Is Solar Heating Sustainable Energy?

What does it matter? Of course solar heating is sustainable… isn’t it? First of all, we need to understand what Sustainable Energy means. What sets sustainable energy apart from other energy sources is that it can only be naturally replenished, and it causes no harm to the environment. The endeavour is to use energy sources that allow Earth to sustain balanced, healthy ecosystems and human life. 

Sustainable energy can also be achieved through energy conservation and efficiency. The worry is that if we do not start investing in sustainable energy sources, the sources of energy most commonly used will run out. If this happens, our future generations will then be forced to do what we are already doing—finding new ways to generate energy.


The sun is one of the most important sources of renewable energy available.
Scientists and engineers have studied in depth the process of photosynthesis and have observed how plants absorb sunlight and convert it into stored energy for development and growth. Viewing this incredible process, and recognising the benefits that could be found if humans copied this, scientists and engineers have created a sustainable energy formula and can now convert sunlight into useful heat or electricity. This is otherwise known as Solar Energy.

So when it comes to using solar energy for heating, what sustainable options are available? There are two main types of solar energy heating systems: photovoltaics, and thermal systems.


What a name. As previously mentioned in our blog “WHAT DOES PV OR PHOTOVOLTAIC MEAN?”

Photovoltaic (PV) essentially means electricity from the energy of the sun and is derived from the words “photo” with the Greek meaning light and “voltaic” meaning voltage. The term “photovoltaic” is used to describe a process known as the “photovoltaic effect” the process by which a material such as silicon converts sunlight into electricity.

These systems can be built as small as to fit on a hand held device, you can have a building-integrated system with capacities from a few to several tens of kilowatts, or they can run large utility-scale power stations creating and using hundreds of megawatts. Most PV systems are grid-connected, while off-grid or stand-alone (hybrid) systems only account for a small portion of the market. PV systems are one of the most flexible systems available.

A photovoltaic (PV) solar system requires solar panels, racks for putting the panels on your roof, electrical wiring, and an inverter. These systems are silent and have no moving parts. Best of all there are no environmental emissions.

A photovoltaic system is especially valuable for remote rural applications where it would be incredibly expensive to connect electricity from the main grid.

With these systems, you can choose to be “On-Grid” or “Off-Grid”

On-grid means that you tie your solar to your local power provider’s system. Most homes will use an On-grid connection because you are then covered if your system under or over-produces energy. Being on-grid means that you don’t have the added outlay in purchasing a battery back-up system to store any excess energy which can be very expensive. An On-Grid Photovoltaic system are the simplest systems and the most cost effective to install.  These systems will pay for themselves by offsetting power bills in 3-8 yrs. These systems however do not provide power during a grid outage.

Off-grid means you are not connected in any way to an external power system or utility company. This can be appealing because you are 100% self-sustaining your energy use. If the power network goes down or, if you have chosen not to be on the grid – these systems allow you to store your solar power in batteries for use.   Off-Grid systems however require a lot more specialized equipment to function and with that comes high costs and more complexities when it comes to installation.

Thermal systems

Solar Thermal Systems seek to store heat from the sun. They differ from Photovoltaic systems. Photovoltaic systems create electricity – Thermal systems heat water. You still have solar panels installed say on a roof, or other location to absorb sunlight. There are active systems like a solar water heater and passive systems like greenhouses. They both collect solar energy on sunny days and utilize it later for warmth.

Solar heating is appropriate for nearly every household. Access to good sunlight is mandatory but in New Zealand most people have enough of it. Solar heating is clean, it can operate independently or in conjunction with traditional power sources, and it is remarkably renewable.  Besides having to manufacture the equipment needed to capture the sun’s heat, there is no environmental impact from making solar energy at your home. Heating your water with solar energy can be a rewarding venture. Solar heating is indeed sustainable energy and a great option for you to consider.