Renewable energy and alternate energy sources

 

Renewable energy is sustainable as it is obtained from sources that are inexhaustible (unlike fossil fuels). Renewable energy sources include wind, solar, biomass, geothermal and hydro, all of which occur naturally.

 

Learn more about Energy Matters

 

Renewable energy, generally speaking, is clean energy and non-polluting.  Many forms do not emit any greenhouse gases or toxic waste in the process of producing electricity. It is a sustainable energy source that  can be relied on for the long-term. Renewable energy is cost-effective and efficient.

 

Enhanced Renewable Energy Target (eRET)

 

Increasingly, governments around the world are turning to renewable energy to end our dependence on fossil fuels. 

 

In 2001, the Australian Government introduced a Mandatory Renewable Energy Target (MRET) program with the goal of increasing uptake of renewable energy in Australia's electricity supply. In 2007, the Government committed to ensuring that 20 per cent of Australia's electricity supply comes from renewable energy sources by 2020. 

 

In December 2008, the Australian Government and the Council of Australian Governments (COAG) released for public consultation draft legislation for an expanded  Renewable Energy Target (RET) that will bring the MRET and existing and proposed state and territory targets into a single national RET scheme. 

 

In February 2010, the Rudd Government announced proposed that from 1 January 2011, the RET will include two parts - the Small-scale Renewable Energy Scheme (SRES) and the Large-scale Renewable Energy Target (LRET).

 

The SRES applies to small-scale technologies such as residential solar power and solar hot water systems and is supported by the Renewable Energy Certificate (REC) system. The SRES is currently uncapped.

 

The LRET covers large-scale renewable energy projects such as wind and solar farms and includes a target of 41,000 gigawatt-hours of renewables-based generation in that year.

 

After last minute amendments, legislation for the enhanced Renewable Energy Target (eRET), was passed on June 24, 2010.

 

Homes, businesses, community groups and schools are being encouraged to install solar power through various incentives such as grants, rebates and feed in tariffs that pay system owners for the electricity they produce.

 

Benefits of the Renewable Energy Target

 

The benefits of the RET aside from cleaning up Australia's energy mix are many - including jobs and billions of dollars of investment. Further information of the benefits of the scheme can be viewed here.

 

Cost of the Renewable Energy Target

 

The cost of the RET overall is estimated at approximately 3.5c to 5c per kilowatt hour. However, the Small-scale Renewable Energy Scheme (SRES), a component of the RET will have zero net cost impact on household power bills by 2015/16.

 

 Alternatives to fossil fuel and system components

 

 

Solar power

 

Solar power is clean green electricity that is created from sunlight, or heat from the sun. Installing solar power systems in a residential setting generally means setting up a solar photovoltaic or a solar thermal system on the roof.

  

Definition of photovoltaic: Photo = “light” and photons = energy particles coming from sunlight; voltaic = producing a voltage or volts.  Abbreviation = PV

 

Solar energy is a renewable free source of energy that is sustainable and totally inexhaustible, unlike fossil fuels that are finite. It is also a non-polluting source of energy and it does not emit any greenhouse gases when producing electricity. 

 

Solar electricity can supplement your entire or partial energy consumption. Using solar power means reducing your energy bills and saving money.  Low maintenance and unobtrusive, installing solar panels adds value to your home.

 

... more solar energy information

 

Wind power

 

Wind power involves converting wind energy into electricity by using wind turbines. Wind comes from atmospheric changes; changes in temperature and pressure makes the air move around the surface of the earth. A wind turbine captures the wind to produce energy. 

 

Wind power is a clean energy source that can be relied on for the long-term future. A wind turbine creates reliable, cost-effective, pollution free energy. It is affordable, clean and sustainable. One wind turbine can be sufficient to generate enough electrical energy for a household, assuming the location is suitable.

 

Because it is a renewable resource which is non-polluting and renewable, wind turbines create power without using fossil fuels, without producing greenhouse gases or radioactive or toxic waste. Wind power is one of the best ways to combat global warming.

 

... more wind power information

 

Micro hydro systems

 

Micro hydro systems convert the flow of water into electrical energy. A turbine can be fully immersed in water. The flowing water rotates the turbine's blades. The amount of energy created depends on the amount of water flowing on the turbine as well as the size of the turbine. 

