Sustainable Building Construction: KEC Solar PV

"Our Common Future"

In 1987, the United Nations released the Brundtland Report, which defines sustainable development as "development which meets the needs of the present without compromising the ability of future generations to meet their own needs".

Seven generation sustainability is an ecological concept that urges the current generation of humans to live sustainably and work for the benefit of the seventh generation into the future. It originated with the Iroquois - Great Law of the Iroquois

"People don't want gas and electricity. They just want hot showers and cold beer" -Amory Lovins

Monday, March 12, 2012

KEC Solar PV

The ground mounted photovoltaic (PV) array is located just north of the building site, facing South for optimal performance conditions. It is a 296kW array and will produce all the energy consumed by the KEC over a year, making the facility Net-Zero Energy, which is expected to be 44.7 kBtu/sq ft annually. The array is connected to the grid and will produces more energy than needed in peak summer months, spinning the electric meter backwards. Then in the winter when solar production is lower the meter would spin forward drawing down on the account balance. The goal is at the end of any given year, the total energy produced and consumed on site balance out to zero.

Since PV is a fairly expensive up-front cost still, it is important to reduce the energy needs as much as possible. The KEC demonstrate a number of technologies to reduce energy needs including building siting, high performance building envelope, ground source heat pumps, earth duct, evacuated tubes, passive ventilation, and sun shading to name a few. Another key element is a commitment from the user group to accurately forecast the expected energy usage and adhere to these guidelines. This will be part of the living and learning experience for those at the KEC. Ultimately, the up front costs are offset by onsite energy production and the overall benefit to avoiding consumption of fossil fuels is a tremendous benefit.

Below are progress shots of the array being installed.