The most common terms that you come across when you make your mind for solar are power and energy.
Let us solve this confusion with simple examples:
Watt in solar panels
When we talk about a watt, we are talking about power. It is the rate at which energy is consumed or produced while traveling or flowing from one point to another.
Let me clear this with the help of a simple example:
Say, your office is on the 5th floor. As you are a health-conscious guy, you use stairs to climb to your office. On Monday, it took you 5 minutes to reach to your cabin while on Tuesday it took a bit longer, 6 minutes, to reach the same destination.
The energy consumption is the same in both cases but you used more power on Monday because the same energy is consumed more quickly as compared to that on Tuesday.
A 100-watt bulb is consuming energy more quickly than 40-watt bulb hence shines brighter.
What is watt-hour?
Watt-hour is the unit of energy.
Whether you run or walk slowly to meet him, the amount of work done or the energy consumed is the same.
Your electricity bill is based on the amount of energy consumed.
What is the difference?
Watt represents how fast the energy is consumed while Watt-hour/kW-hr tells the amount of energy consumed.
A 100-watt bulb when runs for 2 hours (100 x 2 = 200 watt-hour) will consume equal energy to that of 40-watt bulb when left on for 5 hours (40 x 5 = 200 watt-hour).
What is the use in Solar?
The knowledge of watt and watt-hour is very important in sizing the solar panels and designing the overall solar power system.
Say you have following electrical appliances in your home with their quantity and power are as follows:
The average day time running time, in hours, of the above electrical appliances are as follows:
Therefore, we need a set of solar panels which can provide a total of 4760 watt-hour energy in the day time.
Are you interested in installing a solar roof at your home and want to know the complete feasibility beforehand?
Try my solar feasibility spreadsheet, a very simple yet powerful tool in determining the technical and financial feasibility of your residential solar power system.