Tag Archives: climate change

Energy for Future Presidents: The Science Behind the Headlines

I had come across Energy for Future Presidents: The Science Behind the Headlines by Richard A. Muller in a bookstore about a year and a half ago and immediately put it on my to-read list. Assuming I would be able to pick it up the next time I was in the store, I did not buy it that day and ended up not finding it in any bookstore I went to for the next year. However the concept of the book, giving an overview of every type of energy technology and policy that might be relevant in the coming years to future leaders with non-scientific backgrounds, is so important to me that I finally ended up caving and buying it off Amazon.

All-in-all this book provides an excellent overview of the landscape of the energy industry and associated public policies, doing so in a way that is accessible and easy enough to grasp for people who are completely unfamiliar with the topics but also goes in depth in a way that still provides useful and new insights to those who are immersed in the energy world. If there’s one main gripe I have with Energy for Future Presidents, it’s that it was published in 2012 and thus a number of its analyses and conclusions are based on data and technology from even before that year. Obviously that’s not Muller’s fault, and it only got exacerbated by my own delay in finally reading the book, but it’s worth bringing up for anyone who is seeking the latest and most up to date information.

Overall, any of the energy-related nitpicking I have with information in the book are minor compared with the overall success I think Muller found in covering a wide variety of topics for a curious but not-scientifically-based audience– from climate change to the Fukushima disaster, solar energy to synfuels, and electric vehicles to energy productivity. To frame the book on its titular goal of educating ‘future Presidents’ on energy, Muller importantly highlights that its not just important that the President be scientifically literate on energy topics, but he or she must also know the science well enough to explain it the public and Congress to inform the decisions that are ultimately made. Not only that, but often a President’s scientific advisers might disagree and the President will need to know the basics well enough to make the best decisions. In that respect, Muller spends a majority of the book providing the data and facts, but he also can’t help himself from providing his own opinion as a scientific adviser. This provides the reader a fun opportunity to try out that exact role of the President– take in what the adviser is suggesting and, knowing the facts behind it all, determine whether he or she agrees with the subsequent advice. I know I didn’t agree with every piece of advice that Muller gave, but that’s to be expected when discussing such hotly debated topics and it certainly did not take away from my enjoyment of the book.


  • Energy Disasters: Regarding energy-related disasters, such as Fukushima and the Gulf oil spill, Muller suggests that the safe, conservative action of politicians in the immediate aftermath is to declare the incidents as extremely severe emergencies, as downplaying them and later being proven wrong would be a political and PR disaster. However, he goes through a number of these incidents and shows how, after the data is crunched, the real effects of the disasters are often much less significant than what they are initially made out to be. Not only does this do a disservice in diverting resources where they weren’t needed, but the panic caused by such grandiose declarations could end up doing more harm than good (e.g., unnecessary evacuations disrupting communities or overreactions to potential environmental effects harming tourism when it’s not warranted). His detailing of what ‘conservative’ estimates regarding disasters, and how such estimates inherently harbor the biases of those making the estimates, was particularly interesting and showed why a President should demand ‘best’ estimates in lieu of ‘conservative’ ones.


  • Radiation Risks: Specifically regarding the risk for disasters at nuclear power plants and subsequent radiation, Muller details how the city of Denver already has a natural dose of radiation (0.3 rem per year) and suggests using this natural dosage of radiation as a tent pole where any nuclear incident that is found to cause this much radiation or less should not be one to cause panic or action (as has happened in previous nuclear incidents where the panicked reaction came from not understanding this type of natural radiation). Again, it’s important not only for the President to understand this but also to be able to educate and lead the public on the topic.
  • Climate Change: I appreciated Muller’s careful attention to climate change, stressing the idea that an individual cannot sense the temperature variations attributed to climate change on their own because of the difference between weather and climate, and how the part that actually matters is the subtle rise of global average temperatures (a basic distinction that frustratingly gets misunderstood and is often cited by those claiming climate change isn’t happening because it was particularly cold or snowy on a given day in a given location). Further, Muller’s detailing of how he was once labeled as a climate change skeptic was eye-opening, when in reality he did not find himself on one side or the other– rather he was just pushing for certain aspects of the data and science to be strengthened before any conclusions were made. The stories of this time in climate research illuminated just how committed he was to the science behind any policy, regardless of how it was labeled by the media or by his peers, and stresses how important it is that basic science take the lead and not any particular policy or conclusion that we might hope to be correct. Ultimately, Muller adds his voice to those scientists who have concluded that humans are causing catastrophic climate change and certain actions must be taken before it’s too late.
  • Emissions in Developing vs. Developed Countries: In terms of political solutions for climate change, Muller highlights how global of an issue it is (the United States cutting its emissions in half won’t mean much if the rest of the world doesn’t follow suit as well) and points out how a dollar spent in China can reduce carbon dioxide emissions much more than that same dollar spent in America. As a result, Muller suggests subsidizing China’s efforts– an interesting and data-backed idea, though I would be curious to see how a President would be able to sell the public on such a strategy in today’s political environment.  Further, when Muller laid out the economics of certain energy technologies and how they worked in the United States compared with a developing nation like India or China, I was surprised to learn that the cheaper cost of labor in the emerging economies actually flips the script on what solutions are viable (e.g., cheaper labor for solar panel manufacturing and installation means that solar energy can be much more competitive with natural gas in China, whereas the increased labor costs in the United States to not allow such an advantage to solar).
  • Energy Conservation: Knowing just how much information Muller was trying to cram into this book without making it too dense and cumbersome, I especially appreciated the attention he gave to topics like recycled energy and conservation. In particular, Muller’s detailing how much economic sense it makes on an individual basis and on a macro-basis to grab the low hanging fruit of energy efficiency, even to the point that it makes financial sense for a power company to invest in subsidizing the public’s energy efficiency measures in order for them to get the best return on investment (ROI) for their money. The part of the story I was previously unaware of (showing my young age) was how President Carter’s attempts to promote energy conservation during the 1979 oil embargo gave most of the public a bad taste regarding energy conservation as they equated it with a decrease in comfort and quality of life. Once the oil embargo was over, Americans turned the thermostats back up almost in defiance of the false choice the government had inadvertently presented between energy conservation and comfort. Changing people’s preconceptions of energy conservation, how it can be a personal money-maker while not affecting quality of life at all, is one of the most important tasks Muller assigns to the future Presidents reading this book. He does so himself by showing how something simple (but unfortunately not flashy) like installing insulation in attics across America would have a 17.8% annual ROI, while switching light bulbs to CFLs would have a 209% ROI.


