Turn trash into energy in your office parking lot

When a school or office building thinks about distributed energy, it usually means solar panels propped up on a roof.

A small company called IST Energy has another vision: it's developed a shipping container-size contraption that turns your building's trash into electricity and heat. The company is expected to unveil the unit, called the Green Energy Machine (GEM), on Monday.

The idea behind the GEM is to offset a building's energy use while dramatically cutting trash disposal fees. The cost of trash removal can vary greatly, but a university or office park with a number of buildings could pay about $200,000 a year, according to IST Energy executives.

The company says the GEM is clean technology because it doesn't burn the trash. Instead, the machine uses gasification, a process that overall pollutes less than combustion. A number of clean-tech companies are trying to combine gasification with renewable sources of fuel, namely municipal solid waste or biomass.

A demonstration unit of the Green Energy Machine from IST Energy that converts trash into energy.

(Credit: Martin LaMonica/CNET Networks)

The GEM unit is designed to take up as much space as three parking spaces, making it suitable for office buildings, hospitals, and the like. Metal and glass have no energy content, so they should be recycled. But everything else--food, cardboard, plastics, agricultural wastes--can go in.

"Normally, when we tell people what we're doing, they say, 'You can do that? I had no idea that was possible," said Stu Haber, president and chief executive of IST, which is based in Waltham, Mass.

The company, which was spun out of a research and development firm, says it can convert 95 percent of the waste--up to three tons of trash a day--into usable energy. The remaining 5 percent is ash. With three tons of trash a day, a unit can provide enough electricity and heat for a 200,000 square-foot building holding about 500 people, it says.

So far, a handful of universities, a municipality, and a real-estate developer have come by its Waltham, Mass. offices for demonstrations.

Got a big trash bill?
Haber said the unit pays for itself relatively quickly but realizes that the novelty of the GEM could make it a tough sell. He hopes to sell between 5 and 10 units this year. "The first GEM will be the hardest one to sell," he said. Noise from the machine could also be a barrier.

Corporate purchases of solar panels have been growing rapidly, depending on a state's incentives. Haber argued that many companies invest in solar energy to reduce their carbon footprint in a visible way, but a purchase of a GEM can be driven entirely by money, he argued.

Loading garbage into the demonstration unit of the Green Energy Machine.

(Credit: Martin LaMonica/CNET Networks)

Feeding the maximum of three tons of trash will yield about 120 kilowatts of electricity and about double that in heat, which will fulfill about 15 percent of a building's energy needs, IST Energy figures. The bigger financial benefit is in cutting disposal fees, Haber said.

With an up-front cost of $850,000, a GEM unit will have a payback in three to four years, the company calculates. More likely, those interested will go with a leasing option that would eliminate the hefty up-front investment.

"Everybody loves the fact that they're helping the environment, but because we're talking to businesspeople, I have to assume that they're interested because of the very quick payback," he said.

There's also a 10 percent federal tax credit available for this sort of renewable energy, Haber said.

Squeezing more value from refuse
From the end user's point of view, the GEM is designed to be simple. Through a loader, trash goes into the machine, which shreds the garbage.

Then the machine removes moisture and creates pellets--shaped just like the sawdust pellets used in pellet stoves. Then the pellets are put into an air-fed gasifier designed by the company, which generates what is called a synthetic gas, or producer gas, which typically contains mostly hydrogen and carbon monoxide.

The dark pellets were made from office trash. On the right are sawdust pellets used in pellet stoves.

(Credit: Martin LaMonica/CNET Networks)

That gas is the fuel for making electricity or heat. IST Energy recommends that the best energy source would be a natural-gas microturbine, which would need to have its setting adjusted, or a generator. It takes about two hours before the GEM runs from its own energy output, so the main carbon emissions come from burning the synthetic gas.

Garbage is already used as fuel source in a number of places. Some landfill operators capture methane from degrading trash to make electricity. Trash incinerators, too, can create some usable energy, but they are considered inefficient and polluting.

Looking to reduce shipments of diesel fuel, the U.S. Army last year tested portable trash-powered generators in Iraq, but the project is said to have not met all its goals.

For energy technology firms looking for a cheap source of fuel, trash appears to be attracting more interest.

Another Boston-area company called Ze-Gen is pursuing the same general idea as IST Energy. Last week, it raised a Series B round of $20 million to build a facility to take construction debris and make electricity at a central location using a gasification process.

Another firm, InEnTech in Oregon, is pursuing a different technology process to get the most energy out of household garbage.

Many of these firms have yet to test their products at commercial scale. But at a time when people are seeking clean and renewable-energy sources, waste may come full circle and become a valuable commodity again.

