Guide to Solar System for Beginners

Worldwide a lot of peoples want to harvest electricity from the sun. Having it is like having a well, tube well or a borewell at home. Grid electricity is great to run the appliances of higher wattage but the appliances like the LED lamps can easily run from your system. The purpose of this article is to enlighten you about the different components of a solar system and help you to purchase the components one by one, avoiding a huge investment at once. A solar system consists of solar panels, inverter and batteries. The rest of the components are electrical and mechanical. Before going into the details, you should have an idea to limit your expectations.

There are on-grid (or grid-connected) system and off-grid (or stand-alone) systems. This article talks about off-grid systems. Usually, the specialized manufacturers are different for these two systems. The companies who are related to the batteries, inverters are inclined towards the off-grid systems.

Most of the houses and apartments need a 1 to 2 kW solar system. With a 1-2 1 kW solar system, you can safely run the LED lights, fans etc but it is unsafe to operate the water pump. Appliances with compressor (such as air conditioners, refrigerators) are not friendly to the batteries and inverters. If you want to run a 1.5 ton 4 or 5-star inverter air conditioner on solar, you’ll need a minimum of a 4 kW solar system. In my opinion, a 2 kW system is future-proof to run a 1 kW payload. As the price of the lithium-ion battery is prohibitive, we will suggest buying a hybrid solar inverter of 2 kW.

Why We Do Not Distribute the DC Electricity?

The cost to create a safe DC wiring will be very high. You need a 24v DC distribution system as 30v is widely used in the industry for control networks. You need 2.5mm cable at 24v, you’ll need circuit protection, DC rated MCBs. You have to use Z type overload protection. We simply do not understand the risks with AC wires and switches. 24v DC is unlikely to deliver a fatal electric shock but the system will tend towards the creation of fire hazard. Most importantly, you’ll not get many DC appliances, DC sockets have no unified standard. The technicians who work at railways, telecom, control networks are used with DC wiring. To discourage you more, the dc/dc converters generate radio interference that may affect the reception of radio and TV signals. I can not see the justification for distributing 24v DC directly from the battery.

The Hybrid Solar Inverter is the Heart of the System

A hybrid inverter is like a combination of an on-grid system and an off-grid solar inverter. More versatile but more expensive. When you choose a hybrid inverter, then your system is a micro-grid. Apart from solar panels, you can connect other power sources like a diesel generator to power the load. You need an energy management system for a complex strategy. This inverter is the grid-tied part that will switch to the source according to battery backup and condition of the grid.

You can install a solar system without a consumption monitor, but I strongly recommend having one. Without a consumption monitor, your inverter will only be able to tell you how much solar energy your system is producing at any point in time. But, you’ll unable to know the consumption as the graph in your smartphone’s app. Not all solar inverters are equal and it is the inverter’s efficiency that will have a direct impact on the return.

The Solar Panels

Solar panels are the key elements behind power generation. The two types of solar panels most suitable for residential solar installations are monocrystalline and polycrystalline panels. Monocrystalline is slightly more efficient and a little more expensive hence polycrystalline panels are commonly used.

An 80W solar panel would ideally produce around 450W per day on average (it differs from brand to brand and available sunlight). Solar panels can be wired in series or in parallel to increase voltage or current. So, if you have a lot of space, you can think about 100 Watt 12 V solar panels as they are cheaper.

The purpose of solar regulators (charge controllers) is to regulate the current from the solar panels to prevent the batteries from overcharging.

The Batteries

Prefer to purchase lithium-ion batteries. The tubular batteries (lead-acid batteries) will last too short and will need distilled water regularly. One 100 amp hour battery is a minimum need.

Conclusion

Start with a small plan. Solar is cheap when it is DIY and for a lower load. Low power solar PV system can be installed and wired yourself eliminating the labour cost. You can start to harvest electricity with just $100 capital, you need to study low cost systems like this one :

It can power up to 28 watts appliances i.e. enough number security cameras and router. One solar panel of 165 watts with a 750VA hybrid inverter and 150 amp hour battery can run 150 W load for 12 hours. If you find each component and separately purchase it, the total system will cost you $300. I would say, this is enough to get started.

You can buy a 2KVA hybrid inverter, add one 165 watts solar panel and one 150 amp hour battery to get started. Later you can add another 165-watt solar panel, another 150 amp hour battery.