  • Natural Gas: The sections on natural gas were among some of the most immediately relevant and critical of Energy for Future Presidents, notably Muller’s discussions regarding the U.S. shale gas boom, its coming supplanting of coal as the largest fuel source for the power generating sector (which hadn’t yet occurred in 2012, but has now  happened), the importance of natural gas as a fuel that is 50% less emissive than coal as a middle ground, and the challenges but optimism surrounding natural gas vehicles. Regarding the environmental concerns of shale gas drilling, the sentence that stuck with me as a guiding principle  was the following: “companies have a financial incentive not to spend money unless their competition also has to spend money; that means the solution to fracking pollution is regulation.”



  • Extreme Weather Events from Climate Change: Going back to the journey Muller undertook with regard to climate science, one aspect he still resists is the linking of climate change to extreme weather events like hurricanes or wildfires. Muller says none of these phenomena are evidence of human-caused climate change, and linking them with climate change is only harmful to the cause because it’s too easy for skeptics to debunk these connections and undercuts the rest of the science that’s sound (caution that’s no doubt learned from the ‘Climate-gate‘ incident of scientists hiding discordant data and the 2007 IPCC report that incorrectly stated that Himalayan glaciers might melt from global warming). Muller’s position is we should simply rest on the temperature data as evidence, since those data are solid. The issue I take with this is that the effects of climate change on extreme weather events are important to know and consider when looking at the full gamut of motivations to stop climate change. While it is true that you cannot yet link specific hurricanes or other weather events to climate change, the science behind climate change driving an increase in extreme weather events has been growing in recent years. Ignoring these impacts, as Muller is doing, does a disservice to the entirety of climate science and the efforts to contain these extreme events.


  • Oil Prices: Towards the end of the section on liquid oil products, Muller asks “how high can the price of oil go? In the long term, it should not be able to stay above the synfuel price of $60 per barrel…That period of limbo is where we are now and the Saudis are worried.” This was an interesting point given I was reading it six years after the book was published, and I could look at what happened to the oil prices since then. In the short-term, it does show that Muller was right to question whether oil would be able to stay above $60 per barrel, as by 2015 the prices of both West Texas Intermediate and Brent crude oil fell below $60 per barrel again. So in that respect, Muller appeared prescient. However, it’s the idea that the oil prices would just continue unhampered in that trend that I had to nitpick, as Muller didn’t include any consideration of collective action of the Organization of Petroleum Exporting Countries (OPEC). OPEC largely operates as a cartel of countries who depend on the high prices of oil and attempt to control the supply of oil in order to control the prices. As Muller noted, the Saudis were worried and so they (with the rest of OPEC) took action. In November 2016, OPEC agreed on a quota of oil production among its members and a couple non-member nations, with that agreement being extended at this point to last through the end of 2018. The collective action of these oil producing nations, as well as the response of countries outside of OPEC (namely the United States), will have significant impact on the future of oil prices in the coming years and decades. Any assumptions on energy prices that don’t consider the power that OPEC yields aren’t telling the entire picture.

