Category Archives: Sustainable Energy

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.

wind-farm

Opposition to Transmission Line

Pope County Quorum Court opposes clean air, stable climate!

Recently the quorum court voted unanimously to oppose the construction of Plains and Clean Line’s High Voltage Direct Current transmission line. The HVDC line has been proposed to run from Guymon, Oklahoma to Memphis, Tennessee. If built it will move 3,500 MegaWatts of wind generated electricity from the Midwest to Arkansas and the Tennessee Valley Authority (TVA) power grids.

The resolution reads in part “If this power line is built, it will be an enduring eyesore to Arkansas and Pope County, affecting the natural beauty of this area and damaging property values with little positive effect…”

This proposed transmission line is an eyesore compared to what? The welter of transmission lines emanating from Arkansas Nuclear One? Or would it be an eyesore compared to the transmission lines coming from the powerhouse at the Lake Dardanelle Dam. Maybe it is an eyesore compared to the transmission line running from the half a dozen or so other power plants in Arkansas.

Power lines, be they large transmission lines or the smaller distribution lines are a fact of life. Literally hundreds of miles of transmission and distributions lines, owned by both private (Entergy) and co-op (Arkansas Valley Electric) corporations, criss-cross the county already.

It has been suggested that we could free ourselves of these and future electric grid improvement “eyesores” by the utilization of underground cables. That is certainly an option, but a very expensive one. Installation costs for underground transmission lines can be 8 to 10 times that of overhead lines. Although buried cables are less likely to fail due to weather events for example, when they do fail repair times are greatly extended. Repairing or replacing buried cables can require days or weeks rather than hours.

Another option would be distributed electrical energy sources such as roof-top solar PV to avoid the need for large transmission lines but even here there is a need for a wide area distribution grid. Roof-top solar is also much more expensive than utility scale wind power. Many states including Arkansas, are enacting legislation to make roof top solar even more expensive.

Another point in the quorum court resolution is that the line will provide “little positive benefit.” People that appreciate clean air and a more stable climate might quibble with the little part of the resolution. The proposed line will carry the power equivalent of five or six coal fired boilers. That could mean millions of tons of coal not burned every year. Just for perspective, those interminably long coal trains that snarl traffic as they pass through Russellville carry tens of thousands of tons of coal every day from Wyoming strip mines to one power plant in Redfield Arkansas.

The real irony of the quorum court vote is the simple fact that each and everyone of the JPs gets electricity to his or her home via the grid. That means many folks “upstream” have to suffer eyesores and devaluation of their property to keep the lights and big screen TVs powered up in the JPs’ homes. A similar resolution was passed by the Johnson County Quorum Court. Hypocrisy much?

US Oil Booms, But

About 2013, for the first time in over 20 years, the gap between our consumption and production began narrowing, rather than widening.  There are two reasons for this. Production is up due to the fracking boom and of equal importance consumption is down due to the poor economy.  That is good as a snapshot but means little for the future.

As the economy slowly recovers our usage will rise.   At the same time the fracking boom has a limited lifetime. A University of Texas study showed that production of natural gas from three of the largest shale plays; Fayetteville, Haynesville, and Barnett have already peaked. Similar performance is expected in oil from shale fracking. In a few short years we should be back on our inevitible decline in production. Without reduction in consumption we will resume an upward trend on importing oil, currently about a third of what we use.

The danger is fourfold: exporting dollars to buy energy weakens our economy, enriches the economy of some unsavory producers such as Iran and Russia, threatens a stable environment, and impairs our health.

To a large degree all transportation and big chunk of the U.S. Economy is powered from crude oil. The oil is turned into gasoline, diesel fuel, jet fuel, heating oil and a myriad of derivative products such as plastic. Currently we are consuming about 18 million barrels of oil per day, yet we only produce about 12 million. That constitutes an energy deficit of about 7 million barrels of oil per day. Even with the price falling to near 50 dollars a bbl, this creates a trade deficit of over an eigth of a trillion dollars a year. An eigth of a trillion dollars a year that flies out of our economy on an annual basis. An eigth of a trillion dollars that is not flipped in our economy to provide jobs or buy groceries.

The oil comes from friendly and not so friendly countries. Canada is our number one supplier, some might say “pusher” at about two and a half million barrels per day. The members of OPEC, the Organization of Petroleum Exporting Countries, provide about 5 million barrels of oil per day. Iran is a charter member of OPEC and benefits greatly if indirectly from our purchase of oil on the global market. This is not a pretty picture – our dollars going to support a rogue theocracy bent on developing nuclear weapons and their support for global terrorism. Although we are currently a net exporter of natural gas, this won’t last when the shale plays are exhausted.

