There are a lot of factors that go into your solar system installation. You’ll need to determine how much power you use, whether you want to store energy for off-grid applications, what racking and mounting option you’re going with, and how much money you’re hoping to save. Click here for more info.
You’ll also need to apply for state and local solar incentives.
How much energy do I need?
You will need enough panels to generate a minimum of 10,000 kWh per year. This equates to around 28 or 35 panels that produce a maximum of 350W each. Depending on your home’s energy consumption, you may need more or less.
You can get a rough idea of your electricity usage by digging up past utility bills and using online calculators. The best method to determine your power needs, however, is by looking at average kWh usage over the course of a year.
Once you have these numbers, you will need to multiply your annual energy usage by your location’s peak sun hours and by your panels’ wattage. Then you can determine how many solar panels you’ll need to meet your goals. For example, if you want your system to generate enough energy for an electric car, this will add significantly to your kWh requirements.
Do I have enough roof space?
The amount of power your solar panel system will produce depends on its size, and you must have enough roof space to accommodate the array. Additionally, your roof must be free of any obstructions like trees or awnings that shade the panels during parts of the day.
A structural engineer will evaluate your roof to ensure it can support the added weight of solar panels. If the engineer finds that your roof is safe, then the project can begin.
Many cities and states offer rebates to encourage homeowners to switch to solar energy. Ask your local solar company about the available incentives. They may also know about incentives offered by your electricity provider and the local utility. This is an excellent way to offset the upfront cost of your solar installation.
What kind of panels do I need?
As an alternative to relying on the commercial power grid, solar panels generate energy all year round. The amount of energy they produce varies by location, as some regions have longer, darker winters than others.
To calculate your ideal panel size, use a year’s worth of electricity bills or the average American household consumption as a guideline and divide by the average panel wattage (320 watts). You’ll also want to consider factors such as temperature coefficient, weight, and manufacturer warranties.
Most importantly, all PV systems should be grounded using UL-listed grounding clips or lugs. Be sure to follow the racking report and install the system according to the wiring diagram. Always wear the proper safety gear when working with electrical components.
What type of inverter do I need?
The inverter takes DC energy from the solar panels and turns it into AC electricity that your house can use. It’s important to get the inverter sized correctly, taking into account the surge watts of all your appliances.
Power optimizers and microinverters take care of DC conversion at the panel level so that performance problems experienced by one panel won’t impact the rest of the system (as seen in the graph above). Power optimizers are cheaper than microinverters but add more complexity to the system.
Under the Clean Energy Council rules for accredited installers, the inverter size should not exceed your solar panel array capacity. If this is the case, your energy yields through midday can be compromised. This could be offset by morning and afternoon gains though.
How much will it cost?
The size of your household’s electricity usage is a big factor when determining system price. Solar panels are priced by the watt and you want to ensure your system is designed to offset your typical consumption. This is why most pros recommend working with a pro to determine your energy usage and using tools like SolarReviews to estimate the size of the system you’ll need.
Your location also influences costs, as do your electricity rates and peak sunlight hours. Additionally, you’ll need to decide between paying in full for your system and financing. Paying in full is the best option because you avoid interest rates and can qualify for additional incentives.
Lastly, your system will need to be approved for utility connection by the utility representative. This typically involves an inspection and upgrading your meter to allow for Net-Metering. Next blog post.