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.

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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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Saturday in the garden

For most farmers in the Gambia, working on the land means long hours of repetitive manual labour. There are a few exceptions like our neighbour, Radville Farms, a larger commercial operation with about 30 ha adjoining MyFarm and more land elsewhere. They have a number of tractors and implements including a large modern John Deere which occasionally passes through the mango orchard on our boundary on the way to collect fuel from the diesel tank. Radville Farms sounds very English but I believe is an Indian owned business as it is known locally as “The Indian Garden”. Each morning around 7am I hear the chatter of the farm labourers going to work, mostly on foot, with the occasional bicycle or motorbike, and at night they return again, with some of the ladies carrying bundles of sticks on their heads.

The operation here at MyFarm however is not mechanised and is typical of many with a variety of crops grown on a 2ha plot. At present we have lettuces, tomatoes and cucumbers, cabbages, peppers, pumpkins, a few small leeks and some local green leaf crops, all of which have to be watered twice a day by hand.

The pumpkin patch

The pumpkin patch

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Tomatoes and cabbages – note the mulch of mango leaves to keep the weeds down and retain moisture

Normally there are three or four of the gardeners busy watering, but on Saturday and Sunday one of them has the day off. Yesterday, one of the gardeners who should have been working failed to arrive – he has been up country for a couple of days visiting a sick relative and it seems is still there -, and as our cook also has Saturdays off, Jarrai who would normally be working in the garden, was on kitchen duty so we were rather short staffed. As a result I spent most of the day from 7am to 6pm carrying water in two watering cans. There are taps at strategic points in the garden, but much of the time the pressure is too low to use a hosepipe or sprinkler for watering so the cans are filled by dipping in to plastic barrels which are constantly supplied from a network of mixed hosepipes and rigid plastic water pipe/electrical conduit. In some areas there are lengths of flat plastic hose with pin holes at regular intervals for trickle irrigation, but again the low water pressure is a problem and it seems that the plants nearest the tap get more than the ones at the far end of the pipe. I am trying to improve this system by replacing broken pipes and digging rigid pipes underground where they cross the pathways. This had been done already in some places but the pipes were only just beneath the surface and punctured easily by the sharp stones and seashells which form the path. I have dug some of the trenches rather deeper and bedded the pipes in sand so hope they will now last longer without leaking.

Apart from keeping the garden watered yesterday we also had to accommodate a visit by someone from the Ministry of Education to see how we use logic games on iPads as a teaching tool for the children, the usual drop in visitors and Saturday computer classes, and a tour by a bus load of schoolchildren. We host quite a number of school visits – this was the second one in a week, and we have another group next Wednesday. It’s a good opportunity to try to educate the younger generation about deforestation – at present much of the cooking in the Gambia is done using charcoal and as a result the bush is being cut down at an alarming rate. Here at MyFarm, apart from the small business training, we also demonstrate environmentally sustainable methods of cooking using solar powered ovens,

Solar oven

Solar oven – basically a double glazed insulated box which can reach 150 C using only the heat of the sun

and parabolic reflectors, and the production of biogas from pig manure and rotting fruit. Tomorrow is a public holiday so as part of my holiday entertainment for the children I have agreed to demonstrate my culinary skills by baking a fruit loaf. I’ve seen cakes baked in the solar boxes but have not yet tried it myself so hope it will work. Keep your fingers crossed!