June 4, 2023 Friends & Family Letter


Back in Malawi for Solar Pump Distribution

Dear Friends, Family and Compatriots:

   Well, 1000 solar pumps and 900 irrigation hoses have now arrived in Malawi, and I want to say thank you, Thank You! and THANK YOU! for all of the support you have collectively given.

   While we raised about $50k of new donations to make this happen, we have probably used about $50k of other resources to create the capacity to support and implement the solar pump distribution. So the total cost to donors is about $100k or $100/pump. Each of the women's groups will pay about $100 to buy the solar panels to run the pump, so it is a nice 50/50 cost share between the low-income women and the donors. The cost sharing helps make sure that the women who get the pump really want it.

   We now have 11 women-run solar shops up and running in villages throughout the Central and Southern regions of Malawi, and these shops have already signed up more than 160 women's gardening groups to receive the pumping systems.

   We are now ramping up distribution. We have distributed about 25 systems in the last week, and I am hoping to ramp this up to 100 systems in the next week or two. We will probably keep about 100 pumps in reserve for replacements and research. And given that we have about 15 weeks to distribute 900 pumping systems (40/week), it all looks perfectly feasible. Especially if we can show that our peak distribution rate can reach up to 100 pump systems per week when we need it to.


Doing impact research for the pumps

   As I have described in previous letters, for each $1 that donors contribute to help get solar pumps to rural Malawian women's, anywhere between $10 to $100 of new income is likely generated by the women.  If we can prove scientifically that our projects can reach the upper range of impact (i.e. $100 of new income for every $1 donated), then we just might have discovered one of the most cost-effective ways of reducing poverty in the world.

   So one of our key tasks this summer (in addition to simply distributing the pumps) is to start scientifically measuring how much benefit a solar pump creates for a women's group that acquires one.

  The benefit created by a pump depends critically on how the women use it. One can imagine at least two very different strategies that the women might adopt for using the pumps: (A) the women save the pump for the most critical uses and don't expand their gardens to make more income because it is more important secure a steady, modest income; and (B) the women use the solar pumping system to its maximum capacity in order maximize the income that they earn from irrigated gardening.

  In order to maximize the poverty reduction impact of the pump: we want to encourage behavior (B) over behavior (A), and we want to know how common each behavior is so that we can estimate the poverty-reduction impact correctly and report it to our donors.

   What we can do for all of our pumps, is attach a simple kilowatt meter. These meters cost about $6 at the factory door and cost about $10 by the time they get to Malawi. With such a meter, we can periodically visit the groups, see how much they have used the pumps, and then sell more discounted solar equipment to the groups that are using the pumps the best.

   But to be able to estimate the benefit from the pumps, we have measure seven things on average:

   #1: How much water the pump moves per kWh;

   #2: How much irrigation water is needed per unit area of garden;

   #3: How much the gardens yield per unit area for different crops;

   #4: What is the value of the crops per unit yield;

   #5: How much is seed, fertilizer, and other gardening inputs cost compared to the value of the crop.

   #6 How the irrigation effort per unit of garden area changes as one goes from hand irrigation to using the solar pump; and

   #7 To what degree irrigation water supply is the limiting constraint on the size of the gardens that the women cultivate.

   Using these seven pieces of information, we will be able to estimate how much more garden the women can cultivate with the pump, and how much net crop value is likely to be created per kWh of pump use.

   And then once we have some good, solid data demonstrating our very high impact per dollar donated, it should become quite a bit easier to raise funds from that specialty of donors that really care about cost-effectiveness. I will describe the details of courting those donors a little later in this letter.


Integrating the distribution of pumps and solar electric cookers

   By the end of this summer, we should have thousands of happy rural women customers who are now making money with solar pumps.  Naturally, the next thing to do is to provide these customers with access to the next empowering solar technology: solar electric cookers.

   Typically more than 90% of household energy use in rural Africa is for cooking. And when cooking is done with wood, the smoke causes respiratory disease that impacts women and children. It is estimated that millions of people die each year globally from the smoke of cooking fires. Eventually, everybody needs to transition away from cooking regularly on wood and charcoal to cooking with cleaner energy like electricity.

   There is a specialized development program (MECS: Modern Energy Cooking Services, https://mecs.org.uk) supported by UK development aid has helped us figure out how to provide solar electric cooking in rural Malawi. And in the research we have conducted, we have concluded that this is best done in combination with providing solar pumping.

