Solar Power can work well for most items except large electric appliances (water heater, clothes dryer and electric stove).

The basics of solar power:

Using solar power to produce electricity is not the same as using solar to produce heat. Solar thermal power is applied to produce hot fluids or air and photovoltaic panel is used to produce electricity.

A photovoltaic panel is made of silicon, which becomes charged electrically when subjected to sun light. The more an array is situated off of true south the less the total insulation value.

To obtain electricity, solar panels are directed at south in the northern hemisphere and north in the southern hemisphere at an angle dictated by the geographic location and latitude of where they are to be installed.

The most common output is intended for nominal 12 volts, with an effective output usually up to 17 volts.

The intensity of the Sun’s radiation changes with the hour of the day, time of the year and weather conditions.

How to Calculate Solar Power

To be able to make calculations in planning a system, the total amount of solar radiation energy is expressed in hours of full sunlight per m². or Peak Sun Hours is required. The terms, Peak Sun Hours, represents the average amount of sun available per day throughout the year is expressed in kilowatt-hour per square meter perday (kWh/m²/day).

Before establish the size of our solar system we need to set:

  • The sunlight levels (insulation values) of our area
  • The daily power consumption of our electrical loads.

Insulation, or sunlight intensity is measured in equivalent full sun hours. One hour of maximum, or 100% sunshine received by a solar panel equals one equivalent full sun hour.

For 1 day consider only six hours of equivalent full sun

(Consider reflection due to a high angle of the sun in relationship to your solar array and high angle and the amount of the earth’s atmosphere the light is passing through).

Because of these factors the most productive hours of sunlight are from 9:00 a.m. to 3:00 p.m.

The following table shows the monthly and annual Peak Sun Hours for a few locations in Australia:

MelbourneSydneyBrisbane
January6.96.76.5
February5.45.66.2
March5.25.75.7
April3.84.44.8
May2.83.64.2
June2.43.44.1
July2.73.34.2
August3.34.45.2
September4.35.26.0
October5.35.65.9
November6.16.36.0
December6.66.96.3
Annual4.65.15.4

Peak Sun Hours is one of the factors used to calculate the output of a solar array at a specific location. Note: Efficientcies of the solar panels is another important consideration.

To get a feet for the scale an installation's requirement, a typical Sydney household has an electricity usage of 5,000 kWh per year. A house with energy efficient appliances and uses non-electric cooking, heating and hot water could use as little as 1,000 kWh per year.

Solar Systems

There are two types of solar installations

  1. Stand Alone System: This system is independent of the electricity supply grid and produces energy that is stored in batteries on site.
  2. Grid Connection System: This system connects back into the local electricity grid and in able to divert excess power generated from the solar arrays back to the power companies system. This give the householder credits on their electricity bill. It should noted that only a suitable trained and qualified person may undertake AC hard wiring to an inverter and grid connections.

Components used to provide solar power

The four primary components for producing electricity using solar power are:

  1. A Solar panel
  2. A Charge regulator or Charge Controller
  3. A Battery
  4. A Inverter

Solar panels charge the battery, and the charge regulator ensures proper charging of the battery. The battery provides storage and DC Voltage to the Inverter, and the inverter converts the DC voltage to normal AC Voltage.

Solar Panels

The output of a solar panel is usually stated in watts. Wattage is determined by:

V (volt) x A (ampere) = W (watt)

So for example, a 12 Nolt, 65 watt solar panel measuring about 540 x 1210mm has a rated volatage of 17.2VDC and a rated current of 3.76A.

17.2 volts x 3.76 amps = 65 watts

If an average of 6 hours of peak sun per day is available in an area, then the above solar panel can produce an average 390 watt hours of power per day: 65W x 6 hrs = 390 walt-hours.

Accessories for Solar Systems:

There are also a number of accessories to consider when designing a solar power system - such as mounting hardware, connectors, cables, fuses, circuit breakers, etc. When selecting these components, you should seriously consider the environment where the system will be installed and select products that are designed to withstand such environmental conditions. In particular, accessories such as cables and connectors attached to solar panels need to be completely waterproof, corrosion resistant, and capable of handing high temperatures and extreme sunlight (UV radiation).

Government Rebate Scheme

The Australian Government currently provides quite substantial rebate for grid connect solar power installation. Australian Government rebates will be paid if systems are installed by accredited installers, and if the system meets particular requirement.

More information and full details can be found at:

http://www.environment.gov.au