  • Electric Vehicles: The nitpick I found with this book that was the most vexing, which Muller himself identified as the part of the book likely to ruffle the most feathers, was his outlook on electric vehicles and how important (or rather, not terribly important) reducing emissions from the transportation sector is. The point Muller kept circling back to was the assertion that U.S. automobiles have contributed about 1/40 of a degree Celsius to global warming and that in the next 50 years the United States would likely be able to keep the additional warming to another 1/40 of a degree Celsius with reasonable efficiency standards. What I found frustrating about Muller’s take on what he called the ‘fad’ of electric cars is that he seemed so dismissive of their potential impact. First, discussing the climate change impact of vehicles in the United States seems intentionally narrow, as U.S. car sales only accounted for about 19% of global car sales (the below chart shows the top eight countries in terms of percentage of vehicle fleet made up of electric vehicles). While U.S. policy regarding vehicle efficiency would only impact the cars that can and cannot be sold domestically, the advancement of electric vehicles worldwide (particularly in China, India, and Europe where the desire for long-range electric vehicles is less important to consumers than it is in America) will have an even more significant climate impact. Policies that assist companies develop the technology will help electric vehicle sales worldwide and will have much more of a climate impact than the 1/40 of a degree Celsius that Muller predicts. Further, his rundown of the costs of electric cars vs. traditional internal combustion engine vehicles seems overly pessimistic about the technology and how costs will drop as mass production increases and as battery technology exceeds its current capabilities. I agree with Muller the hybrid-electric vehicles are going to be immensely important in the nearer term, but dismissing electric cars in the long term seems overtly shortsighted.



  • Content- 4/5: This book serves as a great primer on a satisfactorily wide swath of energy topics, while providing useful new insights for people who are already familiar with the basics. You will certainly come away having learned something that surprises and interests you. However, the nitpicks that I previously listed are too strong for me to assign a 5/5 for the content– but the highlights are all great enough that no less than a 4/5 felt appropriate.
  • Readability- 5/5: Muller goes out of his way to explain the various topics to an audience that might not be technically literate in a way that makes reading and learning from the book a breeze. Each individual chapter and section isn’t terribly long, so not only do you feel accomplished as you make your way through, but it also serves to be a useful reference later on if you want to brush-up on any specific topic.
  • Authority- 4/5: As noted earlier, one of the difficulties I had with this book is not the fault of the author at all, simply that it was published six years ago. The landscape of energy technologies and markets is rapidly evolving, so while the basics all still apply, there were issues here and there that appeared to simply be caused by it not being the most updated book. But on the technologies and the politics, Muller commands a strong authority from his background as a physics and his work in climate science.
  • FINAL RATING- 4.3/5: If you’re seeking a single book to give you a broad background on energy technologies, policies, and markets to inform your reading of the headlines of the day, this book is a terrific one to pick up. As Muller advises in the book, everybody comes to the table with their own set of biases– and the only criticism I find with this book is that sometimes Muller’s own biases become apparent (though surely that’s also just me reading the book with my own biases as well!). Energy for Future Presidents can serve both as a thorough read or as a type of reference for various technologies, so for that reason it’s a worthy book to add to your personal library.

If you’re interested in following what else I’m reading, even outside of energy-related topics, feel free to follow me on Goodreads. Should this review compel you to pick up Energy for Future Presidents by Richard A. Muller, please consider buying on Amazon through the links on this page. I’m also going to run a giveaway for this book– if you want to enter for a chance to receive a copy of this book, there are two ways: 1) Subscribe to this blog and leave a comment on this page and 2) go to my Twitter account and retweet the tweet that links to this review. Feel free to enter both ways in order to double your chances of winning! The winner will be contacted by the end of February. 

About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.  

Powering the Holiday Symbols: Energy and Emissions of Christmas Trees, Hanukkah Menorahs, and Kwanzaa Kinaras

The holiday season has a handful of hallmark indicators that announce its arrival– the immediate overtaking of popular radio, jack frost forcing you to bust the heavy jackets out from the back of the closet, and the increased crowds at malls everywhere. But if those harbingers of the upcoming festivities elude you, the season has one surefire signal that pops up everywhere to grab your attention– the decorations!

Specifically, as soon as Thanksgiving is over, youwould have to live under a rock not to notice the twinkling lights adorning storefronts, lamp posts, and porches across the country. Whether they’re for Christmas, Hanukkah, or Kwanzaa, lighting is an important part of the holiday season. That got me to pondering, naturally, about the relative energy use of lights and candles for each of these three holidays and their signature decorative centerpieces– the Christmas tree, the Hanukkah Menorah, and the Kwanzaa Kinara. I was interested not only in the question of how the energy use required by these three decorations compare with each other, but also what is the most efficient way to light each of them for the energy-conscious celebrator? Also, how do these three symbols of their respective holidays stack up in terms of carbon dioxide (CO2) emissions?

If these questions have been nagging you since you first spotted Christmas decorations for sale at Target in October (and I know they have), then you’re in luck. Keep reading for some estimates, assumptions, back-of-the-envelope math, and analysis and conclusions!

