Renewable energy producers yesterday urged the Energy Ministry to review the "adder" tariff, saying the current rates are not attractive enough to encourage new business.

Patama Wongtoythong, CEO of Solartron, a solar-module manufacturer, said the current structure was too low. The actual adder for solar modules should be Bt12 per unit, for example.

The adder is the incentive sitting on top of conventional power rates offered by the Electricity Generating Authority of Thailand to small power producers (SPPs) and very small power producers (VSPPs) for their use of renewable energy sources.

Wirachai Roynarin from Rajamongala University of Technology Thanyaburi also told the seminar, hosted by Krungthep Turakij earlier this week, that the state should raise the adder for wind energy over 100KW in the range of Bt4-Bt5 per unit, and for wind energy not exceeding 100KW to Bt6-Bt8 per unit to reflect actual costs.

Wind energy installation requires higher investment than other renewable energies, so the adder of Bt3.50 is not an inducement, he added.

Natee Sithiprasasana, CEO of AT Biopower, a biomass power company, said the Energy Ministry should support other potential biomass materials to replace rice husks, which are already in limited supply and could face shortages in the future as demand grows.

"The adder might not support the investor as it should, if the ministry fails to handle supply and demand for renewable energy. The state should set up an agency to oversee supply and demand to support co-generation," he said.

The ministry should lift the biomass adder to Bt1.30 from the current Bt0.30 because biomass transport costs are higher than for other energy types, he said.

In the VSPP category, solar energy now enjoys the maximum adder of Bt8 per unit, followed by wind energy at Bt3.50, garbage at Bt2.50, water for plants with capacity of less than 50 kilowatts at Bt0.80, water for plants with capacity of 50kw-200kw at Bt0.40, and biogas and biomass at Bt0.30.

For SPPs, solar energy merits Bt8 per unit, while wind energy receives Bt2.50 and garbage Bt2.50.

Narupat Amornkosit, director of the power division at the Energy Policy and Planning Office, said the private sector's proposals would be taken into consideration. But right now, the energy minister is reviewing the incentive scheme to see if it should be extended from the end of this year.

She said the promotion should be continued as Thailand plans to build up renewable energy from 0.5 per cent of total capacity to 8 per cent by 2011.

Because of the adder, many SPPs have shown immense interest in investing in co-generation power plants, she added.