Energy savings and stability are a major motivation in the installation of many distributed generation systems, and that was the case for the Inns of America in Carlsbad, CA. But when a natural disaster struck the northern San Diego County region where the hotel is located, the Inns of America found that the microturbine did more than keep the lights on - the system also helped the Inns of America reach out to its community.

The Inns of America in Carlsbad installed a 60-kilowatt Capstone microturbine as a cost-cutting measure and to guarantee there was always a stable power supply flowing into guests' rooms. The system still allows the hotel to receive supplementary power from the local utility, San Diego Gas & Electric.

Other blackouts had stuck the area around the Inns of America, and the hotel stood alone in having power. So when the worst wildfires in the nation's history struck San Diego County in October 2003, the distributed generation system became a lifeline to the Inns of America and its neighbors.

That fall, flames had raged from one end of San Diego County to the other for seven days before firefighters were able to get a handle on the firestorm. In that week, three separate blazes killed 16 people, including one firefighter; displaced thousands of people after destroying 2,406 homes; and burned nearly 400,000 acres.

While the Inns of America was not in danger of being overcome by flames, the hotel did became a rest stop and shelter for firefighters, people who lost their homes to the fire, those who couldn't get home, and elderly residents of assisted living facilities, all of whom needed the electricity and filtered air the hotel was able to maintain after the inland grid went down due to burning transmission lines.

"We try and be a good neighbor, so when our neighbors needed our facility, we were happy to help them out," says Dennis Harris, general manager of the Inns of America in Carlsbad. "When the fires hit and the grid went down, area businesses started coming. We donated a number of rooms during the fires to help people out who were displaced and otherwise couldn't be alone."

Miles away from the Inns of America, another business, ADCS, which specializes in information management, was able to keep the data stored on its computers safe while the building's fire suppression systems fought back flames as a result of the two Capstone C60 microturbines the company had installed on-site.

The Catalyst

An emergency of a different kind was the catalyst for developing a distributed generation system at the Inns of America site. The 60-kilowatt microturbine was installed during the construction of the Carlsbad hotel nearly three years ago. At the time, California was in the midst of an unprecedented energy crisis resulting from an energy deregulation plan developed by the state legislature.

"We engineered the system during the rolling blackout days of the California energy crisis and installed the system as part of the construction of the new hotel," notes Tom Moore, chief executive officer of Calpwr, the company that installed the unit.

At the end of 2000 and the beginning of 2001, electricity prices were highly volatile, with costs on the wholesale energy market rising as much as 4,000% in one hour of trading at the height of the instability. Rolling blackouts blanketed the state in January 2001 and power-plant outage rates increased to three times the normal amount.

"The owners were looking at the system for two main reasons - the ability to generate needed energy, both electrical and heat, more cost-effectively than what they could buy off the grid and, as importantly, to have a system that could run during an outage," he continues.

Microturbines powered the fire suppression system at the 1 million–square floor building of ADCS during the hours-long fire-related blackout.

Brian Harris of the Inns of America looks on as Calpwr's Joe Silva checks hours of operation on the hotel's microturbine CHP system that has run virtually non-stop for two years.

The Inns of America system consists of a Capstone C60 microturbine with a Unifin heat exchanger that recovers exhaust heat from the Capstone. The resulting hot water from the Unifin's air-to-water heat exchanger is fed to a series of hot water storage tanks that provide for domestic uses in the hotel, such as showers. (Capstone Turbine's latest offering, the C60-ICHP, integrates a compact heat exchanger of its own design atop the C60 system to provide greater efficiency, smaller footprint, and enhanced operational flexibility.)

The Capstone C60 was installed with a dual-mode controller, which allows the Inns of America to start the system during a grid shutdown, thereby providing both electrical energy and hot water during an outage.

"It keeps us running plain and simple - the business center, kitchen, rooms, laundry, lights, et cetera," Harris says.

The C60 is made by Capstone Turbine Corporation, which is based in Chatsworth, CA. The company, 5% of which is owned by United Technologies, is the only microturbine manufacturer headquartered in the United States. It has shipped more than 3,000 microturbines worldwide as of mid-2004, and the documented hours of operation of the installed fleet total 6 million hours.

Calpwr, a San Diego County—based business partner with Capstone, installed the complete system at the Inns of America for about $152,000, including engineering, equipment, and construction, Moore says. It's one of the smallest projects that Calpwr, which provides engineering, feasibility studies, and financing services for such systems, has taken on. The Inns of America in Carlsbad was able to receive a 30% incentive rebate from the state for installing the system.

On a daily basis, the Inns of America's power demand averages about 100 kilowatts, so the Capstone C60 provides 60% of the hotel's electrical needs and 100% of its domestic hot-water needs.

"Since the system is running every day to provide energy to the facility, our costs are fixed but lower than they would be if we took the traditional 'grid' approach," Harris says. "In fact, our costs are stabilized more than they would be without the system since we lowered our power demand spikes and the cost of these spikes from the utility and produce and store hot water during off-peak times."

The Capstone system allows the Inns of America in Carlsbad to run the system and save money every day in normal operating mode, Moore says. It also protects the hotel from unwanted power outages, which don't help in the mission to keep the Inns of America guests happy.

Exhaust is ported from the hotel's microturbine to a separate heat exchanger. Capstone now has a compact pre-intergrated heat exchanger for its C60.

"In the hotel business, the customers' comfort is the name of the game - if the lights are out, the customer isn't happy and they leave the hotel," Moore says. "There are lots of ways of achieving this goal - diesel generators, battery systems, et cetera - but these traditional methods only add cost to the construction of the facility and don't deliver savings."

The Inns of America in Carlsbad has 98 rooms, all suites with kitchens, and is the only one of the six hotels in the family-owned chain that has a distributed generation system.