Preemptive notes

  • As had to be recognized in the other holiday posts (Most Climate Friendly Way to Light Your Jack-O’-Lantern and Talking Turkey: Thanksgiving Dinner Energy Use and Carbon Dioxide Emissions), these calculations are based on some liberal assumptions and over generalizations that are traced to readily available information. There will obviously be differences in the final calculations depending on a variety of factors– number of lights, how long the lights and candles are left on and lit, and numerous other variables that differ from household to household. While each assumption will have a citation to where it originated, rest assured that the final answers will still only be general back-of-the-envelope estimates. If one of the numbers or assumptions looks off, please comment below and discuss! Otherwise, just recognize that the goal is to find these rough estimates based on available information and general conclusions that are in the right order of magnitude for the sake of comparison, discussion, and general insight.
  • Also, it goes without saying that there are many more uses of energy associated with the holidays that are not being accounted for here– especially if you factor in outdoor Christmas lighting (e.g., were you to go as crazy with the outdoor illumination as Clark Griswold, you would be staring at an additional 27.7 kilowatts of additional power usage). This article is ignoring those other uses and is just interested in answering to the average energy use of Christmas trees, Menorahs, and Kinaras, including the range for both the less-efficient and more-efficient options among those three.

Christmas tree and lights

Basic assumptions

To break down the energy and carbon costs of lighting your Christmas tree, a number of very simplified assumptions need to be made about the average Christmas tree and its use. Again, keep in mind that these figures can vary greatly depending on the choices made by the individual household, but we’ll use the following assumptions:

  • There is no standard number here, but for the sake of calculation we will assume that the Christmas tree lights are on for 5 hours every night, as estimated by Christmas Lights Etc.; and
  • Much discussion exists out there for how many days a Christmas tree should be up in a house, with some sources estimating the average tree gets put up the first week in December and taken down sometime between Christmas and the New Year. Another traditional time to put up your tree is the first day of Advent, which this year falls on December 3 (coinciding with the first weekend of December). For 2017, we’ll assume families put up their tree on Sunday December 3 (first weekend of December, first day of Advent) and take them down the first weekend after Christmas– Saturday December 30– for a total of 27 nights the tree will be decorated (obviously this is a key variable that can change based on household habits).

Energy use of Christmas lights

For the Christmas lights used, let’s examine two options using traditional incandescent lights and one using more efficient LEDs. The actual wattage of these options will also vary depending on the specific light chosen, but for the sake of calculation we’ll use the following:

  • As our starting point, we’ll use the top hit on Amazon.com for incandescent Christmas lights. This package comes with 25 bulbs at a power of 7 Watts (W), meaning these lights use 0.280 W/bulb;
  • We’ll also look at the mini incandescent lights that are more common for interior use on Christmas trees, again selecting the top hit of Amazon.com to serve as our proxy for average and popular wattage. This package comes with 50 bulbs at a power of 20.4 W, or 0.408 W/bulb;
  • Lastly, we’ll look at the efficient LED Christmas lights that an energy-conscious consumer might choose. Going back to Amazon.com to find the most popular basic LED Christmas light (ignoring those with additional energy-using functionalities like timers and light effects), we find this package that comes with 100 bulbs at 4.8 W for 0.048 W/bulb;

For each of these three types of lights, we can use the same basic formula to calculate the total energy use of the Christmas lights over the course of the holiday season:

Referencing our above assumptions, we plug in the number of bulbs as 700, the hours lit per day as 5, and the days lit as 27. Combining those numbers with the Watts/bulb of the three types of lights previously calculated gives the following energy uses:

  • Large incandescent lights: 26,460 Watt-hours (Wh), or 26.4 kilowatt-hours (kWh);
  • Mini incandescent lights: 38,566 Wh, or 38.56 kWh; and
  • LED lights: 4,536 Wh, or 4.54 kWh.

Carbon emissions of Christmas lights

As described in the post about the energy use and CO2 emissions associated with cooking your Thanksgiving turkey, Department of Energy data indicates that 1.096 pounds (or about 0.497 kilograms (kg)) of CO2 are released for every kWh of electricity produced in the United States (on average, this figure varies based on where consumers live and their power providers’ energy mix). Multiplying each of those figures the energy use of each of the light types by 0.497 kg of CO2/kWh gives the following CO2 emissions from lighting the Christmas tree:

  • Large incandescent lights: 13.15 kg of CO2;
  • Mini incandescent lights: 19.17 kg of CO2; and
  • LED lights: 2.26 kg of CO2.

Putting these numbers together with the energy use data gives the following results for lighting the Christmas tree:

Click to enlarge

Carbon emissions from the Christmas tree

In addition, the environmental effects of selecting a Christmas tree are something that we can measure and calculate. In fact, a Montreal-based consulting firm put together a life cycle assessment of artificial vs. natural Christmas trees. This analysis will pull out the final numbers they calculated for CO2 emitted, but the entire report is really worth a read.

The life cycle assessment factors in the average life of each type of tree (natural trees have a lifetime use of one holiday season, while artificial trees are used for six years on average before being replaced), how far people travel to get their trees, the CO2 released when a natural tree is properly burned and recycled, the CO2 absorbed by a natural tree while it’s alive, the land occupation and fertilizers required to grow natural trees, the production of artificial trees, the transport of artificial trees from production (oftentimes overseas)to point-of-sale in North America, and more. In the end, the assessment determined that buying a natural Christmas tree accounts for 3.1 kg of CO2 for the year, while purchasing an artificial tree averages out to 8.0 kg of CO2 per year over the course of its six year lifespan.

