Every single month you get your electricity bill.
You pay it angrily, knowing that you are sending more money down the drain. Worse still, every year the price of electricity goes up at random, leaving you with less money to spend on what matters -- your family.
What if I told you that you don't need to pay for your electricity bill? That you could make money off electricity rather than wasting it?
It’s possible with solar power. Put up a few solar panels and you'll never need to pay for electricity again! Going 100% renewable is great for the environment AND your pocket.
Each house will have a different requirement based on roof angle, electricity consumption, and available space. If you are buying your panels from a company, they will assess your property and tell you how many panels you need. For those who want to go the DIY route, use these calculations to find the right number of panels.
The Basic Calculations
To calculate how many panels, you need, you must first figure out how much electricity you use. Take last month's electric bill and check how many kilowatt-hours (kWh) you use. If you have a year's worth of bills, it's best to add all the kilowatt hours together and find an average. Your usage will differ from season to season and it's important to compensate for changes.
January Bill + March Bill + November Bill + December Bill = Total kilowatt hours
Total kilowatt hours / Number of months = Average Monthly Usage(kWh)
Once you've calculated your average monthly usage, think about how your life will change in the future. Will you be adding an extra person to your household? Buying more appliances? Maybe splurging on the ultimate luxury and getting a fancy hot tub? All those things use electricity, so add a few extra kilowatt hours to your calculation to be safe.
Now you know how much energy you need per month, you need to find out how much direct sun you get on average. You can use an insolation meter (which measures sunlight) or do some Google research on your area. Most places in North America get between 3 and 5 hours per day. You can check a full list of averages here. Once you know the numbers, it's time for another calculation.
Average Sunlight per day * 30 = Average sunlight per month
Average Monthly Usage (kWh) / Average sunlight per month = kW Solar System
For example, if you use an average of 1000 kilowatts per month and have 4 hours of direct sunlight, the calculations would look as follows:
4 * 30 = 120 hours of sunlight per month
1000 / 120 = 8.3kW Solar System
This is estimated how powerful your Solar system needs to be to run your entire household on 100%. You can add to your solar array over the years and start off small with 50% renewable. If you have an unforeseen power drain (like an extra-large hot tub), you can add more panels if you have the roof space.
The more complicated considerations
Did you know that all solar panels are not created equal? The newer panels are smaller, output more power and are more expensive. Your key constraint when deciding what type of panel to buy is the limited amount of space on your roof.
The angle of your roof, the shadows cast by trees, the square footage you have available -- these are all factors that can hamper your production of solar panels.
Find your house on google maps and see how much of it is in shadow or obscured. This will give you a good idea of how much usable space you have for solar panels. From there, measure the square footage of your roof so you know how many panels you can fit in.
Solar panels have a different wattage. For example, we sell a 100-Watt panel and a 310-Watt panel. If you buy 10 of the 100-Watt panels, you'll only get a third of the power that the 310-Watt panels would produce. We find that panels which are 250 Watt give the best mix of power capability VS cost VS size.
What are the real savings you'll make?
When you buy a solar panel, be prepared to have it for the next 20+ years. Your investment of solar panels will take time to break even, but it will be well worth it. Let’s look at how much our 1000-Watt house in Chicago can save over 20 years.
1000 Watts per month = $162 per month
8.3kW system cost = $20,000 all inclusive
Yearly saving on electricity bill = $1,944
Time until you break even on the system costs = 10 years
With the sporadic increases in electricity costs, those 10 years could easily become 5 years. Thereafter, you are just making pure profit. Let’s be conservative and assume you’ll pay off the panels in 7 years. From there you’ll be saving $1,944 (plus interest) a year.
Total saving = $25,272
Now imagine if you invested those savings in a compound interest account. With 5% per year you are looking at a total saving of almost $40,000. You could kick-start your retirement savings or put a deposit down on another house!
On days that the need for electricity is high and your system is overproducing, you can send your electricity back into to municipal grid. Instead of paying for electricity, providers may actually pay you! With a few sunny days, you could be paying off your system and earning a profit in no time!
What it's like to have a house that runs on 100% renewable
Imagine proudly telling your neighbors that you don't pay for electricity. In fact, your neighbors are paying for the excess electricity that you produce. Imagine being able to tell your kids that you are doing your bit to save the Polar bears and stop Global Warming. Imagine what you'll do with the extra money you save. Pamper yourself with weekly spa trips? Maybe a holiday in Bali?
The calculations for your solar system are relatively easy, but the install is a little trickier. If you want a helping hand to make sure get it right the first time, send us a mail at firstname.lastname@example.org and we will help you reach your 100% renewable goals!