Volcanoes and Carbon Dioxide

I met someone at a company function a while ago and got into a discussion about green-energy and how cool it was that we were working for a company involved in helping customers better manage their energy usage. We eventually started discussing CO₂ and climate change and I soon realized this person was skeptical about man’s ability to affect climate change. He then stated quite matter-of-factly that a single volcanic eruption emits more CO₂ than man has ever.

I didn't know if he was right or not as I didn't know how much CO₂ is emitted by volcanoes. I decided to look into it and make it a subject of this post.

Natural sources of CO₂ emissions come from many sources, e.g., animal exhalations, burning and decaying of organic matter and from volcanoes. So surely fantastic eruptions from volcanoes like Mt. St. Helens and Mt. Pinatubo have emitted more CO₂ than we ever could right?

Volcanoes are found all over the planet surface as well as underneath the oceans. There are about 50 – 60 active volcanoes on the surface and over 100 active volcanoes underneath the oceans. According to the US Geological Survey, the estimates of CO₂ emissions from all volcanoes on the surface and underneath oceans range from 150 million to about 270 million tonnes (metric tons; 1 tonne = 1.1 tons) a year. This seems like a huge amount but now we have to compare it against what is emitted as a result of human activity.

Some examples of man-made sources of CO₂ come from the burning of fossil-fuels like oil, coal and natural gas for power generation and transportation; from industrial processes like cement production and gas-flaring. Other sources include deforestation from slash/burn farming and from transformation to growing palm trees for palm-oil and the like. The global estimates of man-made CO₂ emissions, based on a study published by Nature Geoscience, is around 35,300 million tonnes. This is roughly 130 times higher than that emitted by all active volcanoes!

What if we wanted to compare volcanic CO₂ emissions to that from transportation and industry only? Estimates from Oak Ridge National Laboratory indicate that CO₂ emissions from light-duty vehicles used throughout the world contribute about 3,040 million tonnes, or more than 11 times that from volcanoes. From the same study, the emissions from industries contribute approximately 6,100 million tonnes, which is more than 22 times that from volcanoes.

And as countries like China, India, Brazil and others continue to industrialize, the amount of man-made CO₂ emitted will only increase, which will adversely affect climate change on Earth unless we make some changes!

In my next post, I’ll compare the percentage of man-made CO₂ against all other contributors in the atmosphere that cause the Earth to warm. Spoiler alert!! Man’s contribution is small but it is still a big deal.

Update

Hi everyone, it’s been a while since I’ve posted on my blog site so I thought I’d take this time to update you as to what’s happened since my last post in February of 2010. You see, I was living in Plano, TX, a suburb of Dallas at the time when I was posting. In the second quarter of 2009, I was released by my employer in a work-force reduction initiative and during my search for my next opportunity I had some free time and decided to use this time to create a blog and post on topics that interest me.

I worked for a manufacturer of power systems aimed primarily at the telecom industry; when the telecom carriers were spending to upgrade and expand their networks, we were making revenue; however, when things were tight – as was the case immediately after the Internet-bubble bust and during the current economic crisis – the carriers cut back on spending and our revenues were heavily impacted. It was also one of the major reasons for the workforce reductions my employer had to undertake to remain viable. All telecom equipment manufacturers were in a similar position; as a result, I wanted to move into a different and growing industry.

During this time, I noticed a lot of activity and investment in alternative-energy, energy-efficiency and energy-management. I was interested in alternative energy especially PV/solar energy and decided to focus my energies to enter this industry for my next-opportunity. As part of this endeavor, I read and research important topics, current issues, opportunities and challenges germane to this industry.

I’ve also wanted to write but never had the time to seriously pursue it; I also couldn’t decide what I wanted to write about. I had heard about blogs and read many of them and thought I could do this! So I decided to combine my two interests and start a blog site to write about the various topics I researched. During the latter part of 2009, I researched and wrote six posts on topics ranging from CFL light bulbs to an experiment I ran in lowering my carbon footprint.

I was also interviewing for my next opportunity during this time and in early 2010, I interviewed with a startup company in Roanoke, VA involved in energy-management and sub-metering; they were looking for a hardware product manager. I liked what I saw and decided to take the offer. So in March, the company relocated me to Virginia.