Adding the artificial and natural tree CO2 emissions to the previously calculated emissions from lighting gives the following environmental and energy impact of your choice of tree and light types:

Click to enlarge

Note that while it takes energy to produce both a natural and artificial tree, for the sake of this exercise it’s assumed that the effects of that energy use is captured in the CO2 output calculations rather than try to estimate the exact energy use of tree production. Similarly, this analysis only considers the energy used to light the tree and not the energy used or CO2 emitted while manufacturing and transporting the lights, because 1) the information on energy intensity to manufacture and transport the lights is not readily available, and 2) the lights are assumed to be reused over and over again (particularly the LEDs with 25,000 hour bulb life), making the portion of energy to manufacture negligible when distributed over each Christmas season they are used. 

Lighting the Hanukkah Menorah

Basic assumptions

To start off the energy and CO2 calculations for the Menorah, we’ll again start with several basic assumptions:

  • On the first night of Hanukkah, the Shamash (the attendant candle used to kindle the other flames) is lit along with one other light for the duration of the night’s ceremony. On the second night, the Shamash is lit along with two other flames. On the third night, the Shamash and three other lights are lit, and so forth until the eight night when the Shamash and eight other flames are lit.

Energy use of the Hanukkah lights

For the Hanukkah lights, we’ll examine three different lighting options that are widely used to light the menorah– lamps lit with olive oil, traditional paraffin candles, and the increasingly used and environmentally friendly beeswax candles.

Olive oil lamps
While using olive oil lamps, we’ll assume the burning of the Menorah for 30 minutes per night and 90 minutes on Friday night (which is the fourth night of Hanukkah in 2017). Given that a single wick in olive oil will burn through 0.4 and 0.5 ounces of oil per hour, we’ll assume a burn rate of 0.45 ounces per hour per wick. Counting each individual wick that is lit on a given night separately, the total number of burn minutes is calculated as follows:22 wick-hours times 0.45 ounces of olive oil burned per hour gives a total olive oil burned of 9.9 ounces.

The only data point I could find on the energy content of olive oil comes from Wikipedia, giving an average specific energy of olive oil of 39.535 megajoules (MJ) per kg.

Finally then we can calculate the energy of olive oil burned as the following:

But that’s not it– as previously noted there is on Shamash candle that will also be lit each night in order to kindle the other flames. We’ll assume a standard paraffin candle is used as the Shamash for 30 minutes each night (plus an additional 60 minutes on Friday night) for a total of 300 minutes, or 5 hours. Using the standard energy content of paraffin wax of 42.0 kilojoules (kJ) per gram (g) and a standard burn velocity for paraffin wax of 7.5 g/hour, we calculate the energy in the burning of the Shamash candle each night to be the following:

Adding the Shamash tot he olive oil lamps gives a total energy use of about 3.52 kWh.

Paraffin candles
For the energy use of paraffin candles for all eight of the Hanukkah lights plus the Shamash, we simply use the same assumptions used before.

For the 8 candles lit for a cumulative 22 hours over the course of the Festival of Lights:

Add that to the previously calculated 0.44 kWh for the paraffin Shamash candle, and the total energy use is 2.36 kWh.

Beeswax candles
Calculating the energy use by the beeswax candles follows the same process as the paraffin candles. The difference this time is that beeswax, which is more energy-rich than paraffin but burns more slowly, has an energy content of 12.7 kilocalories per gram, or about 53.14 kJ/g (over 26% higher than paraffin candles) and burns at 4.0 g/hour (over 47% more slowly).

Plugging those values into the calculations at a total of 27 wick-hours (22 from the 8 candles and 5 from the beeswax Shamash) gives the following:
Thus, using all beeswax candles corresponds to an energy use of about 1.59 kWh.

Carbon emissions from lighting the Menorah

To determine the total CO2 emissions associated with our three Menorah light options, we already have a total time of burn and a total amount of fuel that is burned and we just need to line those up with the carbon output associated with the fuel types.

Olive oil lamps
Going back to the Wikipedia page on biofuels, we see that the CO2 content of olive oil as a fuel is 14.03 MJ per kg of CO2. Using this we can calculate the CO2 emitted by the olive oil when burned to be the following:

We also need to factor in the CO2 emitted by the Shamash over the eight nights, which we can calculate based on the knowledge (which was discussed in the Jack-O’-Lantern candle burning post) that paraffin candles emit about 10 grams of CO2 for every hour they are burned.

Since the Shamash is burned for 5 hours, this adds 50 grams (0.05 kg) of CO2 to bring the total up to 2.89 kg of CO2 emitted.

Paraffin candles
The data point of 10 grams of CO2 per hour of paraffin candle burned makes this calculation easy. We already established a total cumulative candle burn time (including the eight candles and one Shamash) of 27 hours, so the total CO2 released is 270 g (0.27 kg) of CO2.

