This post was Last updated on : 07/31/2020
If you already have a battery backup along with inverter(UPS system) in your home & want to install solar panels and want to..
- Charge battery from grid if solar energy is not being produced. And,
- charge battery from solar if solar energy is being produced. And,
- run on direct solar energy if battery is fully charged. And,
- run from battery if both grid & solar not available. And,
- run from grid(and charge battery) if solar energy is not available. Or
- charge battery only from solar and not grid.
Can we do this?
Yes but there is a catch.
Above mentioned functions are what a SOLAR INVERTER do. Solar inverters are designed to work all the time 24*7, but normal inverters are not.
Normal inverters need to work only during power outage. These inverters are designed for that purpose only. There is no point in increasing cost by designing it to work all the time.
So that is the only bottleneck when we convert existing inverter to solar. Should we make a normal inverter(and battery) work more time or less time. Will it or can it handle working more time.
Reason for this bottleneck is the way Normal UPS system works. When we add solar panel to the system, DC current from from solar first charges the battery. Then inverter takes dc power from battery and convert it to AC current.
Why not directly convert DC from panels to AC. Microinverters can be installed along with each panel to do this. But what we have here is a normal inverter. Plus grid tied Solar panels with inbuilt microcontrollers won’t work when there is no electricity from grid. That is a whole another system and setup, we may discuss in the future.
Some controllers mentioned below have an option to set in different modes Based on availability of sun, battery charge percentage etc. But some of them will just shut down charging battery and thus not make use of solar panels.
In in this post we are going to learn ‘ How can we convert existing inverter to solar inverter‘. This can be done using a hybrid solar charge converter. These are also known as solar conversion kits.
This system is the best option if you already have inverter installed in home and want to generate power using solar panel. You can use existing batteries to store power generated from panels.
Solar conversion kit(single product) is an amazing product because it provides one solution to many problems.
A good Solar conversion kits work as
- Switch between grid and solar
- Battery type selection switch
- Charge controller
- Provide short circuit protection
- Provide over voltage protection
- Provide deep discharge protection
- Provide reverse polarity & reverse current protection
At the same time.
4 Best Solar conversion Kits in India – Convert your existing inverter/UPS to solar.
Luminous Shine 2420, 3650, 4850, 9650 etc
Type : PWM
Display: LCD display
Buy from offer links – Amazon
These are all different models from same brand. Main difference is the amount of current it can handle from solar panels. Some models support only 12v setup while others support 12v, 24v, 48v and 96 volt.
All of these models are PWM based Solar charge controllers.
You can choose one of these model based on voltage & current rate of system.
It is not clear from there product specification what happens when battery is fully charged and still solar power available. Reading through the lines, it seems they just shut of charging completely. But there is different modes like auto, manual mode, charge 100% solar etc.
Smarten mppt solar management unit 30 Amps/ 50 Amps
Type : MPPT
Display : LCD display
Buy from offer links – Flipkart, Amazon
These models are MPPT solar conversion systems. Little bit more costly compared to above mentioned brand. But these have many more features.
You can set different modes like charge only form solar, only from grid or run on solar when battery fully charged and solar available etc.
Microtek solar charge controller smu 10 Amps/ 30 Amps/ 60 Amps Models
Type : PWM
Display : Light indicators
Buy from offer links – Flipkart, Amazon
Microtek controllers are another good option for affordable solar conversion kits. These are little bit bulky and boring designs,
Su-kam SOLARCON Conversion Kit 12/24 V 20 Amp
Type : PWM
Display : LCD Screen
Buy from offer links – Amazon
Input Range: 90V – 300V ± 20V (Float voltage is 3.7 V ± 2%, 27.4 V ± 2%.)
Su Kam solarcon conversion kits were one of the first company with this kind of product. This product is still available but kind of going out stage.