I was excited to work for a startup and came in with preconceived notions of what to expect. I expected a company with a flat-organization with an entrepreneurial sprit and an intense focus on customers with preservation of cash being a major concern; however, to my chagrin, what I saw was just the opposite! We had many executives who were at times working at cross-purposes with one-another to the detriment of the company; individuals were flying to our many remote sites on a whim with no clear purpose, etc. But my biggest concern was that our actual revenues were much lower than the unrealistic end-of-year targets. I had a feeling it couldn’t last long … and it didn’t.

The company had difficulty raising cash from operations and had to look to external investors; in garnering this investment, they had to show their investors they were making strives to shore up their revenue shortfall so a major restructuring ensued whereby entire businesses were shuttered and personnel including me, were released! I had been there only seven months! My first experience working for a startup company was not good.

I really liked the industry and the products the company made – in a future post, I’ll write about what sub-metering is and how it helps companies – and I was disappointed that it didn’t last longer. I also liked the people I worked with in the Virginia office; furthermore, Roanoke is a beautiful and scenic city albeit being small and not having many of the large-city amenities that I was used to.

In looking for my next opportunity, I shied away from startups and tried to focus on large corporations but I interviewed with all types of companies. In whittling through the opportunities that was availed to me, one company really impressed me in the way they pursued me, but it was a startup company! The people at this company assuaged my concerns regarding working for a startup company; they also explained that they had just secured a major investment from a foreign company so cash-flow wouldn’t be a concern. After much deliberation, I decided to take a chance and accepted the position.

So in November of this year, the company relocated me to Indianapolis, Indiana, my second move of this year! I’ve been with the company for about a month now and this company feels more like what a startup company should be like. Also, Indianapolis looks like it could be a lot of fun and I’m looking forward to exploring.

This company is involved in mega-Watt battery power systems in frequency-regulation and grid-stabilization applications with the electric utilities as well as with solar and wind applications and in another future post, I’ll elaborate more on what these are and how my company and our products help.

So that’s what I’ve been doing since my last post. 2010 was a pretty exhausting year for me and I’m really looking forward to a better 2011! I’m still interested in all things related to energy and will be posting shortly again once I get more settled; I move into my apartment in January so it shouldn’t be much longer! I’ll also post on non-energy related topics, i.e., on topics that generally interest me and I hope you’ll find it entertaining and informative.

Finally, I want to wish everyone a happy and prosperous New Year!

Happy New Year everyone!!

CFL Light Bulbs and Energy

There's been a lot of news regarding our need to replace incandescent light bulbs with Compact Fluorescent Light (CFL) bulbs as it will result in more efficient use of our existing energy resources, which should lessen our need to build new carbon-emitting power plants. I did replace most of my light bulbs with the CFL type but I was curious as to how much energy I'd save using them so I decided to look deeper into them.

The incandescent light bulbs and the light bulb socket we use today is pretty much the same as the ones invented by Thomas Edison back in 1897. The incandescent light bulb generates light from electricity running through a tungsten filament that is vacuum enclosed in a glass bulb. The electricity causes the filament to heat to roughly 4200ºC and glow to give off light. Unfortunately, only about 10% of the energy going into the bulb is used to generate light; the remaining energy is wasted as heat.

The CFL bulb is different in that instead of heating a filament, high-frequency electricity ─ generated from an electronic ballast integrated into the light bulb ─ is used to energize mercury gas enclosed within the bulb. Mercury gas emits ultraviolet (UV) light when energized; the inner walls of the bulb is coated with phosphor, which glows in visible light when hit with UV light. The electronic ballast converts utility ac voltage ─ 120Vrms at 60Hz in North America ─ to high-frequency power, usually around 40 kHz.

One of the complaints about CFL bulbs are that the light emitted is too white and harsh and that they take too long to turn on and emit light. However, the latest CFL bulbs have a warm glow to them, similar to the standard bulb and I find them quite comfortable for reading and working. And these bulbs take only a second or so to light up, which I don't find annoying at all.

