What is An Inverter (Power Inverter)?
A power inverter is an electronic device that converts Direct Current (DC) from sources like batteries or solar panels to Alternating Current (AC) for use in the home or office. While Direct Current (DC) is produced from sources like batteries, Alternating Current (AC) is the form in which electric current is delivered to residences and offices usually from the grid. Thermal and hydro power plants are sources of AC, also the generators we have in homes or offices as back-up power supply are sources of AC. AC is thus the form of electricity that powers appliances in homes or offices.
The inverter makes use of electronic components like transistors, battery bank and all other necessary connections, particularly on the utility side. Inverters also provide over voltage protection to connected load. Inverters usually come with integrated or dedicated chargers to power the battery bank.
Both the inverter and the charger work together to provide you with backup power when the regular utility power goes off by doing the following:
- It charges the batteries by converting AC into DC when power supply is available. Remember that DC is the operating mode of batteries
- It converts the energy stored (DC) in the battery to AC energy that powers your appliances when there is power outage.
Inverters can be seen as a form of UPS that can provide backup power to run your appliances when there is a power outage. However, the duration of the back-up supply is dependent on the rating of the inverter and capacity of of battery storage connected. In other words the higher the capacity of both the inverter and the battery storage the longer the duration of the back-up supply. Inverters are noiseless and do not pollute the environment like generator sets.
Implications of Using Inverters
In spite of all its positive attributes, it is important to note that inverters have other hidden or subtle financial implications. These life comfort providers have the proclivity to cause you more financial drain than the orthodox petrol or diesel generating sets. In a few paragraphs we’ll walk through these implications or complications as the case may be.
- Increased Electricity Bills
Do you know that Inverters add to your electricity bills? The logic is simple, the batteries connected to the inverters need an energy source to re-charge after draining in the course of supplying power during outages. Therefore the longer the outage, the more energy the batteries require to re-charge and hence the more power you draw from the grid leading to increased energy bills. Also, it is safe to say that the older the battery storage, the faster the batteries drain and the more frequently you need to re-charge, costing you even higher in electricity bills?
- Operations and Maintenance Cost Implications
Do you know that the useful lifespan of most inverter batteries is two years and after four years, you need to change the batteries!
Finally let’s consider the cost implication for use of inverters;
- Cost Implication
- An inverter of 7.5KVA capacity, and a battery bank of 10 cost approximately N380, 000 and N500, 000 respectively (where each battery costs N50, 000). The pair costs a staggering N880, 000.
- A petrol power generating set of 7.5KVA costs N120, 000. The difference between these two machines is N760, 000.
- The O & M cost of running a petrol generator set is the cost of fuelling and servicing.
- The O & M cost of running an inverter is the cost of electricity units needed to re-charge the batteries after a power outage event.
- In addition to the massive procurement cost, you still spend in charging the batteries, and this will be a recurring event given the state of power supply in the country.
- Additionally you need to replace the batteries (as earlier stated) every four years. In the case of our example here, this means an additional cost of N500, 000 every four years (that is four times the cost of the petrol gen set of equivalent capacity).
This must be very depressing for those who have had the patience to read through this article. Before you decide to runoff the cliff in frustration, I bring you good tidings;
As already pointed out in the introduction, an inverter can be seen as a form UPS. Usually a UPS is used for protection of both electronic appliances and data in case of a power outage event. While UPSs are commonly used as backup power supply for computers and some other sensitive electronic devices, inverters can be used to power the entire house, from your electric fans to lights, ACs, TVs, etc., for even longer periods of time (depending on the capacity of the inverter and associated battery storage capacity).
However, it is good practise to consider the incorporation of renewable energy source like solar panels as this will save you the costs of paying the heavy electricity bills that come from charging the inverter batteries among other things. These solar panels charge the batteries during the day when sunlight is available.