|No casualty of nature: when Superstorm Sandy hit New York City last year, the Overlook Medical Centre lost no power thanks to its trigeneration system
Credit: Atlantic Healthcare
Trigeneration may not have a lot of charisma, like solar and wind energy, and few people know what it is. But the technology finds itself in a somewhat enviable position these days. Many places in the world have developed energy problems that trigen uniquely fixes.
What are trigen’s bragging rights? By providing cooling, heat and power, all in one place with one fuel, trigen units are highly efficient. Also called combined cooling, heating and power, or CCHP, trigen reuses the waste heat produced in electric generation and leads to lower carbon dioxide emissions. Onsite trigen also can serve as back-up power when the grid goes down. And, perhaps most important, trigen helps meet the globe’s heightened demand for air conditioning and refrigeration, without putting further strain on the electric grid.
As a result, trigen plants are springing up worldwide – at data centres, airports, supermarkets, office buildings, universities and industrial facilities.
Still, it is not always easy for trigen projects to win acceptance. Barriers exist that can make inroads hard for the technology, even where trigen makes sense, as it does for facilities with a steady need for power, heat and cooling. Like other forms of decentralised energy, trigen often must compete against utilities that enjoy an incumbent’s advantage. And network connection rules and outdated regulation sometimes work against trigen too.
Sydney’s good and bad
In many ways, Sydney in Australia has become the poster child for trigen – in both its glory and defeat. The city of 4.6 million people has set a goal to reduce its greenhouse gases 70 per cent by 2030 from 2006 levels. Centralised power plants account for 80 per cent of the city’s emissions, much of it from coal-fired generation. So the city has a master plan to swap out coal, decentralise its system and reduce emissions. Sydney wants to have 100 per cent local power and trigen is the centrepiece of the strategy.
Sydney envisions adding 360 MW of trigen, valued at A$440 million ($401 million) in 2010 dollars. The gas-fired trigen would reduce the city’s greenhouse gas emissions by 1.1 to 1.7 million tonnes a year. This could put the city more than a quarter of the way towards reaching its emissions goal.
Further, trigen could reduce Sydney’s electricity consumption 30 to 60 per cent and lop $1.5 billion off its electricity costs by 2030.
To get its plan underway, Sydney issued a tender in 2010 seeking trigen to supply five aquatic centres, the Town Hall precinct and Customs House and the city’s remaining 200 buildings. By spring 2012, the city had an agreement in place with Cogent, a subsidiary of Australian energy giant Origin, as its preferred developer. The company went to work negotiating with private building owners and preparing to install trigen for the city-owned facilities.
It looked as if Sydney was well on its way to rolling out Australia’s first mega trigen system and becoming what Lord Mayor Clover Moore described as “Australia’s leading low-carbon city”.
Then came the bad news. In June, Sydney announced that it was no longer going to pursue the project with Cogent. The economic and regulatory tide had turned against the plan. The city cancelled the first trigen project planned for Greene Square, a light industrial and high density residential area of the city. A combination of factors undercut the project’s economics, including the federal government’s decision to lower the future carbon price, a loss of state and federal incentives, and unfavourable electricity network rules.
But Sydney is not giving up. Its chief executive Monica Barone called the cancellation “a small roadblock”. The city plans to lobby state and federal officials for better rules and renewed incentives with the hope of revisiting the Greene Square project in the future. Sydney also plans to continue to pursue trigen for city-owned buildings and will issue a tender that invites Cogent and others to bid.
Still, city officials lamented that Australia appears to be backsliding on trigen while elsewhere in the world – London, New York, Paris, Berlin, Copenhagen and Seoul – the technology is on the rise. It is important to note that trigen is being built in Australia – just not with the gusto that officials had hoped.
Cogent installed a trigeneration system in Coca-Cola Place in North Sydney in 2011. The project, which provides power, hot water and chilled water, includes a 774 kW gas-fired reciprocating engine and a 650 kW absorption chiller that can supply either chilled or hot water to the building.
More recently, Cogent installed Australia’s first urban distributed energy project in Victoria, which included trigen technology. The 6-MW installation is part of a larger urban renew project in Central Dandenong.
Around the world
Elsewhere in the world, trigen is finding successes in a wide range of businesses and government applications.
In London, PricewaterhouseCoopers won a key UK sustainability award after installing a unque trigen system in its office adjacent to the Tower of London. In Germany, Daimler in May commissioned its third trigen plant at a Mercedes-Benz plant in Rastatt, and Spanish brewer DAMM has installed a trigen system at its facility in Barcelona.
In Saudi Arabia, CES Energy has teamed with Al Aman to build and operate a 16 MW trigen facility in Headquarters Business Park, a mixed-use centre in Jeddah that includes a 52-story tower. Meanwhile, Fleming Gulf, a business intelligence company, has a trigen summit set for 29-30 September in the Saudi capital, Riyadh to create more interest for trigen. The conference sponsors see Saudi as highly suited to trigen because of the kingdom’s rising power demand and its desire to cut costs and emissions.
