Analyzing Your Electricity Loads
Calculating your electricity needs is the first step in the process of investigating renewable energy systems for your home or small business. A thorough examination of your electricity needs helps you determine:
- the size (and therefore, cost) of the system you'll need,
- how your energy needs fluctuate throughout the day and over the year, and
- measures you can take to reduce your electricity use and increase the efficiency with which you use that electricity.
Conducting a load analysis involves recording the wattage and average daily use of all of the devices which are plugged into your central power source, such as refrigerators, lights, televisions, and power tools. Some loads, like your refrigerator, use electricity all the time, while others, like power tools, use electricity intermittently. Loads which use electricity intermittently are often referred to as selectable loads. If you are willing to use your selectable loads only when you have extra power available, you may be able to install a smaller renewable energy system.
To
determine your total energy consumption, multiply the wattage of each
appliance by the number of hours it is used each day (be sure to take
seasonal variations into account). For all selectable loads, you should
also record the time(s) of day the load runs. Some appliances do not give
the wattage, so you may have to calculate the wattage by multiplying the
amperes times the volts. Generally, power use data can be found on a
sticker, metal plate, or cord attached to the appliance.