The Ergosphere
Tuesday, October 17, 2006
 

Micro-AE experiment

I've not had the available facilities to do much in the way of alternate energy stuff, but a happy coincidence made an experiment possible.

Some time ago, I bought a cheap AM/FM radio which claimed you could power it 3 different ways:

This radio initially charged itself and ran on solar power for some time, but its endurance shrank until it would not run on stored solar power at all and could eke out maybe a minute after a good amount of twisting the crank.  I opened it up, and found its battery was a pair of NiCd button cells mounted to the PC board; not exactly the best storage system, and probably the cause of its failure.  But it didn't charge all that quickly to begin with, and I wondered what I could do with this to make it useful again.

Then a busted solar-powered driveway light fell into my hands.  The plastic top and electronics were still intact, so I appropriated it.  It has two AA NiCd cells and a solar array about two inches square on the top.  The cells are in spring-loaded holders which make them easy to remove (no solder tabs or other difficult stuff).

To prevent the cells from discharging at night, I have to remove one from the holder at dusk.  But they fit into the little radio just fine, and I've been listening to it for several hours now.  Am I depleting the cells more than tomorrow's sun can charge them?  I suppose there's no good way to find out except to keep testing them.

Aside from being a useful test of an otherwise-useless device as a solar AA charger, it's an interesting little bit of consciousness-raising.  If I can find a good way to mechanically mount the solar cells to the radio and reconnect the battery circuit so it uses the AA holder instead of the button cells, I could use this unit as either a long-playing solar radio or a hand-crank charger for just about any AA rechargeables.  But the hacking potential of this unit will have to wait until I've built my rotating Scrabble board holder and some shelf-mounting brackets for my windows so I have someplace to put my houseplants.  Got the wood and the tools, now I just need the time....

Update 10/17 21:43  One gray day was all it took to reduce the playing time to 20 minutes or so.  It's supposed to be sunny tomorrow afternoon; I'll tell you how it goes.

Update 10/19 21:43  The radio ran for an hour and a half last night after a sunny afternoon; the batteries still had zing left.  I put them in to charge again this morning, and I've been using them for about two hours so far.  Still going strong.

As a cheap battery charger and recycling method for a busted piece of outdoor ornamentation, this is mighty hard to beat.

 
Sunday, October 15, 2006
 

Open letter about the ethanol lobby

While "The money-grubbing mendacity of the ethanol lobby" has been linked to Alpha Centauri and back, it doesn't make the concise case for discounting ethanol as a solution to the USA's petroleum woes.  The people coming here through searches are probably looking for that, so here it is as a public service.

There are plenty of reasons that we can't replace - or even meaningfully displace - petroleum gasoline with domestic ethanol.  Here are a few of them, with supporting info:

I hear your question:  "If that's true, why is the conventional wisdom so wrong?"  That deserves an answer.  Several answers, actually, because there are a lot of different groups with different interests converging to the same point of emphasis.

There are some voices on the other side.  For instance, the CEO of AutoNation has called for the automakers to produce vehicles which can run at least partly on electricity.  This would cost in the short term, but be much better for the health of the industry and the nation in the long term.  Think about energy security:  if you depend on corn or switchgrass for your fuel, a drought or period of grass fires (like Kansas through Texas this year) could jeopardize the nation's fuel supply as badly as a bunch of hurricanes in the Gulf.  But if your "extra" fuel is electricity, you can make it from wind, sun, coal or even splitting atoms.  The supply of electricity is much more secure than the supply of gasoline or ethanol.

And that's why YOU, dear voter, should be skeptical about ethanol or even opposed to it.  There are benefits from it, but those benefits aren't for you.

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Saturday, October 14, 2006
 

Great strides

More evidence proof that events are getting ahead of me:  GE has a SOFC fuel-cell stack which hits 49% efficiency.  The GE stack is estimated to cost $254/kW for a 5.4kW system (under $1400 for 5.4 kW), exclusive of fuel reformer and electronics.

It's not clear if the efficiency is for the stack alone (probably) or for the complete system, or what the cost and efficiency loss of fuel preparation would be.  If the cells are aimed at use in coal plants, it seems likely that they will take scrubbed syngas (CO + H2 + inert gases) as their fuel and require no further reformation.  If fuels like methane and propane require no preparation and the 49%-efficient stack is followed by a 95%-efficient converter, the fuel-to-juice efficiency would be 46.6%.  That's not half bad.

The system cost for cells such as these is not easily pinned down [1], but if we assume $600/kW we probably won't be far off.  Last, we need a total system efficiency.  Condensing furnaces exceed 95%, so that seems like a completely reasonable assumption.