Beeswax candles
Lastly, emission calculations for beeswax candles are even easier, as they are generally considered to emit zero CO2. Beeswax candles are touted as the renewable and green candle for just this reason, and while they do literally release CO2 upon their burning, this is CO2 that was recently absorbed by plants in the atmosphere and then transferred to beeswax. In such instances where the path from CO2 absorption to re-release is so traceable and quick, common carbon accounting practice is to count such products as carbon neutral.

Taken together, the energy and environmental impact of how you light a Menorah is given as follows:

Click to enlarge

Note that while the production of the candles and oil uses energy and accounts for CO2 emissions, for the sake of this exercise we’ll assume that the effects of that energy use and CO2 emissions are minimal compared with the energy/CO2 content of the fuel itself, rather than try to estimate the energy use of production and transportation. Similarly, the Menorah that is selected by a family is supposed to be ‘the most beautiful one that is within [their] means,’ up to and including Menorahs made out of silver. Because of this tradition, we can assume that a Menorah is reused year after year, possibly even handed down over generations, and the energy and CO2 emissions associated with creating the Menorah are small enough to ignore due to how small they would be on a per year basis.

Lighting the Kwanzaa Kinara

Basic assumptions and calculations

Last but not least is the lighting of the traditional Kinara for Kwanzaa. Kwanzaa is a seven day celebration that also uses the lighting of candles as a celebratory symbol. The Kinara has seven candles (representing the seven principles of Kwanzaa). In similar fashion to the Hanukkah Menorah, the Kinara starts the first day with one candle lit and then proceeds with two candles the second day, three candles the third day, all the way to lighting all seven candles on the seventh and last day of Kwanzaa.

From my research, it does not appear that there is any minimum or standard amount of time that the candles of the Kinara must be lit as there is with the Hanukkah Menorah. However, as a way of estimating the total burn time I looked at the most popular listings for Kwanzaa candles on Amazon.com. One listing had candles that would have a six to eight hour burn time, while another listed a burn time of five to seven hours. From this information, we can assume that the first candle lit (and thus the one that is lit for all seven nights of Kwanzaa) is expected to burn a total of five hours because the candle in the second listing might not have enough fuel to last longer than that. If this first candle is burned for five hours over the seven nights of Kwanzaa, that implies about 43 minutes of burn time per night.

Multiplying by the number of candles lit each night as we did with the Menorah, we get the following:

These candles can again be made either of paraffin or beeswax. Without going through the step-by-step calculations again (just refer to the Hanukkah calculations for reference), the choice of candles would result in the following energy and CO2 numbers:

Click to enlarge

Note that while the production of the candles and oil uses energy and accounts for CO2 emissions, for the sake of this exercise we’ll assume that the effects of that energy use and CO2 emissions are minimal compared with the energy/CO2 content of the fuel itself, rather than try to estimate the exact energy of candle production and transportation. Similarly to the Menorah, we’ll also assume that a Kinara is going to be reused year after year and as such the energy and CO2 emissions associated with creating the Kinara can be ignored because of how small it would end up on a per year basis.


Just because plotting and comparing numbers after all these calculations is interesting and fun, let’s see how the energy use and CO2 emissions of the various options among the three holidays discussed look on a graph:

Click to enlarge

Obviously this graph shows that the Christmas tree comes in (ironically) as the least green among the three holiday decorative centerpieces, which is unsurprising considering its the largest, the one lit the most hours per night and most nights during the season, and the type of fuel required to light it (electricity vs. wax or oil).

If we zoom in on the cluster of Menorahs and Kinaras to get a better view of these options, it looks like this:

Click to enlarge

Even the most sustainable Christmas tree option (using LED lights and a natural tree) come out as less energy- and environmentally-friendly than any of the options of Menorahs and Kinaras. When looking at just Menorahs and Kinaras, olive oil is a less sustainable choice compared with candles, the type of candles make a measurable (though in the end not entirely significant) difference, and, by virtue of needing seven candles instead of nine while lasting only seven days instead of eight, the Kinara ends the holiday season more sustainable than the Menorah.


So what was the point of doing this– should you not put up a Christmas tree or should you not observe the holidays because of the energy implications? Of course not– while these celebrations all have an energy and environmental impact, that’s not a reason to abstain from them. Looking at it all like this is just an interesting exercise. If you do find any of the numbers here alarming, then you can definitely take them to heart and switch to the more environmentally-friendly options– buy natural trees instead of artificial trees, use LED Christmas lights instead of incandescent, or switch from paraffin candles to beeswax candles.

And hey, if any additional use of energy or cause of CO2 emissions nags at you as you sip cocoa by the fire, keep in mind that there is an alternative holiday you can observe that accounts for no energy use or emissions. All you need is a non-decorated aluminum pole and the desire to air your grievances and overcome the feats of strength.


Whatever holiday you observe and however you choose to celebrate– take time to reflect on what the holiday season means, give back to those less fortunate, and share in the joy of being with your family.

Have a happy holiday season!

