Re-thinking things

DC, Service, and Bacteria

Regular readers know I am intrigued by DC (Direct Current) power systems in buildings. This fascination was born while examining a data center UPS system several years ago. The potential efficiencies shouted out to me. This week, I found something new that fueled my interest.

Most consumer devices are DC powered. That brick outside your laptop is to convert AC (Alternating Current) power to DC. Your television has a similar brick built inside it. That annoyingly large plug on your cell phone charger is another AC/DC converter. The digital world is a DC world. The exceptions in your homes are...

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It’s all too cheap!

Even with today’s rising energy costs, most things do not cost very much. This is a good thing. Food, as a percentage of income, is still at historic lows. In real dollars, gasoline is just where it was at the birth of the modern car in 1908. For most people, switching to a more fuel efficient car will not pay back the initial capital outlay in the next five years. Local energy generation just doesn’t pay back its installation cost quickly enough. A penny saved may be a penny earned, but today, everyone leaves their pennies by the cash register. Gas prices do not
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Algal Biodiesel Virtuous Cycles

I am reading more and more about how close algal biodiesel is, perhaps a year or two away. I will reserve my judgment on ship dates, but note that there are claims that algae can produce oils suitable for making biodiesel out of without genetic engineering. I am not as concerned with genetic modifications as some are, but do acknowledge that the presence of such modifications would concern others and throw
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Biodiesel Algae for the Building

I was corresponding with someone from the algal biodiesel group the other day. Genetically modified algae is one of the more intriguing fuel strategies in the mid-term. The short version is to add some oil-production genes from some other plant to fast-growing algae, scoop out algal mats and process into fuel.

Traditionally, algae has been seen as something to grow in plants about the size and distribution of this year’s boondoggle, the corn ethanol plant. Instead of large parking areas for constant transportation of corn, large shallow vats of algae would soak up the sun. Eliminating the need to transport the raw material to the processing plant would be yet another advantage to this process.

Some have suggested that the proper place to build the facility is by a coal plant. Algae grows faster in a high CO2 environment. The CO2 would get sequestered into new biomass, and then converted to biodiesel. The CO2 would make it into the atmosphere eventually, but not until it had done double duty for electricity and transportation.

But I thought, why stop there?

All kinds of moderately complex processes are now being built into small microprocessor controlled autonomous systems. If one could automate the production of Biodiesel on the rooftop, then local diesel generators could run on site generated fuel.

I do not imagine that this process would ever provide all power for, say, a commercial office building. It could, however have a place in zero net energy buildings and in local self-reliant microgrids.

Many organizations, from the AIA to ASHRAE, from the US department of Energy to the UN Environmental program, are chasing after the Zero Net Energy Building (ZEB). The ZEB uses a variety of strategies centering around local generation, storage, and conversion of energy to limit its purchases from the power grid to when the prices are right. The ZEB will likely make use of internal DC to eliminate DA/AC/DC conversion penalties on each source of energy. The ZEB building may well have PV, ST, Wind, and generators, mixing and matching as needed.

The problem with most of these local renewable energy sources is that they are unpredictable. As has been well demonstrated by the German Kombikraftwerk effort (search the archives), you can build a reliable grid almost entirely of unreliable sources as long as they are unreliable in different ways at different times.

Why not BioDiesel generators in the building? Why not algae vats and automated fuel production in the building? I do not see such a system being able to carry the building on its own, but if called on occasionally, as diesel generators are now, perhaps the tank could be filled in the interval.

So, why not Algal Biodiesel in the Building?