earth overshoot day

If you use up your monthly salary before the next payday, you borrow money to tide you over. Which might be alright, if you have a good credit rating and you don't do it every month. But if you spend just as much next month, you just go deeper into debt. In the same way, we use Earth's resources to run our lives, and the New Economics Foundation has come up with the date we go into ecological "resource debt" each year. This year, we used up the equivalent of Earth's annual budget last week, on Sept 23. At the rate we spend, Earth only produces enough to support us for 267 days a year; after that, we use up resources that have been "banked". And these resources are not only fossil fuels, they are also habitats, fresh water, forests, fish, and so on.

Unfortunately, the date this happens gets earlier every year, with the result that we are borrowing beyond our means - and have been doing so since 1986, according to NEF's calculations. We won't be able to repay the loan unless we make drastic changes. One can argue that overshoot day is just a concept, and probably not very accurate, but I don't believe anyone can seriously suggest that we can carry on with business as usual indefinitely. Dependence on finite oil reserves alone makes that an impossibility, but the environmental degradation we are causing makes it an ethical issue.

old fridge design brought back to life

A few years ago, when I witnessed the effects of Eskom's budget-sapping rollout of the national electricity grid to rural Transkei, I wondered how people who rely on a largely subsistence economy could possibly afford to buy, operate and maintain the electrical appliances that they could now run on 220 volts of coal-generated power. Most rural families probably have one or more family members working in cities, sending money back home, which helps pay the bills; but is that really a sustainable approach to community development?

I have written before about alternative financing models for supplying renewable energy to make rural life more convenient, and here is another technology that could help significantly: a fridge design that was invented by Albert Einstein in 1930. The original design was abandoned when freon and cheap power made it possible to sell fridges that operated with more efficient compressors. But the compressor is what makes it difficult to run a modern fridge using solar power, so the Einstein fridge is being dusted off and improved so that its zero-moving-parts design can be powered with solar panels. In addition to reducing reliance on dirty power, this approach also reduces maintenance needs, so it's perfect for rural communities.

Of course there are more primitive systems, like evaporative fridges, but let's face reality: a huge challenge in stemming the tide of human desire for electrically-powered appliances in the developing world is in coming up with designs that don't make people feel like they are being handed second-rate goods. This sounds like one that could work.

crowdsourcing energy solutions

If we leave everything to the experts, we might never make progress. A new alternate reality game called World Without Oil has been developed to stimulate ideas on an oil-free future by engaging online gamers.

The premise of World Without Oil was simple and provocative: What if an oil crisis started on April 30, 2007 - what would happen? How would the lives of ordinary people change? Players were invited to imagine how their lives and communities would be different and how they would cope if the world’s oil suddenly dried up. The “plot” unfolded dynamically. First, the players read the “official news” and what other players were saying. Then, using a combination of blog posts, videos, images and even voice mails, they told their own stories of the challenges they were facing. As the crisis continued, players updated their stories with further thoughts, reactions and solutions.

The game ended after 32 days, having engaged thousands of players around world and woven the fabric of 1,500 stories into what [game designer] Ken [Eklund] describes as “living breathing mega narrative that presented some eerily plausible scenarios, complete with practical courses of action to help prevent such an event from actually happening.”

powering our way to extinction

Most references to biodiversity are in relation to how we are reducing plant diversity by taking over habitats either by expanding the built environment or by extending agricultural areas. What is rarely considered is the role of humans as animals (technically 'megafauna') within the ecosystem. An article published in the August 12 edition of PNAS presents a fascinating argument about the risks of population collapse (ours and other megafauna) in the context of energy and climate change.

The creation of biomass, whether as plants or animals, depends on energy flow through ecosystems, and the source of that energy is the sun. Until the industrial revolution, humans relied on solar energy directly, just as other species do - then we extended our ability to grow as a population by drawing from stored energy sources: wood, coal, oil and natural gas. So our current population growth trajectory depends on finite energy reserves. People have written before about the limits to growth - notably the Club of Rome - and their estimates of the limits of earth's carrying capacity have been shown to be inaccurate. But this new analysis approaches the issue from a different angle: the trade-off of biomass among megafauna.

fossil fuel-free community planned in the US of A

Geos in Arvada, Colorado, plans to be the first community in America to be self-sufficient in energy, using solar and geothermal sources. What I like about this plan is that it recognises that the layout of the street grid has a strong influence on how buildings are arranged to make maximum use of the sun. This is one of the big challenges in reducing energy demand particularly for housing in colder climates. Traditional street grids pay zero attention to energy issues, and that has to change. [via Stacked Tall]

storing energy as compressed air

When my son was younger, he had an Air Hog model airplane that ran on a piston engine that was powered by compressed air. It didn't fly far, but it was pretty cool. I still had a hard time believing that there could really be an air-powered car of the full scale variety. But now I read of a serious proposal by New Jersey electric utility PSEG to use compressed air to store power underground. There's already a compressed air power plant that's been operating in Alabama since 1991 that can supply 110 MW for 26 hours.

