Always check the individual power/energy rating of each of the main components; many installers quote for very small battery banks and only emphasize high power inverters to mislead customers. Here are the main areas to focus on:
power of the solar panels e.g. 5KW
power of the inverter e.g. 5KW
energy of the battery bank e.g. 15kWh
warranty of the total system e.g. 5 years or 10 years
Solar/PV Panels [Optional]: converts sunlight to DC voltage (VDC)
PV Inverter [Optional]: converts DC Voltage to AC voltage (VAC); feeds VAC to home + battery inverter.
Battery Inverter converts VAC from PV inverter to VDC to charge battery, draws VDC from battery and converts to VAC to power home, automatically turns ON/OFF connected generator, automatically switches to incoming grid electricity.
Battery Bank: stores generated electricity in VDC.
Roof Rails: used to secure Solar Panels to roof.
Our priority is to offer superior products at an affordable price to our customers. As a result, we carefully negotiate pricing with manufacturers to minimize the cost without compromising quality.
Hybrid inverters indeed combine the functionalities of most PV and battery inverters in one unit, leading to potential cost savings; while separate solar and battery inverters have the ability for both inverters to generate electricity during the day. For example, a system with a 5KW PV inverter coupled with a 6KW battery inverter can generate up to 11KW combined power during the day compared to a single 6KW hybrid inverter which is always limited to 6KW power. As a result, we continue to carefully evaluate the options in the market for alternatives that achieve our mandate to provide premium quality products at affordable prices. We will only install products we can back up with at least a 5 year warranty without cost increase when compared to our existing solar packages; our priority remains 10 year warranty.
While we strive to make our products available to all customers nationwide, we currently do not have operating personnel and warehouses in every city. Regardless, we will work with individual customers who are willing to cover the additional cost of transporting both the components and installation crew. Please feel free to email us at info@prmsolar.com
We recognize the additional inconvenience and cost associated with returning defective products to foreign countries, as a result, we have taken on this responsibility to eliminate the cost/stress and also make replacements available as quickly as possible. To achieve this, we only warranty products we install, while working directly with manufacturers on behalf of customers. We also partner with only manufacturers that are willing to back their products with at least a 5 year warranty.
We specialize in providing premium solar products/services and lack the expertise in providing and managing financial loans. After getting lots of feedback from customers, we have now created a Power-As-A-Service option for qualified businesses to make monthly payments; these systems are sponsored by investors. For customers who want to pay upfront with a loan, we will be willing to provide any technical/pricing documentation that may support loan applications towards funding the installation of any of our products, if required.
Monitoring is included in all of our installed tiered packages and is twofold.
Firstly, monitoring power generation and consumption is available to the customer to help make usage decisions as needed.
Secondly, 24/7 monitoring the proper functioning of the PV Inverter and array is done remotely (requires internet connection); faults are reported directly to us so we can immediately contact the customer for a resolution. This ensures all our customers enjoy stable power supply.
Inverters are rated based on the maximum power they output continuously; this power is measured in kilowatts (KW). An inverter generating/consuming 6KW continuously for a full hour has generated/consumed 6KWh worth of electricity. This can be stored/drawn to/from battery banks. Battery banks are charged and drained over time; as a result, they are rated at KWh which represents the amount of power in KW and the duration of charging/usage in hours (h). For example, a 60KWh battery bank being drained at 3KW continuously, will supply electricity for 20 hours (i.e. 60KWh/3KW).
Daily generation depends on the amount of sunlight available. This varies from day to day and is expected to average about 4.5 sun hours a day in Western Nigeria and about 3.5 sun hours in Eastern Nigeria. As a result, our package with 18 pieces of 410W solar panels should generate about 18 * 410W * 4.5hrs (i.e. 33.21KWh) of electricity in a day. Expect this to increase on very sunny days and reduce on cloudy days.
Customers should select packages based on how much electricity they hope to both generate and consume. For example, a premium residential packages with 6KW hybrid inverter can power 4 ACs at any time along with other low power appliances including refrigerators and freezers.
The question is how long will this run for? And the answer depends on battery capacity. A 30KWh battery will run four ACs, refrigerators, lights etc. for about 6hrs (i.e. 5KW continuous load); this increases close to 12hrs if two ACs are run. Nightly consumption is only serviced by the batteries; therefore, customers should ultimately select battery banks based on how much they want to store for night usage.
Customers who wish to charge their battery banks through the grid (a.k.a NEPA/PHCN/DISCOs) or generator can do so. Such customers do not need the PV Array and PV inverter; but have the option to do so in the future seamlessly. This system will automatically switch between grid power and battery bank; and can automatically turn ON/OFF generators equipped with such functionality.
The two MAIN disadvantages of this approach are:
customers still have to pay for all power stored to battery and this eventually costs more than the solar panels in about 2 years.
customers are NOT guaranteed 24/7 electricity since that depends on grid power stability.
Usage estimation for any customer is twofold – instantaneous and total usage.
Instantaneous refers to the maximum power demand by the house and this can be evaluated by adding the wattage of all devices connected to the inverter system. These devices usually have the wattage printed on them.
Total usage refers to the overall consumption by the household. For example, using 10 light bulbs rated at 10w each, results in 100w instantaneous consumption; keeping these 10 bulbs on for 10 hours during the night results in 100w*10hrs=1000wh (1KWh) total usage.
As a general rule, pay close attention to heating (e.g. water heater) and cooling (e.g. AC units) when estimating usage since these usually account for the most power consumption. Also, keep in mind these devices turn off once they reach desired temperatures and only come back on as needed. For example, a 1KW AC unit turned on for continuous 10hrs, does not necessarily consume 1KW*10hrs (10KWh); using an energy consumption meter can provide more accurate measurements. We strongly recommend the use of inverter ACs which have shown about 25% energy savings for some of our customers.
While our technicians will be willing to stop by for some measurements, customers are free to estimate the total roof area available with priority given to the south and west roof elevations. This can be done off the house plan/drawing or measured by a roofing contractor. Each of our solar panel measures about 2sqm so a customer needs 36sqm of roof space for our 18 solar panel package.
We will gladly install solar panels that cannot fit on the south and west roofs on other elevations (a slightly lower generation) or issue a refund for those panels if customer prefers.
Asbestos crack easily and cannot last the 25 Year linear warranty on our solar panels; removing solar panels to repair/replace any roofing reduces power generation on those days and increases cost to the customer.
This is our specialty and what differentiates us. Our commercial systems are very scalable and we will gladly entertain requests for additional customizations not already listed on our website; please contact us directly (info@prmsolar.com) with such requests.
