The Time Is Right for CHP

Feb. 28, 2013
15 min read

When officials with Houweling’s Tomatoes installed two 4.36-MW Jenbacher J624 natural-gas engines in their Camarillo, CA-based greenhouse, they made history.

With installation of those engines, Houweling’s Tomatoes became the first greenhouse grower in the United States to unveil a combined heat and power (CHP) greenhouse that captures carbon dioxide and uses it to fertilize plants.

But the installation wasn’t just about making history. Officials with Houweling’s wanted to operate their greenhouse as efficiently as possible. The CHP engines allowed them to do this, cutting the amount of power they consume while also generating heat for the greenhouses and a fertilizer for the greenhouse’s plants.

Richard Vanderburg, energy and water conservation manager with Houweling’s Tomatoes, says that the CHP project allows the grower to burn fuel in the most environmentally friendly and efficient way possible. And for this greenhouse grower, that’s an important mission.

“We try to use everything we can when we’re providing power to our greenhouses,” says Vanderburg. “We’re committed to wasting as little energy as possible. This helps us meet that goal.”

Houweling’s is using the heat generated by the GE-manufactured Jenbacher engines to heat its greenhouses once temperatures drop at night. And they are using the carbon dioxide (CO2) that the engines generate to fertilize the company’s world-famous tomato plants.

“It’s a very environmentally sensitive solution,” says Vanderburg. “Our goal has always been to burn fuel in the most efficient way. This allows us to do that.”

The workers at Houweling’s aren’t the only ones, though, who have discovered the many benefits of CHP systems. The manufacturers of these systems say that owners across the globe are increasingly recognizing the benefits that come with CHP.

Companies and building owners that invest in CHP systems can save fuel costs because these systems capture the heat that they generate, heat that companies can then use in their facilities. Because CHP systems capture heat that would otherwise be wasted during the production of energy, these systems need less fuel than do separate heat and power systems to produce the same amount of energy.

At the same time, CHP systems are friendlier to the environment. Because CHP systems consume less fuel, they also produce a lower amount of greenhouse gas emissions.

Manufacturers of CHP systems have preached these benefits for years. And, they say, this preaching has steadily paid off: A growing number of building owners and companies are realizing that CHP can save them money while providing reliable power.

“More and more customers are starting to see that there is an economic opportunity in CHP,” says Nick Kelsch, business development manager in the electric power division of Caterpillar. “It’s a bit like SUV sales, though. SUV sales go up when gas is cheaper. We see the parallel there. When electricity prices are higher, more companies are interested in cutting their use of it. They are more likely to explore alternatives such as CHP systems.”

The demand for CHP differs by region, of course. In some parts of the country where electricity prices are higher-such as the northeast portion of the country-the demand for CHP systems is rising. In parts of the country were electricity prices are lower, company officials and facility managers aren’t focusing nearly as much on the savings that CHP systems could bring them.

But Kelsch says that the overall trend is definitely pointing up when it comes to CHP demand in the US. “The future trend, what the smart guys in the room are forecasting, is that CHP will grow,” says Kelsch.

Seeking Savings
Scott Nolen, product line management leader for power generation with GE Jenbacher, says the ideal customers for CHP are those that need heat, and these are the customers that will realize the greatest savings from a CHP system. “Ideally, you’d have a situation where a customer is in need of both power and heat,” he says. “Then, the customer can use the heat that comes out of the engine to heat or chill his building. Sometimes customers do both, depending on the season.”

Building owners can gain value, too, when it comes to the onsite power that CHP systems generate. By generating at least part of their own power, companies will rely less on the public power grid. They might even consider selling part of the power that they generate back to the grid to boost the savings already provided by CHP.

No one in the United States, though, argues that CHP here approaches the popularity of CHP in other countries. It has gained far more traction in Europe, as one example.

Nolen points to the government incentives given to companies throughout Europe that invest in CHP as one reason for the greater popularity of the systems there. At the same time, the cost of electricity in European countries is high enough that companies that invest in CHP receive a financial benefit from getting both their heat and power from one system.

“You end up making money versus losing money to use gas to heat an area,” says Nolen.

In the US, the environment for CHP isn’t quite as attractive, Nolen says. For one thing, there aren’t as many incentives available to building owners or company executives interested in installing CHP systems in their facilities.

Then, there’s the challenge of gaining access to the public grid. That can prove difficult in the United States, Nolen says.

Finally, the price of electricity is relatively low throughout much of the US. Because of that, many companies don’t see the financial benefits of investing in CHP systems.

The Drag of Too Much Regulation?
There is a sure way, though, for the United States to boost the number of companies that invest in CHP systems, Nolen says: legislation that makes it easier for companies to gain access to the public power grid.

