A solar PV system will pay its own way in less than 10 years.

“Now is the best time to get a solar panel system,” says Michael O’Connell from the Alternative Technology Association (ATA), “because the rebates – if you qualify – are never going to get better.”

Until the end of June, owner-occupiers can get about $8800 back on a 1 kW solar panel system – that’s enough to generate about a quarter of the average family’s electricity needs. To qualify for the rebate, your household must earn less than $100 000 and the photovoltaics must be wired into the mains grid.

From July, the rules will change again. The government is ditching the means test, but cutting the rebate to around $6500 for a 1.5kW system, depending on the current price of Renewable Energy Certificates. Then, later this year, the Victorian government will introduce a ‘feed-in’ tariff for up to 3.2 kW systems. They’ll pay homeowners 60 cents per kilowatt-hour for any surplus energy they put into the grid.

Mr O’Connell says that while the tariff is not generous enough, buying a 1 to 2 kW system does make sense in the long term. “Under a good case scenario you can expect a payback period of around five to ten years, and the system should last about twenty years. 

You can cut costs even more by teaming up, even with a handful of people in your street. “With bulk purchasing discounts, we’ve heard of people getting panels at massive savings,” Mr O’Connell says. Ask around: enviro-groups, specialist eco-retailers and councils – especially in the inner-northern suburbs – are all organising buying groups.

Solar power will always be a big investment, so do your research. Remember that you’ll need unshaded north-facing roof space to get the best results.

The ATA recommends that you choose well-known manufacturers who offer long-term warranties (up to 25 years). Be sure to get a few on-site quotes and use accredited, experienced installers; there’s a list on the Clean Energy Council website.

Insulation is a key to reducing energy needs.

You can save up to 45 per cent on heating and cooling with roof and ceiling insulation, according to the sustainable building design guide, Your Home.

Despite that, about four in ten Australian houses still go without. Dennis D’Arcy, CEO of the Insulation Council of Australia and New Zealand, says many homeowners don’t know what they’re missing. “People just assume houses have insulation. If you’re buying an old house, you’ve got to inspect it.”

If you’re one of those four in ten, you can now get insulated for free. The Energy Efficient Homes Package – part of the government’s anti-recessionary spending – offers up to $1600 worth of materials and professional installation for houses that have no insulation. Mr D’Arcy says the money will “more than cover costs in a very high percentage of cases”.

From July, eligible owner-occupiers will get the whole shebang by calling a government hotline. If you want it before then, get insulation professionally installed, pay upfront and receive the rebate later. Renters aren’t left out either – landlords are now eligible for up to $1000 for insulation in their rental properties.

Even if you don’t qualify for the rebate, it’s worthwhile checking your ceiling’s status – the insulation is probably gappy and underdone. Insulation’s effectiveness is measured by its ‘R-value’. For Melbourne ceilings, Your Home recommends a minimum level of R 3.7. As a rough guide, Mr D’Arcy suggests between 130 and 180 millimetres of insulation, at least.

There are many different products available: batts, foil or loose-fill, made from an array of polyester, wool, glasswool, cellulose fibres and more. For DIYers, batts are best. You can buy them from hardware stores and they’re easy to manage – choose what suits on price and recycled content.

When it comes to installation, follow the instructions on the pack, and make sure you cover all the gaps right out to the edges. If you choose loose-fill insulation, you should get it professionally installed.

Heal your eco-unfriendly windows.

In a typical home, windows cause more heat gain or loss than any other part of the building fabric. “Standard windows are like a thermal wound in the building envelope,” says Gary Smith, from the Australian Window Association.

You can heal the wound, but it will take good advice and careful thought. “There are hundreds and hundreds of options,” Mr Smith says. As well as cost and style, you need to consider the best fit for the window’s orientation.

When you make your choice, be aware of both the warmth that passes through the window and the frame (conduction), and the radiant heat caused when sunlight hits the glass directly (radiation).

A window’s conduction is measured by its U-value. The lower the U-value, the better its insulating qualities, and the better for your home. For insulation, double-glazing is best – or you can improve existing panes by retrofitting with (much cheaper) secondary window systems. Remember that the frames also conduct heat; preferred options are wood, high-performance or thermally broken aluminium, fibreglass or uPVC.

In Victoria, we spend more time heating our houses than cooling them – with a bit of planning the sun can help you do it for free. Make sure north-facing windows get direct sun in winter, but are shaded during summer. For these windows, choose products with a high ‘solar heat gain coefficient’, but at the east and west cut the solar heat by installing glass or films that are tinted, reflective or coated (‘low e’ glass).

Good windows are expensive up front, but will add to resale value and more than pay back over the life of the home. For the budget-conscious, Mr Smith suggests starting with living areas. “Begin fixing the main places where you spend your time. Better windows and glasses give you a huge improvement in comfort.”

Windows might be transparent, but they’re complex. This information is only part of the story so research thoroughly, seek expert advice and shop around. The Window Energy Rating Scheme website is a good place to start.

In the first of a series on how to reduce the ecological footprint of your home, Michael Green takes a look at water tanks.

“Tanks do fill,” promises Nigel Finney from the savewater! Alliance. If you want to install one, do it before the good rain comes. “They fill in the wetter seasons,” Mr Finney says. “That’s when you can get maximum use out of them for your toilets and laundry.”

In January, the federal government introduced a rainwater tank rebate, adding to the Victorian government’s offer. Altogether, you can get up to $1500 back on your system – depending on its size and use. You get a higher rebate for bigger systems that are connected to your toilet and laundry by a licensed plumber.

A 5000 litre, plumbed tank will cost about $4000 to $5000, so even with the rebates it will set you back thousands of dollars. Mains water is very cheap, so the payback period is long.

On the plus side, a rainwater tank gives you an independent supply for your garden, so you can water your veggies even under tight restrictions. A tank also helps reduce stormwater pollution and eases pressure on dwindling dams.

What size tank is right for you? A good rule of thumb is enough capacity for four weeks’ supply. For use in the garden, laundry and toilets, that’s usually around 5000 litres – though be sure you have enough roof area to feed your tank. The savewater! Alliance website has a guide to average rainfall, roof-size and tank capacity (as well as product lists and handy advice).

“You can put a tank just about anywhere,” Mr Finney says. They come in all materials, shapes and sizes: steel, fibreglass, plastic or concrete; round, slimline or bladders; and capacities from 200 to 100 000 litres.

If you want value for money, go for plastic, round, large tanks. “The cost per litre drops off dramatically once you start getting over 2000 litres,” says Mr Finney.

Maintenance-wise, you’ll need to clean gutters and filters regularly. A ‘first flush diverter’ is useful to drain the dirty, initial water that comes from the roof during rain.