Lochinvar and European partner EC POWER officially launched the XRGI25, a cogeneration system for the North American market, during a press conference, Jan. 15, at Lochinvar’s booth at this year’s AHR Expo in Atlanta.

“The biggest advantage to CHP is economic,” said Mike Lahti, vice president of sales, marketing and business development at Lochinvar, referring to the acronym for combined heat and power. “Immediate energy savings are available by using a cheaper fuel – natural gas – to produce a more expensive one – electricity.”

Spark spread

That difference is called the “spark spread.” A cogeneration system uses relatively low-cost natural gas to generate supplemental electricity on site, immediately reducing reliance on more expensive electricity from the grid. As a result, the system works best where the difference between electricity and natural gas is significant, such as Chicago and New York.

Lahti singled out the work of his colleague, Kris Jorgensen, combustion and simulation engineer at A.O. Smith’s Lloyd R. Smith Corporate Technology Center, during his remarks.

“Electricity is measured in kilowatts and gas in thermal units so it’s not always readily apparent what the difference between the two is,” Jorgensen told us afterward. “But if you were to compare apples to apples, in some cases, it’s not unusual for electricity to cost comparatively three times more than natural gas.”

Even within these regions where the difference is great, however, CHP doesn’t always make sense for every customer. Businesses that would benefit most from the technology have a high hot water load that lasts for extensive periods of time, such as multifamily housing, hotels, hospitals, colleges and restaurants.

As a result, Lochinvar’s approach to the North American market will be commercial, Lahti added, for the unit dubbed a “MicroCHP” solution (< 50 kW/hour). 

How it works

The system, which combines an internal combustion natural gas engine with additional storage tanks and controls, can produce both energy-efficient heat for hot water, plus electricity to reduce energy consumption from external power sources.

The XRGI25 is designed to be an efficient and easy-to-install system that can work in tandem with either existing equipment or in new construction. 

The principles behind combined heat and power are straightforward: Fuel is burned in a combustion engine, the Power Unit. The rotational motion released during this process drives a generator that produces electricity, rather like a dynamo on a bike that generates electricity for the light.

The XRGI is one of the quietest cogeneration systems on the market. With a sound level of just 49 decibels at full power, measured from a distance of 1 meter. (Most dishwashers range from about 46 to 60 decibels.) Fitted with an additional exhaust gas attenuator and soundproofing feet, the sound level can be reduced even further.

Generating this electricity, however, produces a great deal of heat that's typically wasted in the process. A combined heat and power plant makes use of this heat by capturing it in a heat exchanger and feeding it into a circuit – enabling it to be used for space heating or heating water.

To accomplish this, the heat generated by the motor is transmitted via the Q Heat Distributor to the building's heating circuit, to which the storage tank is also connected. The iQ Control Unit is the brains of the system. It controls the Power Unit according to its demand – and optimizes operation automatically.

The iQ control unit learns the consumption patterns in the property and produces intelligent user profiles. It then creates forecasts for expected consumption based on these user profiles, continuously comparing the projected consumption in real time with the actual consumption and optimizing the user profile.

A combined heat and power plant produces electricity for as long as the heat produced can either be consumed or stored. With the help of its forecasts, the iQ control unit then practices intelligent storage management. It makes predictions about when demand for electricity will be particularly high and compares this with the anticipated heat requirement. The iQ control unit also ensures that the storage tank always has the maximum possible capacity free to accommodate the heat produced during electricity generation.

Marketing know-how

Since MicroCHP is a relatively new technology in North America, Lahti, not surprisingly, believes its adoption is being driven by a company with the resources and know-how to introduce new products.

“Since 1939, we’ve worked tirelessly to build trust and build confidence in our brand with contractors, energy managers, facility planners, property owners and other key markets so that we have a recognized brand in this market,” Lahti added. “In addition we have strong reps with their service arms, product application expertise, logistics excellence and post-service support who will provide assurance to building owners who invest in this technology that we have their backs along the way and that’s critical.”

Cogeneration is already used in countries such as Finland and Denmark where 40-50 percent of electric generation capacity comes from cogeneration.

Lochinvar’s commitment to the technology led it to partner with EC POWER, a Danish company, which is the No. 1 producer of commercial MicroCHP systems in Europe. More than 7,500 XRGI systems have already been sold in more than 27 European countries.

EC Power was founded in 1996 by Danish civil engineers with many years experience in heat and power technology. In Denmark, large-scale CHP systems have been in operation for more than 50 years, currently supplying approximately 60 percent of all households.

“No other CHP manufacturer offers a complete package that brings all major components to the table, and that’s why the XRGI25 is such a great fit for our constantly growing product portfolio,” Lahti said. “Our highly advanced line of water heaters and storage tanks pair perfectly with the XRGI25, making installation a snap. Between the advanced technology developed by EC POWER and the high-performing Lochinvar product lines, customers can expect high-efficiency and reliability.”

Optimal efficiency

While providing heat and hot water may be what draws our readers to the technology, the benefits of generating electricity essentially “in house” can’t be overstated.

In conventional power stations, EC Power says almost 60 percent of the energy is lost when fuel is converted into electricity. Most of the energy takes the form of unused heat, which is then dumped into the atmosphere or water.

Conventional power stations are also located far away from energy consumers, making it impossible to make sensible use of that wasted heat.

But this geographical separation between the suppliers and consumers of energy has another disadvantage as well. Electricity generated in a large-scale plant has to be transported to the consumer, causing further energy losses during transmission through the grid.

With cogeneration, electricity is produced directly where it is needed, thus preventing network costs and transmission losses. Up to 96% of the fuel is used, by the waste heat being used for heating and domestic hot water.

Exceeding European Union highest efficiency ratings, the XRGI25 avoids the transmission and distribution losses that occur when electricity travels over power lines. The current T&D loss in the United States is now about 4.5 percent, but can easily increase to 10 percent when the grid is burdened and air temperatures are high. This product can achieve efficiencies approaching 90 percent. 

EC Power, has an eloquent analogy on its website to explain the process:

"Imagine that you have a nice, juicy apple. You take one bit into it and then throw it away. Is that not waste? That's the way electricity is generated in large power stations: today's coal-fired, gas-fired or nuclear power stations leave around two-thirds of their input energy unutilized.

"Now imagine eating all of the apple apart from the seeds and stalk. That's how to visualize cogeneration. The heat produced during electricity generation is also utilized."

The system is designed to provide a payback within the first two and a half to five years.

“In selected markets of North America where the spark spread is wide, adopters of this technology will see immediate savings,” Lahti said. “And the ROI will only continue to improve.”