As homeowners become more environmentally conscious, the shift towards renewable energy sources is gaining momentum. One of the key questions many Australian homeowners are considering is how to integrate solar power with home heating systems, specifically hydronic heating systems.
Solar-powered hydronic heating is an efficient way to use renewable energy to keep your home cozy and warm, without relying on fossil fuels. This article will help give you an idea of how much solar power is needed to effectively run a hydronic heating system, whether you’re considering your first installation in your home, or thinking about upgrading your existing hydronic heating system to run on solar.
Understanding solar powered hydronic heating systems
A solar powered hydronic heating system combines solar energy with water-based heating. Solar panels generate electricity which in turn can power a heat source (whether it be a boiler or heat pump) that circulates hot water through sealed pipes installed under the floor or to wall mounted radiators and towel rails. This method is not only sustainable but also highly efficient in distributing heat evenly throughout your home.
Solar power can fuel the following electric products, which can be paired with your hydronic heating system:
- heat pumps
- electric heated towel rails
- electric boilers
- system pumps
Calculating your solar needs
To determine how much solar power you’ll need to run your hydronic heating system, it’s important to consider several factors including the size of the system, the efficiency of your home insulation, and the local climate conditions.
Here’s a simple guide to help you get started.
Your solar power setup and location
The electricity generated by solar panels is measured in watt-hours (Wh) or kilowatt-hours (kWh). Generally speaking, the maximum amount of electricity created by 1kW of solar panels in one hour is 1kWh.
In terms of the number of solar panels, you’ll need as many as three 350W panels to produce 1kW of energy.
According to the Department of Climate Change, Energy, the Environment and Water, the most electricity you could expect 1 kW of solar panels to generate, averaged over one year, is between 2.5 kWh and 5 kWh per day. These figures would be dependent on various factors, including weather in the location, slope and direction of the panels and other aspects such as the quality and cleanliness of the panels.
How many panels could I fit on my roof?
A 6.6kW system is quite common for an Australian home, which is around 20 panels of 350kW each and would need around 40 square meters to install. One panel is roughly 2 square meters, but it will really depend on which manufacturer and panel system you choose and it’s important to get a professional to measure and quote for your home roof space to see what is possible.
How much energy could I expect to generate in my location?
The table below outlines a typical amount of electricity generated by 1 kW of solar panels in one full day, averaged over one year. Panels will be able to generate more than these averages in summer and less in colder seasons and will be operating optimally if they’re well maintained.
Source: energy.gov.au
The size of your boiler or heat pump
Most residential boilers for hydronic heating range from 12 kW to 24 kW. To power a 12 kW boiler, you would need about 40 square metres of solar panels. This set-up will typically power up to ten standard radiators or 150 square metres of underfloor heating.
Heat pumps are generally more efficient than boilers, with a common size for residential use being 5 kW. To power a 5 kW heat pump, you would need about 17 square metres of solar panels. This can efficiently handle up to five radiators or 75 square metres of underfloor heating.
Considerations for Effective set up
Keep the following factors in mind when installing your hydronic heating and solar power systems.
Insulation
Efficient home insulation significantly reduces the amount of energy needed to heat your home, whichever system you’re using, which also reduces the size of both the hydronic heating and solar panel systems needed.
Home insulation includes:
- the insulation within your ceiling and walls – increase it if possible
- seals on doors and windows – install or replace as needed
- using door snakes to reduce drafts
- window glazing – increase to double if budget allows.
Battery storage
Adding battery storage to your solar system can help in managing energy more effectively, ensuring that excess power generated during the day is not wasted but used during evenings, colder periods, or on cloudy days.
This addition is gaining in popularity in Australia. Data from solar analytics company Sunwiz shows more than 250,000 home storage batteries have been installed around the nation and around 57,000 of them in 2023 alone. Many of these batteries were coupled with a new solar panel system but a large number were teamed with an existing panel set up.
Local climate
Australia’s diverse climate means that the solar panel output might vary significantly between regions. More panels may be required in areas with less consistent sunlight and you also need to consider shade from surrounding buildings, structures and trees that can impact energy generation.
A helpful tool: SunSPOT solar and battery calculator
Designed to help homeowners with reliable, free estimates, the SunSPOT solar and battery calculator is a not-for-profit tool that can help provide you with a guide to how much it would cost to install a solar panel system on your home. The calculator also provides a projected annual bill savings, shows the amount of emissions you could avoid and the payback period. If you like you can also add a solar battery to see how this addition would further impact the savings and the overall costs.
Visit the SunSPOT website to calculate potential savings on your energy bills.
Interested in making the switch to solar powered hydronic heating?
Solar powered hydronic heating systems are a fantastic way to enhance your home’s energy efficiency and reduce your carbon footprint. By understanding the basics of how much solar power is needed to run your system and considering factors like insulation, battery storage, and local climate, you can ensure that your heating system is both efficient and environmentally friendly.
Contact the team at Hunt Heating to discuss your home heating and cooling requirements, or visit one of our showrooms to see our products in action.