 

Micro hydro systems are generally used as stand alone power systems which are not connected to the grid. They are recommended in remote areas where there is a continuous supply of water.

 

Approximately 10% of Australia's energy comes from this source. Australia's biggest hydro system is in the Snowy Mountains. It is a cheap, reliable and non-polluting source of energy.

 

... more water energy information

 

Hybrid systems

 

Hybrid systems consist of combining different types of energy production systems into a single power supply system. The most common type of hybrid system is combining a solar system with a wind generator; however, hybrid energy systems can integrate solar panels, diesel generator, batteries, and an inverter into the same system. 

 

Solar panels create electricity from sunlight. This electricity is then stored in batteries. The inverter converts the AC electricity into a DC current. The diesel generator automatically cuts in when the batteries are low. The generator when running supplies the load and charges the batteries. The key is to find the right mix of solar array, diesel generator and battery capacity.

 

Green power

 

Switching to green power means that electricity providers make it possible for customers to purchase green power from their power company if they pay extra for it. In theory, what this means is that instead of using normal electricity which comes from many non-renewable sources, the provider of the electricity ensures that the equivalent electricity used in your home is fed to the grid via a renewable source, such as solar arrays or wind turbines. However, in the past there has been instances of fraud involved in such schemes.

 

Fuel cells

 

Fuel cells create energy through chemical reactions. A fuel cell is an electrochemical cell which captures the electrical energy of a chemical reaction between fuels. It is an electrochemical conversion device which converts the chemical energy of fuel (i.e. hydrogen and oxygen) into water; and which produces electricity and hot air in the same process. Fuel cells have no moving parts and do not involve combustion or noise pollution.

 

A fuel cell is similar to a battery but does not need to be recharged; a battery gets recharged by using electricity which is then stored in a closed system, whereas a fuel cell uses an external supply of fuel which needs to be continuously replenished. Fuel cells are not commercially available yet, and remain very expensive. They are used as power sources in remote areas. NASA uses fuel cells on space shuttles; they are also used for military applications, and in large public parks.

 

Fuel cells cannot store energy like batteries. Even if the energy delivered from fuel cells is stored, their electrical efficiency is not nearly as high as a battery's efficiency which also happens to be a much cheaper option.

 

... more fuel cell information

 

Nuclear energy

 

Nuclear energy cannot really be termed renewable, since there is only a finite amount of uranium on this planet. Nuclear reactors also produce a by-product other than the power they generate: toxic harmful waste that must be stored indefinitely.

 

Nuclear energy is produced by a nuclear reaction when the splitting or fusion of atoms occurs. Fusion energy is not available on an industrial scale yet. The splitting of atoms is called fission. A typical example of fission energy is when an atomic nucleus of a high mass atom (such as uranium) splits into fragments inside a nuclear power reactor, which then releases several hundred million electron volts of energy. The energy produced by the nuclear fission yields an amount of energy which is a million times greater than what is obtained through a chemical reaction.

 

Nuclear reactors emit no greenhouse gases, and are the closest thing to a non polluting energy source apart from renewable energy. Modern reactors are safer, and are more economic than what they used to be. The main issues with nuclear energy are the safety standards of a nuclear power plant and the storage of its radioactive waste. It is still a debated issue about whether or not nuclear power is a good alternative to limit our dependence on imported oil. France is the world leader in nuclear energy production, relying on nuclear power for 80% of its electricity.

 

... more nuclear power information

 

Renewable energy system components

 

While renewable energy is plentiful, most of the environmental impact is related to the production of equipment to harness the energy. Even so the energy payback time, that is the amount of time it takes to repay the energy and resources gone into creating something such as a solar panel, is quite short. 

 

In the case of a solar panel, the energy payback time is around 1.5 years. Given a solar panel has a life of 25 years, this is quite economical ecologically speaking.

 

The following are descriptions of common components used in solar power systems. 

 

Solar panels

 

Solar panels, also known as photovoltaic modules, consist of a series of solar cells that convert light from the sun into DC electricity.

 

A solar panel is a rugged piece of equipment, built to last decades of exposure to harsh climate conditions - from freezing to searing temperatures, storms and high wind. 

