To provide a view of how we’ve been spending a lot of time, I’m going to write today about our challenges understanding how the Delco (generator) charges the battery bank which in turn feeds the inverter which in turn provides AC power to the guesthouse when the generator is not running.
What we’re really doing is collecting some numbers to confirm the conventional wisdom about how these three interact.
(To those of you who are already yawning, feel free to make smart remarks as I’ve now enabled “Comments” on this blog.)
Our big picture objective is to find out how much it costs to provide electricity for the guesthouse. First, we’re trying to figure out how much fuel is used per hour by the Delco. We also want to know how long the charge lasts in the batteries, and what is apt to drain them. (I’ll put headings on the details below so you can stop reading any time…)
The generator, which is really an SDMO brand, is sized to support much more than the guesthouse.
When the hospital buildings come on line (we hope the surgical center of the Leogane Family Health Center will begin construction this fall), we will notneed a bigger generator for backup power.
As we run the Delco each evening to charge the batteries, it’s operating at less than one quarter capacity. This means we can run the whole house fan and the room air conditioners at the same time as the Delco for very little additional fuel.
Note to non-techies – A/C for a few hours in Leogane, a town with small breezes and daily temps in the 90’s, is heaven.
The Batteries and their Level
Here we have them, the objects of Jeff’s concentration, three banks of 8 batteries each (6-volt, deep draw, lead acid).
What he really cares about is how fast the level of the 24 batteries goes down. He is trying to figure out their capacity and if they are working optimally – lots of googling and calculations.
For the uninitiated, the inverter converts DC power stored in the batteries to AC for use in the house.
When the Delco is running, AC power goes directly to the house while the inverter converts AC to DC for battery storage. Summary – it works in both directions.
And, the inverter’s solid state technology is clever – no moving parts.
(We were amused today to see a headline in one of the New York papers about businesses going off the grid. Maybe Jeff should consult with them before they take precipitous actions?)
Will we ever have Electricite de Haiti here at the guesthouse? Someone thinks we will as all the boxes are already installed here, although not connected to anything.
New EDH poles line the Leogane Road, a closeby intersection – we can see them from the guesthouse. Jeff estimates the power poles are 500 yards away.
Someday soon we’ll talk to more locals about how regular the electrical service is – how many hours a day we could get service, and how often the power fluctuates radically.
If the service has become more regular (it wasn’t when Missy Owen lived in Leogane a year ago), then we can figure out if the cost of using EDH to charge the batteries, as friendJacqui LaBrom does in Port-au-Prince, is a smart move for FHM.