Just how big does your solar power system size need to be?

Solar owners happy overall with their solar installations according to Choice.

With so many solar products on the market, it can be confusing to work out exactly how big your solar power system size should be for effective use.

So Choice has produced an online guide to help you work out the correct size of solar power system to meet your needs. This involves:

  • Understanding how much electricity you typically use;
  • Working out when you use it; and
  • Calculating the size of the solar power system you need.

Let’s look at two important factors that contribute to a perfect solar power system size for your home. The first is understanding the amount of power you use. The second is figuring out out many solar panels you need to match that power.

Understanding how much electricity you use

Firstly, you should assess past electricity bills to work out your power consumption and calculate average daily use.

Choice online guide helps households work out the best solar power system size they need.

Choice helps consumers work out the correct size of solar energy system to suit their needs. Image: Pixabay

Households and businesses with smart meters usually find daily usage noted on their bills. This is measured and billed in kilowatt-hours (kWh).

Typically, an Australian household will use around 15-20 kWh per day. This ranges, however, from about 8-9 kWh per day for a single-person home to 33 kWh per day for larger households of five or six people.

Everybody uses electricity differently depending on work, lifestyle and preferences.

How many appliances get used during the day? Is there a heavier power demand at weekends when everyone is home? Do you use more electricity in winter, powering heaters, or in summer to stoke the air-conditioners?

Solar power system size: Calculating your ideal

The number of solar panels you need will be dictated by system size. Generally, 1 kW of solar panels equals 4 kWh of electricity generated daily. So a 5 kW system will produce about 20 kWh on sunny day.

However, electricity production also depends on location, time of year, panel orientation and age of panels.

Aim to figure out as much about your household use as possible before getting a quote for solar installation. Covering more with a larger system means you get a feed-in tariff of around 7-12 cents per kWh for excess fed back to the grid. Covering less with a smaller system means you pay for any extra grid power consumed.

You won’t get the most out of your solar panels if the majority of electricity is consumed at night – when the sun’s not shining – and little during the day with everyone at work or school. Timers on washing machines, dishwashers and air-conditioners can solve this problem.

But there is a way to combat the problem of getting the most from your solar system. Solar storage batteries are a cost-effective way to store the day’s excess electricity for evening use. A combination of solar panels and a home battery gives you the flexibility you need with your electricity use.

Check out Energy Matters’ tips for buying a solar system here.