Family Hydro - An OTC Product?

TC did a great presentation yesterday. He talked about family hydro and all development possibilities.

So family hydro in Indonesia is defined as very small, less than micro, hydropower that have capacity less than 1 kW and able to serve max 3-4 families. There is now only one technological option: propeller turbine. In the future, there is another option: cross flow turbine.

Let us start with the propeller. There are two types with same operation principle. They need draft tube to make the runner spin. The first type TC calls it “land mine”. It has permanent magnet so that as soon as the runner spins it will produce electricity. TC calls it land mine because of that dangerous aspect. The turbine has to be submerged therefore there is a risk of electrocute. It produces max 100 watts. It needs average 10 liters of water with head at least 3 meters. The second type is also a propeller turbine with max capacity of 2 kW. It needs at least 30 liters per second flow and at least 7 meters head. It is safer than the “land mines”.

Why they call it family hydro? Because usually you need to go a little out of the village to get a decent hydro potential that has enough head and flow. That kind of potential might able to serve the whole village. Many conditions found that hydropower sites near settlements are having only limited head and small flow. At those sites, you can install something small that can serve a family or some more families. This is where the family hydro term came.

Was it user friendly? It turned out that even the “land mines” still need people that have ideas on how hydropower works. The bigger family propeller needs more civil construction than simple gutter. The “land mines” is still too difficult to install for normal user, although it is intended as a product that can be sold easily on a hardware store (Over the Counter (OTC) product). Those products are still too complex to install for normal people.

Those products (land mine and family propeller) have very crucial limitation. They do not operate in a wide operation range. They need specific head and flow. If you have something different, they will not work or work but with poor efficiency. Why they have poor performance? Because they have fixed guide vane that can only work with specific condition. Family cross flow turbine (up to 2 kW so far) will soon eliminate this limitation.

Family cross flow is designed to be simple yet robust turbine. Simple workshop should able to produce it easily with decent quality and performance. It has wider operation range because one can adjust the guide vane. The problem is: it needs people that understands hydropower to install. It needs more complex civil structure than propeller. It also does not operate very well in sites with head less than 7 meters. I never make any site statistics, but finding a site with 7 meters head close to a settlement should not that difficult.

The family cross flow set different standard. It shall be able to service more than one family. It is easily produced in regions (while the propeller is coming only from Bandung – copyright restriction). It should be able to boost the application of family hydropower. It does not need outside support to finance the construction. It has wider operation range so that it can operate all year round with slightest decrease of efficiency. It is safer than the propeller especially the land mine.

Family hydro is still far for being an OTC product. Propeller might have the biggest chance but it needs more improvement. Improvement needed are: safety issue, multi guide vane package propeller, clear understandable installation procedure. For now, family hydro products only provide pre-electrification measures. They need to prove its salability in real market.(picture: CIT, Bandung)