Dear Friends, Family and Compatriots:
As I write this, I am finishing up my latest trip to Malawi. Before this trip, my last trip to Africa was March 2020. That trip was cut short by the pandemic.
Since that time, we have had about nine months of pandemic in the US.
Like most everyone else, I have been sheltering at home in Berkeley, though I did do a little election organizing in Georgia and Nevada. But at the end of December, I headed back to Malawi
How I got COVID-19 on election night:
I was doing pretty well avoiding COVID like most other folks, BUT THEN I did a dumb move and hung out with a friend on election night and didn't keep my mask on. I took my mask off for hours to eat, drink and talk election politics half assuming that it was ok letting the friend into my bubble. Wrong!
Well the friend came down with COVID the next day, and I came down with it a few days later. Both of us had mild cases, so we are both fine ... but you never want to play a game of Russian roulette, even if your chances are 99 to 1 of avoiding death. Just ain't worth the risk.
By the time I started having symptoms, I was in Georgia following up on my election organizing. So I had to quarantine for about 11 days, which I did at a cheap hotel in the south of Atlanta.
In my case, I had a mild fever for about 5 to 7 days and got a bad cough. No trouble breathing or any other symptoms. My temperature would be about 98 in the morning and a little over 100 at night. The cough lasted 4 to 6 weeks for me.
The upside to getting COVID is that now I am "semi-vaccinated", so my chance of getring re-infected is relatively low, though not as low as if I got a vaccine:
So I went back to Malawi to help move the work along over there. And wouldn't you know: I tested positive for COVID again before heading back to the US.
I don't have any symptoms this time though, so my anti-bodies from the first infection likely provided some protection for the second infection. I know the routine now: I quaranteen for 10 to 14 days and then get tested again to see if I can get cleared to head back to the US.
"Forever lights": making solar lights last more than 10 years.
Well, the lights we installed in 2017 reached the end of their useful life in 2020. That apparently was the lifetime of their batteries. It more or less fits the theory.
So now is the time to replace them.
How many cycles a battery is good for depends on how much it is discharged per cycle. For the batteries we used three years ago, the theoretically number of cycles when it is fully discharged is 1000 to 2000. Three and a half years corresponds to 1,277 cycles.
But if during each battery cycle you discharge it only half as much, then the battery lasts actually more than twice as long. And if you discharge only a third of the energy per cycle it lasts even longer. This way it is fairly straightforward to design battery-powered solar lights that SHOULD last 10 years or more.
In fact, with a fairly simple financial analysis you can look at the cost vs. lifetime, use an interest rate to annualized the initial cost of the light over the lifetime, and calculate which lifetime minimizes the annualized cost of the light. And when you do this in our case, you find that the design with the minimum annualized cost should last 10 or more years.
And the net benefit to the villagers is maximized over the long term when the annualized cost is minimized. So we are converting all of our solar lights to "forever lights" with this new and improved design.
Test results: Our "capacitors" are actually hybrid battery/capacitors
An electrical engineering grad student over the last 9 months volunteered to help with the Malawi work. I set him to the task of testing our "capacitors" to verify the manufacturer claims on cycle life.
Not surprisingly perhaps, he found that when you drive the devices very hard: doing a full charge and discharge at a relatively high rate, the "capacitor" loses energy storage capacity at a rate of 3% lower capacity for every 100 cycles. And in fact the charge/discharge characteristics look almost exactly like a "lithium iron phosphate" (LiFePO4) battery. This is for the model that maintains a voltage of 3 volts, which matches the voltage needed by the LEDs that we use for our solar lights.
This rate of capacity loss is pretty high, but not to worry, according to the technical literature for LiFePO4 batteries, the loss per cycle drops by more than half of you discharge only half of the energy per cycle, and it drops by more than a factor of three if you you discharge only a third of the energy per cycle. So we can make the cycle life as long as we want by adjusting the amount of energy discharged during each daily charge and discharge of the light.
And this way, we make the light last as many years as we want. We then take the assembled electronics, encase them in epoxy resin to make them indestructible, and bam! We have our forever lights.
We have a couple of dozen such lights out the field with customers now, to validate the customer acceptance of the new design. So far, so good.
We have about 3000 customers who have gotten solar lights over the last few years. With continued verification of the "forever light" performance we hope to distribute one free light to each of our previous 3000 customers (they can use the old solar panel), and then they can buy any additional lights that they may want for about $7 each. We also have enough solar panels in stock for 1000 new customers. So we will have a busy year ahead--lighting wise--in 2021.