Light in a storm
In the US, trigen has become part of the larger discussion about storms and the havoc they inflict on the grid. Superstorm Sandy knocked out electricity for weeks in parts of New York City last year. Facilities with trigen, such as Overlook Medical Centre, never lost power.
|The trigeneration facility uses biogas from Orange County Sanitation District’s wastewater treatment plant to produce hydrogen, heat and power
Credit: Energy Department
The Summit, a New Jersey hospital, had the luck of good timing – it had begun operating its trigen system only shortly before the storm hit. “We had just started doing commissioning before Sandy – and it was good thing we had,” says Robert Peake, director of facilities construction and real estate for Atlantic Health System, the hospital’s parent company.
When hospital officials saw the massive storm approaching, they decided to island the hospital from the larger grid and rely solely on its new, natural gas-fired, 2 MW trigen system and a 2 MW diesel backup, both Mitsubishi products. The system powered the entire hospital when the grid was down.
When hospital officials installed the system last year, they were not envisioning a superstorm barrelling down upon their facility. Electricity costs were their worry then. The officials initially investigated solar energy, but found the technology wouldn’t provide the facility with enough power. They began exploring trigen and saw that it made sense, given the hospital’s large steam load.
Overlook has cut its $4.8 million annual electricity bill down to about $2.8 million thanks to the trigen system. The hospital received a $1 million grant for the system from the state of New Jersey. Because of the grant, the hospital expects to see a return on investment within about 2.5 years.
Not surprisingly, Atlantic Health System is investigating trigen for three of its other facilities in New Jersey. Peake sees the benefits as many. “Our hospitals are located in residential communities. So we look for ways we can be better neighbours. One way is to become a greener,” he says.
|Trigen biogas system at DAMM brewery in the Spanish city of Barcelona
All eyes of the US power industry are now watching President Barack Obama’s renewed interest in greenhouse gas regulation. On June 25 Obama announced his Climate Action Plan, a series of executive level effects meant to bypass a deadlocked Congress. A central part of his plan involves complex rulemaking by the US Environmental Protection Agency that will govern emissions from power plants.
Although trigen is generally viewed as a green technology – especially when fuelled with natural gas or biofuels – uncertainty exists about how it will fare under the EPA rules. Trigen supporters are hopeful that regulators will take into account trigen’s efficiency. But the industry needs to work to ensure it gets a seat at the table, according to Paul Gutermann, a partner with Akin Gump who specialises in environmental law.
“They are going to need to take a look and get involved in the weeds of the policy development. They have to some extent a sympathetic audience at EPA but [trigen] is a small piece of fruit for the agency to pick up. It is not going to be a major focus,” Gutermann says.
Obama has directed the EPA to submit a proposed rule for new power plants on September 20, a date that could prove important to both the US and international trigen industry, according to Peter Wyckoff, an attorney with Pillsbury and head of its Climate Change and Sustainability Group.
Why? Because the EPA rules will likely influence use of emissions control technologies worldwide, he argues.
“The EPA is developing a vision for what forms of control technology are sensible,” he says, which “no doubt will have big ramifications in Europe and elsewhere”.
Innovating and improving
Meanwhile, the trigen industry is not standing still. In Northern Ireland, ContourGlobal uses what it calls quadgeneration at its Knockmore facility. The unit not only creates power, steam and chilled water, but also food-grade carbon dioxide for a nearby Coca Cola Hellenic Bottling Company.
|Trigeneration system at Pyrmont in Sydney
Clarke Energy was hired for engineering, procurement and construction on a turnkey basis for the plant, which produces 15 MW of power and 13.5 MW of thermal energy from gas engine generators. Exhaust heat from the generators makes process steam for the bottling plant. Additional waste heat gets recovered as hot water and fed to three absorption chillers that provide the bottling plant with chilled water. As a last step, carbon dioxide is removed from exhaust and refined to a food grade. It is then used to used to carbonate the Coca Cola.
In California, a wastewater treatment plant run by Orange County Sanitation District has a trigen system that produces electricity, heat and hydrogen. The system works with a high-temperature fuel cell and biogas from the facility’s anaerobic digestion process. The power and heat are used onsite for the facility and the hydrogen goes to a vehicle fuelling station.
Maersk Oil offers an unusual trigen system; it produces power, clean water and carbon dioxide as part of oil and gas recovery. The company mixes contaminated gas with pure oxygen and burns it in an engine under high pressure and temperature. The separated carbon dioxide is injected under the ground, making oil flow more easily. This improves oil recovery rates. The engine creates steam that drives a turbine to generate power. The process also produces distilled water, a useful byproduct for desert drilling operations.
So trigen continues to experience ups and downs in a world that does not always understand its worth. Yet it is clearly a technology of the times, solving existing energy problems by lowering greenhouse gas emissions and anticipating society’s future needs by fuelling hydrogen cars and bringing clean water to deserts.
Elisa Wood is a freelance writer based in Virginia, US, who specialises in energy issues, policy and markets.
Power Engineering International Archives
View Power Generation Articles on PennEnergy.com