Wind Power

Wind energy is a form of indirect solar power. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth’s surface, and rotation of the earth. As a result, winds are strongly influenced and modified by the earth’s terrain, bodies of water, vegetation and other factors. Humans use this wind flow for many purposes: sailing, flying a kite, and even generating electricity.

How it Operates

A wind turbine operates in the opposite way to a fan. The wind turns the blades, which then spins a shaft that is connected to a generator. Wind turbines convert the kinetic energy in wind into electricity.

A large wind turbo generator can be more than 110 metres tall with blades spanning 130 metres and needs a minimum average wind speed of about 25 km/h.

Location Needs

Sites cannot contain any tall plants and are often placed on outstanding hills and headlands or in coastal areas.

A large wind farm may consist of several dozen to about 100 individual wind turbines, and cover an area of hundreds of square kilometers. The land between the turbines may be used for agricultural or other purposes. A wind farm may be located off-shore to take advantage of strong winds blowing over the surface of an ocean or lake.

Costs

The cost for a wind turbine really depends on 5 factors; location, how big you want it, how much money you have, how much electricity you want to produce and if you require a VAWT (vertical axis wind turbine) or a HAWT(horizontal axis wind turbine). The average cost for a wind turbine is approximately AU$1050 per Kilowatt. Also, big wind farms could be placed on someones land, so the owners of the land would be payed a fee for the use of their land.

Biomass

Biomass is the name given to any material which is recently derived from plants that use sunlight to grow. It is the mass of biological matter on earth. Biomass is sometimes classified as “combustible renewable and waste”.

Converting biomass energy into usable energy has many environmental benefits. It uses waste products which are usually disposed of, and it also uses up methane (a greenhouse gas). Methane has higher energy levels than any other source of biomass energy.

Fuels like Ethanol can be produced from biomass and used as an alternative to petrol in cars.

How it Operates

Biomass can be converted to energy in 2 ways; directly by creating electricity, normally done by burning the biomass (e.g. wood or waste products) in steam generators or indirectly by converting it to a liquid or gas fuel.

Main Sources of Biomass

• Wood from natural forests and woodlands
• Forestry plantations
• Forestry residues
• Agricultural residues such as straw, bagasse (crushed sugar cane), animal slurries and green agricultural wastes
• Livestock residues
• Black liquor from paper manufacturing
• Sugar and grain grown to make alcohol for use as a fuel
• Grains and oil seeds grown for production of biodiesel
• Sewage wastes

Type of biomass	Energy available (megajoules per kilogram)
green wood	8
oven dry plant matter	20
methane gas	55

Figure 1: Sludge digesters at Woodmans Point sewage treatment plant, Western Australia.

Location Needs

A biomass plant needs about 20 acres of land. But most plants are just added on to a sewage treatment plant.

Costs

The cost for a high-tec biomass plant in India is approximately $11,150,000 AUD. Another “cost” for a biomass plant is getting enough of the needed resources to run it.

Hydropower

Hydropower is currently the most used renewable energy source to generate electric power. Hydropower is clean. It prevents the burning of 120 million tons of coal each year. Like other energy sources, the use of water for generation has limitations, including environmental impacts caused by damming rivers and streams, which affects the habitats of the local plant, fish, and animal life.

How it Operates

A power source (falling water) turns a propeller-like object called a turbine, which then turns a metal shaft in a generator, which is the motor that creates electricity. Power lines which are connected to the generator carry electricity to lots of homes. The water continues past the propeller through the tailrace into the river past the dam.

Location Needs

The water used by hydro plants can be flowing in natural streams or rivers, or contained in man-made facilities such as reservoirs, pipelines, or canals. A good source for hydroelectric energy is a dam that is tall and has a high amount of water flowing through the river.

Costs

For a very powerful new hydro plant that can power 115,000 homes the price can be up to $250 million. The cost to produce power at a hydro plant will vary depending on the size of the plant. In general, the larger the hydroelectric plant, the cheaper the cost per kilowatt to produce the electricity.

Wind Power

Advantages

In some places they are a tourist attraction. Wind turbines don’t produce any Co2 emissions. They create reduced pollution; the only pollution they produce is during the manufacturing process and by the heavy machinery used to erect them. There are no external costs such as environmental degradation involved with wind power.

Disadvantages

Wind turbines are known to make a low-frequency sound that humans cannot hear, but can rattle windows. They can even cause disturbance with TV and radio signals in nearby homes. Turbines can be a danger to migrating birds flying at night, but this is a low percentage compared to the amount of birds flying into high buildings and into cars and trucks. The major challenge to using wind as a source of power is that the wind is intermittent and it does not always blow when electricity is needed. Wind energy cannot be stored (unless batteries are used). Many people see large wind turbines as unsightly structures and not pleasant or interesting to look at. Good locations are often positioned in remote places, far from cities where the electricity is needed. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity.

Biomass

Advantages

Biomass is a theoretically inexhaustible fuel source. When direct combustion of biomass is not used to generate energy there is minimal environmental impact. It is available all over the world. Biomass is also very easy to convert to a high energy fuel. It is cheap compared to other fuel sources. The production of biomass can often result to the restoration of waste land.

Disadvantages

The crops used as fuel for biomass plants are not available all year. There is a little loss of energy because energy is used to grow this plant mass. It can contribute a great deal to global warming and pollution if it is directly burned. Biomass energy depends largely on grown crops. These crops will take up huge tracts of land if biofuels are to replace fossil fuels to a significant extent. The land that may be used for biomass crops would have to be cleared first.

Hydropower

Advantages

Hydropower is fuelled by water, so it’s a clean fuel source. It doesn’t pollute the air like power plants that burn fossil fuels. Hydropower is generally available as needed because Engineers can control the flow of water through the turbines to produce electricity on demand. When dams are made they are designed to last many years, so they can produce energy for decades. The lake that forms behind a dam can be used for recreation, fishing and irrigation purposes. Often, large dams become tourist attractions. They do not pollute the atmosphere.

Disadvantages

Dams must be built to a very high standard, which can sometimes be very expensive. Fish populations can be impacted if they cannot migrate upstream past the dams to spawning grounds or if they can’t migrate downstream to the ocean. But sometimes there are solutions for these problems like fish ladders or elevators. Hydropower plants can cause low dissolved oxygen levels in the water, a problem that is harmful to riverbank habitats. This problem can be fixed by certain aeration techniques, which oxygenate the water. Hydropower plants can be impacted by drought. When water is not available, the hydropower plants can’t produce electricity.

Biomass

I have chosen biomass as the best suited alternate method of electricity generation for the Wide Bay region.

This source of energy, I believe is the best suited for the Wide Bay area because we have a lot of sugar cane, which can be used to produce energy. Sugar cane bagasse is one of the best biomass energy fuels. An example of the use of bagasse as a fuel is in the Maryborough Sugar Factory where they use the bagasse produced, as a fuel for the mills boilers. In the Wide Bay we also have pineapple growers. We can use the waste from the pineapples for energy. We also have quite a few pine plantations, which we can use the scraps of the trees for biomass. There is also a lot of waste that is created from trees when we clear properties; land used for residential blocks and powerlines paths. The main producer of biomass energy is methane; we have several sewage treatment plants in the Wide Bay area, which can be used for capture of methane. These are the reasons why I believe there is so much potential for biomass to power the Wide Bay Region.