Solar electric vehicles for African villagers? Problem Solved!
I have mentioned it in passing in previous letters as a side project, but now we have verified that we know how to provides solar electric vehicles to African villagers. Specifically, we have done the proof of concept for a half-ton solar electric tricycle that costs less than $3000 each: delivered and assembled in Malawi with solar panels!
Tens, if not hundreds of millions of electric motored tricycles operate in China. China converted to the electric tricycles and scooters as part of addressing their urban air pollution problems. But it is not so sunny in much of China and grid electricity is accessible and cheap, so none of the small electric vehicles in China have been converted to solar.
So in our last miscellaneous parts container, we brought two electric tricycles. And we can proudly say that they run off of solar ... no major problems: except that you have to operate during the day and sometimes wait for the capacitors or hybrid battery/capacitors to charge. You can see a short snippet of Gilbert and James returning from one of our little test runs in the YouTube video right here:
Next, we will get some metal workers to build the frame for a roof shade for the vehicle, and we will mount the solar panels up on the new roof frame/shade.
Lowering the cost of solar panels in Malawi by 50%
The other big thing that we have done, is that we have successfully demonstrated that we can lower the cost of solar panels in Malawi by 50% by doing direct imports.
Specifically, we bought a container full of 300 watt solar panels. And if you add up all of the costs of getting the panels to Malawi and divide that by 380 panels, our cost is only $75 per panel. That is only $0.25 per watt of panel capacity. The typical retail price in Malawi for such a panel is $150.
For comparison, if you install 10,000 watts of solar panels on your roof in the US, the supplier will typically charge $20K to $30K, or almost ten times per watt as we can pay for just the panel in Malawi. And because Malawians have very little money, they need very inexpensive solar.
So the way we make solar electricity cheap for Malawi villagers, is first we get the panel for cheap, and then we try to keep all the other costs of installing and running a panel in a household solar system very cheap also.
Upgrading our solar cooker to 300 Watts
Last year's solar cookers were about 180 watts because we had 180 watt panels in stock.
Well, now that the panels are 300 watts we are upgrading the cooker to be almost twice as powerful. And because the panels now cost half as much per watt, customers can get about twice the power without much of an increase in cost.
This requires upgrading the design of our cooker, which we have done over the past few weeks.
Selling solar pumps
As I mentioned before, we also sell solar pumps as a side project. When we can get the solar panels for cheap, we can sell a whole solar pumping system for what would normally be the wholesale price of just the solar panels. And we can do this at a small profit amd very little hassle by selling to independent distributors who do all of the retail sales work. The distributors then mark-up the price and sell to farmers.
One pump that costs maybe a little over $300 for the distributor, can earn a farmer thousands of dollars in the course of three months by growing vegetables in the dry season.
Here is a short video of one of our new, more powerful 60 volt DC pumps which are powered by two of the 300 watt solar panels that we just imported:
It works pretty well even when a cloud is blocking the sun!
Four paths to financial sustainability
So we now have in operation: four different solar business lines: Lights, cookers, pumps and cars. Any one of these could create a viable and growing business. So chances are at least one of them will work well enough to be the basis for growth in the coming years.
For our operations to survive at its current level, we need about $1500 per month to cover salaries and operating expenses. Since we want to be a relatively low overhead organization, we don't want more than 20% of revenues to go for operating expenses. This means that when we have sales of $7500 per month (or $90,000 per year) we reach financial sustainability, if we make sure to add 25% to the cost of goods to cover our overhead operating expenses when we sell things.
In 2021, we should be able to sell about $20k in solar lights, $15k in cookers, $15k in solar pumps and $6k in small solar vehicles, for a total of $56k total sales in 2021: in a pandemic year no less.
Note that because of their social benefits, the solar lights and cookers will always receive some level of grant and donation support which I include in the sales numbers above.
I think that without too much effort, there is a very good chance that we can reach $100k in sales in either 2022 or 2023. Simply by growing each of these lines of business in ways that are financially sustainable. This includes systematically growing some of our donations for solar lights and cookers.
And once we have financially sustainable growth, the sunny sky is the limit!
Sorry for the long letter, but a lot is happening. That is probably enough for now.
Here is wishing all of you a happy 2021!