On average, your solar system is going to lose some energy due to wiring, power, inverter efficiency, so you actually end up using 80% of your solar system’s capacity. This means that you’ll need 30 250Wp solar panels or 27-28 270Wp panels.īy NREL, via Wikimedia Commons How much do I save?įinally, let’s find out how much you can save per month on average from your monthly electric bill! This continues to improve ever so slightly, but the losses are unavoidable… because of physics! So you take the AC amount you need: 6kW and divide by. This means you convert about 80% of the DC power into AC power. This ratio of AC to DC is called the ‘derate factor’, and is typically about. Solar panels produce direct current (DC), and your home runs on alternating current (AC).īecause of physics, there are losses in converting the energy from the sun into DC power, and turning the DC power into AC power. So now that we know you need to produce about 6kW of AC output, we can work backwards to figure out how many solar panels you need. That said, there is a simple equation to calculate the amount of kilowatt-hours (kWh) your solar panel system will produce. This is called the ‘nameplate rating’, and solar panel wattage varies based on the size and efficiency of your panel. There are plenty of solar calculators, and the brand of solar system you choose probably offers one.
Typically, a modern solar panel produces between 250 to 270 watts of peak power (e.g.
Related: How many solar panels do I need? This depends in part on the amount of electricity you want to offset with solar power as well as the question ‘how much energy does a solar panel produce’, so in order to get more specific let’s talk about the actual number of solar panels. How much solar power do I need (solar panel kWh)? Or, 30 kWh / 5 hours of sun = 6 kW of AC output needed to cover 100% of your energy usage. Let’s estimate you get about five hours per day to generate that 30 kWh you use. So the kWh divided by the hours of sun equals the kW needed. The US ranges from about 4 hours – 6 hours of sunlight per day, on average, see the below map. Next, figure out the average amount of sunlight you get per day. If you’re going by the national average, then you should be using about 30 kWh per day. Energy Information Administration, the average monthly electricity consumption for a residential utility customer is about 903 kWh per month.ĭivide your average monthly usage by 30 days in a month to get your daily usage. How Much Power Am I Using?Ī kilowatt-hour is a basic unit of energy, which is equal to power (1000 watts) times time (hour). Your electric bills show how the average number of kWh you use per month.įor example, a 50 Watt light bulb left on for one hour would be 50 Watt hours, and 20 50 watt light bulbs running for one hour would be 1 kilowatt-hour (kWh). According to the U.S. However, your location will allow you to do some math and determine how well a solar panel works where you are. How big are the solar panels, and how efficient are the solar cells at converting energy?īecause the seasons and weather conditions affect the amount of sunlight hitting your roof, and the amount of sunlight also varies on the time day, you can’t use just the solar panel ratings to predict how much power you’ll get.How much sunlight does your roof get on average?.Does intermittent shading obscure direct sunlight from hitting the roof?.Solar panels indicate how much power they intend to produce under ideal conditions, otherwise known as the maximum power rating.īut how much electricity your solar panels produce depends on several factors. Its definition, in the context of electricity, is the energy of one watt power flowing for one hour.įollowings equivalent equations are identical but in different units.ġ W h = 1 P t = 1 I V t = 3 6 0 0 J = 2.
A watt-hour is a unit of energy and its units, Wh, are formed with W for watt and h for hour from SI unit system.
0 kommentar(er)
