New Scientist magazine ran a brief report on research into energy use in houses after they were made more energy efficient. Conducted in the UK, it highlights that after insulation, double glazing and energy efficient heating is installed the amount of energy used is still close to the old levels, prior to the improvements.
The article says that some people who have made their houses more energy efficient are more likely to indulge in small excesses — turning up the heating or keeping it on for longer. Kevin Lomas of Loughborough University, UK — who was part of the research team that carried out the surveys — is quoted as saying:
’…..often they are more concerned about comfort than saving energy.’
Or, perhaps they think that because their house is more energy efficient they can indulge in being more comfortable and still save energy.
Whatever the reasons, is this the law of unintended consequences at work? Is it human nature to use as much energy as it takes to be comfortable, to the point that it hurts the wallet? Does having more energy efficient homes actually reduce energy use significantly, or does it just allow us to be more comfortable?
Certainly there have been media reports of people installing energy efficient heat pumps and then getting power bills twice what they were before. That is because they ran these things all day and all night thinking there were cheap to run. Yes, heat pumps are cheap to run, but they still cost a lot when you run them all day every day.
By way of example, one of the guys in the office was talking about how the nights are getting colder. It wasn’t cold enough for him to be bothered to light his wood burner, so he put on a jumper. Later in the night he heard the neighbours heat pump going. So, was the use of heating based on a heat pump being too easy to turn on, for instant reward?
The point is that the highly publicised and popular schemes to insulate older homes in NZ may backfire a little, in that not nearly as much energy will be saved as anticipated, or worse still even more energy is used because of an efficiency perception.
The relative merits of various energy sources to heat homes was provided graphically by Right House recently. Their business is to provide advice on energy efficient home design and performance, as well as individual products.
They show comparisons on various types of energy and their costs for NZ conditions. Interestingly enough, fire wood is the cheapest fuel per kWh of heat by far and the cheapest cost to run per year, despite it being the least efficient.
Electricity on the other hand is the third highest cost per unit, but is the most efficient at turning energy into warmth. The result is that a heat pump is also has the cheapest yearly running cost, making it the same as firewood.
Therefore the amount of energy required to heat a home comfortably is a combination of selecting the right heating method for the size and style of the house, as well as how the occupants use the house, and how ’comfortable’ they want to be.
However, a noticeable trend is the significant shift to using electricity as the energy source. In NZ it is perceived as being clean and green with our significant use of hydro and geothermal generation.
NZ is already under pressure with the need for more generation and no-one wants new wind turbines or hydro power stations in their back yard, let alone nuclear. But with the ever increasing move away from burning things to provide heat, to switching things on, the pressure to provide more generation may force our hand.
We may end up needing to burn things to allow us to switch things on. It’s all a matter or perception really.