   In March, we completed a report describing our solar electric cooking access solution here:


   We now have funding contracted to continue this solar electric cooking access work from now to the beginning of 2025 which should enable us to provide solar electric cooking to 3000 households. Hopefully by the end of 2024, we will have turned this work into a "clean cooking access model" that others can copy and replicate throughout Africa. That is the hope.


Adding "forever batteries"

   In a related development, our absolutely amazing Electrical Engineering Ph.D. student volunteer, Skyler Selvin has perfected the latest round of our battery controller and management system for Malawi-assembled Lithium titanate "Forever Batteries."  I have one of the earlier versions in my room in Malawi, and love it.

   Skyler is going to come to Malawi in August with his latest-greatest version of the battery controller which he will assemble with the Malawian staff and send out for field tests. This is totally exciting.

   Once Forever Batteries are added to the solar cookers, you only need to add a DC/AC inverter and rural Malawians have access to cooking and small amounts of regular AC electricity. Customers can keep adding batteries and solar panels to the system until it provides more and more of the household energy needs. I estimate, once they have added about 1000 watts of panels (which costs $300 to $500 in total) and about 500 to 1000 Wh of battery capacity (which costs $250 to $500) from Forever Batteries, they should have enough energy to supply most of their household needs with off-grid solar, 90% of which is cooking. This cost of $550 to $1000 may seem prohibitive, but if the batteries and panels last more than 10 years customers can have plenty of time to buy the system piece by piece over a period of years at a cost of $100 to $200 per year if they buy it over five years. This is affordable: especially if the people buying the solar system have a solar pump that is generating $1000/year of income.

   See how this works? First you get a solar pump for $100 to $200: you generate $1000/year of new income.  Then you take $100 to $200 per year of this income and buy your home solar system piece-by-piece, and then in 5 years you have a wholly-owned, complete, long-lasting off-grid solar system that is providing the vast majority of your household needs. For the parts of rural Africa that can do small-scale irrigated farming in the dry season, this is how I think a big piece of rural Africa can start being solar-electrified.

   We will see if we can get this concept to work well in practice in Malawi.

   But note, even if this concept works, it will take a decade or two to implement at large scale. I feel that I have gotten too old and tired to be willing to try to lead a vision like this for the solar electrification of substantial part rural Africa in the coming years. Instead, if this vision is going to happen at a large scale, it will be necessary for a younger generation to adopt it, change it, make it their own and implement it. In the next section I will begin to explain how I am trying to set that up.


Informing the donor and philanthropic communities about our success

   The first step of getting people to replicate our success is of course telling people about it. 

   The MECS program which supports our cooker work, has been very good about communicating our work to others (see: https://mecs.org.uk/blog-category/kachione-blog-series/). In addition on my recent arrival to Malawi, I passed through Loughborough UK and gave the MECS folks an update on our work (see: https://mecs.org.uk/talks-on-clean-cooking-and-womens-empowerment-in-malawi/).

   In addition on the philanthropy side, I am engaging with the "Effective Altruism" philanthropy community. Effective Altruism (EA) is a growing movement of philanthropic geeks who try to donate based on cost-effectiveness. They are currently donating about $700M/year and this annual donation amount has been growing at about 30% per year. Now some of our work in Malawi appears to be more cost-effective than their "top charities" so I am now starting to attend EA conferences to educate them on the work that I am doing and to try to set up a system that their philanthropists can use to sustainably finance projects like mine.

   I posted an initial description of the finance system that I am proposing at:



Making this work sustainable so others can replicate it

   IF I can get a significant number of funders interested in donating based on "impact credit sales contracts" and if I can teach other implementers how to do the pumps, cookers, and forever battery projects, THEN there is a chance that I can get the work that I have done in Malawi replicated elsewhere.

   Maybe, maybe not.

   I will continue to explore organizing within the EA community to see if they might adopt a version of my style of development projects more widely. I think my style matches their style, AND there are lots of enthusiastic students who are joining the EA movement who are very enthusiastic about having careers that can have a positive impact on the world.

  If I can get the Malawi work operating in a semi-sustainable way (with me visiting once per year rather than four times per year), then I can maybe do a 5 to 10 year retirement project mentoring EA activists to repeat a version of my work elsewhere in Africa or Asia.

  Perhaps, just perhaps,that will be one way I can help instigate the solar electrification of a decent piece of rural Africa.

   We'll see. Got to keep trying to the extent I am willing and able.

In love and struggle,

Robert VB