Rooftop Solar in Cambodia
A look back and a way forward

Written by Rogier van Mansvelt, Bridget McIntosh and Arjen Luxwolda

History of Rooftop Solar in Cambodia

Before 2018 there was no regulation for customers wishing to install solar. However, customers started installing solar systems as the global cost of solar was rapidly declining. There were cases of EDC requiring rooftop solar systems to be removed or turned off, rumours about a new regulation.

In January 2018, the Cambodian Government introduced a regulation for customers installing solar. The following summarises the regulation and the changes made to date:

  • January 2018 – EAC Solar Regulation released, included:
    • Technical specifications
    • Tariff to include power capacity charge and energy charge (not specified, but to be announced by EAC and updated from time to time)
    • Zero export of power
    • Restrict size to 50% of contracted capacity
    • No Implementation Process or Procedure (e.g., forms, timelines etc) released except indication that it should take 1 month.
  • May 2018 - EAC released first 'tariff for consumers with Solar PV system'; including capacity and energy pricing for different size consumers. The overall tariff favoured customers with 24h/7 production, less useful for factories with daytime load only (e.g., garment factories)
  • August 2019 - Consultation Round 1 EAC release new tariff - customers (not just solar customers) to have capacity and energy charge (peak and off-peak rate) to start January 2021. Although not stated, applied automatically to solar customers; other customers can voluntarily use the tariff before January 2021;
  • January 2020 (14th) - MME Prakas No. 0040 updates pricing for 2020 and 2021 and new tariff arrangement - customers can choose energy only tariff or capacity charge and energy tariff with peak/offpeak rate in 2020 but not in 2021. Solar customers cannot choose – pay capacity charge and fixed energy rate, not allowed to access off peak rate.
  • January 2020 (31st) - EAC Consultation Round 2 – similar to MME Prakas, but the capacity charge for all customers in 2021 is removed from tlhe table and replaced with a note "The option to pay electricity bill, average rate, [for MV &HV] will be expired until 31st, December 2020. Solar customers cannot choose – pay capacity charge and fixed energy rate, not allowed to access off peak rate.
  • February 2020 – EAC tariff confirmed, almost identical to EAC consultation tariff – Solar customers pay capacity charge, fixed energy rate and no access to off peak rate. All other customers can choose to have a capacity charge with time of use energy rate; or just an average energy rate.
  • 2020 - EDC negotiates with CMIC and Cleantech Solar to sell power directly to EDC – otherwise CMIC as a solar customer not eligible for offpeak tariff so it is more economic to turn off the 10MW system.
  • February 2021 – EAC releases updated tariffs, similar rate to 2020 (some slightly lower tariffs for larger customers with solar eg solar for HV customers changed from 11.5 to 11.4c/kWh). Solar customers still not eligible to access off peak rate.
Summary of the Challenges and Recommendations For a Way Forward

Policy Level

The most challenging aspect of any regulation is changes relating to pricing that are made and an applied retrospectively. Customers make investment decisions based on government regulations at the time, and if these changes render those investments obsolete, this makes further investment in the Kingdom difficult. Of course, technical and safety regulations could be applied to all systems.

The following summarises the policy challenges for customers installing solar under the solar regulation and pricing:

  1. Capacity Charge for power – To be fair this should apply to all commercial and industrial customers, similar to most electricity utilities around the world (e.g., Malaysia charges highest load from the last month). This would allow EDC to be paid for providing the grid infrastructure separately to energy. This was proposed by EAC in August 2019 and MME in 2020, but never taken up. Alternatively, the capacity charge could be applied to the solar inverter AC output - it still provides the EDC compensation for the grid connection but currently the installation has to pay double the capacity charge based on the AC solar output. Also, large electricity customers with a small roofspace means solar is not economic because they switch to the penalised tariffs for solar customers even with a small system.
  2. Offpeak tariff access – Customers who install solar are penalised by not being allowed to access offpeak tariff e.g., hospitals. Solar customers actually help EDC with their daily peak (during daylight hours) so penalising solar customers by not allowing them to access time of use/off peak tariffs is surprising.
  3. Export of excess power – Customers are not permitted to export power to the EDC grid, for example schools during holidays; or garment factories on weekends. Both customers and EDC could benefit - EDC would receive power close to the consumption source at a very competitive price; customers don't have to 'curtail' and waste the power. Recommend similar option to Vietnam where up to 110 to 20% of electricity consumed can be exported to the grid.
  4. 50% limit (this wouldn't be a problem if 1 and 3 above were adjusted). Generally, most customers wouldn't install solar more than 50% as it is better to design for self-consumption than export.
  5. Grandfathering existing projects – Customers who invested in solar before there was a regulation should not be penalised.
  6. LV systems – Many households would like to install solar but there is no clarity on regulation for them e.g., is there a limit where the tariff does not apply, what is the tariff for LV systems; and does zero export apply for them.
Implementation of Regulation

Many challenges are faced in the implementation of the regulation. Overall, there is a need for a clear application form and process as some of these issues have been identified:

  1. EDC has been developed a form to apply, however it needs clear instruction on what attached documents are required. According to the solar regulation process time is 1 months however this has often taken much longer. In some cases, no written response has been received.
  2. REEs - It would help to have clarity on the how REE's process applications should be.
  3. EAC has published a tariff structure for PPSEZ, but there is no mention of solar in this tariff. Therefore, in PPSEZ its now unclear how to implement the solar regulations.
Technical Issues during Implementation

Some minor technical challenges are faced in the implementation of the regulation, as follows:

  1. The zero export is hard to setup:
    • Most inverter brands still export a little due to phase imbalance or speed of regulation of power. There should be a few second response time and balance of phases to be zero.
    • For example, if large loads turn off - zero export reacting time could be set to a maximum 3-5 seconds
    • Recommend a monthly maximum allowed zero export of 2% of solar generation
  2. The level of harmonics depends largely on the power output of the inverters. At low power output the harmonics are higher, but the overall harmonics are low. Recommend the harmonics levels are measured when inverters are running at 70% or more capacity, or be calculated as a total of the maximum AC output and the actual output.
  3. Solar inverters can help to improve the power factor. We would suggest to allow up to 5% reverse reactive energy for solar installations.