The total amount of visible light emitted from a source is provided in units known as lumens. A standard GE Soft White light bulb emits approximately 840 lumens; a 13W GE Energy Smart CFL bulb emits approximately 825 lumens. I haven't noticed any appreciable decrease in light-output from the CFL bulbs; therefore I compared a 60W standard bulb against a 13W CFL bulb. In comparing costs, I used values of $0.27 and $3.77 as the cost of an incandescent bulb and a CFL bulb, respectively; I obtained these values from the GE website. 

As the cost of the CFL bulb is substantially more expensive than the standard light bulb, I wanted to determine how long it would take for me to recoup the cost of the CFL bulb from the energy savings. As I needed a light source regardless of the type of bulb it came from, I used the cost difference of the CFL bulb to a standard bulb as my initial investment. Using an energy cost of $0.13kWhr and assuming I'd use the light bulb for approximately 5 hrs a day, I came up with the number of days required to recoup my investment.

It would take approximately 115 days to recoup the cost for the CFL bulb based on an energy cost of $0.13kWhr. This is approximately 3.5 months, which isn't too bad. I then decided to calculate my annual savings using 365 days in a year as shown below.

I would save approximately $11.15 using the CFL over the incandescent light bulb at an energy rate of $0.13/kWhr. Multiply that by the other lights in a typical household and the dollars start adding up! The table below provides payback and savings data at different energy rates.

Payback and Energy Savings Data

Energy Rate, per kWhr	Days To Payback	Annual Savings
$0.10	149	$8.58
$0.11	135	$9.44
$0.12	124	$10.29
$0.13	115	$11.15
$0.14	106	$12.01
$0.15	99	$12.87

 

As the data above clearly shows, substantial energy savings can be had using CFL bulbs. And the energy saved not only means more money in my pocket but also less CO₂ released into the atmosphere and contributing to climate change. All good things!

Now CFL bulbs do contain small amounts of mercury, which is a restricted and hazardous material. According to Energy Star data, each CFL bulb contains about 1.4 - 4 mg of mercury; as a point of reference, old thermometers contained about 500mg of mercury. But the EPA estimates that the US emits approximately 104 tonnes of mercury each year and that most of it comes from coal-fired power plants. Using CFL bulbs, which uses 75% less energy than standard bulbs, would prolong our use of existing power systems without the need to build additional power plants to satisfy our growing energy needs, which will result in less mercury released.

Finally, when CFL bulbs become inoperative and need to be replaced, follow recommended disposal instructions available from the manufacturer or from your local municipality.

Newer and more efficient lighting systems using LED technology are being developed and I'll talk about them in a future post.

According to Energy Star, if every household in the US changed just one light bulb to a CFL light bulb, it would save enough energy in one year to light up 3,000,000 homes. Change your bulbs!!

An Experiment in Lowering my Carbon Footprint - Part 3

In my last post, I discussed the amount of CO₂ I prevented from being released into the atmosphere by increasing the thermostat setting in my house during the summer months in Dallas, Texas. I won't say it was a breeze to do; however, I am pleased by my results and by how much energy I saved.

In researching for my post, I discovered some interesting facts about US power consumption.

In 2007, the energy demand from the entire United States was 4.157 x 10¹² kWhrs; this includes energy used in transportation, utility electricity generation, residential and commercial and for industrial purposes. The total amount of energy demand for electricity generation was 2.5 X10¹² kWhrs. The types of fuel used to generate electricity in the US is provided below:

Breakdown of 2007 Energy Generation
Fuel Type	Energy Generated	Percent of Total
Coal	2.02 MWhrs	48.5%
Gas	0.9 MWhrs	21.2%
Nuclear	0.8 MWhrs	19.4%
All Other Sources	0.44 MWhrs	10.52%

Other sources of energy include that derived from solar, wind, biomass, hydroelectric among others.

The total amount of CO₂ released in 2007 from all sources was 2.5M metric tons (tonnes) or 2.7M tons. The largest contributor to this is from the generation of electricity and burning coal releases more CO₂ than oil or natural gas.

