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 the incandescent lights, and the motors in your appliances: refrigerator, dishwasher, and washing machine.

In commercial buildings, the designers and maintenance staff often refer to building systems and their controls collectively as the low voltage systems. The low voltage systems are powered by DC The controls that manage the air conditioning system and all their sensors are powered by an isolated low voltage DC system. The security system with its window sensors is DC. The video cameras and their network are powered by DC. We live in a DC world.

Several years ago, an APC salesman generated an epiphany as he proudly demonstrated his new data center racks. The racks has built in power conditioning and batteries, and seemed sturdy and well designed. The servers were fed from the batteries at all times, protected from power dips, sags, and spikes by the constant power source. All power coming into the racks was converted into DC and fed into these batteries, keeping them fully charged. The power coming out of the batteries was converted in AC power, and routed into plugs for the servers. Each server, as they usually do, had a plug in the back into a little removable brick, just as in your laptop, converting that power back to DC.

It was the proximity, I guess. I have the same set up supporting the server room at work, but the refrigerator-sized battery is down the hall, invisible during normal operations. Seeing the batteries and the servers so close, I could no longer ignore their absurdity. I was converting power to AC to go a yard to convert it back, losing 10-30% of the power each way, only because it was the way things always were.

Since then, I have paid more attention to DC systems. Since then, I have often wondered how many "almost there" technologies are held back by infrastructure assumptions. How many solar projects, for example, that don't quite make economic sense, are held back by the double tax of DC to AC and back again....

So why this week? Why do I bring this up again?

For the last two mornings I have had the pleasure of breakfast at the B&B with a quiet electrical engineer, unassumingly working on a project I am calling bacteria-powered low-voltage distribution. Much of metabolism can be envisioned as getting rid of electrons to the most available receptor; his company is offering bacteria wires as the as the most available receptor.

He sees his system being used as a third world power source He only needs enough power to light LEDs at night. In many areas wood is burned for light in the evening, contributing to deforestation and reducing the fuel available for other purposes. His company has recently received stage one funding, and is looking for short term revenue in other areas. One potential project is yard lights that are powered by the soil they are pushed into, and that work better than solar for northern latitudes in moist climates.

I got a call from the folks at FreeLight yesterday, to discuss their progress with in-place hybrid installation of DC in existing buildings, and the availability of low power DC lighting. Such lights are programmable to display any color, or even pictures and text. Such lights are very light, with high efficiency, and no local power conversion.

Can such systems work together, moving the power for emergency lighting off the grid and away from batteries? Would labor cost avoidance (maintenance for batteries) be the factor that drives adoption?

Future buildings and local generation are coming. There is no need for future building systems to be powered like those of today. Challenging our power distribution assumptions will be as important as changing our power generation assumptions.

At FIATECH, I spoke on specifying buildings by services, not by technology or process. The engineers at FIATECH agreed that service and performance specifications would free up their creativity and innovation. Energy distribution strategies might be part of that innovation.

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 come down because no one wants to make a left turn against traffic to get a better deal. (See also many articles on the front page of Knowledge Problem this week. The New York Times recently indicated that a load in the washing machine might cost $0.53. Who is going to personally manage that? Who is going to miss their $4 coffee on the way to work to reset when the dishwasher runs for this type of gain?

Life cycle does more than lifestyle to determine energy usage. Homes with small children have different energy profiles than empty nesters. Life-cycle trumps life style in energy use except in the most extreme cases. Extreme energy savings are not ever going to be a mass phenomenon. People would rather get to the beach an hour earlier, and get the complaining kids out of the car and in bed on time than they would drive for greater mileage on the trip. These facts are not likely to change.

Well, if we are not going to manage our devices, our systems, and our energy, who will? There are only two answers: someone else and the systems themselves.

Few people want someone else to manage their power, because few people want to relinquish autonomy over their home to someone else. Service is a possibility here. Services like Sensus could remotely monitor my heating and cooling for peak performance, and let me know when and what maintenance is needed. If I approve it, they could even schedule the maintenance themselves, and verify post-repair performance before I pay for it.

This leaves the devices managing themselves. There are a lot of devices, with a lot of features. If we are going to let these devices manage themselves, they need an economic interface, too.

I could ask my dishwasher to run itself, and manage its own budget for the month. I could also set service standards that the dishes always be clean before dinner the next day. This leads to a relatively simple and consistent user interface.

I could tell my solar panel to sell to the grid whenever the price is above a certain amount, and to store any excess energy. The grid might consistently outbid the dishwasher—and that’s OK. If so, the dishwasher would still run only at night.

I could tell my whole-house storage system to buy power at any price until it has four hours on hand. Thereafter it might buy whenever energy is below a target price. I could even let it take bids from the household systems and devices, or from the neighbor. This system would, of course, need to charge an appropriate mark-up based upon its inefficiency of storage.

If we develop the right sort of abstract business interface between the power grid and our buildings, it can also be used between buildings, or within buildings. Most throw-away cell phones have more computing power than it took to go to the moon. Surely, our embedded systems can do a little day trading…

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 barriers up in the way of permitting.

Biodiesel algae seems to grow best in glass, where it can be exposed to maximum sunlight. It works best when micronutrients can be bubbled through it, although one plan seems to rely on osmosis through a filter from a waste stream.

But what I like best is that this algae (or any algae) seems to grow best when carbon dioxide is bubbled through it. Most of any oil is, of course, carbon and hydrogen, with a little oxygen perhaps thrown in. A good source of carbon is an essential fuel for plants. This is why plants in general, more popularly the rain forest, and more importantly, sea algae are such important consumers of CO2 and producers of oxygen.

Hmmmm – so biodiesel algae would work best with a ready source of carbon dioxide….

One of the fantasies I am enjoying most right now is algal scrubbing of CO2. I do not recall if I ran across this somewhere, or came up with it myself when tossing and turning on a late night. So here’s the deal.

Coal plants scrub their smoke stacks of any chemicals that may be harmful to algae. The result is then bubbled through a huge series of algae vats, which consume CO2 and release oxygen. The oil producing algae is harvested to produce biodiesel. The carbon in the biodiesel would, eventually, end up in the air, but not before another trip, through the nation’s cars and trucks.

Because of the scrubbing, coal becomes one of the cleanest ways to produce energy. The high costs of scrubbing are paid for by biodiesel production.

What’s your energy fantasy?

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?