Frequently Asked Questions
How does solar power work?
Solar photovoltaic (PV) panels turn the sun's light into direct current electricity. Photovoltaic cells are light sensitive and produce an electrical current in the presence of sunlight. Then, an inverter converts direct current (DC) electricity to alternating current (AC) electricity. The inverters feed high-quality electrical AC power to the building’s existing electrical system, and, in most cases, the utility grid supplies the rest. A typical solar module converts 13-16% of the sun's energy into electricity.
- Photovoltaic (PV) modules generate DC power from the sun.
- Inverter – converts DC power into 240V (AC) power for use by standard appliances and grid connection.
- The building uses the solar power generated, any excess power is supplied back into the grid.
- Bi-directional meter – measures electricity produced and consumed
How much solar power is available?
In half an hour, enough of the sun's energy reaches the Earth's surface to meet the planet’s annual energy demand. A typical 5kW school installation generates 28 kilowatt-hours (kWh) of power each day - enough to power an average of two Australian homes.
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Is solar energy really environmentally safe?
Photovoltaics (PV) provide among the safest methods of known power generation. They are silent, produce no emissions, and use emission-free fuel. Solar panels make extensive use of recycled materials and use waste from the silicon industry as raw material. Over 80% of the world's solar panels are made from silicon, the second most common element on the earth's surface. Silicon is non-toxic in PV modules. A standard PV module will re-generate the energy used in its manufacturing process in less than three years.
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Can a solar PV system really produce all of the electricity my building needs?
A typical commercial/office user can put solar systems on their roof or on available land around the building. The solar systems can be placed around air conditioning or satellite units on the rooftop. There is normally just enough room to meet the building’s most expensive peak power. The solar panels need not be visible from the ground, which can – in some cases – avoid architectural design complaints.
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What happens on cloudy days? At night?
Contrary to popular belief, solar panels do produce electricity on cloudy days. While the weather (and amount of clouding) is unpredictable, the amount of solar energy that hits the earth each year varies by less than 5% from year to year. However, the amount produced is approximately 20% of the electricity produced on sunny days. Since solar systems are dependent on light (direct or indirect), the solar energy user must balance their overall energy supply with supplies from the electricity grid at night. During that time, buildings with solar panels automatically receive power from the utility company.
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Isn't solar expensive?
It can be, but Government subsidies make it much more affordable. Solar can be expensive without Government incentives due to manufacturing costs (solar panels themselves account for between 40-50% of the total cost of an installed solar energy system).
Solar does not have fuel costs, which must be incorporated into the cost of fossil fuel generation. In addition, solar energy is delivered on-site while electricity generated by fossil fuels must be transported via transmission and distribution grids. This transportation costs money, strains the transmission system and creates vulnerabilities in the security of the power supply.
On a dollar-per-kilowatt basis, solar is more expensive than other fossil fuels. However, a new era for solar power is approaching. As technologies improve and the cost of traditional energy sources rise, within three to seven years, unsubsidized solar power could cost no more to end customers than electricity generated by fossil fuels.
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Will my electricity bill go down with solar?
Yes, using solar energy during the most expensive – or peak – hours of the day can reduce your electricity bill. The amount the electricity bill goes down depends on the size of the solar energy system and the rate schedule the customer is currently on (i.e. whether it is a flat rate or a time of use rate). With solar, you use less electricity and enjoys peak demand savings. The periods of peak demand coincide with when the sun shines brightest and when the solar panels produce the most electricity.
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Doesn’t going solar involve a complicated process?
The process can be complicated if you do not know how to navigate through it. First you must determine how much solar to install, what type of panels to purchase, what dealer to buy the panels from, how to finance the purchase, how to maintain the panels and what the cash flow of savings will be. An alternative is to work with Solgen Energy, who simplifies solar and takes care of the details of purchase, financing, installation and maintenance – so customers do not have to.
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How do I know if my building is a good candidate for solar power?
The property should have clear, unobstructed access to the sun for most of the day, be north facing and be free from shade. If the location looks promising, a solar provider can trace the sun's path and determine whether the business would benefit from a solar system. All types of roofs can work, as long as they have a minimum of 10 years of additional life. The roof should be able to bear 30 extra kilograms of additional weight per square metre and have around 60 square metres of non-shaded roof space per 5 kWh.
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How long will the solar panels last?
With regular maintenance, solar panels generally last 35 years or longer. While their typical level of efficiency is 13-16%, their performance degrades at approximately 0.5% per year. Most solar manufacturers provide a 25 year warranty for their PV panels.
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Is photovoltaics (PV) a mainstream technology?
Photovoltaics began in the United States with the invention of the silicon solar cell at Bell Labs in the 1950s. Initially, they were used to power satellites and remote applications such as emergency roadside telephones and traffic sign boards. Now that more solar systems are being sold worldwide, solar is affordable for industrial and commercial use in states with solar incentives. There are currently 3,300 megawatts of solar installed worldwide – enough to power 660,000 homes. The solar industry is now almost as large as the wind industry and continues to grow at more than 25% per year. The cost of PV technology continues to come down as the industry grows, which makes solar increasingly price competitive compared to traditional electricity sources. Solar is expected to be cost effective without incentives within the next 5 years.
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Is there a difference between solar photovoltaic (PV) and solar thermal?
Yes. Photovoltaic (PV) refers to the direct conversion of sunlight to electricity through solar panels. They are made of semi-conducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. Solar thermal provides a way to generate heat using a solar collector – usually flat with a black absorption plate – to gather solar radiation that heats the water and/or air for commercial, industrial or domestic use. PV is particularly suited to Australia’s sunny dry climate as it does not depend on water to generate steam.
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What about other alternative energy sources, such as wind and fuel cells?
Solar systems produce highly predictable output, based on more than 30 years of national data. They have low operations and maintenance costs because they do not have moving parts. With solar, there are few zoning or aesthetics issues. Solar installations provide a visible, tangible environmental commitment on behalf of the company that hosts solar systems. Wind farms often have to be built far from the final user and have moving parts which require more operation and maintenance costs. To avoid vibrations and wind impediments, small wind systems have to be placed more than 300m from nearby buildings (as opposed to panels on top of buildings). Fuel cells have not been commercially available for long enough to ensure predictable production. They normally use fossil fuels, creating fuel price risk, and require space inside a building.
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What are the disadvantages of solar?
Solar is more expensive to install than fossil fuels on a dollar per kilowatt basis for now. It remains a small player in the world's energy portfolio, which keeps the costs higher than those of other energy sources. Solar energy requires customers to remain in their location for long periods of time, or else to be able to transfer the costs for the solar system to the next building owner. Even though solar is growing at more than 25% annually worldwide, at present it accounts for less than 0.01% of the world’s total energy supply.
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How do storms affect solar panels?
Most manufacturers produce corrosion resistant frames and many are designed to withstand high wind speeds and 25mm hailstones at up to 80 kms per hour. However, solar panels do not operate when they are covered with snow. Snow must be manually brushed off or melted by the sun to resume normal operations. The snow generally melts quickly when panels are exposed to sunlight. Tilted panels (v. flat roof models) can be up and running a day after being covered with snow due to their tilt angle, even in cloudy conditions.
