4.2 Power generation

2. Flexible sizing of the microgrid: Depending on local regulations, neighboring entities could also be enlisted into the microgrid. Although not modeled herein, if such entities include vital facilities such as hospitals or fire stations, the microgrid facility may be eligible for non-interruptible status with respect to

3.Maximization of renewable energy assets: Buildings would be designed from the outset to maximize both solar and wind generations, thereby decreasing

the carbon footprint of the development overall and the cost of fuel.

A model is presented which incorporates a microgrid utilizing renewable energy assets into a development consisting of three 32-story residential towers and one 57-story commercial tower. The scale of the development is in keeping with current large-scale developments. The model is run in each of the eight cities of interest using local data on environmental conditions, construction costs (exclusive of real estate purchase), and income levels based upon local rents and power rates. Analyses of the benefits of including the microgrid, as opposed to the same scale conventional development, are performed on three

1.Infrastructure impact: Electric load is presented with and without the

2. Economic: Construction cost, anticipated revenue, and time to repay are

3.Ecological: Greenhouse emissions are compared with and without the

Actual hourly electrical usage data and building specifications of one 32-story residential tower and one 57-story commercial tower located in New York City were generously provided by GridMarket LLC, New York City, NY. The dimensions of each tower, given in square feet (sq. ft.) and number of apartments (apts.), are given in Table 5. Rentable area for the entire four-tower development is calculated, per industry standard, at 50% of total square footage, with the remaining 50% designated for hallways, stairwell, elevator shafts, and other such types of general-

Floors Retail

Res. 1916 94 80,333 938,324 32 26,805 0 879,019 608 Comm. 1972 165 127,966 2,689,635 57 216,912 2,319,046 0 0

(sq. ft)

Office (sq. ft)

Res. (sq. ft) Apts.

presented with and without the microgrid.

natural gas supply.

Micro-Grids - Applications, Operation, Control and Protection

4. The development model

levels:

microgrid.

microgrid.

4.1 The buildings

use areas.

Table 5.

8

Built ES Lot

area

Internal area (sq. ft)

Specifications for buildings to be used in the model (provided by GridMarket LLC).

A 2 � 1 (two gas turbines 7.9 MW powering 1 MW steam turbine) was the optimal configuration for the cogeneration plant. This would be supplemented by power provided by 10,500 solar panels and 295 1 kW vertical drum-type wind turbines. The number of solar panels was estimated by covering the entire roof area of the four proposed buildings with standard 77 inch by 39 inch panels, while the number of wind turbines was estimated by placing a turbine every 10 feet around the periphery of each roof. It is recognized that whole-roof coverage with solar panels is impracticable; however, the estimate is valid because some amount of appropriately facing surface area would be available for additional panels. Also, it is assumed for these calculations that the buildings will be boring rectangles. As this is neither likely nor desirable, setbacks will create additional space for more wind turbines. Energy storage devices will be included in the design from the outset in order to balance generated power between times of low load and high load.
