There is a lot of hype right now about the “Bloom Box.” Google installed one, Adobe installed one, and Bloom Energy has an active sales force hitting up the Fortune 500. So what is a Bloom Box and what does it mean for the future of the energy world?
A Bloom Box is a hydrogen fuel cell. The simple picture is that you feed it natural gas and it spits out electricity. How is it different from a regular natural gas power plant? There’s no combustion in a fuel cell, just the silent separation and recombination of protons and electrons.
Fuel cells rely on a catalyst to split hydrogen ions off from natural gas. The hydrogen ions are super positively charged – a hydrogen ion is a single proton – so electrons can be made to do pretty much anything to meet up with them. An electron will flow through your light bulb, or your entire Google office and create power, just to reunite with its long lost proton.
So that’s a Bloom Box. Rip apart some natural gas, separate out the protons, and make electrons do useful work to meet up with them. No combustion, and lots of awesome innovation on the catalyst side of things.
There are two problems though. The first is that there’s carbon in the natural gas, so when you rip the hydrogen atoms away from it, that carbon gets emitted and becomes carbon dioxide (CO2). Bloom Boxes are pretty good, but they are not a carbon free source of electricity like solar or wind. Specifically, a Bloom Box emits 773 lbs of CO2 per megawatt-hour (MWh) it generates. This is quite a bit better than grid power in most states, but not all. Check here for a list of states and their emissions factors.
A Bloom Box, or any hydrogen fuel cell, could be carbon free if you fed it pure hydrogen (or renewable biogas), instead of natural gas. The problem then is where you source the hydrogen. Ultimately, we could get hydrogen by using solar power to split water molecules apart, which would result in zero carbon emissions and result in a really cool way of storing the energy produced by the sun: we could generate hydrogen during the day from the sun, and then use the hydrogen at night to generate clean electricity. This would be an amazing way to store solar energy, and this was in fact the dream of many hydrogen buffs back in 2000. Unfortunately, it is still outrageously expensive. Which brings us to our next problem.
Economics. Federal incentives will currently (2011) pay for 65% of the Bloom Box, and State and utility incentives will often pay for up to another 20% of the total costs depending on your State. That can make a Bloom Box investment very, very good. But what about without incentives? Without incentives, the economics don’t work out favorably for the Bloom Box. And since the Bloom Box is pretty much the best hydrogen fuel cell right now, it means economics aren’t great for any fuel cells. The Bloom Box is about 50% efficient, which is pretty good, but still less efficient than a new central station natural gas plant. Side note: there aren’t electric transmission losses when you generate electricity on site, but there are transmission losses in our natural gas distribution infrastructure on the order of a couple percent, and since methane (which makes up greater than 90% of natural gas) is 20-25 times worse than carbon dioxide in terms of global warming, the transmission losses for a Bloom Box do not work out favorably.
Back to economics. The best info on price we could find for the Bloom Box was between $10,000 and $12,500 per kilowatt (kW), and Bloom Boxes sell in increments of 100 kW. Depending on what state you’re in, and if you sneak in a purchase before bonus depreciation disappears, then you should get about 65-90% of the total cost back, so we’re guessing a 100 kW Bloom Box installation costs about $200,000 after rebates. If you take out a loan at 4%, assume maintenance is a few percent, and you buy gas at $0.90 a therm, then the device will give you power at around $0.10/kilowatt-hour (kWh). That’s not great. The US average is about exactly that. Don’t like our assumptions? No problem. We made a spreadsheet for you to put in all your own assumptions and see the calculations exactly, and you can download it here. Have fun!
So what’s the point of all of this? The Bloom Box is a cool technology that is still expensive and doesn’t get companies to carbon free. If we ignore rebates (which we should if want a sustainable future that can be exported to India and China), then the Bloom Box is still about 8 times more expensive than coal, and more than twice as expensive as solar. Unlike solar the Bloom Box generates carbon emissions, but also unlike solar, the Bloom Box can generate electricity at night. I wouldn’t put my money on fuel cells powering the future any time soon, but I am excited by all the exciting engineering progress that has been made so far, and for another eventual arrow in the quiver against climate change.
I love this article. This is wonderful. Thank you!
Thanks for the clear, concise description of the Bloom Box. I hadn’t read much about it since the media first reported a rather sketchy description of a magical, energy-producing box that was going to revolutionize the electric grid and was glad for an update.
