years ago and radioactive decay of certain elements such as Uranium and Thorium.
 
To economically produce power, hot rock must be within three or four kilometers of the surface. This only occurs in geologically active regions, such as areas with earthquakes and/or volcanoes. In these locations fissures in the earth’s crust allow movement of magma near enough to the surface to be exploited for power production.
 
The simplest design for a geothermal power plant takes advantage of hydrothermal convection. Cool water from the surface seeps underground, is heated and then rises back to the surface. The heated water, now steam, is obtained by drilling wells to capture the steam and directing it to turbines for energy production. The water from the condensed steam can then returned to continue the cycle.
 
Although the heat is essentially free, the cost of drilling and maintenance of equipment can be high. Subterranean steam extracts caustic materials which corrode even the most inert metals. A limiting factor for energy production can be the rate of heat transfer through rock. As heat is extracted from rock surrounding the well site, heat must be transferred through the rock, limiting the rate of heat extraction.
 
The United States leads the world in geothermal electric capacity. The US has about 2.7 GigaWatts installed, a quarter of world capacity. Twenty six plants in one location called the geysers,

geysers north of San Francisco, accounts for three quarters of the total US production. For comparison, one nuclear reactor has a capacity of just under one GW.
 
Parts of Alaska, Washington, Oregon, California, and much of Nevada and Hawaii have potential for geothermal electricity production and much of the Rocky Mountain area could extract useful heat for direct uses such as space heat for apartment buildings, schools, and other large facilities.