About Solar Energy
Solar/“photovoltaic” generated electricity is by now a well-known phenomenon. Nevertheless, it bears repeating that the entire world’s energy needs for one year can actually be covered by the sun generating power for only one minute! In fact, within 24 hours the sun is able to generate more energy than the entire world’s population would consume in over 10 years! So, our God-given sun is not only a truly reliable and lasting energy source but also a very cost-effective and efficient one. Such a gracious situation has led to the growth of an industry that has put a lot of effort into developing efficient techniques to generate, use, and store the sun’s energy by using different types of solar panels and storage devices, as well as converting sunlight into valuable electricity.
Main Components of a Solar Electricity Generating System
The major components of any fully-operating solar (photo-voltaic) electricity generating system include the following:
a) Solar Photovoltaic (PV) panels – solar PV panels convert sunlight into electricity.
b) Inverter – converts electricity from Direct Current (DC) – the form of electricity received from the sun or stored in the battery – into Alternating Current (AC), the form used by our various appliance.
c) Battery – stores the electricity for use for instance when there is “cloud cover”, or it is raining or when, for whatever reason, the sun is not shining (for example, during the nighttime.)
d) Solar Charge Controller – prevents batteries from being overcharged or over discharged.
Extras:
e) E.G., Remote Monitoring Devices – enables you to see the performance of your system on the internet, using your desktop, laptop, tablet, or smartwatch, and/or any internet-enabled device.
Solar Panels
The major types of solar panels are made of monocrystalline silicon or polycrystalline silicon.
Monocrystalline Solar Panels
Monocrystalline panels have a high power output, occupy less space, and last the longest. That also means they are more expensive. Another advantage to consider is that they tend to be slightly less affected by high temperatures compared to polycrystalline panels.
Polycrystalline (or Multicrystalline) Solar Panels
A major differentiating factor is that these solar panels have a blue look. They are made by melting raw silicon, which is a faster and cheaper process than that used for monocrystalline panels. This generally leads to a lower final price for polycrystalline solar panels but also lower efficiency (around 15%), lower space efficiency, and a shorter lifespan, since they (polycrystalline solar panels) are affected by hot temperatures to a greater degree than monocrystalline solar panels.
Inverters
An inverter converts electricity from Direct Current (DC), which is the form of electricity received from the sun or stored in batteries, into Alternating Current (AC), the form conventionally used. Because most appliances are not made to use DC electricity (they are made to use AC electricity) but the power received from the sun is DC, then an inverter is needed to convert the DC from solar panels to AC which is the type we mainly use. Likewise, an inverter is needed because batteries store and emit power in DC form. Therefore, since for example, the public utility provides power in AC form, then it has to be converted to DC to be stored in the battery/batteries.
Batteries
Because the sun doesn’t shine all the time (for instance, at night and particularly cloudy and/or rainy days) the electricity generated from solar panels need to be stored for eventual use. Therefore, batteries or other storage devices are needed.
Lead Acid is the oldest of modern-day batteries. However, as the name implies, they are as heavy as lead (a household system can weigh up to or even more than 500 kilograms or over 1,000 pounds!) and they take up a lot of space. In addition, lead is toxic; the technology is very old; it has to be constantly monitored and maintained, and it has other limitations, such as an approximate 50% “Depth of Discharge”. And they can only go through a limited number of charge and discharge “cycles”, when compared to, for instance, Lithium based storage devices.
Lithium-ion (i.e., lithium cobalt) is more modern and does not suffer the same limitations as lead acid batteries. They are the type of batteries found in a laptop or mobile phone. However, they are prone to overheating, and have been known to burst into flames. As a result, house-hold size Lithium-ion batteries are not allowed to be flown as air cargo, according to the International Travel Authority. Also, because of their propensity to overheat (known in industry language as “thermal runaway”), they have to be paired with complex and costly heat management systems. It is for the fore-going reasons that we are making available:
Lithium-Ferrous Phosphate (LifePO4) based batteries. This is a relatively new technology, they can go as far as a 90% “depth of discharge”, and can do up to 10,000 charge/discharge cycles over the course of the ten years that they are typically under warranty (or their minimum 15 year estimated life.) This is very useful for situations where electricity goes on and off several times. In addition, these batteries will be paired with "inverters", to convert Alternating Current (AC) power – which is the form of power supplied by the central electricity authority – into Direct Current (DC) power, which is the form in which it is received from the sun and/or stored in batteries, and back to AC, which is also the form of power used inside homes. Our batteries also typically have a “user interface”, so that you can see how much electricity you have used and how much is left in the batteries. The inverters we offer also enable you to see your home's electricity situation over the internet so you can always know how much electricity you have. No more sudden outages.
Solar Charge Controller
A solar charge controller manages the power going into the battery (or batteries) from the solar panels. It ensures that the batteries are not overcharged during the day, and that the power doesn’t run backwards to the solar panels overnight and drain the batteries. Some charge controllers are available with additional capabilities, like lighting and load control, but managing the power is its primary function.
Solar charge controllers are available in two different technologies, Pulse Width Modulation (“PWM”) and Maximum Power Point Tracking (“MPPT”). How they perform in a solar/inverter/battery system is very different from each other. An MPPT charge controller is more expensive than a PWM charge controller, but it is very much worth it.
Extras:
These include accessories such as the connectors, and we also offer monitoring devices, which enable you to see the performance of your system on the internet, using your desktop, laptop, tablet, or smartwatch.