What Determines Solar Energy Generation?
Solar generation is primarily determined by the amount of sunlight your panels receive, measured in peak sun hours per day. This varies dramatically by location—from around 2.8 hours in Ireland to over 5.5 hours in Australia. Other factors include roof tilt and orientation, shading from trees or buildings, panel efficiency, inverter losses, and temperature (panels produce slightly less in extreme heat). The calculator accounts for all of these through location-based irradiance data and adjustment factors.
How to Interpret Your Generation Estimate
Your estimate shows expected annual generation in kilowatt-hours (kWh). To put this in context, a typical US household uses around 10,500 kWh/year, a UK household around 3,500 kWh, and an Australian household around 6,000 kWh. If your estimated generation is close to your consumption, your system is well-sized. Remember that generation varies seasonally—you'll produce more in summer and less in winter. Monthly production can vary by 3–5x between peak summer and mid-winter, especially at higher latitudes.
Solar Generation by Country: What's Realistic?
A 1 kW solar system produces very different amounts depending on where you live. In Australia, expect roughly 1,500–1,800 kWh per year per kW. In the US, it's 1,200–1,600 kWh depending on state. The UK averages 800–1,000 kWh per kW. Ireland is similar at 750–950 kWh. Canada ranges from 1,000–1,400 kWh. New Zealand averages 1,200–1,500 kWh. These figures account for real-world conditions including cloudy days, system losses, and seasonal variation—not just laboratory-condition peak output.