When it is time to go green, solar power becomes a favorite source of energy. Many people and institutions continue to adopt this source of energy that is essentially free and available in many places especially along the equator.
But it comes at a cost. There are two matters of concern as far as solar energy is concerned:
Spinning Reserve
A major challenge with wind and solar is that they demand for a spinning reserve in order to compensate for the unpredictable nature of these energy sources. If you have 300 MW, you need to set aside a reliable 100 MW on standby, and this often comes from hydro. The problem with this is that hydro is a very cheap source of power and it is better if we are using it at full capacity. This is something that increases the general cost of electricity.
The alternative could be something different, but dirty, such as coal. As a country increases the use of solar and wind energy, the more it will require to have a different source of power on standby.
Waste
The process of manufacturing solar panels is not very clean. On the other hand, the panels do not last forever, and need to be disposed.
There are many places without a definite recycling plans for these panels, and soon we might see a lot of waste starting to pile up. Recycling is not easy, and is not cheap. Manufacturers have to be compelled to recycle, and this would be after a long time of use – 20 years or so. This makes the whole process difficult especially in Africa where the solar panels are imported.
What’s Next?
While there are such challenges, the future of solar still looks bright. The technology is improving at a very fast speed and some of the current challenges will be solved with time. The future of solar is still bright.
Early on Saturday morning, a power transmission cable snapped somewhere near Nairobi city. The resulting effect was a nationwide blackout in Kenya and Uganda. How did one cable send two countries into darkness?
It is something complicated if you do not understand the power distribution, but we can make it simple for you via an analogy.
Analogy
Let’s assume that on average, one person can lift 40 kg of weight. Some can do 70 while other only can manage 10kg, but the average always comes to 40 kg.
You need to move your house from one point of your farm to another, and you need to hire some people to do it. You estimate that the house weighs 1000kg, and this translates to 25 people if each of them is to carry 40kg. Remember you are moving the whole house as one unit (it happens).
In some parts of the world, we can always move with our houses
Since you know that something could go wrong during the lifting, you will need to have more than 25 people to do the work as failure of one man could cripple the whole operation. However, getting too many extra people will cost you more than is necessary, so you opt to go with 27 people. One person will always be free to help lift any side when people are overwhelmed while 26 will always be working.
When it is time to move the house, everything goes on as planned. At one point one man stumbles and the standby guy moves in quickly. Everything is going on according to the plan.
At another point one guy hurts his leg and you are left with 26 people doing the lifting. This is still safe since you only need 25 people for the work.
But then, something unusual happens. One man who is very strong slips. He was carrying about 70 kg of the weight, and when he stops doing the work, every person around him feels the extra burden. To rescue him, his neighbor stops lifting and helps him move out of the way before he is ran over. The others near him stop moving and try to get everybody else to stop moving so that there is no accident. In the confusion that follows, there is an imbalance and the only safe thing to do is to put the house down so that everyone can recollect themselves.
This stops the whole operation for 10 minutes as everyone realigns themselves and work resumes.
How can such a scenario be prevented? Majorly by having more people so that there can be more tolerance to imbalances. However, this increases the cost and it will not help you when all the people holding one side encounter a unexpected obstacle. They will still have to put the house down.
The other option is to divide the house into equal pieces and let every person carry a 40 kg piece. This is would work, but remember some people can only lift 10 kg while others 70 kg. You will spend a lot of time either cutting unequal pieces and marching them to each person’s capacity, or alternatively you might need to pair up the people with less capacity, thus increasing the number of people you need.
What Happened
The electricity distribution system is called a grid, and involves several electricity generators being connected together into one network so as to serve people all over the country. In Kenya, we have different sources of electricity such as hydroelectric power plants, geothermal, wind, solar and other sources of power, including imports from Uganda.
This interconnection helps keep the load stable even if one source of power fails. It also helps maintain optimum supply such that if demand is low, some sources such as the expensive thermal (diesel) powered plants can be switched off.
Part of the failed cable
Kenya Power engineers at work
The grid has various high voltage lines evacuating power from where it is generated to where it is needed, with Nairobi being the main consumer of power while most generation takes place in remote places such Olkaria and Seven Forks.
In the even that one major power lines fails or a generator is knocked offline, the system adjusts to both to compensate for the changes and to protect the system. However, beyond a certain threshold, the whole system can be overwhelmed, and this time it did.
The line that failed was carrying a significant share of the total system loading, and it affected the whole system which had to shut down. Getting everything back to work is not as easy as a switch flip. It takes time, and in this case some repairs.
