The main objective of a physical map is to show landforms, bodies of water and other geographical features. Features shown include mountains, deserts and lowlands as well as lakes, rivers and oceans.
Depending on your electricity prices, a 400 watt HID will cost $200 â $400 each year of use, plus the cost of replacement bulbs. LEDs meant to replace 400w HIDs average around 180 watts.
The formula for calculating the cost is straightforward: Kilowatt hours * cost per kWh * number of hours used. One kWh is equal to 3412 BTU. A 5100 BTU air conditioner will then use 1.49 kWh for each hour it is running.In the Chicago area we are paying $0.11 per kWh.1.49 * 0.11 * time. The above formula gets us very close to the cost. We only need to figure out how many hours per day we will be using the AC unit. 5100 BTU air conditioner will then use 1.49 kWh for each hour it is running. In the Chicago area we are paying $0.11 per kWh. 1.49 * 0.11 * time. The above formula gets us very close to the cost. We only need to figure out how many hours per day we will be using the AC unit.