“If legislation was enacted that mandated that if users meet a certain minimum efficiency they must be given access to the grid, that would make a big difference,” says Nolen. “That would make for a huge change in the attractiveness of CHP. That would make it much easier for CHP users to send the extra power off to another potential user. It’s very difficult, unfortunately, for customers to get on the grid right now.”

Nolen isn’t alone in pointing to the Feds, or even at state and local governments, as playing a major role in the growth or slowdown of CHP adoptions.

Bill Martini, vice president of sales for the west for Waltham, MA-based Tecogen, a maker of modular CHP systems, says that government interference sometimes plays a role in steering companies and facility owners away from CHP systems.

He pointed to the fees, environmental regulations and expensive metering that some governments impose on companies investing in CHP systems. Martini says he sees much of this in California.

“California has its finger in every aspect of our business,” he says. “Sometimes governments create playing fields that are not level. They create benefits for some technologies and penalties for others.”

Martini pointed to wind and solar as two technologies that have benefited from positive government attention, while CHP systems, at least in his region of the country, have actually suffered because of government regulations that he says are too severe.

As an example, Martini cites a hypothetical nursing home that could benefit from CHP technology. Officials at the nursing home, though, are busy with the hundreds of decisions that they must make each day.

These overworked officials have little time to spend deciphering often-confusing government regulations regarding CHP systems. Overwhelmed by the sheer volume of rules or regulations, these nursing home officials might simply decide to pass on installing CHP systems. They’ll then miss out on the economic benefits of CHP.

What do Martini and the other proponents of CHP systems do in the face of government regulations? How do they keep the industry growing when rules across the country often act to turn potential adopters of CHP away from the systems?

“You just have to stick with your simple message that CHP systems bring an important economic and environmental benefit,” says Martini. “You have to let the sound underlying logic of CHP win out.

“Stripping away some of the onerous regulations, charges, and fees would certainly help take the lid off CHP a bit,” he says. “Demand is suppressed because of those hassles and expenses. Something simpler and more understandable, something that is more even and fair, would make a big difference.”

Jeff Glick, vice president of sales for the East for Tecogen, doesn’t disagree with his colleague. He says that manufacturers and other supporters of CHP must work together to spread the word about the savings and environmental benefits that come with the technology.

The goal is to convince a greater number of building owners that the many benefits of CHP outweigh the hassles of dealing with sometimes-onerous government regulations. “At a real ground-level response, the word has to get out about the successes of CHP,” says Glick. “It’s not a secret society, but sometimes it has that feel. The word has to get out.”

Of course, as there are countries in which CHP will always enjoy greater popularity, there are also portions of the US in which this technology will always be more attractive.

Specifically, those portions of the country that have high electrical rates will always be better fits for CHP systems because of the energy-cost savings that the systems can bring to building owners and company executives.

“One of the issues with cogeneration is always the electric rates,” says Glick. “They are high in the West Coast, and in the Northwest part of the country. But in other parts of the country, they are not high enough to justify the capital investment in CHP. People who have low electrical rates aren’t complaining about it, and they’re not looking for other alternatives.”

There is one area, though, in which CHP is gaining a foothold: the green energy business.

Glick says that he recently met with a representative of a firm that specialized in green engineering. When he stepped into the representative’s office, Glick expected to listen to a long speech about the importance of solar and wind energy.

Instead, though, the representative wanted to talk with Glick about the environmental benefits of CHP systems. “I was sure this engineer was going to be into fuel cells and wind energy,” says Glick. “But he had already made his conclusion. He had decided that he didn’t want fuel cells. He wanted to look at natural gas CHP. That was an eye-opener for us. This guy had done his own research. He wanted to talk about CHP.”

Current events, too, can drive the demand for CHP, something that Glick, who sells CHP systems along the East Coast, found out in early November in the aftermath of the devastation caused by Hurricane Sandy.

That superstorm hit the East Coast hard, leaving millions without power.

And it left many looking for a reliable source of off-the-grid power. “Just as an immediate effect of Sandy, we saw a tremendous up tick in interest for our CHP module that can provide backup power in the event of a power outage,” says Glick.

Shortly after Sandy, Tecogen sent out a press release touting the successes of CHP units throughout the New York market, Glick says, an example of promoting the benefits of this type of power source to entice other building owners to consider investing in CHP.

Even Martini, all the way across the country on the West Coast, says that he saw a rise in CHP interest after Hurricane Sandy.

Martini’s region of Tecogen sent out its own press release promoting the reliability of CHP systems. “The people in my region, though, are thinking more of protecting themselves in case of earthquakes, not hurricanes,” says Martini. “But it’s the same need for critical, reliable power. That is just as important on the West Coast as it is on the East Coast for facilities like hospitals, hotels, and data centers.”

