Suppose there is a sudden, unexpected increase in cost of energy for businesses

Answer: Output will fall

Potential output would likely fall as aggregate supply is shifted left. This is because most nations would experience a negative supply shock if the price of energy increased since energy is an input in the production of all goods and services. This would mean all market supply curves essentially would shift left thus decreasing output. Some nations and markets though might benefit such as Saudi Arabia or the market for solar panels but for most nations/markets, the supply effect would be negative/