Mar. 10, 2023 Friends & Family Letter


Buying solar panels and using them well just might be the key to rural African development

Dear Friends, Family and Compatriots:

I am on my way back from my latest trip to Malawi, where I spent part of my time visiting women's groups in villages and helping with the process of them opening up local solar shops.

I plan to go back to Malawi at the end of May to continue supporting our network of women-run village solar shops and to make sure our solar pump distribution campaign ramps up quickly and efficiently.

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Expanding the work from last summer

Last summer, using a network of five women-run solar shops we distributed solar pumps to about 130 rural women's gardening groups. Next summer, we have to increase our distribution to more than 500 women's groups. To do that, we need to triple the number of shops to 15 and set up the shops to sign up women's groups in their area to be ready to buy the solar panels that they will need to run the pumps.

The deal that we are giving the gardening groups is that if they pay the money needed for the solar panels, we will provide the pump and irrigation pipe for free. The local women's solar shops act as our main local points of contact to coordinate the sign-up of the women's gardening groups in each area.

Why people who earn less than $2/day need to buy >$100 of solar panels

People who earn less than $2/day most likely rely almost exclusively on manual labor to get more than 90% of their work done. Physically, the mechanical power that the human body can continuously output over the course of an hour is only about 100 watts. For most people, sustaining that level of output over several hours per day is very difficult. Anyone who has recorded or measured the watts they produce on an exercise machine knows how strenuous it can be to sustain more than 100 watts of power for more than an hour.

People in rural Africa often rely on their bodies to do the work that produces the crops that give them their income and food. This means their income is often limited by the finite physical labor that their bodies can produce. The low physical labor productivity resulting from their limited manual energy resources is a HUGE reason why hundreds of millions of people in rural Africa live on less than $2/day.

Now, when we are promoting and distributing solar water pumps to women's groups in rural villages, we are not only "doing charity" but we are educating people in the basic principles of the "physics of poverty."

Quite literally we explain in our village meetings that a 100 watt solar panel can do the work of one person: except the solar panel does not need food housing or maintenance. After someone makes the initial purchase of the solar panel, the panel can provide them its energy for free!  So when they put that solar panel to work pumping water, they can expand their gardens, increase their harvest and increase their income!

And when they don't need the solar panel to pump water for their gardens, they can put the solar panel to work cooking their food for them or charging battery-powered lights or cell phones.

So our mission is not just "solar gadget distribution" but includes the educational mission of teaching how solar panels can make life better if people use them well. The reason that the educational aspect is so important is because the productivity and benefit that a $100 solar panel can produce depends critically on how it is used. The solar panel might produce the equivalent of 2 to 8 hours of hard labor per day, but that productive potential needs to be fully utilized to create the maximum possible benefit.

This educational mission is why the women-run village solar shops are becoming so important. It is a learned skill to use a solar panel to its full potential for either solar pumping or cooking. When our staff teach the women running the shops how to use the pumps and cookers well, they are essentially 'teaching the teachers' who will then teach their surrounding community how to use solar panels to maximize the benefit that the solar panels can create.

Why solar panels can help electrify rural Africa even without batteries

There are three key under-appreciated facts about using solar panels which, when combined, indicate that there is a huge potential for cheap, battery-free solar systems that can help electrify rural Africa.

Fact #1:  There are cheap ($25 @factory door), flexible, maximum power point tracking (MPPT) controllers that can take power from essentially any solar panel and convert it to essentially any DC voltage that a device (i.e. pump, cooker, or inverter) might need to operate efficiently. And these controllers can operate even without a battery. When the device powered by the solar panel is an inverter that produces AC electricity, then the solar panel can produce AC electricity during the day without batteries. So for an initial investment of only $100 to $200 per household right now, essentially any household in Africa can potentially access at least small amounts of reliable daytime battery-free AC  electricity for years to come with no monthly fee!

Fact #2: A battery-free solar powered device as small as 100 to 200 watts has the potential of doubling labor productivity and income; and

Fact #3: For every 200 watts of solar panel that one owns, it is possible to cook an average of 2 to 3 kilograms of food per day WITH NO FUEL COST and avoid using 1 to 3 kilograms of wood for cooking each day.

These three facts mean that the existence of inexpensive solar panels creates a huge potential for making life better in rural Africa. But the potential is not realized if the panels are not used well.

The next step: Using incentives as "economic education"

How might it be possible to educate tens of thousands of people on the efficient use of solar panels, when we have a core staff of less than a dozen workers and volunteers?

One hypothesis that we are testing is the use of temporary "demonstration incentives" that pay the women in the rural shops based on the amount of cooking and solar pumping that they do.

How do these incentives work?

Well suppose we know that every kilowatt hour of solar electric cooking, there is on average 2 kg of wood saved? What we do is pay the women a bit less than $1 per kilowatt hour (i.e. $0.50 per kg of wood saved) to cook on the solar cookers.

This payment then makes it economically feasible for women in the shops to spend extra time experimenting with how they might maximize solar panel usage. While $0.50 per kilogram of wood saved might be a rather generous incentive, if the demonstration cooking prompts other people to buy and use cookers with smaller incentives, then the "demonstration incentive" can actually be worth the investment over the longer term.

Preliminary indications are that these demonstration incentives work.  We have started them in two of our initial five shops and each shop is cooking an average of 1 to 3 kilograms of food per day, per cooker in the rainy season. Most likely as we transition to the sunnier part of the year the amount of food cooked per cooker will increase.

Then as the women in the shops are cooking on the new solar electric cookers, people from the community are coming in, seeing the cooking being done and inquiring about buying a system for themselves.

Of course, it is going to take a little more time and money to confirm that the cooker systems are working well in the shops, and then to fine tune the size and configuration of solar panels, wiring and voltage converters to optimize the performance of the cookers.  We will finish that fine tuning over the next few months.

Then as we get all 15 shops up and running, demand and interest in the cookers is almost certain to increase rapidly in conjunction with increasing demand for the solar pumps.

Last but not least: We have a ~$250k grant to bring off-grid solar electric cooking to thousands of Malawian women

Because of the largely successful innovations that we have explored with off-grid solar electric cooking in rural Malawi, we now have a ~$250k grant for expanding our work over the next two years. What this grant will do is enable us to import about 3000 fairly high-quality, durable, affordable chinese-made solar electric cookers over the next two years.

Now including the cost of the solar panels and electronics, the minimum cost of an off-grid solar electric cooking system is actually about $200 per system. So given that the grant is about $83/system, we will have to organize about 3000 women in the villages over the next two years to pay the remaining $117 to cover the remaining cost. That is a lot of money for someone who earns only $2/day. But with enough education, demonstration, outreach, amd income-generating solar pumps, it should be possible to get it done!

In summary, we just might have a solution for the solar electrification of rural Africa ...

So what is the solution? First, everyone should buy >100 watts of solar panel, and second they should learn how to use this solar panel well ... even without a battery by using an adjustable MPPT voltage converter. You do this by adding what we might call "direct use" solar devices: solar water pumps, cookers, rechargeable devices (e.g. battery-powered phones or lights) and DC/AC inverters.

This then will give people access to a good portion of the electricity that they need during the day.

Of course we cannot be satisfied with just "sunny day electricity," In a later letter I will provide in more detail how we are developing a "forever battery." The Forever Battery is custom-designed battery with custom battery charging and discharging management electronics. The Forever Battery will then solve the remaining part of off-grid solar electricity access by supplying nighttime and cloudy-day solar electricity needs in off-grid rural Africa.

Until then ...

In love and struggle,

Robert VB