Sustainability House (LEFSE), 4 kW

What is LEFSE?  The Luther College Sustainability House is a co-ed, two-story home located in a residential neighborhood within walking distance of campus. The Sustainability House, also known as LEFSE (Luther’s Environmentally, Fiscally, and Socially responsible Edifice), offers a living-learning environment where students reside together that share a dedication to an environmentally, socially, and fiscally sustainable lifestyle.

Tell us about LEFSE’s solar power project!
LEFSE (Luther’s Environmentally, Fiscally, and Socially responsible Edifice) now receives electricity from a 3780 watt solar panel constructed near the back of the library lot.  The panel uses 18 210-watt solar modules manufactured by Kyocera and a Fronius IG 4000 watt inverter.

How much electricity will it produce?
The solar power system is rated to produce an average of around 5000 Kilowatt Hours (KWH) per year.  The system is rated for 3780 watts, but because of cloud cover, improper angle, weather change, and many other variables, there will be times when it is not running at peak efficiency.  The projected output of 5000 KWH is adjusted to compensate for these variables.

How will the electricity be used?
The electricity from the solar power system will be used primarily to power LEFSE.  However, on a daily basis much of the solar power will be sent out to other utility customers because the house is using less than the system is producing.  When this happens, the utility meter will keep track of both production and consumption. Any excess production will be credited by Alliant Energy at the retail rate.  Iowa's net metering law enables Luther to draw on this financial credit after the sun has set or on a cloudy day.

What was the cost to build the solar energy system?
The solar cells, inverter, and steel base cost around $22,000, which was paid for with funds provided by a donor during Luther's Sesquicentennial Fund initiative. The solar modules have a 20 year warranty.  It is quite likely these solar modules will be producing 70%+ of their rated power 50 years from now.  The inverter has a 10 year warranty.  It is very likely the inverter will still be working 20+ years from now.

Why did Luther choose to power the Sustainability House?
As a model for students, faculty, staff, and community members, it is LEFSE’s responsibility to demonstrate sustainable lifestyles and how they can be achieved.  Along with changing habits and becoming more environmentally conscious, the ways we generate electricity and use energy are central to sustainability. This solar photovoltaic system demonstrates that electricity can be generated locally and in a sufficient amount to power a an energy efficient home.

When was it constructed?
The solar panel was put into place over the summer of 2011 and became operational in September of that year.

Picture of the solar panel.