In this Bangkok neighbourhood, you can buy and sell electricity using Blockchain

Residents in a Bangkok neighbourhood are trying out a renewable energy trading platform that allows them to buy and sell electricity between themselves, signalling the growing popularity of such systems as solar panels get cheaper.

The pilot project in the centre of Thailand's capital is among the world's largest peer-to-peer renewable energy trading platforms using blockchain, according to the firms involved.

The system has a total generating capacity of 635 KW that can be traded via Bangkok city's electricity grid between a mall, a school, a dental hospital and an apartment complex.

Commercial operations will begin next month, said David Martin, managing director of Power Ledger, an Australian firm that develops technology for the energy industry and is a partner in the project.

"By enabling trade in renewable energy, the community meets its own energy demands, leading to lower bills for buyers, better prices for sellers, and a smaller carbon footprint for all," he said.

"It will encourage more consumers to make the switch to renewable energy, as the cost can be offset by selling excess energy to neighbours," he told the Thomson Reuters Foundation.

Neighbourhoods from New York to Melbourne are upending the way power is produced and sold, with solar panels, mini grids and smart meters that can measure when energy is consumed rather than overall consumption.

The World Energy Council predicts that such decentralised energy will grow to about a fourth of the market in 2025 from 5 percent today.

Helping it along is blockchain, the distributed ledger technology that underpins bitcoin currency, which offers a transparent way to handle complex transactions between users, producers, and even traders and utilities.

Blockchain also saves individuals the drudgery of switching between sending power and receiving it, said Martin.

For the pilot in Bangkok's upmarket Sukhumvit neighbourhood, electricity generated by each of the four locations will be initially used within that building. Excess energy can be sold to the others through the trading system.

If there is a surplus from all four, it will be sold to the local energy storage system, and to the grid in the future, said Gloyta Nathalang, a spokeswoman for Thai renewable energy firm BCPG, which installed the meters and solar panels.

Thailand is Southeast Asia's leading developer of renewable energy, and aims to have it account for 30 percent of final energy consumption by 2036.

The energy ministry has encouraged community renewable energy projects to reduce fossil fuel usage, and the regulator is drafting new rules to permit the trade of energy.

The Bangkok Metropolitan Electricity Authority forecasts "peer-to-peer energy trading to become mainstream for power generation in the long run," a spokesman told reporters.

BCPG, in partnership with the Thai real estate developer Sansiri, plans to roll out similar energy trading systems with solar panels and blockchain for a total capacity of 2 MW by 2021, said Gloyta.

"There are opportunities everywhere - not just in cities, but also in islands and remote areas where electricity supply is a challenge," she said.