# A study on monthly sales forecasting of new energy vehicles in urban areas using the WOA-BiGRU model

## TL;DR

This study uses the WOA-BiGRU model to improve monthly sales forecasts for new energy vehicles in Chinese cities, showing better accuracy than other methods.

## Contribution

Proposes a novel WOA-BiGRU model that outperforms existing methods in predicting urban NEV sales.

## Key findings

- NEV sales growth has reversed the decline in overall automobile sales in China.
- Cities with high NEV sales are concentrated in four major economic regions in China.
- The WOA-BiGRU model achieved a lower MAE than both BiGRU and PSO models.

## Abstract

To accurately predict the sales of new energy vehicles (NEVs) in Chinese cities and explore the applicability of optimization algorithms for GRU models in forecasting urban NEV sales., this paper conducts a spatiotemporal analysis of urban NEV sales data. The Whale Optimization Algorithm (WOA) is then employed to optimize the parameters of the Bidirectional Gated Recurrent Unit (BiGRU) model, thereby proposing a WOA-BiGRU-based model for monthly sales prediction for urban NEVs. Its prediction results are compared with those of the particle swarm optimization (PSO) algorithm. The research findings are as follows: The growth of NEV sales has reversed the declining trend of overall automobile sales in China; Cities with higher NEV sales are predominantly concentrated in four major economic hubs--the Pearl River Delta, Yangtze River Delta, Beijing-Tianjin-Hebei region, and Chengdu-Chongqing. Optimization techniques such as WOA can improve the accuracy of GRU models in predicting city-level sales of NEV. The WOA-BiGRU model outperforms both the standalone BiGRU and PSO models, achieving a Mean Absolute Error (MAE) of 3051.89, which is 526.18 lower than the BiGRU model and 104.72 lower than that of the PSO model. This study improves the accuracy of monthly sales prediction for urban NEVs, offering critical insights for the development of the NEV industry in China, the deployment of charging infrastructure, the stabilization of the power grid, and emission reduction in the transportation sector.