Not all solar panels are made equal and certain factors will drastically impact your bottom line. Below are 3 important things to look for when shopping for the best solar panels for your home:
The amount of watts your solar panel has will directly impact your production and as such your savings. To start it’s important to know that every 1 kw = 1,000 watts. Watts and kw both refer to the power generated or consumed by a given device, watt-hours (Wh) or kilowatt-hours (kWh) on the other hand refer to the electricity produced or consumed over time, i.e – per hour. As such if you have a 300 watt solar panel, in ideal conditions (direct sun) it will produce 300 watt-hours (Wh) or 0.3 kilowatt-hours (kwh) per hour. To get a general idea on your expected production, of course without taking into account your roofs’ direction, pitch and weather conditions you can multiply your solar panel wattage by the amount of panels on your roof and days in the month to get an average production amount.
In today’s market solar panels can range from 250 to 360 watt on each panel. The amount of energy each panel produces will directly impact your savings and cost. A lower producing system such as a 250 watt panel will take more panels to give you the same results as a higher producing system, such as a 325 or 350 watt panel. The better the production, the less panels you need and the more compact system you have on your roof.
2.Efficiency & Degradation
It’s no secret that solar panels have a long lifespan, but how long do they actually last and more importantly how efficient are they when you first put them up. Whether purchasing or leasing a solar panel system it’s important to look at the long term value of your commitment and take solar panel efficiency and degradation into account.
Solar panel efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity. Degradation on the other hand refers to the wear-and-tear of the solar cells within your solar panels over years.
Solar panel efficiency ranges between 12.4 – 22% efficiency. To date SunPower is considered one of the best solar panel manufacturers with solar panel efficiencies upwards of 22%. The next thing to look at is degradation. Degradation rates have decreased with technological advances. According to theNational Renewable Energy Laboratory (NREL) the average solar panel degradation rates from panels produced prior to the year 2000 were less than 0.5% per year and less than 0.4% from panels produced after the year 2000. This means that panels produced prior to the year 2000 would produce 90% of their original power after 20 years and panels made after the year 2000 would produce 92% of their original power. It’s important to note that these are averages and the actual rate of decline with vary based on the manufacturer of your solar panels. For example SunPower’s new SPWR panels have a degradation rate lower than 0.3% per year, meaning they will still produce 94% of their original power after 20 years. Solar panels with high efficiency and low degradation rates are most ideal for long term value and returns.
Your warranty coverage will vary based on the solar panel manufacturer and installer you choose. There are two main types of warranties for your solar panels including a power and product warranty. The power warranty, also known as power production warranty refers to a guaranteed amount of energy that the solar panels will produce over a certain amount of years. In most cases a power production warranty will guarantee 90% of production for 10 years and 80% for 25 years. Premium manufacturers, such asSunPower guarantee 92% for 25 years. The product warranty, which will typically cover both the product and workmanship can range from 10- 25 years depending on your manufacturer. Items usually covered under the product and workmanship warranty include replacing damaged panels or defects that arise from the workmanship in installing your solar panels.Should anything happened, exceptional manufacturers such as SunPower will make the process easy by covering shipping costs, paying for labor to remove and install new parts and provide you with a prolonged product and workmanship warranty of 25 years instead of just 10.
Solar is an investment in your future. We want to make sure you’re getting the best product possible for your home.