6. Conclusions

These results are significant. As seen in Table 15, a development incorporating a microgrid uses over 10 times the natural gas in all cases than the identical development drawing power from the local distribution grid. However, Table 16 definitively shows that the use of a microgrid would greatly reduce the greenhouse gas emissions from the development, with approximately half of

On national power grid Trigenerating microgrid

water

Cairo 1.0E+07 4.3E+09 0 4.4E+09 0.0E+00 2.7E+09 0.0 1.5E+10 1.8E+10 1.4E+10 Lagos 1.0E+07 0.0E+00 0 1.0E+07 0.0E+00 0.0E+00 0.0 1.5E+10 1.5E+10 1.5E+10 Shanghai 1.0E+07 7.4E+09 0 7.4E+09 0.0E+00 4.5E+09 0.0 1.5E+10 2.0E+10 1.2E+10 Mumbai 1.0E+07 0.0E+00 0 1.0E+07 0.0E+00 0.0E+00 0.0 1.5E+10 1.5E+10 1.5E+10 London 1.0E+07 1.4E+10 0 1.4E+10 1.0E+07 9.5E+09 0.0 1.3E+10 2.2E+10 8.8E+09

NYC 1.0E+07 1.2E+10 0 1.2E+10 1.0E+07 7.8E+09 0.0 1.5E+10 2.3E+10 1.0E+10

1.0E+07 7.3E+09 0 7.3E+09 0.0E+00 4.6E+09 0.0 1.5E+10 2.0E+10 1.2E+10

1.0E+07 0.0E+00 0 1.0E+07 0.0E+00 0.0E+00 0.0 1.5E+10 1.5E+10 1.5E+10

Heat AC SUM Hot

Micro-Grids - Applications, Operation, Control and Protection

NG consumption: with microgrid compared to without microgrid.

City Hot

Mexico City

Sao Paolo

Table 15.

Table 16.

16

water

Cubic feet NG annually Cubic feet NG annually Difference

Heat AC Turbine SUM

trigeneration from the outset, all upstream emissions from electricity generation are eliminated. Additionally, the use of waste heat in the building systems eliminates emissions from the production of hot water, halves the emissions from building heat, and also eliminates any emissions from air conditioning (bearing in mind that, in a conventional arrangement, air-conditioning emissions would be included in electricity generation emissions). Finally, Table 14 shows that incorporating maximal renewable assets by design accounts for roughly 20% of the electricity production which, at 50% generator efficiency,

Tons/year On power grid Microgrid Reduction (%) City CO2 SO2 CO2 SO2 CO2 SO2 Cairo 9.84E+04 4.80E+02 4.46E+04 2.67E+00 54.64% 99.44% Lagos 7.54E+04 5.25E+02 2.81E+04 1.68E+00 62.80% 99.68% Shanghai 1.12E+05 6.56E+02 5.58E+04 3.34E+00 50.08% 99.49% Mumbai 7.93E+04 6.73E+02 2.81E+04 1.68E+00 64.55% 99.75% London 1.49E+05 4.93E+02 8.58E+04 5.14E+00 42.53% 98.96% Mexico City 1.14E+05 4.70E+02 5.62E+04 3.36E+00 50.88% 99.28% NYC 1.41E+05 8.04E+02 7.56E+04 4.52E+00 46.21% 99.44% Sao Paolo 7.81E+04 5.01E+02 2.82E+04 1.69E+00 63.87% 99.66%

Comparison of greenhouse emissions for development: without vs. with microgrid.

the CO2 and virtually all SO2 emissions eliminated. By incorporating

Urbanization of populations is occurring at an accelerating pace worldwide, and, in all countries, the increasing densification of population is putting a strain on the pre-existing infrastructure. Depending on the state of national economic development, that infrastructure could be robust, aging, or nonexistent, but was not designed to support the increasing strain. Additionally, this seismic population shift requires housing and employment opportunities in relatively small geographic areas. While growth has always bought opportunity, that opportunity was never immediate or evenly distributed. Hence, slum populations are increasing, and both housing and economic opportunity are increasingly scarce.

History has shown that economies cannot be managed, but it is the job of the government to "promote the general welfare" [69]. At present, various local, national, and international entities are promoting the general welfare through establishing programs to create sociological and environmentally sustainable opportunity. These incentives recognize the existence of a need which can be addressed by a new model of urban growth, one that is economically advantageous and sociologically and environmentally sound, such as the design model proposed herein. The work presented develops a new model for urban development, a model which incorporates a myriad of mature technologies into a real estate development at the design stage. The model bases the development around a self-contained microgrid using trigeneration of power where, at the first stage, fossil fuel-powered turbines produce electricity and heat which, at the second stage, powers a steam turbine to produce more electricity. The third stage of trigeneration is to use the remaining exhaust heat to provide building heat, hot water, and air conditioning. The system is supplemented by renewable solar and wind power, with the buildings designed from the outset to maximize such assets. Modern power storage assets are included in the design to balance the load between times of high usage and low usage.

The study demonstrates that the proposed model succeeds in meeting all sustainability requirements. It is more profitable than constructing the same development on the national power grid. This is vital since economic sustainability is a sine qua non for any urban development. It balances load and generation capability on a large scale, allowing the construction of large numbers of buildings to accommodate increasing populations with essentially no impact on the existing power distribution infrastructure. It is also environmentally sustainable, producing fewer emissions than traditional developments on the same scale.

These conclusions point to the viability and the economic and environmental desirability of proceeding with urban development under the model herein presented and also lead to a sociological conclusion. Cities are historically built by the poor striving to make a better life for themselves and their families. In developed countries, the consequence of real estate development is too often to push such people out of their homes and further to the fringes. In developing countries, such people are often not even considered, relegated to living in shanty towns. The economic and environmental advantages of this development model present an opportunity to promote the general welfare of all. Environmental financial incentives, coupled with increased profitability, will allow for the maintenance of exceptional living conditions at comparatively low rents. Since renewability and regeneration are incorporated into the building design,

heat and hot water, so necessary for everyday life, will be readily available. Lower rents are economically possible since all these usual living expenses are being provided for by the same source. Most importantly, the model is scalable and variable and power is fungible. A commercial tower was included in this study to both provide an economic focus point to start the development and to provide jobs to the people living in the residential towers because real-world data was made available. The model could be applied to any combination of residential, commercial, retail, or industrial spaces providing centers for human advancement, with both jobs and housing provided at an economically and environmentally favorable rate.
