Solar Power FAQ

All the questions that you had about Solar power, Solar panel, PV and going off grid are answered here

How does a residential solar electric system work?
Solar cells in the modules convert sunlight directly into DC power. There is a component called an inverter converts this DC power into AC power that can be used in your home. You can choose to totally disconnect from your grid but most of the systems build are interconnected with your utility. During the day, if your solar system produces more electricity than your home is using, your local power company may allow net metering or the crediting of your utility account for the excess power generated being returned to the grid. Your local power company will provide power as usual at night and during the day when your electricity demand exceeds that produced by your solar system. There is another option in which the excess power created during the day is saved to a battery, which provide power for your critical loads in the event of a power outage or during the night

What is PV? 
PV is short for photovoltaic (photo=light, voltaic=electricity). PV is a semiconductor-based technology used to convert light energy into direct current (DC) electricity, using no moving parts, consuming no conventional fuels, and creating no pollution.

Do solar panels only work in sunny weather?  
Solar photovoltaic panels will generate electricity anywhere as long as there is daylight.  The light does not have to be direct sunlight so solar PV panels will work on shady days although their power output will be reduced.
Solar water heating panels will heat water almost every day of the year and will heat water to a significantly high temperature in direct sunlight.

Will my system work at night?
No. Sunlight must be present for your solar modules to produce power. At night, you draw power from your local power company or from the stored power in your battery.

Don't solar panels only work in hot countries?
No. Solar photovoltaic (PV) panels will generate electricity anywhere as long as there is daylight.  The light does not have to be direct sunlight so solar PV panels will work on shady days although their power output will be reduced.
Solar water heating panels will heat water almost every day of the year and will heat water to a significantly high temperature in direct sunlight.

How are solar hot water panels and photovoltaic different?
 There are two ways to harvest the sun's energy via panels - solar thermal (solar water heating systems) and photovoltaic (solar PV). 
Solar water heating uses thermal energy radiated from the sun and converts it to hot water.
Solar PV utilizes the light from the sun and converts this directly to electricity.
To say it simple - Solar panels take light from the sun and make electricity. Solar hot water systems take heat from the sun and heat water. It is easy to remember:
• Heat from the sun heats the water.
• Light from the sun turns on the lights

How does electricity get stored for use after sun goes down?
Two options are available: an off-grid or a grid connects system. Grid connects systems direct excess electricity produced during the day back into the local electricity grid. This turns your electricity meter backwards in the process. You then receive credit for any power that you put back into the grid. At night time, you automatically use electricity straight from the grid. Off grid systems store energy produced during the day in batteries for use as required.
Will I need to re-roof my house? 
In most situations, the PV panels can be easily installed, with no changes to your roof.

What can affect the amount of solar energy received?
The strength of the solar energy (radiation) available depends on the time of year, the time of day, and the latitude of the generation point. The amount of energy generated can be further affected by the amount of dust and water vapor in the air, the amount of cloud cover and any shading of the solar panels

Does roof orientation really matter?
Very much. In the northern part of the globe a southern facing system will produce much more than one facing the west or east. On the southern part of our globe a north facing system will produce more than a westerly direction

How long will my grid connect solar power system last?
Solar modules have been tested in the field showing small reductions in power output after 20 years, mostly because the glass surface becomes a bit dull and reflects more light. There are solar panels delivering power today that were installed more that 30 years ago.  The electronic components such as inverters, being the most sensitive, will last 10 -15 years

How much of a reduction in carbon dioxide emissions will I achieve?
Using a comparison to a car, if an average vehicle travels 20 000 km (12,500 miles) per annum, which is equivalent to 3.3 tons of carbon dioxide discharge annually. A 2kw grid connected system will prevent 3.3 tons of carbon dioxide being generated through coal fired power generation - so it's the equivalent of taking a car off the road each year.

Is there any maintenance involved?
With a grid connected system, there is very little maintenance required. Electronic components should be maintenance free.

How does a hybrid wind-solar system work?
Hybrid wind-solar systems utilize both a wind turbine and one or more solar panels to generate renewable energy for your home. The wind turbine harnesses the wind's kinetic energy. Should the wind speed drop below the "cut in" speed (7 mph in most cases) the solar panels will be there, converting sunlight into usable electricity. As the two systems complement each other, a hybrid wind-solar system works well for most locations.

What happens during a power outage?
There are two types of solar residential systems. One type of system powers your home during daylight hours, but does not provide power in an outage, even on a sunny day. Another type of system powers your home during daylight hours, but also has a battery designed to store excess energy and provide power to your home’s critical loads during an outage, day or night.

How do I know if a residential solar electric system would work on my home?
Solar electric power works for most homes and locations. Most of the systems are engineered to work with most roofing materials, in most locations where direct sunlight is available. You need a sunny place on your roof about 120 square feet or 11 square meters for small systems, and up to 1,000 square feet (93 square meters) for very large systems. Shading from trees or other obstructions can reduce the practicality of a specific installation.

What if I need a new roof or am building a new house?
This is the ideal situation for installing solar. Before laying the roof, you can install mounting brackets that will be the basis for mounting the panels on your roof.
How many solar panels do I need to produce enough electricity for my home?
To approximate the array size you need, multiply your average daily electrical demand in kilowatt-hours by 0.25. The result is the approximate size of solar array, in kilowatts, needed to meet your electrical demand.

Will a system produce enough energy to cover all my electricity needs?
Usually solar electric system does not need to provide all of the electricity you need to be of great value. A small system that displaces an average of one-quarter to one-half of your average demand reduces your electric bill. With battery backup, it can deliver uninterrupted power to critical loads during utility outages for days or weeks.

What other options do I have if the system cannot be mounted on my roof?
If a roof-mounted system proves impractical, a ground-mount application may be an option.

Are government incentives available to reduce the price?
Yes. Many countries and states offer rebate and incentive programs for homeowners and small businesses to promote the installation of renewable energy equipment such as ours. You can contact your department of energy at your country or state for more information.

How can I tell how my system is performing?
One of the most important components is a power meter. Located in your home, your power meter tells you exactly how much electricity you generate and use, and when you send power back to the utility grid. You will be able to manage your household usage like never before.

Can I have solar electric system at home and still be connected to city power?
Yes. In fact, many people that built such a system usually build an on-grid system, meaning they are designed to interconnect with utility power.
Can I be totally independent from the utility?
Yes. You can build a system that will provide all your needs and disconnect from the local utility company.

Want to know more? Take a look at Home Solar power page

You have more unanswered questions? check our other FAQ pages