Sources and additional reading

Beeswax Candles: Alive

Candle Burn Time Calculator

Comparative Life Cycle Assessment (LCA) of Artificial vs. Natural Christmas Tree: ellipsos

Earth Hour 2013: Does It Really Save Energy? CSMonitor

Energy Content of Biofuel: Wikipedia

How Many Christmas Lights for Christmas Trees? 1000Bulbs.com

How Much Does It Cost To Power Your Christmas Lights? Wired

How to Decorate a Christmas Tree: Lowes

How to Light the Menorah: Chabad.org

How to Make Your Own Olive Oil Lamp: Instructables

Lighting the Kwanzaa Kinara: Holidays.net

So, How Much Electricity Do Christmas Lights Use? Christmas Lights Etc.

State Electricity Profiles: Energy Information Administration

The Energy Content of Fuels: University of Virginia

Tips and Tricks for Using Oil Lamps: Preparedness Pro

Trees by Height: Balsam Hill

Weird Questions About Beeswax: Beesource

When Should I Put My Christmas Tree and Decorations Up, When Should I take them Down and When Does Advent Start? The Sun

When Should You Put Up the Christmas Tree? Professor’s House

About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.  

What is the most climate friendly way to light your Jack-O’-Lantern?

The truest sign to me that Autumn has arrived isn’t the changing of the leaves, the advent of sweater weather, or even the pumpkin spice lattes everywhere you look. The real sign of the Fall season in my life is when the seasonal sections of Target fills up with Halloween costumes, decorations, candy, and trinkets. On my recent trip to this holiday mecca, I was looking at the decorations– specifically the little lights that are meant to go into jack-o’-lanterns instead of candles– and realized the sustainability factor for these decorations has not become nearly as pervasive as it has for Christmas lights (which now commonly advertise how efficient they are on the front of the package). After a bit of research, it appeared that this topic had not garnered any real investigations. Being ever the energy-conscious consumer, I could not let that stand!

What follows is some ‘back of the envelope’ type number crunching to figure out the most efficient and green option for illuminating your carved pumpkins. Very specific data is not really available, so there are certainly some liberties taken. However just for the sake of finding ballpark answers, I’ll hope this slight lack of statistical rigor is found acceptable. But if the Senate and Natural Resources Committee is looking to tackle the issue, then this will be a good starting point.


One of the main differences between Christmas lights and Halloween pumpkin lights that changes how the market approaches them is surely that Christmas lights get plugged into an outlet. Families with large Christmas light displays will see a noticeable bump in their monthly power bill, making the efficiency of these lights more present in the forefront of their minds. However, jack-o’-lanterns are instead lit up with either candles or lights that use portable, disposable batteries. Not only does this fact (and the relative smallness of pumpkin lights compared with full house Christmas lights) reduce the necessity of efficiency to most people, but it also makes efficiency calculations more difficult to come by. The power of the lights come either from the candle itself or from portable batteries, the comparison becomes fairly difficult.

But wait!

The choice of what to light your pumpkin up with is tied pretty strongly with a debate that arises every Earth Hour (an event organized where everyone turns off their lights for one full hour to symbolically support climate change and energy reduction efforts)– and that debate is whether candles, as a form of fossil fuels, actually end up emitting more carbon dioxide (CO2) than the electricity to power light bulbs do. Without jumping too deep into that issue, the point is that while candles do not require any electricity, they do release CO2 into the atmosphere (depending on the specific type of candle).

That being the case, it seems that comparing the CO2 emissions tied with various jack-o’-lantern lighting sources might be the easiest and most digestible exercise in determining the ‘greenest’ pumpkin lighting method.

Jack-O-‘Lantern Lighting Options

Real candles

  • Traditionally, jack-o’-lanterns were lit up exclusively by candles. The idea of candles in jack-o’-lanterns is so ingrained in people’s minds that the artificial lights often include a ‘flicker’ to mimic the actual look of candles. Because of this, the baseline lighting source is the traditional and widely-available paraffin candle. These candles are found at virtually any store that sells candles, and are created from a by-product of the refining of crude oil (hence their CO2 emissions).

  • As people became more environment- and health-conscious, alternative types of candles that did not emit the pollutants of traditional paraffin candles became more popular. So a second alternative are more the more eco-friendly soy or beeswax candles.

Artificial lights

(for these I’ll find a sample of flameless artificial lights that are readily available on Amazon.com and cover a variety of options for the batteries that power them)


Again I just want to stress that what’s about to take place are rough calculations that should not be taken as 100% accurate, but rather to gain a general idea of the scale of CO2 emissions for each of these pumpkin lighting sources (wow it’s hard to try and sound scientific and serious while typing that phrase…). With that said, here’s a look at the back of the envelope on which these calculations were done:

Real Candles

Paraffin candles
For paraffin candles, considered the standard and classic candle with which to light up a jack-o’-lantern, a number of sources cite a figure of about 10 grams of CO2 released per hour of candle burn, so that is the number we will go with. For these candles, we’ll also ignore the CO2 emissions associated with the production and transportation of the candles because 1) paraffin is a by-product of various petroleum refining processes, meaning if not used then the material would go into the waste stream, 2) the low cost of the product suggests that the energy used to produce and transport them (called embodied energy) will be relatively low compared with the tangible CO2 released in burning, and 3) data for such questions is not readily available.