The concept is similar to Eskom's use of hydroelectric dams to store energy for use during peak periods - water runs downhill through turbines to generate electricity, then is pumped back up when there is excess electricity available. It's not very efficient, but it avoids having to build extra power stations just to provide for peak demand. The PSEG proposal, though, is intended to make wind power more feasible. Since wind is sporadic, storage of wind power allows the supply to be provided when it's needed, not just when there happens to be wind.

hydrogen from biofuels, lithium from underground

I wrote in July that hydrogen as an energy storage medium uses more energy than you can get from it - using energy directly is more efficient than converting it to other forms. It took a commenter to remind me that this is a simple law of thermodynamics. Duh! The point of energy storage - whether in conventional batteries or hydrogen cells or fuel in your car tank - is to be able to use it when and where you want to. And that's key to most forms of transportation.

(One reason I like the suburban trains in South Africa and parts of Toronto's TTC public transit system is that they run on overhead electric cables, making it possible to use absolutely any energy source you care to pump into the grid. You can change the energy source without requiring an overhaul of the transport vehicles. But these are more the exception than the rule.)

So improving energy storage efficiency and cost is going to be important for transport, whether public or private. Last week it was reported at the American Chemical Society meeting in Philadelphia that a new, efficient catalyst has been discovered to convert biofuels into hydrogen with a 90% yield, at a lower cost than other methods being developed.

And for many vehicles, the obvious competitor to hydrogen is good ol' batteries. The Tesla Roadster, a high-performance electric sports car, uses lithium ion batteries, just like your cell phone. While car manufacturers are investing heavily in electric car technologies, AutoBlogGreen asks whether it's realistic to expect the price of lithium-based batteries to fall far enough to make them a viable storage medium for cars. As with nuclear energy, it's easy to forget that supplies of the mined raw material are sometimes limited. In the case of lithium, that doesn't appear to be the case, but with mining there are always other impacts to consider. We need to maintain a diversity of options.

DIY electric cars

Ever wondered what it would take to convert your car to an electric-powered vehicle? A Finnish group is launching what it hopes will be the start of a global movement for retrofitting petrol-powered vehicles. eCars - Now is a forum for people wanting advice from experts, and to bring together buyers and sellers, and mechanics with the know-how to carry out electric car conversions.

And if you want to see what electric and other alternative-fuel vehicles can do over long distances, the Zero Rally Africa takes place in January 2009 from Victoria Falls to Cape Town, followed by a conference focusing on renewable energy and potential applications for development, especially in the context of Southern Africa.

hydrogen economy is more hype than substance

I have said before that hydrogen's usefulness is more as a storage medium than as a source of energy in its own right. But here's a well-referenced assessment of the science by Alice Friedemann, suggesting it isn't of any value even for storage:

The laws of physics mean the hydrogen economy will always be an energy sink. Hydrogen’s properties require you to spend more energy than you can earn, because in order to do so you must overcome waters’ hydrogen-oxygen bond, move heavy cars, prevent leaks and brittle metals, and transport hydrogen to the destination. It doesn’t matter if all of these problems are solved, or how much money is spent. You will use more energy to create, store, and transport hydrogen than you will ever get out of it.

And the conclusion? The energy and environmental challenges facing the world are far too serious to spend effort on dead-end technologies. Policy needs to guide investment based on a firm grasp of both science and geopolitical realities. The risk is that lobby groups will sway government to create misguided incentives, such as the US corn subsidies aimed at ethanol production.

algal biofuels: the next wave

Using a third-generation biofuels technique to create ethanol from algae in seawater, one company claims it "will be the largest consumer of CO2 on the planet". Algenol Biofuels says it will be able to create 100 million gallons of ethanol from 1.5 million tons of CO2 at a facility in Mexico, with a yield of 6,000 gallons per acre per year. In comparison, corn yields only 360 gallons per acre per year, and sugarcane 890 gallons. Expecting to be producing at scale by the end of next year, the company hopes to produce "the cheapest fuel on the planet".