It’s been more than half a decade since grid watchers first began talking about the concept of trading energy with your neighbors across peer-to-peer platforms.

Since then, the idea of selling the power generated by your rooftop solar panels to other individuals in the same way you might let your spare room through Airbnb has gained plenty of attention thanks to the pitches from blockchain platform developers such as Grid+. Such pitches often come with promises of lower electricity prices and more stable grids.

In terms of real-world activity, however, peer-to-peer energy trading remains challenging in practice almost everywhere, and that's especially the case in the U.S., an expert says.

Despite isolated microgrid experiments such as the one running on an LO3 Energy blockchain in Brooklyn, New York, “the U.S. is a bit of a laggard,” said Henri van Soest of the University of Cambridge, author of a March 2019 review of peer-to-peer electricity trading regulations.

“The electricity system in the U.S. is definitely far behind the European Union in terms of modern approaches to energy regulation," van Soest said.

Of 10 research and development projects listed in a January 2019 academic study of peer-to-peer markets, just one was in the U.S. The rest were in Europe, which — notwithstanding a monolithic, committee-based approach to electricity system reform — has emerged at the forefront of regulatory efforts to open the door to peer-to-peer trading.

In the past year, the European Union has passed directives mandating that all member states smooth the way for peer-to-peer energy trading by 2021.

“The big innovation in Europe is at least [peer-to-peer energy trading] not explicitly forbidden, which in many situations around the world would still be the case because of the strong lobbying power of incumbents [and] the market being less liberalized,” van Soest said.

Europe and Australia at the vanguard

Even in Europe, many jurisdictions still have some way to go to implement the EU’s rosy vision of a peer-to-peer-trading-for-all future.

Spain, for example, only last month published detailed guidelines on how electricity from distributed generation could be shared — despite having at least 35 million euros ($39 million) of investment ongoing in public-sector solar self-consumption schemes alone.

Elsewhere, though, countries such as Germany, the Netherlands and the U.K. are starting to show what can be achieved in benign regulatory regimes.

In the U.K., “peer-to-peer energy trading is possible on a production basis behind the meter,” said Jiro Olcott, chief technology officer at Power Transition, which is involved in a microgrid scheme in Corby, Northamptonshire.

But “regulators are up against major organizations [that] are very reactionary,” Olcott added. “I would say over the next five years we’re going to see some serious progress.”

Outside of Europe, Australia is moving fast on peer-to-peer thanks to a liberalized energy sector, high renewable penetration and a grid structure that favors the development of microgrids.

Last month, the Australian energy blockchain firm Power Ledger announced a collaboration with PV installer EPC Solar in Canberra, in a scheme that will allow a commercial site owner to trade solar energy with its tenant. It is Power Ledger’s second energy trading scheme in Australia, and the company is also looking to run a pilot in India.

Similar schemes have been hyped worldwide over the last couple of years as startups have sought to develop peer-to-peer trading platforms using blockchain technology.

In the U.S., for example, LO3 Energy last month trumpeted the launch of the country’s first commercial local energy marketplace for customers, in association with Green Mountain Power.

“This is a landmark moment for energy in the U.S., as it is the first time a community scale local energy market has been developed, regulated and commercially operated,” said LO3 Energy founder and CEO Lawrence Orsini in a statement.

But the ability to trade electrons across peer-to-peer networks still seems a distant prospect for most Americans, said Jenny Chase, head of solar analysis at Bloomberg New Energy Finance.

“If it’s happening, it’s on a small scale,” Chase said, reflecting the reality that it remains "administratively difficult and the rewards don’t justify it.”