Advanced Systems Conserve Costs

May 27, 2005
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HOLLAND — Your company wants to reduce its energy costs. So what's the most economical way to do it?

A commercial advanced energy system could be the answer and could be the key to a 20 percent to 30 percent reduction in energy costs.

Advanced energy systems generally fall into four distinct categories: Energy conservation systems, waste energy recovery systems, combined heat and power systems, and renewable energy systems.

The first two — energy conservation and waste energy recovery — form the foundations that more advanced energy systems can be built upon, said Steve Hamstra, executive vice president for GMB Architects & Engineers of Holland.

Any type of company can benefit from an advanced system, he said.

"The applications where this works best are when the thermal loads — the requirement for heat — are matched at the same times the facility needs a requirement for electricity," he explained. "So if we put in a combined heat and power system, as we're generating power on site we also have a use for the waste heat."

The application comes up a lot in the furniture industry and in different chemical industries where there is a need for heat as well as power year-round. It might not be as attractive an alternative for an assembly line setting that doesn't have a need for processed heat year-round, he said.

GMB typically recommends clients first consider energy conservation because it's the most cost-effective way to start, Hamstra said.

To begin that process, GMB will analyze the existing use of energy on the client's site to determine how it can be used more efficiently. From there, GMB will determine the feasibility of an advanced system, do the engineering and assist in getting bids from contractors. The final step, he said, is reviewing construction to ensure it complies with the design intent.

After energy conservation, the next move up the ladder is a waste energy recovery system, which takes the energy left over from a process and applies it to some other use. That could include recovering heat from exhaust air streams and reusing it to process water heating, Hamstra explained.

The next step up is a combined heat and power system, also referred to as cogeneration, which is the process of generating electricity at the very location it's used and using the heat byproduct it generates. According to Hamstra, most large utility power plants "waste" this generated heat because it's usually released into the environment as water vapor from a cooling tower or dumped into a local river or lake.

"Usually, these systems have some form of natural gas-driven engine or turbine that spins a generator to make electricity and then the waste heat is used for something else," he explained.

Hamstra noted that a number of industries, hospitals and colleges in West Michigan have installed combined heat and power systems.

The city of Holland, for instance, uses some of the waste heat from its power plant to melt snow on downtown streets and sidewalks. GMB has done all the major expansions to that system. Since the early 1980s, Zeeland office furniture maker Herman Miller has been powering its facilities with a system that uses steam created by burning scrap waste from the plant, then uses the steam to spin a turbine to create electricity. GrandValleyStateUniversity's Michigan Alternative and RenewableEnergyCenter in Muskegon uses fuel cells to create electricity and then uses the waste heat for building heating or cooling.

Some clients may have applications that aren't appropriate for combined heat and power, and in that case GMB may skip over that step and jump right to renewable energy, Hamstra said.

"It's so variable. It's not a one-size-fits-all approach."

Renewable energy systems are at the top of the pyramid and can take the form of solar, thermal, solar electric or wind energy.

Solar thermal takes the sun's heat and collects it for heating water and air. Solar electricity converts sunlight directly into electricity. In fact, one of the world's major inventors and producers of photovoltaic systems is Michigan-based UniSolar. Hamstra said it's a great technology with no moving parts, but the return on investment is not as high as that of other options.

"We most often see this technology applied in industrial applications where the client wants to demonstrate a commitment to sustainability and is willing to tolerate a long payback."

If not for current economic incentives such as federal grants and rebates from utility companies, renewable energy systems cost the most for the benefit received, Hamstra pointed out.

"It's getting better and better all the time, but renewable systems should only be looked at after you've gone through the first three steps and minimized your energy use and minimized your demands on the grid, and then look at the renewables — unless there are other reasons.

"Some of our clients are looking at renewables from a marketing perspective or from a stockholder desire that they be more sustainable in the marketplace and have a better environmental footprint as a corporation."

According to Hamstra, wind power is an "excellent" renewable energy source and has demonstrated to be as cost effective as other forms of electricity. GMB sees many opportunities in Michigan for the application of wind energy, but the toughest hurdle, he said, is educating the public on the benefits of wind power and getting communities to try it.

GMB has designed wind turbine systems and solar photovoltaic systems for several schools in West Michigan and has designed geothermal heat pump systems for 2 million square feet of facilities. Geothermal heat pump systems capture solar energy stored in the earth.

Solar thermal and solar electric systems are dependent on the weather, so in Michigan they are best suited to the summer months, which are the months when demand for electricity peaks.

"But if you look at the actual return on investment — without any grants or financial incentives from other sources — wind energy is the winner in the renewable category, solar thermal is probably second best and solar photovoltaic is third."

Hamstra's company has come up with a concept it calls the "GMB Energy Chassis," which combines all four categories of advanced energy systems.

"It's kind of a universal platform that allows us to plug in all these technologies," Hamstra said. "It's a way to combine all these technologies that seems to make sense for a lot of applications." 

GMB has used the concept on two projects thus far. The new DavenportUniversity campus on the South Beltline, for instance, combines the idea of heat recovery chillers with a geothermal ground loop. The result? The waste heat from air conditioning of the academic building is used to heat the domestic hot water for the residence hall.

"We are not creating new energy, we're moving existing energy around and recovering it for other uses instead of throwing it away. That's really the concept."     

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