Electricity Planning Engine: An Hourly Arbitrage API for Batteries and Solar, Plus the Timezone Bug That Almost Broke It

The Electricity Planning Engine is a Laravel API that optimizes household energy consumption based on hourly market prices. In Germany, negative wholesale power prices are common due to excess solar and wind energy. The engine decides whether to draw from the grid, charge/discharge a battery, or export solar surplus. It's available on GitHub and can be used as a starting point for similar projects. The engine also considers reserve capacity for peak hours.