Lightbulbs = Water?

You save electricity you get water, it's rare that's you get to see how our valuable resources can be so interconnected, unless one or both are a bit scarcer than we’re used to. As a point of comparison, recall the recent events during the California drought, when water became scarce and residents were limited to only 25 gallons a day. At the time, California was considering mitigating the water situation by bringing online the continent's largest desalinization plant, a huge draw on power. You spend power, you get water.

I bring all this up because we had the opportunity to witness a similar sort of microcosm of managing resource constraints in Batey Cuchilla. When we were forced to connect the community water pump to the AC electric grid, we were then faced with the reality that available power is not always guaranteed.

Two weeks prior to travel for what was planned to be purely an observation and assessment trip, the solar panels powering the community's well water pump were stolen, leaving the community without a method for retrieving water from their well, which was contaminated to begin with. As a group, we then agreed that one of our primary objectives of that trip should be to return well water service to the community. After careful consideration of available resources, it was decided that the pump should be tied to the electric grid as a band-aid solution until we could return.

The well pump that the community had available was rated at max 1.4kW, and after some quick and dirty math we estimated that we needed 600W for the pump to provide the needed amount of head to fill the water storage tank. We got 130W as the max power we could pull from the AC electric grid. Not a chance that this amount would be sufficient, we needed more available power, and the way to do that was shed load. This theory was tested by disconnecting one light bulb from the community center, and seeing the corresponding increase in power at the pump house. It should be noted, that when the power is on at the community almost everyone leaves their lights on regardless of the time of day, hence the most reasonable solution towards shedding load from the grid meant targeting the lightbulbs. It was known that many lightbulbs in the community were 100W or greater.

Could we really get community members to volunteer to turn their lights off so that they can get water? Well when it came time to test whether we could really get the pump working on the grid we asked the Peace Corps to find 5 homes that were willing to turn their lights off in the name of science. They found 10! We were assuming 2 bulbs per house at an average of 60W each, meaning 5 homes by themselves would allow us to reach the minimum 600W to provide the needed pump head to fill the tank. After 10 homes turned their lights off, we found with great excitement that the pump operated at its full 1.4kW design capacity.

So, turning off lights certainly worked as expected (or better), but could it really work in the medium term? It was expected to be at least a year before we could possibly arrange for the installation of new solar panels. A social approach would certainly require a lot of social coordination and possibly a change of lifestyle for it to work longer term. Instead of requiring a change of lifestyle and awareness toward electrical usage, which arguably is still a good idea given more time in-country, what if we just made their usage more efficient?

It was observed that >90 percent of the lightbulbs found in the community were incandescent, with many operating at 100W or greater. If we were to replace a number of those with CFLs we could get a large amount of savings assuming the CFL lightbulb power usage was closer to 20W. So we put the plan into action, purchasing 30 CFL bulbs (including 10 for contingency).

Making an afternoon of it, we went around to about 15 community homes replacing their old incandescent lightbulbs with CFLs. However, we had to maintain one strict rule where we required that we take the old lightbulbs after we replaced them, knowing that they were likely to be put back into use if we didn't, hence electrical load would not be reduced. The process was fascinating, particularly the community reaction, which in every case was to welcome us into their private spaces to replace a couple lightbulbs.

The plan worked beyond expectation, and rarely things work as expected given these resource constraints. Once the electric grid came back online following the typical daily schedule, we walked through the community seeing their new CFL bulbs shining. We then returned to the pump house and fired up the well pump. Boom…1.4kW! We let that run for a while to fill up the tank, then opened it up to feed the community supply.

There is no feeling like the one you get when walking through a community while being asked if you're the ones who restored the water.