Do you know?
Do we need the grid to supply electricity to power our residential/commercial loads! ??
Yes, right! we can avail of this with an “off-grid solar energy system”
At many remote/rural locations such as a farmhouse or cottages, access to the grid is a difficult and costly task, we often experience a frequent power failure and yes we know how irritating it is!
Solar energy ends up being the most productive and solid sustainable power source with a series of economic benefits to cater to all your loads.
The off-grid solar energy system is a popular choice in places with frequent power cuts and remote areas where access to the grid is difficult.
You must be wondering how this solar energy works without connecting to the grid, and what are the pros and cons, is it worth installing this solar energy system, how an inverter works in an off-grid system?
What is an off-grid solar system?
Off-Grid Inverter
How to connect an off-grid inverter?
An inverter is placed between the solar panel and the loads. The inverter is not directly connected to the solar panel, it is assembled with a battery and the charger to control the energy supplied to the inverter from the solar array.
Optional generators such as diesel, fuel etc. can be added with the inverter to supply energy in case the battery gets exhausted or if the solar panels operate below the required efficiency level.
How does an off-grid inverter work?
The DC power generated from the solar panel or battery is supplied to the inverter, the inverter consists of a capacitor and inductor circuit that opposes the sudden change in its direction and the current begins to rise and fall thus generating the sinusoidal waveform. The generated waveform is either a pure or modified waveform.
With the basic conversion function, the inverter also functions as a monitoring device, it is used to record and store the solar PV system data.
The advanced inverter is equipped with a maximum power point function to ensure optimum tracking of solar radiation.
For a place where a power halt can cause a huge loss, an inverter can be equipped with a generator and battery to ensure a continuous power supply.
Pure sine wave inverters:
Pure sine wave also known as true value inverter comes with a stable sine wave output i.e. it generates continuous repetitive oscillations in both positive and negative directions. It proves to be a good choice for sensitive electronic appliances. Depending on the frequency it is further classified as :
Low frequency: This inverter generates a high starting current, hence it proves to be more beneficial for compressors and air-conditioners that can be used for long run time.
High frequency: These inverters are reliable and efficient with an ability to run both inductive as well as resistive load as compared to modern sine wave inverters. They are free from electromagnetic pollution and offer a higher power conversion rate with minimum losses.
How to select off-grid inverters for your home?
While choosing any inverter one needs to know some basic technical terms (link to be given) like power, energy rating, efficiency etc. Let us consider a few below points that one must check before selecting the inverter.
Types of target appliance: In the market varieties of inverters are designed depending on the appliance requirement, one should target the required appliances and choose accordingly.
Power Consumption: After the identification of target appliances, the next task is to calculate the total power consumption by these loads.
Once the total power consumption is identified a suitable inverter rating is to be selected, if we consider a 100% efficient inverter(with zero losses which is practically not possible) then the power requirement rating is equal to the inverter rating.
But in the practical condition, an inverter with a sufficient higher rating than the total load rating is selected.Choice of an Inverter: The present market consists of an inverter with some advanced features such as remote control, inbuilt alarms, advanced cooling fans, etc for better durability and maintenance of the inverter.
An off-grid solar inverter ranges from less than 1kW for small appliances to more than 16kW for commercial buildings.
Advantages:
Independent of grid
The output voltage can be regulated as it is not loaded dependent
Easy to install in remote areas where connectivity to the grid is a tough task
Reliable as power can be stored in batteries
Synchronisation of voltage and frequency between grid and inverter is not required