It’s that time of month again. You open your mailbox (or, for the more progressive, your email) and find the most dreaded bill: your Hydro bill.
Many homeowners accept the fact that they will continue to pay for this service. Yet another group is quietly exploring alternatives. These people are looking for ways to generate their own power and reduce, or in some cases eliminate, their dependency on the electrical grid.
The solution this article explores is the combination of solar photovoltaics (PV) and small-scale battery storage to generate and store the energy the home needs. To be honest, there is a cost to exploring this alternative; however, it is one that will benefit you and your family in the future. By installing a solar array (or if you have the capacity) near your home, you can generate power. This energy is then stored in a series of batteries that can be “used” when needed. Through inverter technology, your array can prioritize demand to draw from the batteries before the grid is used.
Depending on how much energy you use and how many solar panels and batteries you install, payback can take as little as 6 years if you use equipment that will run for more than 20 years (which means about 14 years of life). ‘free’ energy through the installation of a system). Sounds interesting, right? But where do you start?
If you’re trying to figure out how much “solar” you’ll need, there are some simple calculations you can do. If you look at your utility bill, you will see how much energy you used. This is displayed in kWh. Your bill can also show your usage in kWh for the past year.
There are two ways of looking at this. First, there is your average usage over the twelve months. Using this method will result in a system design that will result in periods where the power generated will not be enough to power your entire home, but will average out throughout the year. The second way is to design for your ‘peak’ usage: in most residences this will be during the summer when air conditioners and swimming pools add to your electricity costs. In this case, you may produce too much power and end up ‘giving back’ some power to the utility once the batteries are fully charged. In both cases, you want to calculate the average daily usage in kWh. For illustrative purposes, let’s assume you need to produce an average of 30 kWh per day.
To determine the number of panels, we need to take the daily kWh usage and divide it by the number of hours of sunlight. If we use seven hours for the calculation, we would have 30 kWh divided by 7 hours or 4.29 kW from your solar panel. If you are using 250W panels as a whole, the following formula would apply: It would take 4.29 (kW) divided by 250/1000 (kW) or 17.1 panels to offset 30 kWh per day under *ideal* conditions.
At this point, you need to make sure that your roof or “area” can accommodate 18 (you can’t have 17.1) panels and that it gets seven hours of sunlight a day and that there are no obstacles blocking the panels.
The best thing to do after doing these simple calculations is to find someone who can help you with the engineering and calculations, as well as the implementation of your project. Completed correctly, this solution could eliminate, or at least drastically reduce, your energy bill.