SESB repairmen at work
I am very happy to report that our Phase 3 system continues to function smoothly and is creating significant savings in day-to-day operations at Holy Cross Anglican School. Over the 3 month period ending 12/24/2018, power consumption through this meter/breaker amounted to 7.36MWh (Megawatt-hours), with the solar array producing 3.17MWh -- meeting 43% of our needs for this part of the school. Over the last month, as temperatures have cooled and A/C demands (used in the computer learning lab and staff office) have decreased, we have needed 1.67MWh and generated 0.866MWh, providing 51% of our power demands. Unfortunately --- it could be better if BEL (Belize Electricity) would just allow some sort of net-metering --- but they are still not offering such a program after many years of stating they would begin one. As long as this remains the case, the Phase 3 system is pretty much maxed out in terms of the benefits we can expect in the near term.
Further, we have completed some overdue repairs on our Phase 2 system. These repairs became necessary do to a combination of problems with individual panel micro-inverters and issues with wiring. In many developing world locations, structures are not well protected from invasive species like mice and rats that enjoy gnawing on electrical wiring -- and our school is among those that has such a problem. The work converted the Phase 2 array -- which consists of 20 250Watt TRINA solar panels -- from micro-inverters to two string inverters, and repaired/protected the wiring. Due to temperature in Belize, age of the modules and the fact that it is an “East-West" lay-out, the max we are expecting is around 4.3KW, and we have already seen a day when we achieved 4.1KW (kilowatts -- noting that KW and MW are measures of the rate at which power is generated, whereas KWh and MWh are measures of the total generated. Analogy: think of a rain gauge -- it measures the total that fell (like MWh); and if I know how long it took it to fall, I could calculate the rate, like MW). The existing e-Gauge is back on-line, displaying the PV production and the energy usage from BEL (see earlier reports for URL).
By comparison with Phase 3, over the last 3 months, power consumption through this meter/breaker amounted to 5.64MWh, with the solar array producing only 1.23MWh, lower than expected due to the problems with the micro-inverters (21% offset). The repairs were completed a little less than a month ago, and during this period we generated about 27% of total demand. Thus, we believe even if BEL net-metering policies do not change, there is room to add additional panels to "this side of the house." I've attached a few pictures from the repair crew.
Thus, thanks to you, our generous supporters, we are officially on to Phase 4!! In the next few months, we will re-visit all options for Phase 4 -- including the possibility of investing in some battery storage, since it would be prudent to be able to store power (rather than send it back to BEL when we over-generate), and then use it at a later time, like overnight. I will review the results of our Phase 4 planning period in the next report. We want also to extend sincere thanks to Baker Renewable Energy in Raleigh and Solar Energy Solutions Belize in Belmopan for their partnership on the project.
May you each have a meaningful and peaceful holiday season and New Year ahead.
Phase 2 (foreground); Phase 1/3 (background)
Micro-to-string inverter conversion