Shandrew (shandrew) wrote,

Bloom Box: Holy Grail for Energy or the next Segway?

Short answer: Neither, though I may be biased since they're fellow Sunnyvale neighbors.

I was pointed to this ridiculously uninformed piece of hype created to advertise the 60 Minutes story on the Bloom Box last week.

So, wow, 60 Minutes is awful. I used to watch it every week when I was a kid. Is it a lot worse now, or is it me? Here's the actual 60 Minutes story. I suggest ignoring it and simply reading Bloom's informational web site, even if it does use the ridiculous new buzzword "Energy Server".

The story offers pretty much nothing of value beyond the preview. They completely fail to explain what a fuel cell actually is! Instead, they seem to treat the box as some sort of magic energy for free device that makes electricity...this does a disservice not only to the viewers, but also to the Bloom Energy company. Instead, they choose to show off hype-filled parts, such as "oh look, they're using it at Google and eBay thus it must be awesome!" Electricity sources are easy to hype because they require actual numbers to evaluate. With a good enough sales pitch virtually any kind of source can sound good to a lay person. "Oh yes, the amount of energy that we generate stepping on the sidewalk can power an entire city!"

Here is my Bloom Box for dummies:

The Bloom Box is a fuel cell which is purported to be significantly less expensive than existing fuel cells. A fuel cell is a device that converts fuel into electricity through chemical means (in this case, natural gas->hydrogen->electricity). Similarly, a fossil fuel power plant is a device that converts fuel into electricity through combustion and physical generation (turbine).

The primary numbers you need to evaluate this sort of thing are:

1. $/Watt : The fixed cost for buying the powerplant and associated pieces
2. $/KWh : The cost to generate each unit of electricity, mostly fuel cost
3. Lifespan

With these three numbers you can make a rough calculation of the $/KWh that you need to sell the electricity for to come out ahead. That's not nearly the whole story, but if you don't have these three numbers you may as well be looking at a perpetual motion machine.

Bloom box:
$/Watt : $8/W (@100 kW size), projected to reach $3/W. Already this should be raising eyebrows. The DOE states, "Today, the most widely deployed fuel cells cost about $4,500 per kilowatt", $4.5/W. So they're not yet beating existing fuel cells. Bloom appears to claim price advantage based on not using platinum as a catalyst, but the truth is that other companies also have fuel cells that don't use platinum.

$/KWh : Things get tough here. Natural gas pricing is volatile, up from $.17/1000cf in 1970 to $10/1000cf in 2005 to $3.5/1000cf today. Actual current customer pricing with PG&E is roughly $.7/therm, $7/1000cf.

Bloom's site claims .661 MMBtu of natural gas to generate 100 kWh electricity.

100 kWh * therm/29.3kWh * .1MMBtu/therm * 1/.661 MMBtu = 52% conversion efficiency

If we assume $7/1000cf:

$7/1000cf * 100cf/therm * therm/29.3kWh / .52 = $.05/kWh

If prices return to 2005 levels:

$13.5/1000cf * 100cf/therm * therm/29.3kWh / .52 = $.09/kWh

Lifespan: 10 years. Well, that's what the warranty is for, and that's what the 60 minutes story claimed. 10 years isn't great for a power plant. Hopefully a lot of it can last longer and be reused.

Now, the final tally:

$800,000/10 years/100kW * 1 year/8760hr / 100kW + $.05/kWh = $.14/kWh

or at $300k, $.08/kWh

or at $300k and $13.5/therm, $.12/kWh

Those numbers look pretty competitive with PG&E (inexpensive gas, expensive electricity) though are pretty pricey compared to most of the country. However, this doesn't include any associated costs, other overhead, taxes, interest. Can it be a profitable tech even at $.20/kWh?

Yes! Most analysts have failed to understand is that power is much more expensive during the day. Businesses can pay over $.50/kWh during summer peak usage hours. Any sort of small-scale local power generation that can beat those rates can be competitive, as long as it's small and especially if it can efficiently be started up and shut down. This is micropower.

Is this a worthwhile replacement for diesel generators? It depends on your requirements. A diesel generator is at least an order of magnitude cheaper, and is smaller and lighter (think ~250 HP engine). For portable applications, you also need roughly 4x the size of tank to store CNG versus diesel, however, for fixed applications natural gas delivery is easy. Diesel is noisy and smelly, a fuel cell is not. Diesel fuel pricing is more predictable, while natural gas pricing varies a lot by season and by locality.

Will this defeat global warming? No. You're still dumping roughly the same amount of CO2 into the atmosphere as a conventional natural gas plant, and more than cogeneration plants[*].

Is this "wireless power"? I really have no idea what 60 Minutes meant by that. If you live in the boonies and don't have a grid connection, this might be a good solution. You still need feed it fuel, but a 250-1000 gallon tank, just like many rural people already have (though for propane), would be sufficient for a month or so. However, it's really only efficient to run for a single house if it has variable output, which as far as I can tell is not there.

Is this house-scale power? Business-scale? Well, PG&E can buy these boxes too. The question is whether having the boxes on their end, where the gas is, or on your end, where the electricity usage is. People like talking about transmission losses, but it's really just 7% average. The infrastructure is already there. The other factor is how well the prices scale down. What this will do is bring down peak power pricing (again, assuming startup and shutdown are efficient).

Will Bloom succeed? Unsure. Competitors already have similar, less expensive, products with a similar lifespan in production. Here's a competitive product from UTC, 4x the capacity of the current Bloom Box for ~$1M and has been available for over a year (smaller scale ones have been available for longer), plus includes the ability to channel the waste heat for heating.

I don't know what, if any, large competitive advantages Bloom has. The fundamental technology is different, solid oxide fuel cells for Bloom vs phosphoric acid fuel cells for everyone else. Solid oxide is apparently slightly more efficient, but that'll save less than a cent per kWh. Solid oxide may be easier to scale down to ~10kW, but as I stated before, the advantages of that are limited.

What would I consider an electricity holy grail?
1. efficiently scalable to one house or globally available
2. variable output, fast and efficient startup and shutdown
3. no CO2 emissions, minimal pollutants
4. inexpensive cost
5. inexpensive, reliable, and convenient fuel

Bloom meets none of those criteria, though they plan to meet #1 someday. The Bloom Box is definitely no holy grail and is not likely to transform Silicon Valley into green energy valley, but I believe they may one day have a competitive mass-produced product.

[*] Cogeneration uses waste heat for heating. The Stanford power plant, Cardinal Cogen is a 50MW natural gas powered cogeneration plant. In addition to using waste steam to heat the campus, it also has a huge ice/chilled water tank that is cooled at night (when electricity is cheap) to supply cooling to the campus.

[**] Don't get these fuel cells confused with the sort you would need to power a car. To power a car purely on fuel cells, you need something with the maximum output of the Bloom Box (the Honda FCX fuel cell car also has a 100kW fuel cell), but is a lot lighter, smaller, and can ramp power up and down instantly. That's why auto fuel cells are still several big discoveries away from being competitive with batteries.
  • Post a new comment


    default userpic

    Your reply will be screened

    Your IP address will be recorded 

    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.