While I think your analysis is very good, and the flat rate for electricity may be no better than from the grid, it strikes me that the bloom box has a few other aspects that may make it an attractive technology. If your local utility charges you based on the price of electricity at that time of day, as it often does for industry, then the daytime cost of electricity will be higher than the average. You could save money by using the bloom box during peak daytime hours and drawing from the grid at night. Furthermore, decentralized generation can be very helpful in the case of grid outages. In NJ this year, many people have been left without electricity for days in the wake of hurricane Irene and various large storms. However, I am connected to a small energy facility which continued to function even when the larger grid was down; as a result, I have had electricity the whole time. Similarly, something like the bloom box can make the electric system more robust by providing electricity on a local level even if the grid goes down.
Hi Elena, thank you for the great thoughts.
You’re right to point out the benefits of self-generation during a blackout, and your comments about peak reduction benefits are important too. Bloom Boxes, however, need to be run as close to 24/7 as possible to maintain efficiency and operational integrity, so you can’t just run them during peak while using the grid at night as a price arbitrage system. That being said, if you run them all the time you still help reduce peak load through a distributed source, so that is a major benefit both to the customer’s peak demand charges and to the grid’s ability to maintain itself during peak.
Best,
Brenden
and…
Once you make the investment in the equipment, it would be silly to not run it 24/7 to get the maximum output from it. …at least to the point where time-dependent maintenance costs start to offset the benefit.
What a great post! I enjoyed reading this, thank you for sharing. Keep up the good work!
You’ve left out on of the prime potential advantages of fuel cells: the opportunity for cogeneration of heat on-site. A fuel cell is typically comparable with a turbine in terms of heat loss, but either solution, adopted locally, allows for heat harvesting. If you need process heat, or even water for space heating or domestic consumption, you can easily double the useful output of the fuel cell.
One other thing: why does no one talk about ClearEdge? They’ve had fuel cells on the market for several years now, and they sell a 5kW unit (for about $100k, I think, but they’re trying to achieve better economy of scale). Is there a problem with their units that makes Bloom a better option?
Great post–thanks!
Hi Jeff, thank you for the questions. A couple of things:
Bloom Boxes come in units of 100 kW, microtubrbines in units of 200 kW or 250 kW, depending on the manufacturer. A ClearEdge 5kW unit is really not a competitor to a Bloom Box or microturbine; it’s designed for the residential market, not commercial or industrial applications. Also, was $100 for cost on a ClearEdge a typo? That would be 10 cents/watt, which would make that the cheapest source of power on the planet by an order of magnitude or so…
In terms of waste heat, Bloom Boxes do not provide useful waste heat. The device is tuned entirely towards electricity generation, so the waste heat coming off the unit is not high temperature enough to do cost-effective heat recovery. This is not the case with a microturbine, which can get up above 60% overall efficiency if you have a use for the waste heat. The problem with devices this size though is that a heating load year round of that size is usually not available to the facility, so much of the waste heat potential goes uncaptured.
Best,
Brenden
Sorry, that should have been $100k…
Ah, that makes more sense. If that’s right, that would make a ClearEdge fuel cell about $20/watt. We just saw a bid for a residential solar array that came in at $5.50/watt for the total installed costs, although solar doesn’t produce all year round like a fuel cell can. Wind farms are coming in between $2/watt and $3/watt depending on the area, and produce around 30% of the year.
A large central station natural gas plant comes in at less than $2/watt though, so the economics are definitely still on the side of large, central generation.
Thank you for the great comment and discussion Jeff, keep them coming!
Best,
Brenden
Although there are certainly some reality checks required before installing the bloom box, I can’t help but get excited about the prospect of fuel cell adoption in general. They are not limited by Carnot efficiency, capable of using a variety of fuels, and have both power and transportation applications.
As engineers and scientists, I think it’s important to simultaneously advance the technology through research while remembering the life cycle implications of different fuels. Hydrogen fuel cells are great (emissions = electricity + water), but the value chain leading to the finished product may not be so pretty.
Hi Matt,
This is a good point about the potential efficiency not being limited by Carnot, which makes fuel cells potentially much more exciting than turbines. You’re also correct to emphasize that if we do find a renewable source of pure hydrogen that fuel cells would then become incredibly beneficial for the planet. Great points.
Best,
Brenden
Anyone know anything about the embodied energy in solid oxide fuel cells like the Bloom Box? How about the useful lifetime of the ceramic catalyst and electrolytes?
