Spent coffee grounds contain between 11 and 20 percent oil by weight. That’s about as much as traditional biodiesel feedstocks such as rapeseed, palm, and soybean oil.
Growers produce more than 16 billion pounds of coffee around the world each year. The used or “spent” grounds remaining from production of espresso, cappuccino, and plain old-fashioned cups of java, often wind up in the trash or find use as soil conditioner. The scientists estimated, however, that spent coffee grounds can potentially add 340 million gallons of biodiesel to the world’s fuel supply.
U.S. diesel usage is around 40 billion gallons per year for on-road transportation, so at 340 million gallons, biodiesel from coffee grounds represents just a drop in the coffee cup. I wonder if it makes your exhaust smell like a Peet’s Coffee shop?
Jacobson analyzes 12 energy sources for their beneficial impact on global warming, air pollution, and energy security – the ten electricity sources are solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology; the two liquid fuel options are corn-ethanol (E85) and cellulosic-E85.
Jacobson said that while some people are under the impression that wind and wave power are too variable to provide steady amounts of electricity, his research group has already shown in previous research that by properly coordinating the energy output from wind farms in different locations, the potential problem with variability can be overcome and a steady supply of baseline power delivered to users.
As the bottom line in the study, Jacobson writes:
In summary, the use of wind, CSP, geothermal, tidal, solar, wave, and hydroelectric to provide electricity for BEVs [battery electric vehicles] and HFCVs [hydrogen fuel cell vehicles] result in the most benefit and least impact among the options considered. Coal-CCS and nuclear provide less benefit with greater negative impacts. The biofuel options provide no certain benefit and result in significant negative impacts. Because sufficient clean natural resources (e.g., wind, sunlight, hot water, ocean energy, gravitational energy) exists to power all energy for the world, the results here suggest that the diversion of attention to the less efficient or non-efficient options represents an opportunity cost that delays solutions to climate and air pollution health problems.
Note that the study ranks the various energy alternatives without regard to cost. That’s going to be controversial. Jacobson says:
Costs are not examined since policy decisions should be based on the ability of a technology to address a problem rather than costs (e.g., the U.S. Clean Air Act Amendments of 1970 prohibit the use of cost as a basis for determining regulations required to meet air pollution standards) and because costs of new technologies will change over time, particularly as they are used on a large scale.
In the real world, costs do have a major impact, especially given that we do not have a Clean Air Act regarding carbon today. This is why it’s so important that the price/kW of solar panels, for example, is dropping and will continue to drop.
In fact, when you leave cost out of the equation, is it surprising which energy sources came out on top? Let me know your thoughts.
Olive stones can be turned into bioethanol, a renewable fuel that can be produced from plant matter and used as an alternative to petrol or diesel. This gives the olive processing industry an opportunity to make valuable use of 4 million tonnes of waste in olive stones it generates every year and sets a precedent for the recycling of waste products as fuels.
The difference between fuel from corn and fuel from olive pits? The pits otherwise are waste, while corn grown for fuel displaces crops grown for food.
I think Michael Pollan would approve. What do you think? swanksalot
Michael Pollan (The Omnivore’s Dilemma, In Defense of Food) gave some advice to the next president (Obama, as it turns out) in the NY Times October 12 Sunday Magazine. If he didn’t know already, Pollan warned him that food policy is going to be a big issue, and provides some advice on what to do about it.
It may surprise you to learn that among the issues that will occupy much of your time in the coming years is one you barely mentioned during the campaign: food.
Modern U.S. agriculture (especially as embodied in “The Farm Bill”) is not only a giant user of fossil fuels, but also arguably the major contributor to health crises like obesity and diabetes.
Agriculture in the U.S. uses a surprisingly large amount of fossil fuels (about 14% of the total), and actually generates proportionally more potent greenhouse gases than other uses of the same feedstock. The green revolution was all about fossil fuel-based fertilizers, pesticides and herbicides, and monoculture. Furthermore, the incentives are perverse, especially in the U.S., anti-health and anti-family farm.
Summarizing Pollan’s article, the key recommendation is the “resolarization” of American agriculture:
Right now, the government actively discourages the farmers it subsidizes from growing healthful, fresh food: farmers receiving crop subsidies are prohibited from growing “specialty crops” — farm-bill speak for fruits and vegetables. … Commodity farmers should instead be encouraged to grow as many different crops — including animals — as possible. Why? Because the greater the diversity of crops on a farm, the less the need for both fertilizers and pesticides.
Pollan was also on Fresh Air on October 20, a fantastic interview following up on this article, which you can hear at http://freshair.npr.org. I have the mp3 of the show if you want to listen to it on your pod-player (let me know – I’ll make it available for download).
I plan to do an in-depth post or series on fuel cells soon, because there is so much breakthrough work going on in this research area. Fuel cells are interesting on so many fronts – for example, they’re probably the best way to use the hydrogen generated by Daniel Nocera’s new hydrogen splitting method, announced in mid-August. And just since August, researchers have announced big improvements or cost reductions in every component of the fuel cell – membrane, catalyst, and electrodes.
This latest story from Technology Review covers a new membrane improvement for methanol fuel cells. As the article points out, methanol fuel cells have some key benefits compared to hydrogen cells, in particular that methanol is a liquid at normal temperatures, but they also have technical challenges. Paula Hammond and her team are addressing one of these:
In her lab at MIT, chemical-engineering professor Paula Hammond pinches a sliver of what looks like thick Saran wrap between tweezers. Though it appears unremarkable, this polymer membrane can significantly increase the power output of a methanol fuel cell, which could make that technology suitable as a lighter, longer-lasting, and more environmentally friendly alternative to batteries in consumer electronics such as cell phones and laptops.
Do you have questions about fuel cells that you’d like me to find answers to as I research my upcoming series? Let me know in the comments.
The biggest energy stories in August were about fuel cell-related breakthroughs and big solar projects. But the world of biofuels had some big news percolating as well. The beauty of biofuels, of course, is that they provide us with that extremely energy-dense liquid that we already know how to use (that is, gasoline, diesel, and ethanol), by sucking CO2 out of the atmosphere using solar energy.
In this post I highlight some of the biofuel-related items that caught my eye in the past few weeks, from algae that make diesel from atmospheric CO2 and sunlight, to harnessing bacteria and microbes as our refineries. This is just a small slice of the activity going on in biofuels, of course. Just as in solar PV, and batteries, and fuel cells, and wind, and alternative energy investing, there’s an ever-increasing flood of news every week. If I’m missing one of your favorites, please let me know in the comments!