MEGA micro hydro: Lower Bondo
The Lower Bondo micro hydro has now been operational for one month. It has performed well with no instances of unscheduled power outages. The repaired generator and ancillary equipment are performing well.
Improvements have been made to improve performance and safety including raising the wall along sections of the power canal, installing a v-notch weir and pressure gauge for measuring flow, raising the ballast tank off the ground and strengthening pipe work, replacing 25mm2 cable with 50mm2 cable from the powerhouse to transformer. The system was offline for a few days whilst these improvements were ongoing.
The Lower Bondo power canal with raised sides for increased flow.
A 25kVA transformer has proved faulty despite repair efforts. One of the transformers assigned for Upper Bondo is in its place whilst we attempt to repair it or decide whether to purchase a new one.
The meter system has been installed and is operating well. Many houses have already consumed the free 10 units loaded on the meter and have applied for and been issued tokens to top-up.
Demand for household connections has increased markedly. We are reviewing applications using new criteria to ensure the efficient use of materials -to merit connection an individual house needs to be within close range of the existing grid, or in proximity to other connecting households. GPS data is enabling this way of working.
MEGA micro hydro: Upper Bondo
With Lower Bondo operational, attention has turned to Upper Bondo construction making September an extremely busy month. The work plan below sets out the construction timetable for completion by the end of September. It is a demanding schedule, but achievable.
The 6m, 400mm diameter PVC pipes in storage before being carried to site.
The turbine/generator /ELC manufacture is complete and ready for inspection. The manufacturer is struggling to obtain a Certificate of Origin to enable export, but hopes to receive in coming days. A cargo company has been engaged to freight to Dar es Salaam (expected 1-2 weeks), and a freight forward company will import to Malawi. The manufacturer has not met the dispatch date agreed in the procurement contract, and communication has been a challenge.
600m of conveyance PVC pipe has been delivered to the site. Teams of 10 people have been carrying each 6m length from the road head 2-3km to the conveyance channel. Connecting the pipes is scheduled for first two weeks of Sept. The de-silting basin is under construction, and will be finished this week or next.
The de-silting basin with foundation / flooring and form work for the sides.
A penstock supplier has been identified, a South Africa company that will provide 100m of steel pipe in 3m sections, 12mm thickness as soon as funds are available in Malawi.
A rental jackhammer (pneumatic hand drill) has been sourced (after much searching!) for breaking rocks at the intake and in the conveyance channel. The company engineer is visiting the site on Tuesday to verify the suitability of equipment and accessibility of site. The plan is to have the equipment on site from 1st Sept for about 8 days. The weir construction will run concurrently and take 3 days. Heavy rains last Sunday swelled the river, although have now subsided. A good spell of dry weather is required to complete the weir.
The medium voltage transmission line has been completed from the powerhouse to the village. The distribution network to customers remains. Remaining construction activities include: intake and weir construction, pipe conveyance connection, penstock laying, powerhouse construction with electro-mechanical placement, distribution grid.
The conveyance pipeline with PVC pipes in place.
There are many groups of labourers from the community (and surrounding communities) that are working on the construction; doing building works, ferrying sand, cement, breaking rocks for gravel, and carrying components. Huge amounts of aggregate is required and proving difficult to supply with manual carrying alone. A trailer has been designed and purchased for the project but unfortunately cannot be used until completion of the access road.
The MEGA Board will meet next Friday. At this event Lower Bondo assets and operational responsibility will be formally handed over from Practical Action to MEGA.
