We are frequently asked about solar panels and the passive house model.
Although solar panels are included in many passive house projects, the fact is that they are not part of the core design elements or criteria for a passive house.
Solar panels are certainly a good companion to a passive house, but not perhaps for the reason you might think.
Passive House vs Off-Grid
Unlike home building that is focused on being ‘off the grid’, passive house design has a different agenda. Passivehouse is concerned with creating extremely low energy buildings which are inexpensive to operate. The central concern of a passive house is really just to dramatically reduce the need for external energy inputs, thereby making it cheap to run. (In real terms, a passive house will use under 15 kWh per square metre, per year.)
Most off-grid homes tend to rely on fuel (oil, gas or propane) to operate a water heater, as well as the heating and cooling system(s). Geothermal is also common, but can be expensive to implement.
The superbly low energy requirements of a passive house design make it a great candidate for an off-grid project, as the need for additional energy input – from solar panels, for example – is so low. This makes the inclusion of a solar photo-voltaic system or array (an installation of solar panels) very cost effective, as it can be considerably smaller to meet the much reduced energy demands of the passive house.
The EkoBuilt Model Home will make use of a 6kW solar array to meet its total energy needs for roughly six months/year. Watch for future posts on our own installation.
Passive House & Solar Energy
Any home designed using the passive house standard begins with the ‘site’; the home will be optimized to face south if at all possible in order to maximize solar exposure.
Preferred siting of a passive house will be due south or within 15 to 20 degrees of south. Having said that, even in a wooded area the most efficient home to build is a passive house.
Building on the principle of southern exposure, in optimal circumstances between 25 to 35% of the home’s southern wall will comprise windows. With modern window technology, passive house is the only proven style of home where windows are actually used as part of the heating system. Solar gain in winter from well positioned windows is essential, and strategic shading helps with cooling in the warm months.
This focus on making the most efficient use of the sun results in a home that is not only extremely inexpensive to run, but also superbly comfortable.
Intrigued to find out more about our own solar project? Follow the blog or give us a call, we’d be glad to tell you more.