Typically, before designing any power system, we first conduct a power audit to determine the peculiar energy needs of the client. This is done either by asking the client to supply information on the nature of his appliances or by paying a visit. Recommendations are then made based on the findings of the audit. An audit as such is undertaken chiefly to determine the load requirements for the client. The amount of grid power available to the client is also taken into consideration, if the system would be tied to the grid which is often the case. Installation space and the client's budget are also considered during the stage.
For this project, the final call was a system that would offset the deficit and provide uninterrupted power supply. This warranted designing a hybrid solar-prioritizing system tied to the grid and supported by a battery bank to maximize self-consumption.
Twelve (12) 405W monocrystalline Jinko solar panels were connected in four (4) strings of three (3) panels each.
Half-cut panels were used for the system. The choice of a half-cut cell solar panel for this installation was decided by space considerations as well as market realities. Since at least 2019, half-cut panels have been displacing the traditional mono and poly panels. Manufacturers of high-powered panels, that is panels that are rated from beyond the 360W that is the optimum for most panels, to panels with power ratings up to 600W, now exclusively depend on half-cut technology.
In a half-cut solar panel, more solar cells can be squeezed into the module without any significant increase in the size of the panel, whilst at the same time reducing the resistance of the module. Learn all about half-cut solar panels here.
The solar panels were mounted on the roof.
An 8kVA Growatt Inveter was used. Growatt inverters are pure sine wave hence they produce a clean electricity for appliances and appliances that use them do not make a continuous humming or buzzing sound. The major advantage of a pure sine wave inverter is that all appliances which are sold on the market are designed for a pure sine wave. Using a pure sine wave inverter guarantees that the appliances will work to its full specifications and achieve optimal efficiency. Also, appliances run faster, quieter and cooler on pure sine wave.
The definitive feature of Growatt inverters is that they are transformerless inverters. The major difference between the conventional inverter and the transformerless inverter is that the transformer is replaced with a computerized multi-step process and other electronic components. These components play the role of the transformer, that is, convert the DC generated by the solar panels to AC. As TL inverters has no transformer, Growatt inverters are light, compact, and far relatively cheaper than conventional inverters.
The inverter used has hybrid capabilities meaning that it will simultaneously manage inputs from both solar panels and a battery bank, then charge the batteries with either solar panels or the electricity grid, depending on availability, consumption or preference for use at a later time, mostly night time.
Twelve (12) Ritar AGM batteries, at 48V each were used for the installation. They were installed under the staircase in a metal rack with front end terminals. The role of batteries in a solar power system is provide the DC that is to be converted to AC by the inverter for use in appliances and to store energy produced from solar panels for later use especially in the absence of sunlight and grid power. They contribute the most to the total financial investment on the system.
The choice of AGM batteries was because they are the safest battery design. They emit gases only when severely overcharged. They eliminate worries about explosions. They are also maintenance-free for life and do not require constant maintenance.
A 120 Epever MPPT charge controller was used in the installation. A solar charge controller or charge regulator, as implied in the name, is a voltage and/or current regulator which serves to keep the batteries in a solar panel-deep cycle inverter system from overcharging.
The MPPT solar charge controller is the ultimate in solar controllers. Though relatively very expensive and larger in size, they can help users save considerable money on larger systems since they provide 10 to 30% more power to the battery than the PWM and have efficiencies reaching up to 98%. MPPT charge controllers operate by measuring the Vmp voltage of the panel, and reducing the PV voltage to the battery voltage.
In addition to the protection features provided by the inverter against reverse current, overload and overcharge, the system incorporates extra protection features including AC and DC circuit breakers and surge adapters. They offer additional protection to the client's investment. They also make it easy and safe to disconnect the system from the panels in the case of emergencies like lightning that could damage the inverter or solar panel fires.
SolarKobo helps its clients in Lagos and elsewhere in Nigeria make the best possible choice of all solar products including solar panels, batteries and charge controllers that meet their peculiar power needs and fits their budgets. We also have university-trained engineers who provide the best possible installation services on order.