Electricity accounts for about 50 % of the energy used in Australian households, but creates around 85 % of the greenhouse gas emissions because most electricity is generated by burning non-renewable fossil fuels such as coal, oil and gas.
Renewable electricity power systems (REPS) use energy sources such as the sun, wind and water which are continuously replenished from natural sources to produce electricity with very low greenhouse gas emissions. REPS usually operate at low cost but can be expensive to install. However, Government rebates may be available to offset the initial cost of installing REPS.
There are many options for using clean renewable energy sources in the home. These range from sophisticated systems like solar and wind electricity generation, through to the simplest of technologies like the clothes line.
The Office of the Renewable Energy Regulator (go to http://ret.cleanenergyregulator.gov.au/) is a statutory authority established to oversee the implementation of the Australian Government's mandatory renewable energy target commenced on 1 April, 2001, the aim of which is to increase the production of renewable energy in Australia's electricity supply.
The most common renewable energy systems used in Australian homes are photovoltaics, wind turbines and micro hydro generators. These can be used alone or in combination.
Photovoltaic (PV) modules convert sunlight into electricity. They have no moving parts and are therefore reliable and require little maintenance. PV panels can be expected to last 20 years or more. PVs are suitable for use in urban areas as they take up little space and make no noise.
Being one of the sunniest locations on earth, Australia is an ideal place for the generation of solar power, the advantages of which include:
- Saving around $200 a year on the average household electricity bill for a well-located1kW system.
- Saving up to 1.4 tonnes of greenhouse gas a year for a 1kW system, more than what a typical car produces in 3 months.
- Householders with solar power can sell excess energy back into the grid
- Buy-back tariff, for customers who live in the EnergyAustralia network area.
- Generous Federal Government rebates of up to $8,000 for households and $12,000 for community organisations are now available for grid-connected systems.
- Providing support for the renewable energy industry.
Wind generators or turbines use the wind to turn a propeller that drives a generator as part of a stand alone power system or designed to charge a battery bank. They come in many shapes and sizes, the most common being the 'horizontal axis' turbine with blades like an aircraft propeller and a tail or vane to direct it into the wind. Wind generators are more suited to non-urban areas as the turbine needs to be mounted on a tower and makes some noise in operation.
Micro hydro generators convert the mechanical energy of flowing water into electrical energy. With a suitable water supply, micro hydro generators can produce energy more reliably than solar or wind generators. Domestic micro hydro generators are usually used in stand alone power systems and can be either a DC unit, designed to charge a battery bank or an AC unit designed to supply the household loads directly.
Most renewable systems are unable to provide electricity at all times as there may be insufficient sunlight, wind or water available. To fill the gaps, electricity can be supplied from storage batteries or generators in stand alone systems or from the electricity grid in grid connected systems with PVs as the usual energy source.
If the household uses more energy than the renewable source can supply, the shortfall is provided by the grid so power is always available. If the system is supplying more energy than is needed, the excess is fed back into the grid. Often the meter just "runs backwards" when electricity is going into the grid, so the household only pays for the difference between what is imported and what is exported. Different suppliers have different buy-back rates and metering arrangements. Grid connected systems do not have storage batteries and do not provide a guaranteed continuous power supply.
Generating electricity through burning coal is the biggest contributor to greenhouse gas pollution and consequently, global warming and climate change.
For a clean energy future, it has become imperative that we reduce our electricity use by being more efficient and wherever possible, using alternative, green, and renewable energy sources.
For more information:
Clean Energy Regulator http://ret.cleanenergyregulator.gov.au/