If we assume 46.6% electrical efficiency and 95% total efficiency (48.4% output as heat, 5% losses) here's what we'd get out of a therm of natural gas, assuming a price of 65¢/therm for gas and $.68/therm for the produced heat:

  Product     Quantity     Units     Value/unit     Total value  
  Electricity     13.65     kWh     $0.08     $1.09  
  Heat     0.484     therm     $0.68     $0.33  
TOTAL     $1.42  

Looks like the unit would just about double your money.  If you had a 5 kW unit running at 25% capacity factor for the year (providing both space heat and DHW), it would consume 802 therms of gas at a cost of $521 and yield heat and electricity worth $1139.  The gross profit before depreciation and maintenance would be $618/year, sufficient to pay off a $3000 unit in 5 years.

Most households don't use 5 kW of electricity during the heating season except for electric stoves or heat pumps.  I haven't looked at the net efficiency of the fuel cell plus heat pump in at least a week, so it's time to scribble on another envelope.  5 kW into a heat pump with an EER of 12 would yield 60,000 BTU/hr.  The example fuel cell system producing 5 kW would burn 0.366 therm/hour of gas and yield 17,700 BTU/hr of heat; together, the two could produce 77,700 BTU/hr of heat from 36,600 BTU/hr of gas.  This is an EER of 212%, cutting fuel requirements by 54% compared to a 98%-efficient condensing furnace.

I'll come back and look at the combo of FC/heat pump plus wind power and PHEV later.  For now, it looks like a replacement of gas furnaces with FC/heat pump combos could offset quite a few years of natural gas depletion, and make it even cheaper to adopt alternative energy supplies when we develop them (so long as they're SOFC-compatible).  Samples suitable for these purposes are in testing at the Department of Energy, and the projected price is right.

[1] I found Assessment of Solid Oxide Fuel Cells in Building Applications which specifies the cost of an inverter as $400/kW and so forth, but the exponents for scaling most of these costs with size are specified as zero.  I can't tell if the authors assumed that the cost would be roughly the same across the 1-5 kW power range (which seems likely for elements such as the water heater), or if this is a typo.  This report is also 7 years old and way out of date.  The SECA report 10 kW SOFC Power System Commercialization SECA Semi-Annual Report 41244R04 states a goal of $400/kW system cost for the third and final phase.  It is far more recent, and probably more trustworthy. (back)

 
Wednesday, October 11, 2006
 

Another "holy crap!" moment

After investigating a couple readers who had clicked in via a Google search for "ethanol lobby", I was floored to see that The Ergosphere has the #1 hit for that phrase.

How the hell did that happen?!

What's depressing is that my polemic gets lots of links, but more technical pieces like the one on carbon cycles and sustainabilty that's coming in the next few days will probably reach few readers.  I still strive for quality at the detail level, but it's sad that the public at large appreciates it little and understands it even less.

Update 10/13:  "Scamwatch:  Steorn" is the #1 hit for "is steorn a scam?" on Google.com.mx.

All of this is determined by link counts.  I'm utterly flabbergasted to see the stock some people put in what I write.  I hope to be worthy of it.

 
Thursday, October 05, 2006
 

The real scandal

It's amazing what does - and does not - move the body politic these days.  To paraphrase Stalin, exploiting one person is a scandal, exploiting 300 million is a statistic.

Rep. Mark Foley is accused of sending provocative e-mails and instant messages to teenage Congressional pages.  He appears to have done this for the satisfaction, however vicarious, of his own very personal sexual urges.  This, and the refusal of his political superiors to put a stop to it or force his resignation earlier, is becoming a huge issue in this election.  It may be the key factor in a number of races and even shift control of Congress.

This was one person influencing the lives of a handful of near-adults, and without any grave effect.  Any male page attracted to Foley was - face it - already gay or trending gay.  Affairs conducted at the distance of IM have no potential to transmit STD's or cause any other significant harm.  As an experience which removes unwarranted trust in authority, it could even be regarded as an important step in growing up (however unwelcome the form).

But entire political parties which carry on affairs with the oil and coal interests attract little attention.  The stories go unremarked even when the companies whose interests they advance and whose campaign contributions they take are the objects of widespread public anger.  It's as if the body politic is too dim to see even a small part of the big picture.

Now, why is that?  Why is there only a Proposition 87 in California, and not a huge movement to oust the legislators - and executive - who move to keep the US addicted to the products of Exxon-Mobil (and Saudi Arabia)?

People are outraged that it cost them nearly $100 to fill a big SUV last summer.

If that SUV ran on batteries, it might have cost $25 to charge it instead.  And that SUV would have been a cleaner, quieter, safer, superior vehicle in almost every way.

Why isn't there outrage over that?  Why isn't that the scandal on every editorial page and running as a crawl on CNN and Fox?  I'd tell you, except that I honestly don't have a clue.

 
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