"We have had such success with this system that we wouldn't build another one without this type of system," Harris says. "We save at least 40% over what we had originally figured for energy. We have lowered our daily per-room energy cost from over $8 a room to under $4 a room.

"The system is really a big piece of the building operations - it operates every day and supplies most of the electrical and hot-water needs," Harris adds. "This system can be considered our electrical utility, our hot water heater and boiler."

In many ways, the hotel staff had come to take for granted the advantage of being able to run even if the grid was down until the fire. Harris says there were several major outages before the fire and, other than a brief flicker of the lights, the only way they ended up finding out about it was when neighboring businesses started asking if they could set up shop at the hotel.

The issue took on a different seriousness in October 2003. Many areas of San Diego County lost power during the weeklong period when a series of fires burned from the Mexican border to Los Angeles. Some of the blazes were caused by arsonists; others were set by accident.

All of the fires were fueled by the dry weather and gusty Santa Ana winds that hit San Diego at the end of October that year. The fires produced such massive amounts of smoke that the sky was dark even in the middle of the day. Everywhere in the county was covered with inches of ash, even right up to the Pacific Ocean. The region's major freeways were shut down for days, the mayor of San Diego called for businesses to shut down to keep the roads free for emergency vehicles, and day-to-day activities ground to a virtual halt for most San Diego County residents.

Harris said 12 to 15 people stayed at the Inns of America in Carlsbad each night because of fire-related issues. They were given $1,000 in room credits, but some people needed to stay longer and were accommodated by the hotel. Some were firemen taken off the front lines of the fire for some rest and a chance to shower. Others were stranded away from home by the flames. Several were residents of assisted living facilities while some others had lost their homes and were referred to the Inns of America by the Red Cross.

"Since the outages have happened on a number of occasions and we have been able to stay operational, a number of businesses - assisted living facilities, schools, financial services companies, local offices, et cetera - have written us into their emergency action plans," says Harris. "We provide a safe and fully operational refuge for them."

While the Inns of America may be worlds apart in terms of trade from the information management emphasis at ADCS, a reliable power supply is important to both businesses. The ADCS site spent about $173,00 to install two Capstone C60s. Like the Inns of America, the system also has a dual-mode controller, which allows the system to automatically start itself during a grid shutdown and provide electrical energy during an outage.

All Capstone microturbines comply with the California Public Utilities Commission's Rule 21 grid interconnection safety standards. The switchgear, protected relays, and other interconnection needs are already built in.

ADCS is headquartered in the city of Poway, near one of the hardest-hit areas of inland San Diego County. The business's 99,000­square foot complex was in the path of one of the fires and lost power when flames were melting SDG&E's high-voltage transmission lines.

The building was able to operate for six hours on a large UPS battery storage array. But the outage lasted far longer and the company used the Capstone microturbines to recharge the UPS, which enabled the company to save the data it stores, Moore says.

The Capstone system is designed to run parallel to the grid and uses a grid signal to start the system and synchronize when the grid shuts down so the system doesn't "island," Moore says.

"By putting in the dual-mode controller and battery pack, we can restart the system and run off-grid, safely, to provide power to the UPS system and keep the data center up and running," Moore says.

"In the computer-based data storage business, highly reliable power is critically important - we cannot afford to shut down," he continues. "The typical system approach is to have grid power as well as redundant backup power systems - i.e., UPS systems, diesel gensets, in order to keep the data storage systems and critical building infrastructure - HVAC systems, fire suppression, et cetera - running."

"All of these systems cost a lot of money to install and maintain and do nothing to enhance our ongoing cost of operations," he says. "With the Capstone system, we're able to achieve two goals at once: provide daily operating savings for our power as well as provide critical backup for the data center and building support systems."

The Systems

Capstone microturbines can operate on natural gas, propane, diesel, and kerosene, as well as renewable landfill, sewage plant, and oilfield "flare" gases with up to 7% hydrogen sulfide "sour" content.

Up to 20 grid-independent microturbines can be arrayed without external hardware. And up to 100 can be multipacked via one network controller to serve loads ranging from a few kilowatts to a few megawatts, according to Capstone. The company's largest single-site placements are 50 C30 systems fueled by waste flare gas at a Los Angeles landfill and a 44-unit placement of C60 microturbines at a Sanyo Chemical plant in Japan.

Moore says he has seen more and more businesses, large and small, looking at distributed generation systems in the wake of the California energy crisis and the East Coast blackout, which have more than likely played a role in that turnaround.

The first anniversary of the August East Coast blackout is fast approaching. Millions of homes and businesses were plunged into darkness from New York City to Ohio to Pennsylvania and even into Canada due in part to an antiquated grid system and heavy demand loads.

Over the last several years, these types of situations have helped convince many businesses to change the way they look at the need for a stable energy supply. Instead of viewing power as a certainty, if not a fixed cost, to depend on, nowadays many businesses are taking a hard look at providing a portion of their own energy needs, especially after watching others learn difficult lessons about power resources.

"Customers who wouldn't normally consider a backup power system are asking, 'What is it going to cost?'" says Moore. "People are much more aware and are interested in doing it. So there is definitely an uptick to it."

Harris says he too has a new view about the distributed energy system at the Inns of America and now sees more than a source of energy stability and a cost-cutting measure after going through the fires. The Inns of America in Carlsbad is looking at installing an additional distributed generation system to provide more onsite electrical capability and to heat the pool.

"During our earlier build-outs, energy costs were not as much of a factor as they are now and, frankly, we didn't realize how effective a system like this could be to us. Like most people, we didn't realize the value until something like the fires happened," Harris says.

KIMBERLY EPLER, a native of San Diego, is a writer based in Arcata, CA.

DE - July/August 2004