Around the World with the Woltjers

Despite the fact that we have a power substation less than 1 km from our station and power lines running right alongside the border of our station, the Nazarene ministries at Kudjip don’t receive any power from the PNG Power grid.

This might seem odd in most circumstances, since power is quite an important utility for a hospital to have. But, since about 2013, when the hydroelectric plant was completed, the Kudjip Station has been generating its own power, primarily because of power quality concerns.

Over the years, there have been many thousands of dollars of equipment destroyed or damaged due to power quality issues. This, together with the high cost of running backup generators during the (sometimes extended) power outages of the national grid, had made it a clear choice to seek project funding to build a small hydroelectric plant right on our station.

We won’t go over the hydro power plant in detail today. If you want to read about a previous time where we had performed a major service, you can see the post “Service to the Hydro”.

We are very blessed to have affordable and relatively reliable power due to the hydro plant, but it is a lot of work to maintain. One of the biggest challenges for us is the large volume of sand and gravel that is continuously washed down the river from up in the mountains. This ends up filling our reservoir, blocking the intake to the canal, and even filling up the “forebay” at the end of the canal, right before the turbine.

Keeping the reservoir clean requires attention and frequent scheduled outages, where we open the gates of the dam and let the river wash some of the sand and gravel out. Cleaning the forebay is much more involved, as there is no easy way to let the water safely remove the sand and gravel. Instead, we have to bring an excavator to the overflow channel, right by the penstock, and have a team of guys with shovels move the sand (sometimes quite a mountain of it) to where it can be removed by the excavator. We also have a small drain gate at the end of the forebay that we can open and use to allow sand and gravel to be flushed out, but this hasn’t been very effective on its own.

Last month we had enough heavy rains in the mountains that brought with them enough gravel down the river to nearly fill our reservoir to the top. Opening the gates only allowed for a channel of gravel to be removed, so we had to take further action. We painstakingly found a company that would let us hire their large excavator (about 3 times larger than our Komatsu PC-78) for a few days. The amount of work this machine was able to get done was amazing.

After two days of work, the reservoir was in significantly better shape. The far side of the reservoir still had a good amount of gravel (that had been there for a long time), but we could only afford to keep the hydro off for a couple of days this time. We are thinking through how to improve this for the long term – whether it means finding a company that can come once or twice a year to clear out the reservoir, changing how we clear out the reservoir with the help of the river, or saving to purchase another piece of heavy equipment.

Regardless of what will be decided, we are extremely grateful to have the reservoir and hydroelectric plant providing efficient and reliable power for the hospital and our station. You can be praying for the NMS team as we continue to maintain the hydro over the years.