Seneca Falls, NY Customer's New 5.4 kW Solar Electric System

Challenge

This homeowner in Seneca Falls wanted to take advantage of all the sunlight that hits their home and turn it into energy.

Solution

This 5,400 W (5.4 kW) grid-connected solar electric (PV, photovoltaic) system was installed as a roof-mounted array of twenty-four (24) SunPower 225W solar modules. Due to limited space and Customer preference, the array was arranged as two rows of twelve (12) modules in portrait facing South on the slightly pitched (10°) North-facing house roof. A UniRac SolarMount racking system with tilt legs and flashed standoffs was used to optimize system orientation, avoid snow buildup, and ensure a water tight connection to the roof. The resulting pitch of the array was 12° for the front row and 35° for the back row. The system is configured electrically as three (3) DC circuits (strings) of eight (8) series connected modules providing input through one (1) DC disconnect switch to one (1) SunPower 6000m, 6.0kW inverter. As designed, this system should generate an average of 14.6 kWh/day = 443 kWh/month = 5,312 kWh/year, where daily energy production is both weather and seasonally dependent. This energy production is equivalent to 84% of the customer's present home electrical usage, and corresponds to a CO2 (greenhouse gas) emissions savings of 6.55 kg CO2 per day = 199 kg per month = 2,390 kg per year. Full monitoring of system production and house consumption is also included, and used to guarantee performance.

Update (2014):

3.5 year after the installation of their 5.4 kW system, our happy customer is producing 85% of their annual power needs.   The owners are planning on more energy updates with the installation of a hybrid high-efficient air-to-air heat pump system.  This system adds a forced air heat pump to their existing high-efficiency furnace.  The heat pump will provide heat to their entire home until the temperature drops to 25 degrees, at which time the furnace will take over.  By doing this, the owner will lower their gas usage and increase their electrical usage.  To compensate for the extra power consumption,  they also decided to add another 3.2 kW solar PV system to the roof of their existing barn/shed. 

Based on our calculations after adding the hybrid heat pump and additional solar, the annual gas and electric energy bills for their 2200 sq. ft. home will be around $600 total.