Jua Jammi house, which has just been erected in Morocco, is not only beautiful. It is designed to be good for the environment. And the National University of Lesotho (NUL) Masters of Sustainable Energy student was part of the brains behind its solar designs. “My role was to make sure that the house was producing enough energy from solar such that, on balance, it doesn’t pull electricity from the grid,” said Limpho Kokome, the student who contributed to the design.
He spent a month in Morocco working with a highly talented team of various skills from all over Africa.
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His assignment was simple—well, not that simple. He was required to make sure that the house would produce enough solar energy to cover the energy needs of the environmentally friendly house (eco-house). There had to be no need to get electricity from the grid.
Sounds simple, does it not? It was far from simple!
But first, what is Jua Jamii? Let’s get it from the horse’s mouth, “Jua Jamii is a team of African students enrolled in world-class graduate programs, which provide a broad foundation in theory and practical skills, having a collective mission to create and contribute to the development of green and energy self-sustainable building in Africa.”
With such brilliance, what more can we say?
They’ve said it all.
Our focus today is on this part… development of green and energy self-sustainable building… or should we specifically pick this part… energy self-sustainable building?
This is pretty much what Limpho Kokome had to figure out— energy self-sustainable building.
Here is why this was not going to be a walk in the park.
We all know solar— solar energy, solar panels, solar this, solar that. But how many of us have ever really sat down and thought about the realities of solar?
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When you burn coal or oil to produce electricity, you have a great degree of confidence about how much electricity you are going to produce. That is because you know your source of energy very well, it is consistent and reliable and highly predictable (although it is bad).
Solar is tricky.
It varies, it varies.
The energy you capture in the morning differs from that which you capture during the day. At night, you capture almost nothing. In cloudy days, there is less energy than in sunny days. When it is too hot you capture less than when it is just warm. When it is windy you get more than when it is not. It varies from month to month.
Despite all these variations, Kokome had to get it right. He had to ensure that the solar system (not the one with Mars and Jupiter) he designed met the requirement—produced enough solar energy.
In real life, and therefore in his case, you connect your house both to the grid and to the solar panels. When solar is not supplying enough energy for a house’s needs, say at night, then the grid kicks in. With modern technology, it is such a smooth transition, you won’t even notice the change.
During the day, when the solar is producing, the grid is put aside. In fact, when the solar energy is being produced, and it is now far higher than the energy needed by the house, the extra energy is put into the grid. The owner of the house may be rewarded with either cash or, preferably, energy credits.
“In all this, I had to make sure that the electricity being produced by the solar plus the electricity we got from the grid cancel each other in a month,” he said.
Simply put, even though the house does import grid electricity in times when solar is low, the house had to pay back to the grid in full when solar energy was high.
If your neighbour lent you five bowls of flour when you were low during the month, you make sure that before month-end, you have returned those five bowls. This you do, despite ensuring that everyone one in your house is still eating every day of the month.
So he had to develop a model that took into account so many factors. For instance, he had to ensure the solar panels were tilted right to capture as much energy as possible.
When you provide solar energy to a house, you contest with factors that may seem nothing to you, but a lot to others.
For instance, the architects wanted a flat roof, for aesthetic reasons. That went against his desire to capture the sun’s rays better. So he had to increase the number of panes on the roof.
He had to use satellite data focusing on the specific area in Morocco where the house was erected. That was so he could get irradiation (solar rays), temperature and wind speed data and many more to draw a model that worked.