We even import uranium to fuel nuclear reactors. The import export balance is negative to the tune of several billion dollars a year. Generally we import low grade Uranium ore and export enriched nuclear fuel. Regardless we are operating at a net dollar loss.

The only fuel that we don’t have to import is coal; however, as society becomes more aware of the risks of damage to human health and the environment, it will become less useful in our economy.

There is no easy answer to this bleeding of cash from our economy. We will not drill our way out of the problem because the oil and gas are just not here. We must adopt energy from clean indigenous sources as the only long term, sustainable answer. The bonus for home produced sustainable energy is the money stays home and cascades through the economy.

Electrical Energy Future

A sea change in electrical energy production and utilization will be occurring over the next few generations which will make for a cleaner, more sustainable future. The current model for energy generation and distribution relies on relatively inefficient thermal power plants, power by fossil fuels or uranium. They are inherently inefficient, converting only a third of the energy available, the remainder is unusable waste heat. Fossil fueled plants have the added disadvantage of adding Carbon Dioxide to the atmosphere and driving global warming.

coal smoke

coal smoke

In 2009 the United States Environmental Protection Agency found that Carbon Dioxide and five other gases constitute a threat the human health and welfare and are a primary cause of global warming. After several years of planning they recently announced actions to mitigate this risk. Over the next 15 years states will on average have to reduce their emissions of CO2 by 30 percent. This will be achieved mainly by moving away from burning coal to produce electricity.

Although the national mandate is 30 percent, the Arkansas requirement is to lower our carbon emissions by 44 percent. That’s the bad news. The good news is that we have recently started in the right direction by demand side management. There are two ways to meet the EPA mandate, either find a way to replace the electrical production with non carbon energy sources (supply side) or reduce demand for electrical energy through efficiency (demand side.)

Recently the American Council for an Energy-Efficient Economy (ACEEE) lauded Arkansas for its progress in enacting aggressive energy efficiency measures. Arkansas was named as one of four “most improved” along with Kentucky, Wisconsin, and the District of Columbia, moving up six spots from its 2013 ranking. Specifically, the ACEEE noted that “[Arkansas’s] budgets for electric efficiency programs increased 30 percent between 2012 and 2013, while electricity savings more than tripled.”

The beauty of demand side management is that it not only save energy, it saves money. Every kilowatt-hour you don’t use, you don’t pay for. Energy efficient light bulbs such as compact fluorescent (CFs) bulbs or even better light emitting diodes (LEDs) save money and energy. Shade trees on the south side of a home save money and energy. More efficient electric motors save money and energy. Examples abound. A nifty term encapsulates this kind of savings – the negawatt. It is the energy you don’t use, hence money you don’t spend, through efficiency.

The next step is to gradually phase out our older coal fired power plants. This makes sense because as the older plants are the least efficient. You pick the low hanging fruit first, right? Prices for solar panels to generate electricity have been falling rapidly in recent years. Currently the price is such that a solar panel array pays for itself in about 10 years, after that the electricity is essentially free.

wind-farm

wind-farm

A lot of wind generated power is available to us from the west. A large project, Plains and Clean Line transmission line will be bringing clean wind generated electricity to Arkansas and parts east over the next few years.

If we make the right choices the world will be a better place in the future – our children’s children’s future.

Energy Costs and Financing

It is difficult to compare the costs for energy from various sources, but it is an important issue. In Arkansas we are blessed with (or cursed by, depending on your point of view) relatively low electrical energy costs. We pay about eight to nine cents per kilowatt- hour (kWh) which is about three cents below the national average of twelve cents. In some locations and at some times of the day the costs can go over 25 cents per kWh. These costs do not include externalities such as damage to health and the environment, risks associated with global warming, political instability and direct subsidies to insure risky technologies.

It has been estimated that the inclusion of these costs could raise a monthly electric bill by two to five times. An average Arkansan’s electric bill would be closer to five hundred dollars rather than slightly over one hundred dollars per month.

Clean renewable energy from for example photo voltaic systems (PV, solar electric panels) can be prohibitively expensive when you compare the costs without consideration of the external costs of traditional electricity production. It would seem only fair then to subsidize PV systems and that is happening to a limited degree.

