HOW DO THESE SYSTEMS WORK

Solar Systems

Perhaps even before French physicist Edmond Becquerel discovered the photovoltaic effect with the first solar cell in 1839, the human race was on to attempted to harness the power of the sun. Many built upon and improved solar technologies from then, so now individuals can have solar power systems that are reliable, efficient, cost-effective and environmentally friendly.

Gerelec Projects designs and installs solar power plants all over Gauteng, allowing our customers to turn sunshine into usable electricity. Here’s a basic overview on how solar electric (photovoltaic) power technology works for both homes and businesses:

The Sun is an abundant energy source that showers the Earth with an immense amount of solar radiation every day. When the photons in sunshine hit crystalline photovoltaic cells (as part of a solar panel), DC electricity is generated.
This DC electricity can be inverted to household AC power (usually operating in parallel with utility power, being grid- interconnected or “grid-tied”) so a building’s power needs are always met and completely seamless between the solar and utility, day or night.
As a home or business will use an average number of kilowatt-hours per day, installing enough solar panels to harvest this same average amount will make the building net-zero. This is an ideal goal where you have all the reliability of being connected to a grid while offsetting your entire energy usage.

A typical grid-interconnected PV system is quite cost-effective because no energy storage (batteries) is needed, significantly reducing equipment and labor costs. Solar panels produce electric power but do not store electrical energy like a battery. Without energy storage, a grid-interconnected system will automatically shut down in the event of a grid-down situation. This is to ensure the grid is not back-fed with electricity, which can endanger utility workers making repairs. Although not as popular as grid-interconnected, battery back-up systems (off-grid or with grid-interconnect) are available to ensure continuous power regardless of availability of utility power, but they come with a significantly higher investment.

HOW DOES BACK-UP POWER WORK

The unit is permanently connected to Eskom power supply so that while mains is present the extra large 4 stage built-in battery charger recharges the batteries and keeps the batteries fully charged until a power failure occurs. The equipment you want to back up is also permanently connected via the system. In case of a power failure the backup system automatically switches over, via an extra fast transfer switch to the inverter, which will continue to provide power to the equipment within 15 msec. This is extremely fast and standard equipment like TVs, DSTV decoders, microwaves, fans, etc. are unaffected. The sinewave systems can also backup computers but it is possible that a very small percentage of computers could reset during the switchover time.

When Eskom power returns, the whole procedure is reversed and the unit will switch back to utility power and will automatically start re-charging the batteries. Your equipment remains connected to the system even when power is restored. The whole process is fully automatic.

HOW LONG WILL THE INVERTER SYSTEM RUN WHEN THERE IS A POWER FAILURE

The amount of backup time is determined by the size of the connected battery bank and the load drawn from the system. The backup time is normally calculated at full load (i.e. if the system is a 3000VA system, full load is 3000VA. If you remove some of the load, then the backup time will extended relative to the power used. For example, if your system is calculated at 6 hours backup at full load and you reduce your load to 25%, you backup time can be extended up to 24 hours.

A UPS is typically used to protect hardware such as computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business single computer without a video monitor (around 200 volt-ampere rating) to large units powering entire data centers or buildings.