President Obama while attending the UN Climate Summit in Copenhagen, Denmark proposed a target reduction in US greenhouse gas emissions by 17% below 2005 levels by 2020. In order to maintain a somewhat pleasant lifestyle, I'll have to find additional ways in which to reduce my carbon footprint as I won't maintain the thermostat setting I used in my summer experiment in future summers.

In future posts, I'll share my thoughts on some of the ideas I came up with to lower my carbon footprint. I'm also going to start tracking my monthly energy consumption to see how effective my actions are and I'll share them periodically.

So why is reducing CO₂ in the atmosphere such a big deal? For most of pre-industrial humanity, the level of CO₂ in the atmosphere was approximately 275 parts per million (ppm); this is a ratio of the number of CO₂ molecules to all other molecules in the atmosphere. As we started to burn coal and oil to create energy, the amount of CO₂ in the atmosphere started to rise. Scientists have estimated the amount of CO₂ currently in the atmosphere to be 390 ppm and rising roughly 2 ppm per year. They have also stated that we need to curtail our activities and bring the number to a sustainable 350 ppm.

Most of the sunlight emitted from the sun is in wavelengths shorter than 4 μm, which pass through the atmosphere and gets either absorbed or reflected by the earth. When reflected from the earth, the wavelengths are stretched longer than 4 μm and the heat energy gets absorbed by the CO₂ molecules in the atmosphere. When a molecule of CO₂ absorbs heat energy, it goes into an excited and unstable state; to become stable again, it releases this energy. Some of the heat energy will fall back to the earth and some gets released into space.

If the amount of CO₂ in the atmosphere increases, the amount of reflected heat energy increases, which results in temperature increases. This is called the greenhouse effect and is similar to sunlight warming the interior of a car that has all its windows closed.

There are many things being done to combat this starting from greater use of renewable energy to generate electricity; higher gas mileage for cars; energy efficiency initiatives to name just a few. There are many initiatives being implemented at the local, state and national levels by many countries. I believe if we all work together, we can have combat climate change and at the same time intelligently meet our energy needs going forward.

Converting Solar Energy into Power - Photovoltaic Cells

My last post discussed how energy is created in the sun and arrive on earth via packets of energy called photons; it also discussed the amount of sunlight power that falls on the earth, also called irradiance. This post will discuss one of the ways in which we can convert the sunlight into usable power.

One of the ways it can be converted to usable power is via the photovoltaic effect. It was noted that semiconductor materials like selenium release small amounts of electricity when exposed to sunlight. When photons strike these materials, their energy is absorbed and transferred to electrons within the materials. With this energy, the electrons are able to break free from their atoms and flow as in an electric current. Further research into material science resulted in using silicon doped with impurities such as phosphorous and boron.

Adding these impurities to silicon required less energy from the photon for the electron to break free. Silicon doped with phosphorous forms a negative or n-type semiconductor material and silicon doped with boron forms a positive or p-type material. Placing an n-type material in close proximity to a p-type material creates an electric-field at their junction. If free electrons and holes happen to get close to the electric field, the field will send the electrons from the n side to the p side and positive charges or holes from the p side to the n side.

If we add leads to either sides of the semiconductor material and connect them to a load, a circuit is created and electrons can flow through the circuit. The electron flow provides the current, and the cell's electric field results in a potential difference or voltage between the two material types. PV-cells develop direct-current or dc voltage.

The original PV-cells were made from materials such as selenium. These cells were only 1% efficient, meaning only 1% of the sunlight that fell on the material was converted into power. Research using doped silicon yielded cells with efficiency as high as 6%. Current manufactured cells have efficiencies in the range of 14 – 18% and laboratory tests on new cell-designs have shown efficiencies as high as 42%.

A standard solar panel is made from interconnected cells housed in a metal frame and protected with anti-reflective glass; they are typically 1200mm by 600 mm in size. A standard condition for testing solar panel rated power is under an irradiance of 1000W/m², at 25 ºC and a sunlight attenuation factor of AM1.5. This represents the typical conditions in the 48 contiguous United States at noon in the spring and autumn with the solar cell aimed directly at the sun. A panel rated at 14% efficiency is rated to deliver approximately 100W under the standard test conditions.