[flareback]

When can I get a portable version for my DeLorean?

[YankeePoodle]

beautiful. I like this idea because no landfills and energy security.

[mcrhoads]

It was stated in the video that the GEM unit operates under self-generated power after it gets going. Has the designer thought of building in a battery that could be recharged from its operation and used to start it the next time, thereby eliminating the need for any outside power once it is delivered to the end user?

[ToddWBeaver]

Another technology for processing waste is thermal depolymerization. Thermal depolymerization technology still needs to become more economical and something needs to be done about the smell.

[iamarcin]

It doesnt have to be small/portable just reletively clean and open to public. <br />Id bring my trash there... There are shopping centers all around me... Get some pelets in return... 75/25(for me) split should be fair... or money by the pound. <br />They can sell the extra pelets. I know people are investing in home heating systems that run on this and fireplaces because the pelets are suposedly cheaper. I dont have one but i would get one if this would be possible in my area. <br />*** I am assuming these are the same pelets *** <br /> <br />Enough people do this and it should be very helpfull. Seems to me like it is better then wind energy.... <br />And i bet you people droping off their trash would go to these shops to buy..

[mlamonica]

The pellets that this machine makes and the pellets that you burn in a home pellet stove are different. Biomass pellet stoves burn compressed sawdust (or corn). If you look in the bottom picture, you can see the difference.

[Vegaman_Dan]

@mlamonica: <br /> <br />Would these pellets be biodegradable? I wonder if they would make a good mulch or seeder material for compost piles. <br /> <br />Heck, if the absorb moisture, they could be good pet bedding. Woodstove pellets sure work well for that.

[Vegaman_Dan]

While this is exceedingly cool, I suspect that the garbage companies who are awarded government contracts to service an area will fight for some sort of legislation against this or to put up some sort of extra roadblocks against deployment. The more trash that is consumed on site means less trash to be hauled and less money for the carrier to make. <br /> <br />Now a clever trash company would buy up a bunch of these units and then lease them out to larger facilities like schools, hospitals, and other corporate customers under a green banner. That could make some good money and provide a service and supply chain that those customers need.

[bob_n_forjohnson]

No. A clever trash company would buy up a bunch of these and become a local energy provider AND trash company thereby making money on multiple fronts possibly even undercutting the local power company. That seems far more clever.

[Wak_Em]

I wonder what the carbon footprint is for this thing.

[Joe Real]

It depends upon your definition of carbon footprint. <br /><br />For example, I can argue that it is carbon neutral, simply because it doesn't add more carbon than it is taking in. The issue about starting it would become negligible once it is up and running for longer period. And also if you use batteries or solar, then indeed, this is carbon neutral.<br /><br />Another example is that it can also be argued to be negative carbon sink in terms of substitution. We get energy from what otherwise would be waste, and by using that energy, we would have substituted the energy that we use from natural gas or petroleum and their products, so that we lessen the need to mine for these fossil fuels.<br /><br />Still others would argue for the Life Cycle Analysis. They would claim that it takes energy to create this machine, and the machines that creates this machine would also have their own carbon footprints, and those energy traced back to fossil fuels, and passed along the transport, refining, distribution, so on and so forth, from cradle to the grave accounting of carbon balance, including all indirect and indirect sources during the creation, operation, and disposal of this machine.

[schaleff]

Putting trash in the ground for a few thousand years seems like Carbon Negative. <br /> <br />Burning trash and putting the carbon in the air seems Carbon Positive. The plastic trash is from fossil fuel. It is just like burning gasoline, that has been recycled. <br /> <br />I don't know the full answer, but putting carbon in the ground seems the best solution at this time, since we put so much in the air with cars and such.

[gdmaclew]

Ahhh. The carbon footprint argument. <br />When are people (and more importantly the media) stop this nonsense. <br />There is no carbon (or more precisely, carbin dioxide) problem in the world. <br />Already half of the world's knowledgeable scientists dispute this man-made global worming hoax. <br />The media just won't report it. <br />The sooner we get off this carbon footprint/global warming kick and concentrate on pollution in these hard times the better off we'll be.

[RecycleBill]

Duh! Can nobody read that one of the major emissions from this little GEM is carbon MONOXIDE? That's CO, not CO2. CO is like the major Greenhouse gas. CO is the stuff that kills you dead when you seal yourself inside your garage and leave your car running. Someone has been spending far too many nights sniffing tailpipes: http://recyclebills.squarespace.com/recycleblog/green-energy-machine-dreams.html

[willdryden]

Don't stop reading half way through the article. The syngas is CO and H which is then burned. The result of burning CO and H is H2O and CO2.