Paraffin candle CO2 emissions: 10 grams of CO2 per hour of candle burn

Beeswax/soy candles
On the other hand, beeswax or soy candles (the touted green alternative) are often considered carbon-neutral. This assumption is made despite the fact that they do also release CO2 when they are burned, as the released CO2 was recently absorbed by plants in the atmosphere (which was transferred by a bee to the beeswax used in those candles, or was still in the soy used for soy candles). In these instances, common practice is to not count such CO2 emissions, as they used CO2 that was in the atmosphere and will cyclically release it back, as opposed to fossil fuels (such as those in paraffin) that are releasing CO2 that had long been stored in oil reserves underground. We’ll again ignore the CO2 emissions associated with the production and transportation of the candles because 1) beeswax and soy plants are both renewable sources for material, 2) the low cost of the products suggests the embodied energy, and thus associated emissions, are relatively low (especially if these candles are bought locally, as they are commonly found at farmer’s markets and the like), and 3) we don’t have such data available.

Beeswax/soy candle CO2 emissions: 0 grams of CO2 per hour of candle burn

Artificial Lights

Each of the three artificial light options found, their equivalent CO2 emitted per hour of use will be calculated based on the batteries required to run them. Making the comparison this way will require a number of generous assumptions (back of the envelope here, don’t forget!):
  • The associated CO2 we’ll look at is only coming from the batteries used to power the light, not the construction or transportation of the light itself. Again, the data to find the CO2 associated with producing/transporting the light is not easy to find– but moreso, we’ll assume that the lights will be used year after year, thus minimizing how much CO2 per hour would end up being.
  • The California government sponsored a study on the emissions associated with producing alkaline batteries, one of the conclusions of which was that the CO2-equivalent produced for primary batteries was about 9 kilograms (kg) per kg of battery produced. This figure assumes that batteries are single use (either thrown in the trash or recycled after use) and accounts for the energy needed to store power in the batteries that will eventually add a sparkle to the eye of your jack-o’-lantern. We’ll use this number, combined with the weight of the batteries for the lights and the lifetime of that battery, to find the CO2 per hour of use associated with the lights.
  • Assumptions will be made on how long the batteries will last in these lights, using either the product’s page or a best guess based on battery capacity and typical drain.
  • Additionally, we’re assuming the use of the typical disposable batteries– any rechargeable batteries would throw off the calculation, but this analysis won’t go there.

Combine these artificial lights with the real candle options, and the final values for the five options in terms of associated CO2 released per hour of jack-o’-lantern operation is as follows:

Or in graphical form:Click to enlarge.

Very obviously, the environmentally friendly soy or beeswax candles that account for no CO2 release in their production or burning are going to come out on top here. But what might surprise you is that the options that use batteries come out significantly ahead of the typical paraffin candle. While the industrial production of the batteries to power the artificial lights (and even if you add in a fudge factor to account for the production of the artificial light itself) seems like it would obviously be energy-intensive and account for greenhouse gases, the less obvious fact of paraffin candles outdoing that by direct emissions is not as clear until you look into the numbers specifically.


In the end, this might come across as a silly exercise– and maybe it is, just in the name of holiday fun. Releasing 10 grams per hour with paraffin candles compared with the significant reductions possible with the other options might seem like small potatoes in the grand scheme of things– in a world where a single cow can release up to 200 grams of methane (a greenhouse gas that contributes more strongly to climate change per gram of it released than CO2) through flatulence and belches, why even question the CO2 released due to halloween decorations?
I would agree that’s a fair point, but let’s keep the calculations going really quickly. In the United States, there are about 73 million children under the age of 18. Let’s just say that half of those kids have a jack-o’-lantern (some families might not celebrate Halloween with jack-o’-lanterns, some families might not see the need for one for each child, but on the other hand many adults such as myself might still find joy in carving and lighting up pumpkins– so 50% will be our randomly chosen number. Back of the envelope!). And let’s say that for the two weeks leading up to Halloween, those jack-o’-lanterns are lit up for 3 hours per night. All of a sudden, we’re dealing with 1,533 million total hours of jack-o’-lanterns being burnt. If all of those jack-o’-lanterns are releasing 10 grams of CO2 per hour with paraffin candles, all of a sudden that’s 15,330 metric tons of CO2– or the equivalent of the annual CO2 released in a year by over 3,000 cars.
The point of all of this to show how much of a difference small changes can make. Are you an environmental criminal for lighting your pumpkin up with a paraffin candle? Certainly not. But you can be an environmental warrior by noting all these small choices that surround you (during the holidays and in your everyday life). And if you want to add some more energy-efficient related fun to your jack-o’-lanterns, check out these stencils from the Department of Energy!

Sources and additional reading

About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.