General Solar Power FAQs

 

What is PV?  

 

PV is short for photovoltaics (photo=light, voltaics=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.

 

How long has PV been around?  

 

The photovoltaic effect was first recognized by Edmund Bacquerel, in France, in 1839. Scientists made solar cells of selenium in the 1880s. And, modern PV technologies were developed at Bell Labs and RCA Labs in the mid 1950s.

 

Will solar panels  in the Energy Matter's online store heat my hot water?  

 

No - these solar panels provide electricity. If you are interested in a Thermal Solar system to heat water, you'll need a special type of collector unit - for more information, try our solar hot water section

 

How does electricity get stored for use after sun goes down?  

 

Two options are an off-grid/RAPS (Remote Access Power System), or a grid connect system. Grid connect 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. RAPS systems store energy produced during the day in deep cycle batteries for use as required.

 

What happens with grid connect systems during a blackout?  

 

The grid connect inverter will automatically shut itself off within a few milliseconds of a blackout, to avoid the potential of a dangerous "brown-out" in your home and to prevent back feeding the grid.

 

With grid connect systems, what can I do to keep power during a blackout?  

 

You will need battery back-up.

 

Can you retro-fit battery backup into a grid connect system?  

 

Yes, battery backup systems require additional components similar to RAPS, such as, solar regulator, batteries, and inverter.

 

What sized system will I need?  

 

Any size Grid Connect solar system will make in impact on your yearly power consumption. The bigger the system, the bigger the impact. To figure out how much of an impact, please try the Energy Matter's System Builder.

 

Will I need to re-roof my house?  

 

In most situations, the PV panels can be easily removed and reinstalled, with minimal, if any, changes to your roof.

 

Building suitability for Solar System?

 

Several aspects will need to be evaluated to determine if your home is a good solar site, such as orientation, space available, shadows on the space available and your current electricity usage. The best site will be one with adequate unshaded northerly facing roofing. Variations on that will cut into the productivity of the system.

 

What is the cost of a solar power?

 

Please try the Energy Matter's System Builder. It will ask you a series of questions and then calculate a system to suit your needs.

 

Can solar panels work in the shade?

 

The output of any panel will be reduced or cut off if shaded. However, some solar panels do work better than others in the shade. If a single cell is heavily shaded, that cell is cut off.

 

All solar panels sold by Energy Matters have "bypass diodes", which send output from the remaining cells around that dead cell. However, you have lost the output of that cell, so the total panel voltage will drop by about 0.48 volts per cell. Most panels are in the 16 to 18 volt range, and most batteries need at least 13.5 volts to charge completely. So, if 2 or more cells are shaded, the output voltage of the panel may drop too low to charge the battery.

 

Uni-solar solar panels are somewhat more shade tolerant than multi-crystalline solar panels  because each cell cuts out only when totally shaded.

 

Dirt, dust, leaves, bird droppings, shadows from trees, vent pipes, etc can all cause reduced output due to shading. Wash panels down occasionally, especially if mounted flat on a roof, eg. caravan installations. A quick wash with a soapy brush or mop and then rinse. However, some tree waste may need to be cleaned off with a solvent such as turpentine.

 

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