Solar and other renewable energy supply options have the capability to supply a large proportion of our energy requirements. The increased use of renewable energy technologies will reduce pollutants and greenhouse gas emissions as the energy is derived from the natural sources of sun, wind, water and biomass. Renewable energy technologies already exist in a wide range of forms suitable for satisfying energy demands for many end uses. However, the implementation of these technologies is hampered by myths and misinterpretations.

This brochure has been published by the Australian and New Zealand Solar Energy Society to clarify the issues and to dispel some more commonly held misconceptions...

• Solar energy can only heat water
• Solar energy can't be used at night
• Solar energy is too expensive
• Current solar devices aren't effective; a breakthrough is needed
• There isn't enough solar energy to maintain our current lifestyle
• Solar doesn't yet supply much energy on a national or global scale
• More energy is used to manufacture a piece of solar equipment than is saved in its lifetime

Solar energy can only heat water

Reality

Solar (renewable) energy includes the production of electricity and heat directly from solar radiation for many applications. It also includes the utilization of indirect forms of solar energy like the power of the wind and water and all forms of energy from biomass (plant and animal material).

• Designing your house to use solar energy passively can provide 60%-100% of your heating and cooling requirements
• Photovoltaic (solar cells), wind generators and hydro can supply electricity for any use. Biomass fuels include wood, alcohol, and methane for heating, electricity generation or transportation

Solar energy can't be used at night

Reality

Solar heat can be stored in thermal mass or thermo chemical reactions so it is available on demand at any time.

• In a solar efficient designed house, the building elements themselves store the energy in their thermal mass for night-time comfort and for cloudy days
• Electricity from photovoltaic can be stored in batteries
• Wind generators run day and night
• Hydro power, derived from the solar evaporation of the oceans, can be used at any time, with water storage buffering the effect of river flow variations
• Solid fuel crops, biogas, (methane) and alcohol fuels can be stored and used when needed

Solar energy is too expensive

Reality

Some solar technologies require no additional costs, eg: Houses designed to make use of natural energy flows employ "design" not "devices" or additional equipment. Also, some solar equipment costs less than conventional alternatives to buy and install and also has lower running costs, eg...

• Solar pool heaters compared with gas heaters
• Solar clothes lines compared with electric driers
• Photovoltaic panels for lighting or power supplies in areas too costly to connect to power from the grid
• Some solar equipment costs more up front but is cheaper overall due to lower running and environmental costs. eg...
  
  
  • Water heaters for domestic, commercial and industrial purposes
  • Wind turbines for electricity generation and pumping
• Also, many costings are distorted to solar's disadvantage, eg...
  
  
  • Solar water heaters would be even more attractive if you could get the same loan terms that the utility gets to build a power station. Remember, consumers don't have to pay for the power station when they buy their electric water heater

Current solar devices aren't effective; a breakthrough is needed

Reality

While researchers continue to produce further improvement in a wide range of renewable energy technologies, the big breakthrough needed is equality of financing terms with conventional energy. eg...

• Australia leads the way in solar pool heating
• There is a wide range of Australian and New Zealand solar water heaters which are amongst the best in the world
• Wind generators are operating commercially world-wide
• Photovoltaic have steadily improved in performance and cost to where they are now cost effective in many applications

There isn't enough solar energy to maintain our current lifestyle

Reality

• There are 25 times the yearly energy needs of Australia and New Zealand falling on those land areas on an average day
• The southern coastline of Australia and New Zealand is in the "Roaring Forties", one of the best wind regimes in the world
• Biomass resources (vegetable matter including waste and specifically grown energy crops) could sustain ably supply all of Australia and New Zealand's liquid fuels without interfering with food and fiber production from arable land

Solar doesn't yet supply much energy on a national or global scale

Reality

• Energy statistics tend to be biased; eg, they include energy used in drying food by oil fired drier, but ignore energy used in drying food in the sun
• Even ignoring the bias in the statistics, solar (renewable) energy supplies 20% of the world's energy now - made up of 14.4% biomass and 5.7% hydro. In comparison, nuclear supplies 4.4%
• In California, 'windmills' generate electricity to a peak of 1700MW, and solar thermal power stations provide over 350MW of generating capacity. (By comparison, the latest power station in Victoria's Latrobe Valley can generate 1900MW while Darwin's power station is 300MW, more than enough for that entire city.)
• Solar supplies all the energy used to grow plants, to evaporate water for rain and to maintain the temperature of the planet, all necessary for human life
• Hydro and geothermal power stations already supply 25% of Australia and New Zealand's electricity needs

More energy is used to manufacture a piece of solar equipment than is saved in its lifetime

Reality

• A solar water heater will repay its energy "debt" in only 6 to 18 months, depending on the location, and will last well in excess of 15 years
• A photovoltaic module will collect over its operating life four times the energy used in its production
• A wind generator will produce the energy used in its manufacture in 1 to 4 years, depending on the wind regime