Would including these factors bring SOFCs closer in overall lifetime efficiency to solar cells?
Hi Steve,
This is a great question. I haven’t seen research on the embodied energy in solid oxide fuel cells, but that doesn’t mean it’s not out there. If any of the other readers know, please chime in.
As for photovoltaic, the energy payback time for polycrystalline seems to have shrunk to less than 2.5 years in most operations now. Some of the thin film outfits like First Solar claim an energy break-even of as little as 6 months.
It should be noted that the energy payback, unfortunately, is not the same as the carbon payback. Most polycrystalline cells are manufactured in China now, which means they’re being made from coal power. The largest markets are still areas like Germany and California, however, which have relatively clean grids powered primarily by nuclear, hydro, and natural gas. The difference in grid carbon emissions could easily be 4x from where the cells are manufactured to where they are offsetting energy use, so a 2 year energy payback could translate into an 8 year carbon payback. We need to be concerned with emissions over several decades though, so an 8 year payback is not bad over a thirty year life of the panels.
Best,
Brenden
I understand that natural gas, despite its high methane content, does burn quite a bit cleaner than gasoline even in internal combustion engines (ICEs). A fuel cell is even more efficient, so I don’t see how this wouldn’t be an advantage over ICEs, whether in autos or small generator sets for residential use. The latter are rather expensive and so are autos, which entail about the same or more additional expense than equivalent gasoline ICEs. The higher efficiency means you burn less of it, so that’s another factor on top of this. I would think almost any significant improvement in emissions and efficiency would be helpful over what we’re doing now.
I’m wondering, however, if the Bloom Box also works with straight hydrogen. This article seems to imply it does. Do we know?
Hi Robert,
Putting Bloom Boxes everywhere certainly would be cleaner than grid if our grid was powered by gasoline. Only about 1-2% of US electricity comes from gasoline each year though, the rest of it comes from nuclear, hydro, combined cycle natural gas plants, and coal. Bloom Boxes are 1.5 to 4 times cleaner than most coal power plants, but they create more emissions than hydro or nuclear plants. A new combined cycle natural gas plant is about even with a Bloom Box. So it’s not as simple as replacing car engines with Bloom Boxes when the power grid is concerned. Fuel Cell cars have been in serious research considerations for more than a decade now, but costs and the limited range have kept them from the mainstream.
As for a Bloom Box being able to run on pure hydrogen, the answer should be yes theoretically. Hydrogen, however, bonds with everything, so unless Bloom has coated every surface of their Bloom Box with substances that won’t erode under the presence of H2, I wouldn’t recommend trying to run a Bloom Box directly on pure hydrogen. That, however, would be a great question to ask Bloom.
Best,
Brenden
While it is true that the Bloom Box is relatively expensive, is there a particular reason for it being so? Perhaps if it were implemented at a larger scale as suggested in the above posts, the cost of the Bloom Box would decrease significantly. Another suggestion would be to outsource the production of the Bloom Box itself, maybe in China or another country which has cheaper labor and resources available to it. But would that mean loss of the tax incentives since the product production is not supporting US economy, I am unsure. Overall, it is a wonderful idea and with time like all things do this technology will become more efficient and hopefully cheaper also.
Good article and I am glad that SOMEONE is writing intelligently on these devices. I have had to correct numerous reporters and others who erroneously champion Bloom boxes as a “green” or “clean energy” source! Akin to a perpetual motion machine.
As you point out they are simply a fuel cell. A good one. But not magic. And not even overwhelmingly more efficient than others.
And they are definitely not a magic bullet for our fossil fuel dependence as they are simply another way to burn fossil fuels. In fact, it appears that their efficiency has been over-stated and they are less efficient than a combined cycle natural gas plant even after transmission losses.
They are instead a useful tool for backup and distributed energy generation. As a distributed energy source they do provide some benefits. They also may help companies decrease demand charges significantly.
Part of the mis-perception can be blamed on the media’s sloppy reporting. Part on the “greenies” who are too willingly to believe any good news. But most on Bloom’s hyper-active marketing/pr and lack of transparency, which are hallmarks of its investor Kleiner Perkins….
I live in LOS ALAMOS NM USA and I would love to see the inventors / promoters of BLOOM BOX to come here and try to sell the IDEA and the PRODUCTS to our scientific community and residents of our small city.