Because things like lighting systems, air conditioning, and hot water systems expend tremendous amounts of electricity, natural gas, and diesel fuel, the sky is the limit as far as energy conservation is concerned.
由於飯店的照明系統、冷氣空調、熱水系統等，需要耗費龐大的電力、瓦斯、柴油能源，節能的空間極大，作法也相當多元。