Page 60 - Designing for Zero Carbon - Case Studies of All-Electric Buildings

CASE STUDY NO. 2
MAKERS QUARTER BLOCK D OFFICE BUILDING
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Designing for Zero Carbon: Volume 1
Energy Production versus Energy Use
The roof-mounted solar PV system was fully operational during 2019 while the occupancy was only partial for the first seven months of the year. The result was that the solar energy production was higher than the energy used for those months, including even the tenant spaces, as can be seen in the chart on the opposite page, Solar Photovoltaic System Performance.
When the building went to full-occupancy in August, energy use exceeded energy production except for the Common Area. In fact, the energy produced by the solar PV system remained greater than the energy used in the Common Area throughout the year. Thus, the goal of achiev- ing a ZNE performance for the core-and-shell (Common Area) was realized in 2019 as shown by the recorded data.
The second chart, Cumulative Net Energy Performance, sums the net energy production each month to that of the month prior, so that the total at the end of the year would be exactly zero if the performance is zero-net-energy (ZNE). If the curve is above zero at the end of the year, the building’s total energy performance is net positive. If the curve falls short of the zero axis, the building is said to be performing at net negative.
The chart shows two curves: one for the Common Area and a second curve for the entire build- ing (Common Area + Tenant Area). The curves clearly indicate that the entire building cannot perform at the zero-net-energy level, especially when a normal year of occupancy ensues. How- ever, the core-and-shell portion of the building (the Common Area) achieved net positive perfor- mance in 2019. Since the energy performance of this part of the building is expected to remain the same under normal occupancy, that particular ZNE project goal has been realized.