Independence, Ore. — Independence Station, a mixed-use, net-zero building, with the ability to run off the energy grid for extended periods of time, may receive the most U.S. Green Building Council LEED points ever awarded, becoming the greenest building in the world when it opens in 2010.

Located in the historic downtown area of Independence, Ore., the mixed-use building has more than 50,000 sq.ft. and offers office, retail and warehouse space, plus, 15 condominium-style homes. The entire building will utilize an ice-based cooling storage system, biofuel cogeneration system, photovoltaic system, a water conservation system, and other sustainable technologies and products.

“This will be the most comprehensive, highest-performing, smart-grid building,” said Steven Ribeiro, owner and developer of the project at Aldeia Development. “It might be able to slide into new LEED 3.0. If we are able to get the LEED award at this version, we would be the No. 1 green building, according to LEED. Our goal is to earn between 64 and 66 LEED points out of a possible 69.”

Calmac's IceBank energy storage technology is the key feature of the building's HVAC system. Ice is created during off-peak hours inside two ice storage tanks. This system allows the building to run off grid, during the daily peak power times, minimizing the building's electricity demand. Smaller chillers in the 35-ton capacity range are used with the IceBank system, which often offsets ice storage costs.

“The chillers are run off of wells that have a low temperature relative to daytime air temperatures,” said Mark MacCracken, Calmac CEO and USGBC board member. “The chillers run at night with 54°F water, thus, it is more efficient to run the chillers at night to store the cooling, so they can be smaller machines, and the ice storage system is nothing but a big thermal battery.”

According to MacCracken, when designing a building, there is a rule of thumb for cooling: each ton of cooling handles approximately 300 sq.ft., or 1-ton of cooling handles about 400 sq.ft. if it was more efficient — Independence Station is somewhere in the range of 670 sq.ft. per ton of cooling required.

In addition to the IceBank system, other cooling sources will be utilized.

“We are storing it in the concrete in the building, we are using PEX piping throughout the concrete slabs, plus the construction is insulated concrete forms,” said Ribeiro. “There will also be a couple of wells on the property, acting as a mode of cooling. Fifty-four degree water will be pumped 30-ft. deep, where it passes by a heat exchanger, and then is put in a well 150-ft. or so away.”

The building will operate on a biofuel cogeneration system, a concept of several different generators — one being a tugboat engine and the other being a generator run on biodiesel — while being cooled by the ice storage plant during peak demand periods. During this time, excess power generated by the 125 kW photovoltaic system, by Sunlight Solar, will be sold back to the electric utility, helping the utility meet peak demand load. At night, the computer-based building management system will decide when to shut down the generators and start making ice.

The entire building's radiant heating and cooling will run off of the biofuel cogeneration system, and during the project's second phase, a green house will be heated, so crops can be grown all year long.

“Our photovoltaic system will feed the grid when it needs it the most — we are taking the full smart-grid approach and close to all our PV will feed the grid at the peak time,” explained Ribeiro. “Rather than burn even more fuel during that time for the cooling, we are going to take care of the cooling during the night before, using the grid power when there is a lot of capacity and the cost is lower.”

Independence station will also use water conservation techniques, including rain water tanks, low-flow plumbing fixtures and no-clog drains, to have the lowest water use possible, helping the building attain such a high LEED rating.

PermaFlow's Never Clog Drain will contribute to the building's water conservation. The drain is compatible with low-flow faucets and minimizes indoor chemicals and pollutants that are often used to maintain plumbing. The drain is transparent and engineered to remove drain build up before clogs develop.

“The PermaFLOW Drain not only supports the water conservation efforts defined in the LEED standards, but will also eliminate the need for chemicals in the plumbing maintenance, making the world's greenest building not only friendlier to the environment, but also to the people who will live, work and visit there,” said Sanjay Ahuja, vice president of PF Waterworks.

Another aspect of the water conservation system is harvesting and storing rain water in tanks. During the summer, the driest season in Oregon, stored rain water will be used for laundry, toilet flushing, janitor closets, the green roof and a living wall, located in the main lobby.

According to Ribeiro, 92,000 gallons of rain water will be stored in pre-cast rainwater tanks, and Kohler products will be used throughout the building, having the lowest water use allowable by law — the building will be run on a residential size water meter.

Independence Station will also have an alternative energy research center, a biofuel research lab and satellite classroom, which will take vegetable oil from the local restaurant and convert it into diesel fuel, in partnership with Oregon State University.