complexify

Image from Environmental Law Institute

Ecopolitology.org posted this visualization of the relative subsidies received by fossil fuels and renewables in the US over a six-year period.  This is a helpful rebuttal to those who think that renewable energy is too highly subsidized.

However, like any visualization, it’s important to understand what has been omitted in the name of simplicity.  In this case, nuclear seems to be ignored, and the absolute dollar amount comparisons don’t account for the differences in scale of production.  A graphical comparison of the subsidies per kWh (or BTU) would be helpful, but even that might be misleading as subsidies and costs have changed significantly during the 2002-2008 time period.

While nanotech batteries, fuel cells and black boxes receive most of the attention, the most cost-effective methods for storing large amounts of energy are relatively down-to earth: pumped water and compressed air.

A compressed air storage firm, General Compression, announced today that it raised a $17 million round of venture capital.  The basic technology is far from new.  Essentially, it uses motors to compress air into tanks or caverns when electricity is plentiful (and cheap), which is then released when energy is needed (and expensive).   The result is remarkably cost-effective, at least when compared to the other options.  From a post today by earth2tech on the subject:

In general, big (100-300 megawatt) underground gas-fired CAES storage costs about $600-$750 per kilowatt of storage capacity built, according to the Electric Power Research Institute. Smaller scale (10-20 megawatt) above-ground CAES costs about $1,000-$1,800 per kilowatt and $250 to $450 per kilowatt-hour, EPRI reported, cheaper in kilowatt-hour terms than the battery technologies EPRI surveyed in its 2008 cost comparison.

What further efficiencies General Compression has brought to the technology remain to be seen, but it’s an important reminder that a technology’s “sexiness” does not necessarily correlate with its efficiency.

With all the current hoopla about Bloom Energy’s unveiling of a clean “power plant in a box,” it’s important to step back and look critically at the context in which this device is launching.  An affordable solution for cleaner, efficient distributed power would indeed be game-changing, but two factors give me pause:

1) Cost: At $700,000-$800,000 each currently, this isn’t an easy purchase for businesses, let alone individuals, despite generous tax incentives.  Back in 2006, BusinessWeek reported that Bloom Energy was trying to get the price below $10,000 each. Now they’re aiming for ~$3,000.  Ambitious, to say the least.

2) Competition: Bloom Energy is hardly the only well-funded company with the same goals.  earth2tech.com has a good round-up of “10 Fuel Cell Startups Hot on Bloom Energy’s Trail.”  (The Bloom Box may have the catchiest name and the best PR, however.)

Given the level of secrecy surrounding Bloom Energy for the past seven years (and John Doerr’s continued enthusiasm), I wouldn’t be surprised if more tantalizing details emerge soon.  I’ll be following them closely and rooting for the Bloom Box’s success, for an affordable power plant in a box would bring tremendous benefits not only to our congested grid but also to developing countries who currently make do with highly-polluting, expensive diesel generators.

Further reading:

• Ecogeek.org - Bloom Energy: Should you Believe the Hype?
• 60 Minutes - CBS News - The Bloom Box: An Energy Breakthrough?
  
• Earth2tech.com - 10 Fuel Cell Startups Hot on Bloom Energy’s Trail

Fuel cell vehicles are well and good, but the problem I’ve had with predictions of a hydrogen-based transportation economy is that of efficiency.  How can we get cheap, abundant hydrogen? Making electricity from sunlight is inefficient on its own, further compounded by then having to use that energy in electrolysis to reach the ultimate goal: splitting water into its components.

A new technique reported by the New Scientist this month simplifies that process, using sunlight to directly separate hydrogen from water.  The process uses gold, indium phosphide, and sulphurous iron with a remarkable 60% efficiency.

The claims are bold: “400 times better at netting photons than organic molecules used in previous systems” and “In fact the 60 per cent figure is probably a worst-case scenario.”  The technology is still just a proof-of-concept, but let’s hope that similar efficiencies in the real world materialize soon.

New Scientist: New Way To Split Water Into Hydrogen And Oxygen Developed