Currently, the most prevalent material used to make solar cells is crystalline silicon. Silicon is a well-understood semiconductor material with good stability, physical, electrical and chemical properties. Furthermore, silicon cells have benefited from the enormous economies of scale achieved from the semiconductor and microelectronics industry. However, the manufacturing process used to make silicon wafers is complex, which makes them expensive in solar power applications. Furthermore, demand for silicon from the microelectronics and semiconductor industry has driven up material costs.

There is considerable research and development into so called thin-film PV-cells, which use less silicon material. Some of these new types of thin-film PV-cells include CdTe (cadmium telluride), a-Si (amorphous silicon) and CIGS (copper indium gallium selenium). Solar panels formed from these materials have efficiencies in the 11 – 12.2% range, which are lower than that of silicon based panels; however, are much cheaper to manufacture and have higher manufacturing yields. Efficiency advances through continued investment in R&D and in manufacturing techniques could get efficiencies that are comparable with silicon based technologies over time.

Solar Energy is poised for high growth especially with issues related to climate change, a strong desire to diversify sources of energy and from national security concerns. In my next post, I'll continue discussing photovoltaic power and applications for it.  

An Experiment in Lowering my Carbon Footprint - Part 2

In my last post I discussed an experiment I ran over the summer months of 2009 in Dallas, Texas where I attempted to reduce my carbon footprint. In this post, I discuss my attempt to determine how much CO₂ I prevented from being released into the atmosphere and contribute to climate change.

In order to do so, I had to first determine two pieces of information: 1) estimate how much energy I saved over the duration of the experiment; and 2) determine the sources of power being delivered to me and the amount of CO₂ they emit.

To get the first piece of information, I went to my account on the TXU website and compared my energy usage for the summer months in 2009 to what I used in 2008; TXU is the energy company that bills me for the electricity I use. I assumed all other factors are equal and the only major contributor to the differences in energy usage result from my experiment. Below is a summary of my findings.

Table I. Energy Usage Data

Month	2008 Energy Used, kWhr	2009 Energy Used, kWhr	Difference, kWhr
June	1,025	716	309
July	1,820	1,128	562
August	1,690	1,212	608
September	900	473	427
Total	3,529	4,750	1,906

As a result of my experiment, I saved approximately 1,906 kWhrs of energy. In order to determine the second piece of information, I first had to determine how the power that was distributed to me was being generated. There a number of ways in which power is generated and each emits carbon in different amounts in the generation process. I had to determine for example, what percentage of my power was being generated from a coal-fired plant, from a natural-gas plant, etc.

I first contacted TXU and inquired as to how the power being delivered to me was being generated. They referred me to Oncor as TXU provides metering and billing functions to their customers. I then contacted Oncor who referred me to Luminant as Oncor provides transmission and distribution services. I never got a response from Luminant, the power generating company that serves me. I went to their website and did some digging around. I found that Luminant generates electricity using coal-fired plants, natural-gas plants and nuclear plants.

I determined the power generating capacity from all their plants and then determined what percentage of total the type of plant represents; they are summarized in the table below.

Table II. Luminant Power Plant Data

Plant Type	Generating Capacity, MW	Percent of Total
Coal	6,396	38.27%
Gas	9,018	47.97%
Nuclear	2,300	13.76%
Total	16,714

I was able to find the amount of CO₂ released per thousand-Watt-hours (kWhrs) of power generation from various fuels used in power generation systems from the US Government's Energy Information Administration website; they are summarized in the table below.

Table III. CO₂ Emissions Per Fuel Type

Power System Fuel Type	CO2 Released, lbs/kWhrs
Coal	2.117
Natural Gas	1.314
Nuclear	0

Note that nuclear fuel used to generate electricity produces no CO₂; however, a small amount is released from processing the uranium that is used in the reactors. I decided to ignore that fact as it wouldn't be meaningful in my estimates.

I assumed the power delivered to me was generated in the percentages shown in Table II. I then calculated the amount of CO₂ I saved by the following:

CO₂ = ((2.117)(38.27%)+(1.314)(47.97%))(1,906) = 2,743lbs.

This is equal to 1.37 tons or 1.24 tonnes of CO2 not released. I think that's pretty good and in future posts, I'll try to comment further on this.

