Cincinnati Zoo conserves resources via 1.56 MW solar array, LEED buildings

Cincinnati Zoo conserves resources via 1.56 MW solar array, LEED buildings

CINCINNATI — This spring, visitors at the Cincinnati Zoo & Botanical Garden will be greeted by the largest publicly accessible, urban solar array in the country, a 1.56 megawatt system consisting of 6,400 panels installed on a canopy structure over the zoo’s Vine Street parking lot. Construction has begun and is slated to be completed this April. Not only will the zoo boast an impressive solar array, it is also home to a handful of LEED certified projects. Since 2006 the zoo has pledged to construct only sustainable buildings that meet LEED certification requirements.

The solar array will provide approximately 20% of the zoo’s energy needs, enough to generate electricity to power 200 homes each year. Additionally, there will be days when the zoo will be completely off the grid, sending power back to the utility.

“We believe that the combination of size and public accessibility makes this solar array the most impactful array of any in the entire country,” said Mark Fisher, senior director of Facilities, Planning, and Sustainability at the Cincinnati Zoo. “No where else has an array of this magnitude been placed in such an urban environment, allowing our visitors, and the general public at large, to be able to see first hand what solar photovoltaic energy is all about. The education potential of this advanced energy project is off the charts. If we [the zoo] can do this, then others can do this. When this project is up and running we will have more installed renewable energy capacity than every other zoo and aquarium in this country combined.”

In regards to the pledge to build only sustainable buildings, Fisher told CONTRACTOR that the zoo has been very aggressive on its building stock.

“Our water usage is down 55%, electricity usage per square foot went down 25%, literally we have saved millions of dollars,” said Fisher. “We have looked at everything. It’s making buildings better, they are more efficient, the lighting is better, the heating systems are better, the water quality for animals is better. It’s been a slam dunk for us.”

Melink Corp., the developer, designer, installer, owner and operator of the multi-million dollar project, was supported by PNC Bank, Uptown Consortium, National Development Council and FirstEnergy Solutions.

“Melink is proud to serve as the developer for this high profile solar energy installation,” said Steve Melink, president of Melink Corp. “It will help put Cincinnati on the map as a national leader in the adoption and promotion of clean energy.”

The solar array is taking approximately three months to install, according to MeLink Project Manager Craig Davis, and consists of 6,400 monocrystalline 245 Watt panels by SolarWorld, which are manufactured in the U.S., and two 500 kW inverters, one 250 kW inverter, and one 100 kW inverter by Satcon.

The idea of a solar array at the zoo started a few years ago at the U.S. Green Building Council’s Greenbuild.

“I went to Greenbuild in Arizona, and I met a Melink representative, and they were interested in doing a large solar array in Cincinnati, so we spent the next 15 months working on the engineering and financing models,” explained Fisher. “Financing is where is gets tough. There is the federal tax credit and new market tax credit, so that was huge. Then in Ohio there is a mandated energy portfolio for utilities using renewable energy, thus, utilities are trying to find renewable energy projects. It was a tedious process, going though several months of discussions and meetings about financing the solar project.”

As a leader in eco-friendly development and green building practices, PNC Bank and PNC Equipment Finance provided transaction structuring assistance for an equity investment with the purchase of New Market Tax Credits through partnerships with the Uptown Consortium and National Development Council, as well as energy financing.

Economic, work force development

All the major components of the solar canopy will be manufactured either locally, or in other locations within the U.S. to help promote economic growth. Plus, all of the contractors, subcontractors and engineers for the project are based in Cincinnati, which is very important for economic development in the area, according to Fisher.

The project is also funding 10 scholarships for students in Cincinnati State Technical & Community College’s Green Workforce Development Program in which students need to become certified in solar installation. To receive certification, students need to have experience on two solar projects.

“You almost have to get experience for free if you are not already certified to install solar,” said Fisher. “So we decided to fund 10 scholarships for local residents to attend the program and be part of the construction team, so students would at least have one project they worked on. We are trying to use this project to help ramp up solar installation contractors.”

In an effort to educate zoo visitors about green products and technology, the solar array will include a real-time educational kiosk near the zoo’s go-green garden, allowing visitors to learn about the performance of the array and benefits of solar energy in general.

“There will be many days where the meter will spin backwards, so it will be neat to show this to people who come to zoo,” said Fisher. “We have 73 buildings, and to be able to spin the dial backwards is pretty huge.”

A pledge to build LEED

Of those 73 buildings on the zoo’s campus, four are LEED certified and two more are in the process of being constructed — both buildings will be registered for LEED certification.

The Cincinnati Zoo’s first LEED certified building (and the first Silver certified building in Cincinnati) was the Harold C. Schott Education Center, which opened in 2006. With the success of the Education Center, the zoo pledged to pursue LEED certification on all new construction projects, including the Historic Vine Street Village, which opened in May 2009 and received Platinum status. The Platinum project includes a ticketing building, restroom building, stroller rental building, a go-green garden area, a food vendor area, the turnstiles structure, plus all of the pavement in this area.

The building utilizes geothermal, a solar thermal system, a 1.2 kW wind turbine and a 10 kW solar PV system. Water conserving features of the building are waterless urinals, dual-flush toilets, timed faucets and a storm water management system in which water is collected in a 10,000-gal. tank and then used as irrigation water. All storm water projects are in partnership with the local sewer district.

The closed-loop geothermal system is made up of 60 wells, 225-ft. deep, and WaterFurnace heat pumps. Bill Spade Electric installed the system, which took approximately three months, and Maria T. Ramos, Innova Engineering Inc., designed the system.

“Overall, design and installation were pretty smooth,” said Ramos. “During installation of the well field, some underground water was found in an unexpected place, and the well field was reoriented slightly to accommodate this.”

The solar PV system installed by Dovetail Solar at the zoo entrance includes 48 Sharp 224 Watt PV modules made in Tennessee and two SMA Sunny Boy 5,000 Watt inverters, which are mounted under the panels.

“The primary challenge was the various debris we dug up while installing the concrete foundations for the array mounting structure,” said Matthew Bennett, president and operations manager of Dovetail Solar. “We had to switch from individual concrete footers to large trench foundations as a result.”

When asked about payback regarding the geothermal system, Fisher told CONTRACTOR that the zoo is looking at a five year payback, assuming certain criteria is met.

“A five year payback for the zoo is very reasonable since our buildings are here forever, so if I can get a payback in five years that’s great,” said Fisher. “We have almost 24 months of data, and we are beating our model right now, so we will be better than a five year payback. This is all based on real data.”

Fisher also told CONTRACTOR that based on building to meet LEED certification, everything learned from that process has been applied to updating existing buildings with energy-efficient products, such as boilers, chillers, lighting, etc.

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