We all do risk management intuitively – when we decide on uploading our data to the cloud where the NSA may spy on us. Or when we install heating systems that depend on electrical energy. The previous post triggered an interesting discussion about the risk of a power outage.
Is it more risky to pick a heat pump – compared to other systems?
In Austria, nearly all private homes use central heating systems and thus rely on circulation pumps – no matter if you run a natural gas boiler, a wood pellet burner, or a heat pump. Heat is distributed via hot water, powering floor loops or radiators. Heating circuits powered by gravity only are hardly installed today. So a heat pump system does not score worse in case of a power outage. It might hurt even more if you have a cellar full of wood pellets or a tank full of fuel oil – but you cannot get the fuel or the heat to the place where you need it.
You might also compare heaters of the same level of convenience – heat pumps would compete with natural gas boilers that don’t require storage facilities for fuel but access to a grid. I am concerned about gas pipelines traversing countries that make headlines periodically because of the next political gas crisis. But I am less concerned about electrical power – this is the view from our office:
In Austria the average power outage per utility customer and year is less than 1 hour. We had an outage of about half an hour every few years. There are no issues with cable nibbling squirrels, and we worry more about hackers attacking the grid than about breakdowns.
But experts in disaster management tell us that we rely too much on highly available power. This is called the Vulnerability Paradox: The more dependable a service is, the less prepared you are for outages. According to a recent study anarchy will reign a few days after a large-scale blackout in Germany: Police would not be able to refuel their cars as modern gasoline pumps don’t work without power. Sewage systems and toilets would not work.
The impact of ‘just’ not being able to heat might be less dramatic. The lowest average daily ambient temperature here, in Eastern Austrian lowlands, is -12°C. We have encountered it on 4 days in 20 years; the lowest minimum was -17,8°C. If power would be cut off for a day in winter the temperature will fall by a few degrees only. It might irk me more if our internet connection is down for this period of time.
And many Austrian home owners have a backup strategy that blends with aesthetic preferences. Artisanal tiled stoves are popular here!
Local building code demanded us to have an emergency chimney – so we installed the Free Flow Bullerjan stove shown below. I learned now from the company history that it had been invented in Vermont and built in Canada before it became a viral hit in Europe. It can heat our 110m2 open space second storey just fine:
Now why not using a traditional stove for each room as the only heating system – to be independent from the grid all the time? If nobody is at home for several days to put wood on the fire the house will cool off. This is not only a risk, but it will happen with 100% probability, e.g. if you travel for business often.
What happens if power is cut off for several days – and we are traveling? I think the probability would be lower than the likelihood of a tractor crashing into the wall of our house – which is actually a risk listed in our home insurance contract.
Heating 2003 to 2012 by fuels used and heating system (in Austria). Less than 15% of (primary) heating systems are stoves, and they have been on a decline in the last decade. (Link got broken, fixed with new link: 2015-06-04)