Renewable Energy Rabbit Hole
“Energy is essential for development, and sustainable energy is essential for sustainable development.” - Tim Wirth
Introduction
On the 1st of June, I made a decision. I was going to study a lot of content on solar energy as the reality of the Nigerian economy has proven petrol to be unstable and high in price. This didn’t happen overnight as it was inspired by Bigbrovar, who I have been following for a long while on Twitter.
I grew up fascinated by technology and at 14 (soft bricked my Samsung Galaxy Star), I was already tweaking with ROMs thanks to XDA Developers. However as time went by, that passion sort of almost fizzled, until I saw his posts and it got rekindled. A Nigerian living in Nigeria tinkering with tech hardware? Please, more of that.
Anyways let’s get down to business. This is a short summary of my experience but If you need detailed resources and a place to ask questions and share experiences, you can join DIY Solar Nigeria on Telegram. Also, check out this article by Bigbrovar.
Step 1: Energy Audit
The first thing I needed to know was how much energy my appliances at home were going to consume. I needed to know their rated wattage and how long I intended to run each.
Appliances;
TV = 120w
Freezer = 120w
Bulbs 6w x 10 = 60w
Starlink router = 40w
Laptop and phones = 100w
Ceiling fan 50w x 2 = 100w
Total rated power = 540w
With the rated power, I knew my total load was 540 and this was essential to determine the size of the inverter. Optimally you wouldn’t want your inverter running at max power for a long period of time. So what do you do? Pick a size with enough room even for future appliances. Although other things count like surge consumption (check the group), a good rule is getting at least 1.5 of your current load. For 540w that is 810va but I choose to get a 3kva (3000w) capacity because it just made sense. At least even if my power needs increase in the future, it will take a while to exhaust it. I could also run things like pumping and washing machines for short time usage without problems.
Step 2: Determining System Specs.
There are lots of factors to consider here before you pick an inverter, panel to use and battery too. Overall I picked a 24v system. There are 12v, 24v and 48v systems etc. I picked 24v because it works and it is easier to upgrade to 48v from it than from 12v. The inverter I got was the 3kva 24v 100vdc SRNE hybrid inverter with inbuilt 60A MPPT recommended by Mr Sam. It is rated 3000w/3000va and has a PV input of 1400w, which means it can only take in 1400w from the panels at max.
There are other specifications too to read from the datasheet before making a choice. Both inverters, batteries and panels have their datasheets. Also, there are several brands in the market, both good and bad. Everything depends on your budget. Still, make sure you ask questions and check reviews. There is also this misconception that the number of batteries determines how much you can carry, as you can see, it is the inverter that does it. Although the battery discharge and charge rate can determine how much load it can carry and the rate it will charge up respectively.
Step 3: Battery
So how much energy was I to consume daily?
TV 120w x 10 hrs = 1200w
Freezer 120w x 6 hrs = 720w
Bulbs 60w x 8 = 480w
Laptop and phones 100w x 8 hrs = 800w
Ceiling fan 100w x 6 hrs = 600w
Total daily consumption= 3,800wh
This means based on my calculations, I will be consuming 3,800wh. However, this is still more like a guide and not a fixed amount. I needed to get a battery with such capacity and there are currently two popular types of batteries, Lead Acid/Wet Acid and Lithium/LiPo batteries. As for which is better, it’s left for you to DYOR. However, I can tell you that for Lead Acid, you are not to draw more than 50% of its battery power. While for Lithium you can draw up to 90%, although 80% is considered the safe spot.
I picked a Lithium battery as although it was more expensive, it would give me peace of mind. I can say most bad experiences Nigerians have with solar energy are because they constantly drew too much power from the Lead Acid batteries and didn’t do regular maintenance (Lithium doesn’t need any maintenance). I got a 160ah 24v Grade A Eve Lithium battery locally coupled which has a capacity of 4096Wh (3.2v x 8pcs x 160ah). 80% of it gives me 3,276.8Wh of usage, which isn’t bad for only battery usage calculation. It also comes with a BMS (Battery Monitoring System)to monitor its voltage, temperature and energy left at any time.
Step 4: Panels
There are a lot of brands as I said but one of the best in the market are the Canadian Solar and Jinko panels. This means there are bound to be knockoffs, so the best thing is to buy from an authorised distributor or trusted vendor. I chose to get the 550w 24v Jinkos as Canadian Solar was in shortage from authorised distributors. I checked the datasheet to confirm that my inverter could take four of them, with pairs of 2 in series all connected in parallel (and I thought I was done with Physics after EE211).
I bought four which gives a total of 2,200w on paper. Remember my inverter can only take 1400w, so why did I “waste” money? I choose to oversize because, in the end, reality is different from paper. To be on the very safe side (oversizing panels), you calculate that you would get only 70% of the panel’s rated watt. So this means those four panels will produce 1540w on average, which isn’t bad. Although there are times when panels (Canadian Solar and Jinko so far from what I’ve read) produce more energy than their rated watt it doesn’t happen every day.
Ideally depending on the location the amount of sunlight hours differ. Bard said it’s 7.5 hours for Port Harcourt but I used 5 hours. My panels performing at 70% efficiency for 5 hours means 7,700w of generated power. The inverter system is able to feed my house load directly from the DC supply (panel power) and excess is stored. It is also able to use the AC supply (nepa/grid) to feed the load. This is why it is able to run an inverter with only a battery (grid power source) and with only solar panels (excess battery is not stored).
Lastly please tell whoever you are buying from to carefully package them so they won’t break. One of my four panels broke on its way to Port Harcourt from Lagos. The seller sent a replacement at no extra cost and mentioned he would handle the case with the haulage company.
Conclusion
I also had to get MCBs (Miniature Circuit Breakers), SPDs (Surge Protector Devices) and earth the house properly, to make sure my system was adequately protected against external electrical problems like lightning, voltage spikes etc. Reading the datasheets of your inverter determines the type you should buy as it varies. Getting the exact ones was a hassle and we had to settle for the available ones in our market suited to my system.
I also bought the SRNE Wifi dongle to help me monitor data from my inverter remotely from the app. I bought most of my inverter setup components I needed by myself because I don’t trust the average company to not compromise on quality. However, I outsourced the installation to one which looked competent and they delivered.
Prices as of June when I made the payments
160ah 24v Lithium battery - ₦640,000 (Valto on Nairaland )
550w 24v Jinko panel - ₦161,000 x 4 = ₦644,000 (HM Solar Ltd)
3kva 24v SRNE Inverter - ₦198,000 (HM Solar Ltd)
Wifi dongle - ₦29,000 (HM Solar Ltd)
100A AC Schneider electric MCB 230v - ₦41,000 (Okelco Global Resources)
63A DC Schneider electric MCB 230v - ₦15,300 (Okelco Global Resources)
500Vdc Schneider electric SPD - ₦24,300 (Okelco Global Resources)
250Vac Phoenix contact SPD - ₦22,100 (market)
63A A Schneider electric RCCB - ₦35,000 (Okelco Global Resources)
Installation - ₦170,000 (Solar World Electric Technologies Ltd)
Total cost - ₦1,818,700
Disclaimer: I do not bear the risk for any of your transactions with any vendor
I plan to increase my setup by getting more batteries so I can store more power. Also to get a Raspberry Pi to tinker around with the data and get something like this and more. If you do the calculation, don’t worry, someone already did it here and here, burning a generator for 2 years on average is more expensive than my solar setup.
The problem however is the upfront cost. In the end, go for the best materials you can afford at the time. All these wouldn't have been possible without the DIY Solar Nigeria community, especially Mr Sam, who helped from texts to calls to checkups.
