# Advancing Smart Zero-Carbon Cities: High-Resolution Wind Energy Forecasting to 36 Hours Ahead
## 7 Applications and Contributions
### Smart Wind Energy Deep Decarbonization (SWEDD) Framework  
The carbon-city transformation curve (CCTC) presents a conceptual model for the transformation of cities based on greenhouse gas (GHG) emissions, illustrating the progression from high-carbon to carbon-negative cities over time as shown in Figure 22. CCTC highlights various stages of urban carbon reduction, from high-carbon cities (emitting over 80% GHG), through low- and nearly-zero carbon stages (around 20% GHG), to zero-carbon and ultimately carbon-negative cities (around zero GHG). The CCTC shows a decrease in net CO\({}_{2}\) equivalents over the years, depicting a clear downward trend in emissions as cities transform. This transformation period is marked by an orange arrow indicating the period required to achieve the GHG reductions. The CCTC maps out a trajectory towards decreasing city carbon footprints and integrates a system of classification for city types based on their carbon emission levels. Such classifications are essential for policymakers, urban planners, and developers engaged in projects aimed at enhancing urban sustainability. On the other hand, the CCTC serves as a visual aid to complement studies and discussions focused on transitioning towards sustainable, zero-energy urban environments, underpinning the necessity for robust wind speed and power forecasting systems that support renewable energy management and contribute to achieving these ambitious carbon reduction goals. The Carbon City Index (CCI) is a simple method to assess the effectiveness of a city's efforts in reducing its carbon footprint to a predetermined baseline level of city CO\({}_{2}\) eq emissions as in Equation (5):  
\[CCI=\frac{City\;Net\;CO2\;eq}{City\;CO2\;eq\;baseline}=\frac{CO2\;eq\;produced\;-CO2\;eq\; absorbed}{City\;CO2\;eq\;baseline} \tag{5}\]  
Figure 22: Carbon-city transformation curve (CCTC). Net CO2 eq is calculated as the difference between the city CO2 eq produced and the city CO2 eq absorbed. City CO2 produced encompasses all emissions from sources such as transportation, industry, and buildings. City CO2 absorbed includes carbon uptake through means such as urban greenery and other carbon sequestration practices. The city CO2 eq baseline is a reference value against which current CO2 eq emissions are compared. The city CO2 eq baseline typically represents a historical emission level from a specific base year or an average over a selected period. Establishing a baseline is crucial as it provides a point of reference to measure reduction efforts. CCI (Carbon City Index) is the ratio of the net CO2 eq emissions to the baseline CO2 emissions. This index provides a quantitative measure of the city's efforts to reduce GHG emissions relative to its baseline. A CCI value lower than 1 indicates that the city has reduced its net emissions below the baseline level, reflecting effective carbon management and mitigation strategies. Conversely, a CCI greater than 1 suggests that emissions have increased relative to the baseline, indicating that dramatic reduction efforts are needed. The lower the CCI, the greener the city will be, ranging from a high-carbon city to a negative-carbon city. This index is particularly useful for city planners, policymakers, and environmental scientists to monitor the progress of urban areas toward becoming more sustainable and carbon-efficient. CCI helps in understanding the impact of various initiatives and policies aimed at reducing GHG and promoting a transition to a low-carbon or zero-carbon future. The city transformation period is the number of years needed to transform a city into a zero-carbon city, where CCI equals zero and netCO2 eq equals zero. The Smart Wind Energy Deep Decarbonization (SWEDD) framework depicted in Figure 23 is a comprehensive framework that integrates wind energy to facilitate urban deep decarbonization strategies. SWEDD involves wind energy generation and the wind speed-power forecasting system (WSPFS), both crucial for predicting and managing the energy output from wind resources.