We all love showers,
and we love them hot, or more precisely, warm. Instant hot showers are loved
for just that. In the age where we want all things instant, instant hot water
shower is the instantest of all. Just a flip of the switch and one enjoys water
which is not cold, at least.
But this dearly loved
device is a scam. For some reasons, I never get to understand what goes inside
the head of the shower. I heard someone who used it for the first time claim
that the water was both hot and cold at the same time. I had never made such an
observation, but I immediately agreed that such a phenomenon exists. Instant hot
showers have the following shortcomings:
Risk of
electric shock. Faulty wiring would deliver 240 Volts down your body. This is
rare, but I have seen it happen.
Water is
both hot and cold. You have to solve a complex matrix in order to maintain
water at the same temperature.
It is a
major power guzzler. Instant shower can account up to 50% of all electricity
costs in a small household.
It cannot
work under low pressure. Water at low pressure may lead to the shower being too
hot to use, or worse, the shower might not heat.
Short life
span, especially if it is a fake brand.
Their use
might be coming to an end, as the government might consider banning them. This is
according to a ministry of energy consultant.
One solution to
instant water heaters is use of solar water heaters. These have the capacity to
heat considerable volumes of water at very low costs, and their costs is
cheaper in the long run. Not only are they maintenance free, but they also can
deliver high volumes of water since they have water reservoirs attached.
In Kenya, solar water
heater with a capacity of 200 litres cost approximately KES 50,000 (USD 500).
Once installed on the rooftop or any other convenient place, they can serve
effectively for up to 20 years. Their water tank is insulated to minimize heat
losses, enabling them to store hot water for up to 72 hours. In Kenya, there is
the Solar Water Heating regulation that requires all buildings with a
consumption of more than 100 l of hot water per day.
Wondering what happens
during the rainy season or non- solar day? No problem. These solar heaters have
a secondary electrical heating element, which allows water to be heated directly
from the mains.
Everyone is going
solar. Some want to use renewable energy, others want green energy, some want
to save the planet, others want to cut carbon emissions, and some simply think
it is cool. If you want to join the bandwagon, I will tell you why you should, and
why you should not, depending on your needs.
First, there are some very good news about solar energy (In this case, we are talking about Solar Photovoltaic, which involves converting solar energy to electrical energy. There are many other uses, such as solar water heater).
The cost
of solar power has gone down, and is on the downward trend. This means that it
will keep getting cheaper in the future. Good news.
The cost of
storage is also going down, and storage technology keeps getting better. This
is important because any meaningful solar installation requires storage. You can guess why; the sun never shows up at
night, and solar panels convert solar (sun’s) energy into electrical energy.
You can
now seamlessly switch between mains ac and solar power, meaning that you use
solar power when it is available, and switch to mains electricity when
necessary.
Who can use solar
power?
Solar power is freely
available, as long as you can see the sun. This means that if you have a roof,
or some grounds available, you can mount solar panel. Any house owner or
property owner can install solar panels, but if you are in a rented apartment
things may not work good for you, unless if you are a friend to your landlord,
or you are influential 😊.
Solar power can be used nearly in every part in Africa, as the sun is a
friend to Africa. The Sunshine duration in Nairobi is 6.8 hours in Nairobi, 9.4 hours in Cairo, and 8.4 in Cape Town. In Kenya, the average
sunshine duration is 6.9 hours, which means that we have the sun shining almost
all throughout the year, with peaks in January. In short, everyone can board!
But,
You need to have your priorities right. If
your side hustle is welding steel gates in your house, or running a posho mill,
you are not eligible. To put it more accurately, you can consider solar, but
your investment will be in millions. Here we are addressing domestic consumers.
Hybrid Solar system diagram
Sample case
If your monthly power consumption is 55
units of electrical power, your electricity bill would be approximately KES 833
in Kenya, or KES 10,000 per year. This could be the following devices running
in the house:
100 Watt fridge running full-time
30 Watt TV running for 4 hours per day
Two 10 W bulbs running for six hours per day
A laptop running for three hours per day
Three 15 Watt bulbs running for 4 hours per day
For the above, you would need to have at least a battery capacity of 230 Ah, a solar panel of 262 Watts, and an Inverter of about 300 Watts. This would cost about 75000, exclusive of installation costs. This means that it would take you about 10 years to recover your investment. Solar panels have a long usage life, up to 30 years, while for the battery, you might need to replace it at most every 7 years.
Solar Water Heater
I would want to mention a few things about solar waters heaters because they have one of the easiest application. One of the huge costs in small households is heating water, and adopting one can help reduce your electricity consumption significantly. Read about Solar water heaters in this article.
