How big do your solar panels need to be?

So you’ve been giving some thought to installing a solar panel system but you’re not sure what size you need to power your home and/or office? Picking the right size will ensure a system that will deliver maximum efficiency and financial benefits, and also ensures that you get the best solar deals. Most Australian households get a solar system installation between 5kW, 6kW/6.6kW and 10kW. So how do you decide which one fits your property and life? There are three basic things to look out for:

Energy requirement: The first thing to check, of course, is what your energy needs are. This is easy enough to check — just check your utility bill; it should mention the number of units consumed for the month. Based on this, you can calculate your average daily usage (divide by 30 days) and your estimated annual usage (multiply by 12 months).

The per capita power consumption of the average Australian home is about 9,400 kWh per year. A 5kW solar array has the potential to produce around 7,000 kWh per year, hence this set-up is just right for a couple or small families. We say ‘potential to produce’, since the efficiency of a solar array also depends on available sunshine and other factors. A 6.6kW solar system produces around 9,500 kWh per year, which would cover the needs of most medium-sized families. On the other hand, if you have a large family, or high energy requirements, then you might consider a 10kW system which can produce 14,000 kWh per year. This size is also ideal for small offices and businesses.

Cost: For anybody going solar, of course, COST is at the top of their mind. While solar panels can seem like a big expense, it’s smarter to look at this as an investment that will save you money on utilities and, before you know it, will pay for itself! A 5kW system, for instance, can save a household around $350 in every bill cycle. And, a high-quality 5kW array could pay for itself within 2-4 years. A 6.6 kWh system, while slightly more expensive, will also break even on the cost within 3-5 years. With a 10kWh system, your investment is obviously larger, but so are the savings — save as much as $700 every month on power bills! In addition, you can feed the excess energy back into the power grid and make a tidy profit there too, making sure you recover the solar panel installation cost within 3-5 years as well.

Space available: This is a factor the layperson tends not to pay too much mind to, however, it greatly impacts how much energy your solar system can actually generate. The more space you have available (with unimpeded, direct sunlight) on your rooftop or property, the bigger the system and the more energy you can enjoy. A 5kW array will require about 25-35 sqm of rooftop space, for example, while the 6.6kW system will need 37-40 sqm. The 10 kW system, by far, needs the most space — 50-65 sqm of rooftop space.

Remember, that there are many more complex formulae and factors to consider, so if that sounds intimidating, reach out to Solar NextGen, a CEC approved retailer for both solar power for home and commercial solar installation. And no matter which size solar system you pick now, it can always be expanded without much difficulty later on. Happy saving!