Economical and efficient "Energy Positive" house built in Wales, just in time for standards to be killed by government
In 2006 the British government brought in regulations that would have meant that all new housing had to be zero carbon by 2019, generating as much energy on site as they use. One does this by reducing demand, by having tighter buildings with better insulation, while adding supply with wind, solar or green offsite power. And just in time for the unveiling of a house that meets those standards at an affordable price, the new Conservative government has gone and scrapped the standard, in what is called by some call a "short-sighted, unnecessary, retrograde and damaging to the house-building industry, which has invested heavily in delivering energy-efficient homes."
Conservatives ditch Zero Carbon standards for new homes after killing onshore wind: Cameron may as well hug a coal power station— Edward Davey (@EdwardJDavey) July 10, 2015
Which is a shame, because the Solcer House, designed by The Welsh School of Architecture's Ester Coma at Cardiff University and built for the Low Carbon Research Institute, was a prototype for a carbon positive house that could be built at an affordable price. The architect notes:
The low carbon systems have been designed to be affordable and replicable, for small to medium size enterprises, using market available technologies. This systems approach aims to use a very low amount of energy to provide a comfortable environment for building occupants.
The house has glazed photovoltaics that let light through to below, which they claim costs less than bolting solar panels on a conventional roof. I do not understand how this could work and it certainly isn't standard, but Professor Phil Jones tells the Guardian that "We save money and space by making the photovoltaic panels the roof itself and by dispensing with radiators and making the air collector part of the wall."
© graphic from the Welsh School of Architecture
The walls are a structurally insulated panel (SIP), a sandwich of OSB board and BASF foamed insulation. And there's a lot more:
The house's energy systems combine solar generation and battery storage to power both its combined heating, ventilation, hot water system and its electrical power systems which includes appliances, LED lighting and heat pump. The TSC solar air system preheats the ventilation air which is topped up from a thermal water store.
Professor Jones is not happy that the government killed the low carbon targets.
It was disappointing to see Osborne scrap the plans,” said Jones. “But the devolved Welsh, Scottish and Northern Irish governments can set their own building standards. One reason we built this house was to demonstrate to builders that you could meet the standards at an affordable price with off-the-shelf technology. The housebuilders could do it too if they wanted to.
The Guardian has put together a lovely graph showing how much power is exported in the summer and used in the cold dark months of December through February. They don't explain how the grid copes with so much supply in summer and so much demand in winter, a problem that Passive House people claim is better solved by putting more money into reducing demand than by generating local supply (See Is a net-zero energy building really the right target?).
Others think that "Buildings as Power Stations" are the future of building. Kevin Bygate of Specific, a supporter of the project notes:
Buildings that can generate, store and release their own renewable energy could be a game-changer. The SOLCER House is intentionally built with the best off-the-shelf, affordable technologies, so it proves what’s possible even now – and there’s plenty more technology in the pipeline.
But thanks to Chancellor Osborne, it's all moot now.