How to Install an Inverter System at Home?
How to install an inverter system at home? How much will it cost to have an inverter system, with or without solar that can power a 2-bedroom flat?
These are the common questions we often get asked by people, clients, and companies when they learn that we design and install the inverter and solar systems for homes and companies.
Coincidentally, it is also the most difficult question to answer as there are a lot of factors to be considered before a figure can be arrived at.
Factors to consider include – what will be powered, power consumption of desired appliances/loads, the load duty cycle (if applicable), surge rating of the loads, available charging sources, choice of components, the desired life span of the system especially the batteries, and the brand of choice. Detailed explanations are provided below.
What will be powered: The fewer the load, the lower the system’s cost. When discussing with potential clients, their first statement is often to add one to two air conditioning units (AC) to their request but I often advise them against doing this as it will increase the cost of the inverter system astronomically. A system designed to exclude an AC unit can cost as low as NGN300,000 while adding just one AC can increase the cost to NGN2.5 million and more.
Load power consumption: This merely refers to the amount of electricity an appliance consumes while on. The lower the load, the lower the cost of the entire inverter system, and vice versa. Therefore, I encourage homes and businesses that want to install inverter systems to ensure that the appliances that will be connected to the system have low energy. For instance, if you want to have your TV connected to the system and you have an old Cathode Ray Tube (CRT) television that consumes 120W, it will be wise to replace that with an LED television that consumes 30W to 50W. A small inverter can be used to power the LED TV but that same inverter may not carry the CRT TV. When purchasing a refrigerator, emphasis must be placed on the energy rating of the product, the higher the rating, the lower the energy consumption and therefore, the better. Typically, older refrigerators are not as energy efficient as most of the newer products.
Load duty cycle: This is the state of an appliance automatically turning itself off or on according to the design. A typical example of loads with duty cycles are refrigerators and air conditioners. When the ambient environment is cold (like during harmattan), they are off for about 60% of the time (and on, 40% of the time) but when the weather is hot, they are on for about 70% -87% of the time. This has a direct impact on the entire system because the batteries are drained less during harmattan but more, during hot weather.
Furthermore, regardless of weather, a refrigerator/AC on its lowest setting consumes less power than when on its highest setting.
Surge rating of the loads: A CRT TV may have a surge rating that is 3 times its nominal power, so a 120W CRT TV can have a surge rating of 360W or higher whereas an LED TV has no surge. The same applies to certain brands of refrigerators, air conditioners, borehole pumps, etc. This affects the choice of components as an inverter that powers appliances with high surge ratings will cost more.
Available charging sources: The inverter batteries must be charged regularly and adequately otherwise they will be depleted quickly and will ultimately result in premature failure. What options are available for charging the inverter batteries – solar; PHCN or generator or both? Each has its own cost and consideration. One of the best options is just to add solar panels to the inverter system so that the batteries will be charged daily. Obviously, it will cost more to add solar panels to the entire setup.
Choice of components: Here, the type of product to use has a direct impact on pricing. For instance, a pure sine wave inverter is at least, double the price of a square wave inverter of the same rating. An MPPT charge controller is a least 4 times the price of a PWM charger controller. In the examples here, these more expensive product types are actually better; it is like comparing carrying logs of wood on a trailer versus a pickup truck. The trailer is more expensive.
The desired life span of the system especially batteries: The weakest link in any inverter system are the batteries as they can die within 6 months or last as long as 20 years. The most common inverter batteries – the lead-acid type – have a lifespan of up to 4 years while the more expensive ones – The lithium-ion type – can last up to 25 years.
Brand of choice: American and European brands like MorningStar, Xantrex, Victron, Studer, etc. can cost about NGN300,000 and above for a 3KVA inverter while the Chinese brands are cheaper, prices are between NGN50,000 and NGN140,000 for the same 3KVA inverter.
In conclusion, when deciding to use an inverter system, it is advisable to start off by ensuring your switch off all loads when not in use. This attitudinal change will go a long way in helping your appliances and inverter system to last long.
In addition, by carefully reducing the load to be powered to the barest minimum, and researching the various brands in the market to decide on the battery and brand of choice. The cheapest 3KVA inverter system with two 12V 200A batteries can be as low as NGN300,000 naira and can go as high as 3.5 million Naira. The onus lies on the designer, to discuss with the clients and work within his/her budgets and needs.