I believe there is increasing scientific evidence showing our burning of fossil fuels such as coal, oil and natural gas are contributing to climate change. Burning fossil fuels in generating electricity is responsible for 39% of all carbon emissions.

In 2007, the per capita emissions in the US was 19.1 tons/CO₂; this represents approximately 20% of the total emitted by all nations in the world. The average American in their daily routine emits roughly 9.44 tons/CO₂. Assuming I fall into the average camp, by my experiment over the summer, I reduced my CO₂ emissions by 14.5%. I'll provide more details and analyses in my next post.

Getting Power from the Sun

I wanted to learn more about solar energy and I decided to start from the sun because that's where it all starts. The sun, our star is central to all life on Earth! Current theories state that the sun and everything else in the solar system formed from the leftover clouds of gas and dust from a massive star that went supernova. The cloud was mostly hydrogen and helium with trace amounts of other materials.

The sun formed from the coalescing of the materials in the clouds due to their mutual gravitational attraction. After a period of time as the proto-sun continued accumulating more material, it started to collapse under its own weight and build up pressure at the core. As the pressure increased, the temperature at the core started to rise. The pressure at the core is 340 billion times that of the earth at sea level and temperature is approximately 13,600,000 ºC. The present state of the sun is such that the inward pressure of all the material in the outer layers is matched by the outward pressure at the core.

The sun is enormous: it's diameter is approximately 864 million miles and equal to about 109 earths; it's volume is equal to approximately 1,300,000 earths. It is so massive that it comprises approximately 99.9% of the total mass of the solar system including that of the planets, moons, proto-planets, asteroids and comets. It is comprised of about 75% hydrogen, 24% helium and small quantities of other elements like oxygen, neon, iron, carbon and silicon.

At the very center of the sun, the pressure and temperature conditions are favorable for nuclear fusion to occur. Nuclear fusion is the process by which atoms are able to overcome their repulsive electrostatic force and bind to another atom by their attractive nuclear force and release tremendous amounts of energy in the process. The only place this can happen is at the core of stars. 

In this process the mass of four hydrogen atoms fuse into a single helium atom and release roughly 0.7% of the combined mass as energy per Einstein's famous equation E=mc², where E is the energy released, m is the mass lost in the conversion process and c is the speed of light in a vacuum. In one second, the sun converts 600 million metric tons (tonnes) of hydrogen into 595.8 million tonnes of helium; the missing 4.2 million tonnes are converted into energy. Every second, the sun releases approximately 386x10²⁶W of power; the sun releases more energy in one second than used by man in our entire existence!

In the mass-energy conversion process at the core, photons or "packets of energy" are released. It takes anywhere from 10,000 to 170,000 years for the photons to get from the core to the outer edge of the sun called the corona. This is due to the photons continuously being deflected from their path by electrons. Once free of the corona, the photons reach the earth, about 93 million miles away, in about 8.3 minutes. The photons are received by the earth as light and heat.

The sun also emits charged particles (electrons and protons) through its corona as the solar wind. Every second a million tonnes of these charged particles are emitted by the sun as the solar wind; we detect these particles as they interact with the earth's magnetic field as polar auroras or the northern and southern lights. The matter-energy conversion process also release neutrinos, inert particles that aren’t affected by and pass right through matter.

The sun has so much mass that even with the tremendous mass loss through the matter-energy conversion process and through the solar wind, it is estimated it has enough material to last for another 5 billion years. And it is estimated our sun has been in existence for approximately 4.6 billion years!

The photons or sunlight received by the earth is used by plants for energy in synthesising carbon into sugars and releasing oxygen, a process called photosynthesis. We can also use sunlight to create energy using various techniques. The estimated amount of power that the sun deposits on the earth is approximately 1300W/m²; however, due to atmospheric effects, the power is approximately 1000W/m². It is estimated that amount of energy that falls on the earth for an hour could satisfy the entire energy needs of the world for a year!

As this abundant source of energy will be available for a very long time, we should find ways to utilize it. It is free, clean and with our ingenuity, could satisfy all of our energy needs. My next post will discuss some of the ways in which we can use this energy to create usable power.