# Solar Panel Price Per Watt Calculator

Hi. im amy at the alte store. probably the most frequently asked question we get here is, How much solar does it take to power my 2,000 sqft home? My answer is always the same. I dont know. How much power do you use? Im not trying to be flip, I honestly dont know. The power usage for different homes are going to be so wildly different, there is no way of knowing how much power someone uses based on their square footage. Is the house located in the north with bad insulation and electric baseboard.

Heaters? or is it a house with a tight building envelope and gas heat? is it located in the south with the highest loads being air conditioning run 24/7, or is it in a mild environment with a couple of fans occasionally? Are you heating your water with an electric water heater, or an oil furnace? Do you have family members who find it challenging to turn off a light when they leave the room (you know who you are)? Are you lighting with incandescent or LED light bulbs?.

The best way to determine how many solar panels you need is to look at your electric bill and see how many kWh a month you buy. You can then go to our gridtied calculator to see how much solar would be needed to offset a percentage of your bill. Heres an example of my electric bill. It shows 13 months of usage, so I can compare the latest month with the previous year. It is amazing what you can learn by studying your electric bill. By comparing the usage.

In different months, i can see my biggest use is in the summer, with the air conditioner running all day because of the home office. You can see that my usage dropped significantly from August 2013 to August 2014, as well as from July to August in 2014. lt;highlighting bar as I mention themgt; We went away every weekend in August 2014, and turned the AC off while we were gone, saving us \$85 from the previous year. But unfortunately, we went away for a week that July and forgot to turn down the AC, so it stayed on high, cooling.

An empty house all week. you can see thats the highest usage in 13 months, and was completely preventable. That mistake cost me about \$160. In November we switched the minisplit from AC mode to heating mode to delay turning on our oil heat, bringing our electric usage back up. It cost an extra \$135 to heat the house with electricity that month, but saved us at least that much on our oil bill. By December it was too cold for the heat pump to work, so we turned it off and turned on the oil, dropping our electric use. So even.

In the same house, with the same people, behavior changes the electrical use dramatically, thus changing the answer to the original question, how much solar do I need to power my house? I recommend you look at your monthly usage and analyze it, what was your big energy user each month, and could a change in behavior reduce it? Once you understand your electric use, then you can start to figure out how much solar you need. Our average use is about 1,500kWh a month. I used that number in our ongrid calculator.

And decided to see what it would take to make all of our power with solar, netting us down to 0. That would require around a 13,000 Watt solar system for my area, around 50 solar panels. This chart shows my last 30 months of electric use, and the estimated output of a 13kW solar system on my house for that time. With Net Metering, I can use any power I generate during the day, and sell the extra to the grid. Then at night, when my system isnt generating any power, I can buy it back from.

The grid, spinning the meter back and forth. any additional power i need gets bought from the grid, same as usual. Likewise, with months that I make more power than I use, like in the spring, I can bank the credits to use them in the summer and winter when I dont make as much as I use. Todays average costs would be around \$26,000 to buy the equipment to install it yourself, or about \$52,000 to have one professionally installed (depending on equipment and location). A combination of federal and local incentives could cut.

## How to Size Your Solar System

I’m going to talk about how to truly properly size your solar system how much power batteries can really store and the way of solar system really works because it’s pretty amazing how many people that have solar systems don’t truly understand how much power they have and it’s important to know because if you end up with a situation where your modules break your solar panels aren’t functioning.

For a period of time or you have a series of cloudy days it’s good to understand exactly how many kilowatt hours you can actually pull out your battery safely so how many days and how you can ration your power and also that really helps you sighs your system properly without with what appliances you’re using so I’m.

Going to start by explaining how the batteries are set up that first one to say the caps are off the batteries right now because I’m equalizing explain that in another tutorial but hydrogen gas is escaping right now and you don’t want these caps on while that’s happening so right here I have eight Deka LT16 batteries now these are 350 amp hours batteries.

I’m going to explain as part of what i can explain today what that means but before I do that these are set up in two strings parallel together so we have four batteries a group of four batteries that are in series which means that they’re wired from the positive to the negative positive to the negative positive to the negative and then positive to the positive and negative to the negative.

Over to the next string when you wire for batteries in series every time you do that the amperage stays the same but the volts double so each of these batteries is 6 volts so when I put 4 in series i end up with essentially one bigger 24 volt battery the amps are still the same though so what i have here are two 24 volt batteries and then they’re parallel together negative 2 negative and positive to positive and when you parallel.

Two batteries together you double the amprage so i have sized my battery system to make this 24 volts with double the amperage of a single battery so each of these batteries is 350 amp hours ok so first i want to clarify that when your solar panels on the roof the electricity that they generate you’re not using that electricity directly.

You’re never using that electricity directly any time you pull power from solar system you’re always pulling from the batteries the solar panels send electricity to the charge controller and the charge controller reads what the voltage of the battery system is and maybe even a couple other metrics and it determines how it should charge these batteries so if you’re using power during the day the pleading power from these batteries when.

The sun’s out that electricity from the panels is actually directed into the batteries to charge them but it’s not actually but the the power that you’re using your pulling power from the batteries and the solar modules through the charge controller are charging the batteries back up that’s the best way to look at this so that being said you only have as much power to use as what’s stored in the batteries.