Passive and Active Solar Gain in an Eco Home

Passive and Active Solar Gain in an Eco Home

When it comes to energy, we’re all inclined to think about those energy companies which bill us each month, but there’s only one source which gives life to all things on earth – the sun. Without it, no life could exist and today, we’re better at harvesting that energy than ever before.

From the minuscule solar panel on your calculator to innovative water purification systems for the developing world, more and more we’re learning to harvest the energy that our resident star bestows upon us.

In eco homes, the free energy of the sun is being made use of in a variety of exciting and ingenious ways, but they can all be categorised in two ways: passive solar gain and active solar gain.

In this guide, we’re going to break down the differences between the two and show how, when taken together, they can contribute to a highly efficient eco home.

Passive Solar Gain

Passive solar gain is best described as the energy your home gains through the everyday shining of the sun. Typically, this energy manifests itself as heat when the sun shines through your windows and heats your home.

Every home benefits from passive solar gain, especially during the summer months when the intensity of the sun can dramatically reduce our heating requirements.

In this sense, every home can be ‘eco’, but a dedicated eco home makes special use of passive solar heating by being designed specifically to take advantage of the energy released from the sun. This is done in a number of ways, including angling and positioning the property to ensure that it enjoys the most sun during autumn, winter and spring months.

Additionally, eco homes make use of ultra-efficient glazing, superior cladding and specialist thermal masses inside the floor and walls which absorb the heat for re-radiation during the evening. Together, these ensure that an eco-home requires significantly less additional energy to heat.

Other examples of passive solar gain are solar water heating arrays, which are placed on a roof and make use of suns rays to heat up the water required for the property.

Active Solar Gain

In constant, active solar gain makes use of the suns irradiance to convert the energy of the sun into electricity to power your home. If that sounds a lot like a solar panel to you, you’re quite correct – it’s exactly how solar panels work.

In a solar panel system, it doesn’t matter how hot the suns rays are, as long as the rays are hitting the solar panels. From there, the silicon or thin-film (highly conductive material) technology converts the radiation from the ways into electricity, which can be used to power your home and reduce (or remove entirely) your reliance on the grid for power.

Taken together with passive solar gain, an eco-home can extract huge amounts of energy at almost no ongoing cost. It’s a huge benefit of eco-homes, which help to save their owners potentially tens of thousands of pounds over the course of the lifespan, as well as dramatically reducing the carbon footprint of the home in the environment.