Facing the Operational Challenges of Mini-grids - Discussion

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Analyzing Drivers and Barriers for Renewable Energy Integration to Small Islands Power Generation – Tapping a Huge Market Potential[1]:

  • The implementation of regulatory frameworks (e.g. feed-in tariff) or any other support from the governments was taken into consideration.
  • A unique regulatory framework for islands should be supported. The current ones do no work perfectly. The share of renewable energies is increased by incentives such as feed-in tariff (no matter how bad the tariff is, it always helps to increase the RE share).

A Community Managed Micro-Hydro Connected Mini-grid in Nepal

Example community managed Micro-Hydro Connected Mini-grid in Nepal[2]:

  • Handling the load of the MHP: the challenge is the load capacity, during the day only 3 or 4 MHP have to run, not all of them.
  • If a connection to the grid is present, then no load management would be needed. The hydro plants could be controlled with valves and control units that depend on the actual load, instead of controlling them manually. – The load is being controlled with the synchronizable electronic load controller (ELC), not the flow.

Overcoming Grid Instability in Micro-grids by Using a Flywheel Energy Storage System While Operating a PV / Diesel Hybrid System[3]

1. What could be said about the price of the whole system?

  • It is hard to say, prices depend on the size of the system, the required capacity and used technology, e.g. if lower power supply quality standards are acceptable, cheaper systems can be realized.

2. Has this system been used in combination with other RE-sources?

  • There has been a solution for hydro-plant on the Acorean Island in the Atlantic, where the total system was able to run for a couple of days in a row. Spinning reserve is needed to ensure a failure of the plant can be covered (since there is volatility in the RE-source).
  • Two diesel-generators are the minimum needed, even if only one of them is in use, the other should be a back-up.

3. Why is the load of the system so high (2 MW) in the Ross Island project?

  • The research-basis has a lot of technical equipment, that causes the big load. Even though it is critical to have a stable supply, this system can now operate with a lot of renewable energy contribution, meeting the required quality.

Open Discussion and Questions

1. Are there common regulatory frameworks on islands?

  • The regulatory frameworks on islands are crucial for the deployment of RE, but they are related to the countries. Semi-autonomous countries have a strong link to their former colonial countries and most of them use feed-in tariffs.

2. How big is the influence of regulatory frameworks in reality, for example in Nepal?

  • In Nepal there is no feed-in tariff existent. Due to this, there are technical solutions for cooperation.
  • The utilities have to take care of power quality.

3. Does a framework for the framework exist, something like an international overlook from all countries?

  • Not exactly. IRENA (International Renewable Energy Agency) exists and advices countries in policies setups or prevent mistakes while regulatory frameworks are being developed. Caribbean islands for example have a strong influence from the US. In addition, frameworks help to develop better business plans for RE.

4. Difficulties in financing huge projects?

  • Two points of view: (1) People have the money and invest because they know that the system in going to be paid. (2) Small communities that need the energy supply are mainly financed by NGOs and third parties.
  • Suggestion of ABB to the control system used in Nepal: control the valves by the load differences.

5. Are there any problems concerning the paying strategy/financing in Nepal?

  • No, the project is financed by the people who are paying for the electricity.

6. Outlook of the Nepal project: follow-up projects without the need of financial support from the outside.

  • Gradual shift to community credits, no tariff by connecting to main grid.

Further Information


  1. Information by Enrico Howe - Reiner Lemoine Institut - http://www.reiner-lemoine-institut.de/en
  2. By Bhupendra Shakya - Renewable Energy for Rural Livelihood Programme AEPC - http://www.aepc.gov.np/?option=aboutus&page=aboutsub&mid=1&sub_id=3&id=3fckLR
  3. By Martin Baart - ABB