Photovoltaic (PV) panels
PV electricity generation is coming into its heyday in NZ. With panel prices at an all-time low, and electricity retailers currently buying power from micro generators, market conditions are favourable for solar power.
The trick with solar is to look at the payback times for your investment. It is pointless to get an enormous array, where most of the power will be exported to the grid at a low buy-back rate. The average home will get the shortest payback time with a solar array of between two and three kW.
The cost of battery storage is not financially viable yet - unless you "rent" the batteries, as with the Vector solar scheme.
Eco-friendly heating options
Pellet fires, wood burners, wood stoves, heat pumps and solar space heaters are the best heating options. If you have space, why not plant quick-growing trees for use for burning? The ancient art of coppicing stimulates quick growth of trees.
A wetback water heater is a good way to heat your hot water, but keep in mind a dual plumbing system is required and will require some modification for a retrofit. It's likely you'll only be using your fire in the evenings, so water heating then will favour an evening bath or shower.
Insulation
Keeping heat indoors during winter months is the job of insulation and double glazing. The energy savings and health benefits of insulation are well known, thanks in part to the Warm Up New Zealand government scheme, which has seen over 235,000 homes insulated since 2009.
There are a number of different materials available for insulation. Wool is becoming more popular, but fibreglass is still the undisputed king in terms of installation numbers. The fibreglass is often made from recycled glass (Pink Batts boasts 80 per cent recycled glass content). Find out the R-values of insulation suitable for your area - you may need an extra couple of centimetres of thickness in the Waikato than you do in Northland.
Glazing
Glazing has evolved to the point where there are thermal breaks between the aluminium on the inside and outside of the window frames, so heat cannot escape as effectively. High quality timber window joinery with double or triple glazing gives the best thermal efficiency.
Hot water heat pump
The most efficient hot water heaters on the market, turning each kW of electricity into 4kW of water heating. Combined with low-flow shower heads and taps, it's possible to save up to 80 per cent of your hot water heating bill (which makes up over 30 per cent of the typical power bill). Check out the Ecospring or Econergy units.
Energy efficient appliances and bulbs
A 75W incandescent (standard) bulb under average usage will cost around $22.20 per year to run, and will last perhaps one year. Compare this to the equivalent LED (13W), which will cost around $3.80 to run per year and will last for more than ten years. The purchase price of an LED is up to $25, compared to $2 for an incandescent bulb, but payback on the investment is about 18 months.
A great example is the NZ-made 9 Watt Ecobulb LED that comes in either an Edison screw or a bayonet fitting. Each of these bulbs saves up to $243 on your electricity bills over its life - up to 15 years. This is based on replacing a 75 watt incandescent bulb with a 15,000 hour average life with the 9 Watt Ecobulb LED used three hours per day costing $0.25/kWh.
The savings calculation above doesn't take into consideration that the price of electricity is going up year on year, or the costs of buying replacement bulbs.
Whiteware and appliances
When shopping for new whiteware or appliances, look for the blue Energystar label. Products with this mark are in the top 10 per cent of their category for their energy use.
Customer power
New Zealand energy companies are in an arms race to educate their customers about their power usage. Powershop is at the forefront, with customers quickly coming to grips with how the electricity wholesale market works, and buying their power at the cheapest price.
It's not everyone who wants to learn about their power usage, and cares about which company it comes from, but savings can be made by using the company's 'toolkit', which allows customers to buy 'packs' of power, some of which can be used immediately, and some in the future (such as stocking up for winter rather than being surprised by large power bills). There's also an option to buy 'Greenpacks', which offset the carbon created by the creation of the electricity.
The company launched a smartphone app last year which allows customers to keep track of their power usage while they're on the move. It also estimates what your monthly power bill will be, what you owe, how much power you have left, and your daily usage.
Every fortnight Powershop sends its customers an email alerting them to a special pack deal, which can be purchased at the touch of a button on a smartphone, and a weekly usage email which customers use to track their power usage.
Mercury Energy has introduced GEM (Good Energy Meter) for its customers, which allows them to track their energy usage right down to half hourly intervals, so it's easy to track which appliances are big users and may need to be replaced.
It shows you how customers' homes compare to similar homes in their area, and how it compares to the previous bill. If it's looking markedly higher than last month, GEM lets customers know through alerts. Customers can set a savings goal, which the GEM system tracks for progress to attaining it.
Trustpower has upped the ante a little bit, updating energy usage every 15 minutes and displaying it through its suite of online tools, which include an 'Energy Saving Tips' section, which displays where New Zealanders squander their power, and the dollar savings that can be made with relatively simple changes.
Trustpower has also recently allowed customers to pay for all household utilities on the one bill - power, broadband, phone and gas - with up to 15 per cent discount for customers who opt for the whole suite.
The Genesis Energy website also has plenty of good power saving tips, and its 200,000 installed Advance Meters send information to customers via the My Meter smartphone app. The app also allows customers to set ceilings, which alert customers when they are going to be reached, and budgets for the month.
Check out more tips:
• The Ultimate Green Home: Air
• The Ultimate Green Home: Water
• The Ultimate Green Home: Waste
Further reading: A Deeper Shade of Green, edited by Johann Bernhardt, is a seminal work in green building and living. To get a copy contact the publisher aaltobooks.co.nz or to email aaltobooks@xtra.co.nz.
If you'd like to learn how to make your building or renovation project more eco-friendly, you can book a free two-hour consultation with a specialist eco design advisor through Auckland Council. To book a meeting or to arrange a presentation at an event, call 0508 326 337 or email Eion Scott on eion.scott@aucklandcouncil.govt.nz.
