The Road to Net-Zero: Solar
In our last post, we focused on lighting. Next up, solar.
To achieve our goal of Net-Zero Energy, a solar array has been designed and implemented to offset energy use in Entegrity’s historic East Village office. Entegrity engineers used an energy model representing the building consumption to determine the size of the rooftop solar array and improve the efficiency of the building’s entirety. As shown in the photos below, a 50 kw, 155 solar module array, was installed and is expected to produce 70 mwh annually.
Completed solar array.
The graphs below display the comparison of our Little Rock office predicted performance to the actual performance. Using energy modeling and solar PV production models, our energy team developed a predicted energy use for our building and an expected energy production from our rooftop solar array. Figure 1 (predicted) and 2 (actual) show the total consumption and production for a portion of November and all of December. As shown in both graphs, the energy production falls below the energy consumption. This difference between production and usage is expected due to less hours of sunlight (sun-hours) during the winter months and a consistent amount of occupancy. Graphs displaying the daily comparison are provided at the end of this article.
Table 1 shown below, represents the totalized values for the first two graphs. When comparing these two sets of numbers, the actual production and consumption are both lower than their corresponding predicted values. The lower production can be explained by lower than average solar irradiance during these months, while the lower consumption is attributed to dynamic energy controls and employee awareness of energy management strategies. As the sun-hours increase during the spring and then summer, we predict a larger amount of production. This will result in a reverse between the production and consumption ratio.
More to come on our Road to Net-Zero in future building updates.Interested in learning more about our rooftop solar array and other sustainability features of our Little Rock headquarters? Join us for our Flip the Switch and Open House Celebration Thursday, February 8th at 5 pm.