Micro Hydro Power (MHP) - Pros and Cons

Micro Hydro Pros - Advantages

It only takes a small amount of flow (as little as few litres per minute) or a drop as low as 1 m to generate electricity with micro hydro. Electricity can be delivered as far as 1 km away to the location where it is being used. If planned carefully and well adapted to the environmental conditions, micro hydropower schemes produce 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. MHP 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. In comparison to large hydropower, MHP thus only has a little negative environmental impact. Negative socio-economic impacts are even insignificant in comparison.

Furthermore, MHP can be considered a 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. Due to the low-cost versatility and longevity of MHP, developing countries can manufacture and implement the technology to help supply much needed electricity to small communities and villages. If the MHP plant produces a large amount of excess energy, some power companies might buy back electricity overflow. Furthermore,it is possible to supplement the micro hydropower with intake from the power grid.

Micro Hydro Cons - Disadvantages

There are, however, a number of disadvantages that need to be taken into account. MHP plants require certain site conditions and are thus not suitable for any location. 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.

Furthermore, the size and flow of small streams may restrict future site expansion as the power demand increases.

As MHP plants require no reservoir, electricity generation is highly dependant on an constantly sufficient river discharge. 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.

Finally, environmental impacts need to be taken into account. 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.