CHP units today are used at a wide variety of building types, everything from data centers that will bleed valuable clients if they ever lose power, to hospitals and nursing homes in which power outages can be life-or-death occurrences.

In Bitburg, Germany, for instance, a CHP plant at the Bitburger Brauerei brewery has surged past 50,000 hours of successful operation.

A GE Jenbacher J312 gas engine powers the brewery’s CHP plant. The engine converts biogas into electricity, steam and hot water. It’s an example of how efficient the CHP process can be; very little is wasted in this application.

Since this CHP plant began operating in 2005, it has reduced carbon dioxide emissions by an equivalent of 10,000 tons. At the same time, it provided the brewery with significant cost savings when compared to the steam boilers that the brewery previously used for power.

The Jenbacher gas engine at the brewery produces 624 kW of electricity and 700 kW of thermal power, a figure that includes 330 kW of steam, according to GE. The brewery can run the engine either on the biogas generated as a byproduct of the engine’s operation or on natural gas. This gives the brewery the flexibility to run independently without interruption should the public power grid fail.

CHP systems have made a significant impact in Australia, too. In Mach 2012, an urban school district in Melbourne, Australia, installed a 2-MW GE Jenbacher gas engine to supply power, heat, and cooling.

The gas engine here is expected to save the equivalent of about 9,000 tons of carbon emissions every year. To put that into more easily imagined terms, it’s like removing more than 5,500 cars from the road.

The cogeneration plant being used by the Dandenong Commercial District, in Victoria, is designed not only to reduce harmful emissions, but also to reduce the amount of energy that the district consumes. The plant can also produce surplus hot water. Cogent Energy, which built and owns the plant, can then sell this hot water back to local commercial buildings to provide cooling though these buildings’ absorption chillers.

So not only does the CHP plant provide reliable and more efficient power for the school district, it also gives it an opportunity to make some extra money. That’s always important when school districts across the globe are facing budget cuts and tightening.

Vanderburg, with California’s Houweling’s Tomatoes, says that he’s more than happy with the way the CHP system at his greenhouse grower has operated. “The engine is working just as well as we had hoped,” says Vanderburg. “It does need maintenance, of course. It needs the proper amount of attention to keep running. But so far, we haven’t had any major hiccups. The engine we have is pretty sophisticated.”

The engines have served as a more efficient alternative to the traditional boilers that the greenhouse once used to
produce heat.

Officials with the Encina Wastewater Authority in Carlsbad, CA, don’t need to be educated on the benefits of CHP. They are already sold on the technology.

The authority, which provides about 350,000 customers in north San Diego County with wastewater treatment services, has relied on four G3516 engine generator sets from Caterpillar to provide about 71% of the wastewater authority’s power needs. The generator sets went into service in 2008 and 2009.

The authority powers these engines through biogases generated from an anaerobic digester designed to reduce solids in wastewater. The digester converts these solids into carbon dioxide and methane-biogas-that is in turn converted into reusable energy.

The generator sets are also flexible, able to run on both the captured biogas and natural gas. According to Caterpillar, on most days, three of the wastewater authority’s generator sets run on biofuel while one set runs on natural gas alone for four to eight hours during peak rate times.

The generator sets produce about 12 million kWh of electricity a year.

Octavio Navarrete, resource recovery manager with the Encina Wastewater Authority, says that the move toward a CHP system has been a financially rewarding one for his employer. “The economics just made sense with a CHP system,” says Navarrete. “By going to CHP, we increased our energy efficiency. By generating our own power onsite, we reduced our electrical costs because we don’t have to purchase as much power from the utility. It has been a great benefit to us to have that reliable onsite power.”

This last benefit is an important one. One of the goals of the wastewater authority is to reduce its reliance on purchased energy. Specifically, the Authority wants to produce 96% of its own power needs onsite by the year 2020.

The CHP system helps the Authority get closer to that goal, Navarrete says. “You can reduce your operating costs by producing your own power,” he says. “That makes a difference. The CHP technology has proven to be optimal for the goals that we are trying to reach.”

As always with a CHP system, little goes to waste in Encina’s power system. Thermal energy created from the cogeneration process is used to heat the authority’s anaerobic digesters. Thanks in part to this, the Caterpillar generator sets saved the wastewater authority more than $2 million in energy costs in 2010.

Results like this are important ones to the manufacturers of CHP systems. These are the success stories that, if manufacturers promote them properly, can provide an even bigger boost to the industry.

“It’s not just in the United States, of course, where you are seeing interest in CHP,” says Kelsch with Caterpillar. “In the last couple of decades, Europe has primarily been where we’ve been playing. But we are seeing more of shift now. We are seeing more of the growth in CHP coming in North America, too. That’s a good sign for the industry and its future.”

About the Author

Dan Rafter

Dan Rafter is a technical writer and frequent contributor.
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