Mini-hydro Power Plants in Irrigation Canals.

The National Irrigation Administration (NIA) is planning to put up 40 mini-hydro power plants. NIA administrator Antonio S. Nangel said they have already identified 20 locations in Luzon, 10 in Visayas and 10 in Mindanao.

Nagel came up with the idea of putting up mini-hydro powers in irrigation systems following his recent visit in Japan where he saw mini-hydro power plants installed in irrigation canals. He said while it can be done in Japan, it can also be done in the country where the same elevation of irrigation canals abounds.

"Our irrigation systems are mostly located in far-flung barangays and putting up this project is a great help to the prospective beneficiaries," he said.

An irrigation system, the NIA said, could produce at least 20 megawatts of electricity daily.

Each mini-hydro power plant would cost P20 million and would be shouldered by local investors. 

Nangel expressed optimism that the project will take-off as 12 firms have submitted Letter of Intent (LOI), and targeted 12 sites for development.

He said there are two memorandum of agreements (MOAs) already signed for the project but he declined to name the investors.

What is Mini-Hydro Power Plants?

Mini-hydro power plants is a type of hydroelectric power that typically produce up to 100 kW of electricity using the natural flow of water. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks. An example of this is the Momura micro hydropower in Japan. 

The Momura Micro Hydro Power Plant in Japan

Mini-Hydro Power Plants Pros and Cons

A study on the pros and cons was published by the Alternative Energy on October 26, 2006 citing that there are some common misconceptions about micro-hydro power that need to be addressed.

PROS

1. Efficient energy source
It only takes a small amount of flow (as little as two gallons per minute) or a drop as low as two feet to generate electricity with micro hydro. Electricity can be delivered as far as a mile away to the location where it is being used.

2. Reliable electricity source
Hydro produces a continuous supply of electrical energy in comparison to other small-scale renewable technologies. The peak energy season is during the winter months when large quantities of electricity are required.

3. No reservoir required
Microhydro is considered to function as a ‘run-of-river’ system, meaning that the water passing through the generator is directed back into the stream with relatively little impact on the surrounding ecology.

4. Cost effective energy solution
Building a small-scale hydro-power system can cost from $1,000 – $20,000, depending on site electricity requirements and location. Maintenance fees are relatively small in comparison to other technologies.

5. Power for developing countries
Because of the low-cost versatility and longevity of micro hydro, developing countries can manufacture and implement the technology to help supply much needed electricity to small communities and villages.

6. Integrate with the local power grid
If your site produces a large amount of excess energy, some power companies will buy back your electricity overflow. You also have the ability to supplement your level of micro power with intake from the power grid.

CONS

1 Suitable site characteristics required
In order to take full advantage of the electrical potential of small streams, a suitable site is needed. Factors to consider are: distance from the power source to the location where energy is required, stream size (including flow rate, output and drop), and a balance of system components — inverter, batteries, controller, transmission line and pipelines.

2. Energy expansion not possible
The size and flow of small streams may restrict future site expansion as the power demand increases.

3. Low-power in the summer months
In many locations stream size will fluctuate seasonally. During the summer months there will likely be less flow and therefore less power output. Advanced planning and research will be needed to ensure adequate energy requirements are met.

4. Environmental impact
The ecological impact of small-scale hydro is minimal; however the low-level environmental effects must be taken into consideration before construction begins. Stream water will be diverted away from a portion of the stream, and proper caution must be exercised to ensure there will be no damaging impact on the local ecology or civil infrastructure.

My Verdict

Micro hydro power is a very good source of clean alternative energy. It is a source of energy that is both efficient and reliable.These small hydropower systems should never pose any problems like wind turbines that noisily dot the countryside, or stack gas emissions coming from fossil fuel fired power plants. There won’t even be a vapor flume from a cooling tower. Any way you look at this form of hydropower, it comes up a winner. 

The only question here is what would happen to the surplus electricity that this mini-hydro power plant produce? I'm sure it would be feed to the grid, but then, will the consumer  feel the effect of this cheap energy source?