 

... more about how a solar panel is made

 

Solar hot water

 

30% of total greenhouse gases households produce is due to water heating. Solar water heaters can dramatically reduce energy bills without any environmental impacts. Installing solar hot water also reduces our dependency on fossil fuels. The technology for solar water heaters is entirely different to a photovoltaic grid connect system. For example, solar heaters use a flat plate with collector panels or evacuated tubes to absorb the heat from sunlight and then raise the temperature of the water.

 

... more solar hot water information

 

Solar pumping

 

Widely used on farms and outback stations in Australia to supply bore water to livestock, solar powered water bore pumps provide an ideal water delivery solution in areas where mains electricity is not easily accessed.

 

... more solar pumping information


 

Batteries

 

Batteries are devices that convert chemical energy into electrical energy. Batteries are classified according to their application and the way they are constructed. The main applications are in cars, boats and deep-cycle. Deep cycle batteries can be charged and discharged repetitively. Deep cycle batteries are used in solar PV systems. 

 

The construction type of a battery are flooded (wet), gelled and AGM (dry). Dry or wet / flooded refers to whether or not the electrolyte is liquid. A dry cell means that the electrolyte is a solid powder electrolyte; a wet cell means that the electrolyte is liquid and is allowed to flow freely in within the cell casing. Dry cell batteries are used in flashlights, toys, radios, laptops and mobile phones.

 

Batteries are usually used in stand alone power systems - such as a rooftop solar power system or wind turbine system – however, stand alone power systems can be designed to run without battery backup. In a stand alone power system, the house in question is not connected to the electricity grid (the distribution of electricity through high-tension cables).  It is "off" grid. This means that the stand alone power system is the sole source of energy available to the home. In a stand alone solar power system, the energy created during the day is stored in a battery bank for use at night. Sometimes batteries are used in grid connect systems as a backup.

 

... more battery information

 

Power and solar inverters

 

A solar inverter is a device used to transform direct current electricity (DC) from solar panels (AC).  A power inverter does the same, but the source is a battery.

 

AC current is the standard current that makes all household appliances work. The inverter converts the DC power of the battery bank into 240 volts, 50 Hz AC. There are two types of inverters: the Sine Wave Inverter and the Modified Sine Wave Inverter. A Modified Sine Wave Inverter can adequately power some household appliances and power tools. It is cheaper, but presents certain compromises with some loads such as computers, microwave ovens, laser printers, clocks and cordless tool chargers. 

 

Virtually all low-cost inverters are "Modified Sine Wave". They are usually about 70% efficient, so expect some significant power losses if you are using a Modified Sine Wave Inverter in your system. A Sine Wave Inverter is designed to replicate and even improve the quality of electricity supplied by utility companies. To operate higher-end electronic equipment, a sine wave inverter is recommended. 

 

Efficiency has reached up to about 94% and the electricity from these devices is of a higher quality than grid power almost anywhere in the world. A high quality inverter usually has an auto-start system, tweaking ability and a high quality heavy-duty power transformer.

 

... more power inverter information

 

Solar regulators/ controllers

 

A regulator is an electronic device which controls the voltage of the charging source. Regulators are used to stop the batteries from being overcharged. When the batteries are fully charged, the regulator halts the flow of power from the solar panels to the batteries. Additionally, a regulator stops any power flow from the batteries at night. The controller is also used so that the batteries get charged at the correct voltage. In order to calculate the Amp rating of a controller you must follow this simple equation: 

 

Amps x Volts = Watts. 

 

So, if you have a 175W panel at 24 volts the following calculation should be made Amps x 175 = 24, then the regulator should be at 175/ 24= 7.3 Amps.

 

... more regulator information

 

Generators

 

Though not a renewable energy product, generators are used extensively in renewable energy system. They are primarily used as a source of backup electricity. Generators are a petrol or diesel motor. It is basically a machine that converts mechanical energy into electrical energy. A generator can create a supply of 240 volts AC and can be used for charging DC batteries. 

 

A generator is used in a backup situation when required. A generator is hooked to a battery charger which recharges batteries when they are running low otherwise damage can occur if the battery discharge is too high. Generators can be automatically started when the batteries reach a certain state of charge ("SOC").

 

... view our range of petrol/diesel generators

 

Battery chargers

 

Battery chargers are used in conjunction with the generator or main power to provide DC power to recharge batteries. There are many types of battery chargers, including solar chargers, and they primarily vary in the amount of time they take to charge batteries and how they take care of the batteries while charging them.

 

... more battery charger information