₦airaland Forum

sathob: Well, great people of FTA, I think I should start this on behalf of George_D because of the request made by others who have expressed interest in alternate electricity, especially solar energy. Our FTA independence is not complete if we are to suffer frequent power outages and been dependant on the nation’s electricity grid system always. I have read in this house many times, from members “PHCN don go off, so I will track later when they come back”. No one can run away from power outages in the main electricity grid – not even the west, it happens. Hence, we all should have alternate electricity and using renewable energy is, to me, the best. This means one can enjoy their FTA fully by being totally free and not “dom” (dominated).

Look at some advantages
• Lower or no electricity bills
• Compared to generator users, there is no fuel cost and stress of getting it and no fumes.
• People living in the remote locations where power is unavailable or too expensive to hook-up too can have electricity.
Just to mention but a few.

Without going into detail, one can enjoy electricity by means of using solar energy (energy from the sun), wind mill (using energy from the wind). Don’t forget, where there is frequent electricity supply from the utility company, you can store some energy for back up.

You will need the following to complete a solar project or back up.

1. Solar panels
2. Power Inverter
3. Charge controller
4. Batteries to store energy
5. wires and cables
6. Monitors/meters

The solar panel consists of cells called photo voltaic cells and these, covert the energy received from the sun to electricity in simple terms (this electricity is a direct current
d.c). The panels can last up to 20 years plus. The panels can be fixed, adjustable or of the tracking type. You can decide to go for a complete panel from manufacturers (already made) or build panels by yourself using solar cells- the latter is for the hobbyist. The panels are rated in watts eg 80w solar panel supplying 12v continuous at a given time

The inverter
Power Inverters are available in 3 basic designs, two of which I remember very well now – the one that out sinusoidal waves and those that are modified sign wave type (meaning not pure sine waves and do have limits when it comes to its application) . The power inverter converts your storage battery power into the 240 volts AC that runs your appliances. It is the heart of your solar energy system. Unless you only run 12 volt DC appliances you will need a power inverter to supply your AC. This is just the basics.

The Charge Controller
A Charge Controller is necessary to protect the batteries from over charging and supply them with the proper amount of energy to promote long battery life.

Batteries
Without Storage Batteries to store energy you would only have power when the sun was shining. There is a lot more to batteries than just the ordinary car battery. Yo may need to change batteries over the years.

Wires and Cables
Without the right size of cables, you are likely to experience inefficient transfer of power (greater losses) and overheating.

Meters
This is required to monitor the performance of your solar system.

Firstly, it is very necessary to know what gadgets you will be using (eg.tv, sat. receiver) and how long you will use how long you would have them on the solar power and how much energy your battery can store and which solar panel (rating in power) will supply the required energy.

A lot goes into calculating the cost of setting up a solar system. First one has to consider the period of usable sunlight available at their location to do this calculation. For us here close to the equator, we get about 7 to 8 hours or more of sunlight during dry season, just a rough estimate.

How do I know I need 100w or 80w or 300 watts solar panel for my project?

The power consumption of appliances is given in Watts. To calculate the energy you will use over time, just multiply the power consumption by the hours of use.

Eg. If I have 90W tv set which I want to use for 6hrs, 25W satellite receiver for the same period, and a 50W fan for 3 hours. What will be the energy required from the solar panels for the period?

1. the energy for each appliance is Watts x time (hours) = Wh

So, the watt hours for the tv = 90 x 6 = 540 Wh (watt hours)

Watt hours for sat. receiver = 25 x 6 = 150 Wh

Watt hours for fan will be = 50 x 3 = 150 Wh

2. sum the watt hours for the individual appliances ie. 540 + 150 + 150 = 840 Wh (watt hours)

This means that the solar panel will need to supply 840 watt hours of energy to the battery each day to cover the total power required by these appliances.

3. since there are bound to be losses in the system However, to account for natural losses, we multiply the result by 1.2 (this factor allows for natural system losses, assuming 85% efficiency). Therefore, we will assume the panels will actually need to be able to supply a total of
840 x 1.2 = 1008Wh

4. so, to supply 1008Wh of energy the panel we assume to receive 7 hours of sunlight will be rated at 1008 Wh / 7 h = 144W
So, I will need 144W solar panel to supply energy to my appliances above at the given time.

Regarding point 3, it also means, if I have a solar panel rated at 100W receiving sunlight for 7 hours a day, the total energy supplied considering 85% efficiency will be 100x7x0.85= 595Wh and not 700Wh

5. Your battery should be able to store 1008Wh of energy. Since batteries capacities are rated in Ah (Ampere Hours) you need to multiply Ah by the Volt rating to know the Watt Hour. Power(W) = Voltage (V) x Current (I) ; Watt hour = VxIxHour

Therefore Ah (which is I x h) = Wh / V = 1008 / 12 (the number 12 represents a 12v battery)
= 84 Ah

So it means you will need not less than a 84Ah, 12V battery (deep-cycle batteries, not ordinary car batteries) to do the job.

NB. Another way of calculating battery capacity is explained in this example. Should my battery be rated at 84Ah, 12V the watt hour (energy) will be 84Ah x 12 V = 1008Ah

It implies that the battery can supply a 150watt appliance for 1008/70 = 14hours

Pls don’t just play around with batteries they are dangerous.