The energy efficient home
Adding up the running costs of a house over the average term of a mortgage makes investing in energy efficiency the proverbial no-brainer.
What is your home costing you?
Earlier this month, on the wharf outside the Viaduct Events Centre, Samsung threw open the doors of its Home Smart Home (pictured above) – a re-configurable bach designed by architectural whizz-kids Jasmax, and stuffed with appliances that use just a fraction of the electricity and water that your appliances at home manage to plough though.
Electricity, gas and water bills are no longer just a minor bump in the monthly financial road. For most they now have to be seriously budgeted for.
It begs the question: when we buy a home, why don’t we measure its running costs?
The average home in New Zealand uses around 25kWh of electricity each day, equating to just under $2500 worth of power each year. Multiply that by 25 years, the term of the average mortgage: $62,500, and consider that this cost doesn’t take into account the inevitable and depressing annual price rises.
First things first. Energy efficiency is key. In a recent report from the World Future Council on how San Francisco can reach 100% renewable energy, a full 50% of the means to achieve it came down to energy efficiency. And so it is with your home.
The ‘Zero Energy Home’ in Point Chevalier, Auckland requires no gas or electricity for heating, relying solely on a concrete pad which absorbs heat when the sun is shining, and slowly releasing it again in the evening when it is required. This, combined with good insulation and smart ventilation, means that a heat source simply isn’t required.
While installing a concrete pad may not be possible unless you’re building or renovating, insulation can be installed, and draught-proofing can be carried out.
Double glazing can also be retrofitted, the advantages of which include being warmer in winter and cooler in summer, reducing condensation and cutting noise.
Insulation and heating
Before boosting your heating system, carry out energy efficiency measures and you’ll find you might need a unit with a smaller heating capacity. When you consider that (electrical) space heating makes up almost a third of the average power bill, it’s worth getting the smaller model. In descending order, choose passive solar options, wood or pellet burners, heat pumps or flued gas heaters. Avoid panel heaters, oil-filled column heaters and especially unflued gas heaters.
It’s going to cost you the guts of $7000 – $10,000 to do it right, but solar photo voltaic (PV) panels are going to cut a swath through your power bill. Wait until you’ve made your home energy efficient and re-measure your power use before choosing what size array you need. Get a slightly larger inverter than your panels need, because in future you may want to add more panels to charge your electric vehicle. Provided you choose the right-sized array for your needs, PV should pay itself off within eight years.
Another third of your energy is used for heating your hot water. Fortunately the days of the traditional hot water cylinder are drawing to a close, as they are being bullied out of existence by their radically more efficient successors.
Top of the list are heat pump water heaters, which will immediately slash your water heating bill by up to two thirds and can be installed for as little as $2500.
Solar hot water, effective and efficient while the sun is shining, is nonetheless expensive to install so has a relatively long pay-off time.
Gas hot water, whether through storage systems, or ‘on demand’ systems, come next for efficiency, but rely on fossil fuels.
Electronics take up around 18 per cent of power usage. If you have solar power, charge all your mobile devices during the day. Turn off appliances at night, as left on standby they are just wasted money. Appliances with the Blue Energy Star mark are among the top ten per cent for efficiency.
Refrigeration takes around 11% of the electricity used in your home. Over the 15-year life of a fridge, an efficient model will more than pay for itself.
Ever burnt your hand on a bulb? That’s wasted energy, converted into heat rather than light. It’s also why lighting makes up eight per cent of your energy use.
Changing your bulbs to LED models will save 80% of that energy and last for years. Over the life of the bulb, it will save around $110 dollars, dwarfing the initial investment.