Alternative Energy

When I was last in the Gambia I used a small solar powered cell on occasions when our area had power cuts. It was about the size of a small paperback and provided just enough power to charge my tablet or mobile phone a couple of times. Here at MyFarm however we rely on the sun for most of our energy needs and on cloudy overcast days some activities are curtailed as a result. All the electricity on site is provided from solar panels which charge a battery bank and provide all our lighting, power to run a number of computers and a printer, a fridge, and most importantly the water pump. The water used here comes from our own borehole and is pumped to a network of standpipes and storage tanks strategically placed round the gardens. This provides the water necessary for regular (usually twice daily) watering of the food crops and some of the ornamental borders, a fishpond, and of course all washing up, laundry, and personal bathing. The last item usually includes a most welcome cold shower each evening although sometimes when the tanks are fairly empty, I have to supplement it with a bucket which I keep filled ready for use on days when the water pressure is low. Last night however I was pleasantly surprised by a decent flow in my bathroom rather than the expected trickle. Either the sun had been shining for longer than the previous day and pumped more into the holding tanks, or we had used less water in the garden.


These four panels power the water pump but had to be removed for a new building, so we are on a temporary setup with only two at present

The panels which power the pump were moved to make way for the new food processing building just after I arrived here and at present only half of them are connected so it will be interesting to see what a difference to the water supply it makes when all of them are functioning again.

I mentioned using the solar oven last week to bake cakes and sterilise jars for filling with jams or beauty products and we also use parabolic reflectors to heat water. We have several in the kitchen area which are used daily but as with the solar ovens they have to be correctly aligned to the sun and regularly repositioned to be effective.

2 parabolic solar cookers

2 parabolic solar cookers

The other main use of solar power here is to dry products such as moringa, lemon grass, and fruit. We recently took delivery of a new solar drier from the local joiner, and I have spent some time this week treating it to preserve the wood, and fitting a solar powered fan and the iron hoops over which is stretched a transparent PVC cover. The frame is mahogany which glows a rich dark colour as I rub on a coat of shea butter and my hands now feel soft and smooth – shea butter is a fat derived from the nut of an African tree and is widely used in the cosmetics industry, as well as some chocolate. Yesterday morning we began a trial run drying a few sliced mangoes, but it seems the solar cell (recycled from an old lamp) is not providing enough power as the fan is slow to start in the morning and not turning fast enough to keep an adequate air flow through the drier, so we’ll have to see if we can find another solar panel.

New solar drier – trial run

The finished product

The finished product

These mango chips have dried too slowly and are starting to turn black

These mango chips have dried too slowly and are starting to turn black

We also produce biogas from animal manure and other organic waste which is mixed with water to form a slurry and fed down a pipe into an underground digestion chamber. The gas produced (mainly methane) pushes up a 300 litre plastic barrel “gasometer” and the digestate then passes on into another tank from which it is extracted and either diluted to use as fertiliser, or fed back into the start of the system and put through again. It is a very small scale operation for demonstration purposes, but can produce enough gas to boil the water for our breakfast tea.

The biogas plant

The biogas plant

What goes in at one end

What goes in at one end

What comes out the other end

What comes out the other end

A group of students from Bwiam learning about biogas. The

A group of students from Bwiam learning about biogas. The “gasometer” is the blue barrel with blocks on top to push it down.

This week the gas ring would not light so I have been trying to find out why. The delivery pipe from the tank was partly blocked, but after cleaning it out the pressure still seems low although the gasometer is raised and the stove will still not stay alight. I will have to investigate further.

The training courses continue – we have had two more groups here this week making soap and body butter, and it seems they enjoyed themselves as there was much singing, clapping, and dancing from both groups when they were due to leave. Their trips to market to sell soap went well and both groups made enough money to take a set of soap moulds back to their villages so they can start production at home.

Meanwhile the joiners have arrived to fit doors and windows to the new building (and also some fly screens in my windows), and a gang arrived on Thursday with a lorry load of grass from “up country” to re-thatch the schoolroom. They worked hard all day but hadn’t brought quite enough material with them to complete it so had to go home although they have promised to return on Sunday and finish the job off.

Trying to cut costs - the roofers didn't bring quite enough thatch and will now have to buy some more locally at their own expense.!

Trying to cut costs – the roofers didn’t bring quite enough thatch and will now have to buy some more locally at their own expense. Meanwhile we hope it doesn’t rain as the apex is open to the sky!

At this time of year, as the rainy season approaches the roof needs to be closed as soon as possible. We were expecting the roofing gang ten days ago but apparently they had a “programme” (party!) of some kind to attend up country and have only just re-appeared.


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