Attending Microhydro Workshop in CRCS ITB (Part 1)

On 11-12 December 2018, I had an opportunity to participate in national seminar on instrumentation, control, and automation, as well as microhydro workshop. This event was held by CITA ITB (Center for Instrumentation Technology and Automation Institut Teknologi Bandung, Indonesia). It was a really awesome event, especially workshop on microhydro. In this post, I want to share to you what I got from the workshop.

The microhydro workshop was presented by Ir. Kusetiadi Raharjo, owner and director of PT Heksa Prakarsa Teknik. PT Heksa Prakarsa Teknik is one of microhydro technology provider and training provider on microhydro in Bandung, Indonesia. Ir. Kusetiadi Raharjo is alumni of engineering physics department of ITB.

If you follow this blog, you see that I shared several posts on renewable energy resources, such as solar photovoltaic, wind power, hydro power, geothermal, etc. I was so excited that my interest is matched with this workshop. In this post, you will see potential of microhydro power and several photos of microhydro turbines.

[Read more: Renewable Energy Sources: Solar, Wind, and Hydropower]

Microhydropower is one of potential source of energy. It is renewable, applied in small scale, and to maximize it, it can be combined with other type of renewable energy source, such as solar photovoltaic, to become hybrid renewable energy. Potential of microhydropower will be maximum during rainy season. During dry season, solar photovoltaic utilization will be at its peak.

In term of range of power produced, there are several differences. Microhydro power plant will generate electricity less than 500 kW. While minihydro power plant will generate 500 kW – 5 MW electricity, and megahydro power plant will generate more than 5 MW electricity.

For microhydro power, local content has already achieved 100%. Furthermore, PT Heksa Prakarsa Teknis already exported water turbines to several countries, such as Japan, Africa, and Europe.

Mr. Kusetiadi Rahardjo believes that microhydro technologies can compete with China products. It is because, microhydro power is tailor-made, it is not mass products. The product should considered actual field condition.

Microhydro power plant is actually suitable for location where access to electricity or main electricity grid is far. Power generated can be distributed off-grid or on-grid. The power can also be utilized for centrifugal pump for irigation.

In Indonesia, most old hydropower plant can be utilized. The turbines are still OK. However, the generated must be repaired because long time ago, Indonesia used 110 V system. But now, we used 220 V.

How can we know if we can build microhydropower plant? This table show the guidelines.

Nowadays several softwares are used to model turbines so that the turbines are efficient. Those softwares are CAD, Solidwork, and Ansys.

Microhydro power plant projects usually consist of 70% civil work and 30% mechanical.

Basic energy equation of water to power is very simple:

P_net = e_o * 9.8 * Q * h_gross

Basic energy equation of water to power is very simple:

P_net    = power generated, in kW

e_o    = overall efficiency (function of efficiency of civil works, penstock, turbine, generator)

Q    = flow of water through turbines, in m³/s

h_gross    = gross head/geodetic on turbine, in meter

For microhydro power, debit data is taken annually.

There are several ways to measure head of potential place for micro and minihydro power.

Method	Comments	Advantages and Limitations	Accuracy	Precautions
Water-filled tube and rods (or person)	Weight: light Expense: low	Long-winded for high heads	Approx. 5%	Repeat measurements
Water-filled tube and pressure gauge	Calibration chart must be drawn up Weight: light Expense: low	Fast, quite foolproof, can measure penstock length at same time	Good (<5%) if gauge is calibrated	Recalibrate the gauge. Repeat measurements
Spirit level and plank (or string)	Weight: light Expense: low	Unsuitable for long gentle slopes. Slow to use Best done with two people	Approx. 5% on steep slopes 10-20% accuracy on gentle slopes (1:10)	Repeat measurements
Altimeter	Weight: can be heavy, some are light Expense: high	Useful on medium and high heads (>40 m) Can be fast, but more reliable if continuous monitoring undertaken	Gross error (30%) possible. Used with skill, 2% at high heads	Experience and skill needed. Must be calibrated and temperature corrected

 

 

 

 

There are several steps in developing micro and minihydro power plants, which are desk study, reconnaissance visit, pre-feasibility study, feasibility study, and detailed design.

• Desk Study. The purpose is to become familiar with the physical, hydrologic and socio-economic profile of the project area without visiting the site but using maps, data from Bureau of Water Resources (BWR) and the statistical office only. In many cases, the desk study will reveal the absence of a good hydropower potential and time and expenditures for travelling to the proposed site can be saved.
• Reconnaissance Visit. It is a short (one-day) visit to the proposed site (upon invitation by project promotor) to verify the hydropower potential and the approximate power demand.
• Pre-feasibility Study. The purpose is to determine which of several proposed projects or sites are most attractive for minihydro power development and therefore deserve priority development and further investigations.
• Feasibility Study. The purpose is to definitely assess whether the implementation of the proposed scheme is desirable or not.
• Detail Design. The purpose is to prepare the scheme layout, the canal and structure drawings in final detail.

I can’t believe that this post will be this long! This is not end yet. This post will be continued in the second post.

I hope you find this post is useful.