5.4 kW solar array

5.4 kW solar array

The federal government provides a thirty percent tax credit for residential and small commercial systems which makes these systems more competitive with traditional energy sources with their hidden subsidies. Recently the state of Arkansas through the Arkansas energy office has begun an additional subsidy based on energy produced by renewable energy systems. For program details see: http://arkansasenergy.org/.

The current program from the state provides for on-bill financing for qualified energy efficiency improvements that consumers can install on their premises: energy efficiency measures, distributed generation (e.g., solar photovoltaic, combined heat and power), and demand response (DR) technologies.

shade trees same energy

shade trees same energy

Consumers typically have extensive experience making utility bill payments, it is already a routine part of their lives. It is also conceptually attractive to make an investment where the energy savings that result are reflected in the same bill as the payments on the loan that funded the investment. This method of financing is particularly attractive for projects which have long pay back times. If the original owner sells the property, the financing remains with the improved property.

Low-E glass saves energy

Low-E glass saves energy

Because we have relatively low electric costs here in Arkansas, the payback for subsidized systems can be on the order of a couple of decades for large projects such as PV systems. In locations with much higher electric rates, say 25 cents per kWh, the payback would be much sooner.

The question then becomes, do you want to continue wars, and general global political instability because of our reliance on oil imports? Do you want to continue to support scraping the tops off of mountains to get at “cheap coal”. Do you want to continue to contribute to the degradation of the environment from oil spills? Do you want to contribute to the degradation of health through air pollution? To the deaths of miners and drillers? Global warming and ocean acidification?

You can walk away from all that now, but sustainable clean energy supplies are a future you can make happen now.  

 

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.

Solar PhotoVoltaic Primer

The cost of photovoltaic systems (panels and inverter) has dropped to about 2 to 3 dollars per watt. At this price systems have payback times in the 10 to 15 year range, regardless of size. This assumes a cost of about 10 cents a kilowatt hour (kW-hr) for electricity.

Here are a number of nuts and bolts issues for those interested in solar power. First and foremost you must have a location with southern exposure. Even a small amount of shade can seriously reduce energy production. For most this means a roof top location, but it needn’t be if you have the space to put the array on the ground. The simplest mounting puts the panels flat on the roof. The pitch of the roof is not all that important as long as it faces south.

sun's path

sun’s path

The amount of space needed for an array of course varies as to how much total power you want to produce. Different manufacturers make panels in different sizes (watts) but the total space needed is the same because all PV panels have the same efficiency, about 15 %. Five 100 watt panels will take up the same space as one 500 watt panel. One kW requires about 80 square feet of space.

A big decision is whether the array is isolated or connected to the electrical grid. Grid-tied systems here in Arkansas can take advantage of net metering. This means that the power produced by the panels can actually make a meter run backwards if they are producing more power than the home is consuming at any time. About the only disadvantage of a grid-tied system is that when the line goes down, so does the solar power production. This is necessary to protect power line workers.

PV Grid-tied system

PV Grid-tied system

The alternative to grid-tied is to go entirely off line by buffering production with batteries. This avoids the aforementioned problem, but greatly increases the cost and “hassle factor” of the system. This is only practical when connection to the grid is cost prohibitive, as in remote locations.

The total amount of energy produced by a system is obtained by the total wattage of a system. For example a 1 kilowatt system can produce a maximum of one kilowatt hour only when the sun angle is ideal. Averaged over a year, a simple rule of thumb is that you can get 4 hours of net production per day. Hence a 1 kW system can be expected to produce 4 kW-hrs per day, more some days, less others.

Let’s use an average consumption of 1000 kW-hrs per month (close to the average in Arkansas) to determined a system sized to replace 100 % of electric needs. 1000 kW-hrs per month means 33 kw-hrs per day. Divide that by 4 to get a a little over 8 kW system. To allow for some inefficiencies say we use a 9 kW system. At 2.5 dollars a watt, the total cost would be 22,500 $. The 30% federal tax rebate brings the final cost down to 15,750 $. Sales taxes and installation will add to the cost, but these numbers can be used to approximate a cost if you are interested in going solar.

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.

Phantom Loads

A while back a congressman at a town hall meeting suggested that federal research dollars were being wasted and gave as an example a study examining how much energy is used when a consumer electronic device was turned off. Everybody knows that electronic devices don’t use power when turned off, right?

I am sure the line drew a laugh and the was object of derision of the crowd, but the irony is that the questioned study aimed at reducing waste and therefore saving, not wasting dollars. Real money is wasted on a daily basis due to phantom loads.

image credit: www.nativeenergy.com

image credit: www.nativeenergy.com

Many consumer devices such as televisions, computer printers, video gaming devices, and others are actually in standby, not off when switched off. These phantom loads or sometimes called vampire loads use significant amounts of energy.

