We presented with Al Cobb, founder of Panelwrights LLC and SIP School, at the American Solar Energy Society’s annual conference, in Baltimore, called ‘Solar 2013’.  The title of the presentation, Q&A, was:

Passive House Power: net PLUS Now

The focus of this presentation, which was included in the Passive Solar Design sessions, was:

Leveraging comparatively less-expensive assemblies, components, mechanical & operational systems, optimized by active monitoring, to employ renewable energy generation most cost-effectively for achieving ‘net PLUS Energy’ performance.

The common energy-rating HERS Scale was used for comparative analysis of numerous popular ‘Green’ or ‘Energy Conservation’ building programs.  Then this common scale was turned on its ear, to graphically demonstrate the bridge which needs crossing to reach ‘net Zero’ and ‘net PLUS’ energy performance.

Energy ‘performance’ measurement is a growing frontier of high-performance building. We presented a definition of energy ‘performance’ to include:

• actual measured & actively monitored site energy consumption & generation
• informed, elective self-modification of occupant behaviours
• intelligent response, adaptation and adjustment of building systems based on lessons learned

Energy consumption was then examined, utilizing energy modeling of low-load homes. Energy and cost were compared for space heating, space cooling, domestic hot water production, whole-house ventilation, lights & appliances.

Site renewable energy generation was quantified for a sample home built to a Passive House level of energy conservation, utilizing both solar thermal and solar PV.

The challenges to constructing buildings to a ‘net PLUS’ energy performance level were discussed, including “R Values” for building enclosure components, air tightness, as well as durability concerns.  Although strong focus is rightly placed on insulation and air tightness, these ‘high performance’ buildings feature ‘low-energy’ enclosure assemblies which are less-forgiving of designer or builder error.