There are two basic reasons for the phantom energy use. One is for convenience. Televisions, DVRs and such, are left in stand by mode so that they will come on more quickly. These are so called instant on devices. My LCD television has a little red light which glows when the television is “off” meaning of course that it is still on even though it is turned off. It may be off for 20 hours a day, but is still using power so that it will come on six seconds faster that if it had been unplugged. I use a couple of bucks a year for that six seconds. A couple of bucks a year for just one device is no big deal, but most homes have several instant on devices.

image credit: www.nativeenergy.com

image credit: www.nativeenergy.com

image credit: www.nativeenergy.com

image credit: www.nativeenergy.com

The other type of phantom load comes from the need to transform alternating current (AC) to direct current (DC). AC is the type of electricity that comes out of the wall. It is what the power company delivers and sells to you. Direct current on the other hand is what is used to power some devices and especially to charge anything with a battery. Collectively these are the devices with “the brick”, a transformer. You plug the brick into the wall and then it gets plugged into a device, say a cell phone. Even without the cell phone plugged in (or the computer printer or the computer speakers, or the wireless telephone, et. al.) they are still using power.

The instant on devices use only a fraction of the power when in stand by mode, but the fact that there are numerous devices in a home and they are in this mode most of the time means it can add up. The power bricks are especially inefficient, wasting anywhere from twenty to a whopping eighty percent of the energy consumed. This wasted energy is ultimately lost in the form of heat, adding to air conditioning loads in season. For the average household six to ten percent or more of total power to consumer electronic devices is attributed to phantom loads.

image credit: www.nativeenergy.com

image credit: www.nativeenergy.com


The only answer to reducing these phantom loads is to unplug or “unpower” the device when not in use. A few power strips at strategic locations around the house can save energy. And every bit of energy not used is beneficial to the environment and your pocketbook.

Distributed Energy Production

Long term solutions to power society should be sustainable, clean, safe, and affordable; but all of these descriptors are relative. Sustainable has the least wiggle room in its definition. Fossil fuels which took 100s of millions of years to accumulate, but are being consuming over a century or two obviously don’t qualify. For that matter they are neither clean, safe, nor affordable if consideration is given to all the hidden costs of health care and environmental degradation.

Large hydropower facilities are generally thought of as clean and affordable, but how about sustainability and safety? Large scale hydropower sites, dams with lakes behind them, don’t exist forever. Depending on the facility, life spans of 50 to 100 years seem to be an average. The reason is simple, rivers carry more than just water, they also move silt. Eventually the dam site will fill with silt. After time silt accumulates, filling in the reservoir.

The silt can be dredged out but that can become a large expense, impacting affordability. Hoover Dam, because of it size, and more importantly the silt trapping effect of Glen Canyon dam above it, has a projected life time of several centuries.

What about dam safety? Actually catastrophic failures are not unheard of. In the last 10 years in the United States alone close to 200 dams have failed. Obviously living downstream of a dam is not the safest place to be. One dam failure in 1975 in China resulted in 26,000 deaths due to flooding and another 146,000 deaths due to illness and famine.

Nuclear power is considered by some to be a sustainable energy supply, and as long as everything operates as it should it can be clean and safe. Nuclear power however suffers from the risk of catastrophic consequences when things go wrong.

Three Mile Island suffered a partial core meltdown with minimum release of radioactive material. Three million people live within a 30 radius of the site.

A reactor in Chernobyl, Ukraine caught on fire and burned uncontrollably for days, spewing radioactive material for hundreds of square miles. Radioactivity set of alarms at a reactor site in Sweden within two days.

Damage due to a tsunami caused failure of several reactors at Fukushima and the problems are ongoing. A radioactive plume of seawater is making its way across the Pacific Ocean towards the west coast of North America.

So we are left with wind, solar, and geothermal. They are all sustainable, clean, safe, and compared to the real costs of the alternatives affordable. An especially attractive aspect of these sources is that they are quite diffuse compared to the aforementioned alternatives. Nobody will knock out the grid by flying a plane into tens of thousands of solar arrays, it just can’t be done. A terrorist might take down one wind turbine, but not hundreds in a wind field.

Any centralized power plant can be a target for terrorism. Our energy supplies of the future should be sustainable, safe, clean, and affordable. We should add distributed to the list as very unlikely targets for terrorism.