Spectral – Project “Jouliette”

Growing awareness around the impacts of climate change has propelled a rapid movement towards fully renewable, emissions-free energy supply. At this moment, most grid infrastructure can only support a limited amount (10-20%*) of renewable energy input while remaining stable, due to the fluctuating nature of renewable energy streams. Current market models are based on a largely supply-driven energy economy which lacks the flexibility needed to allow for higher penetration of renewables. New, intelligent ways of managing energy supply and demand, combined with innovative business models, are needed in order to effectively manage our transition towards a clean energy economy.

When ?

2017- 20xx

About ?


Spectral have implemented the Jouliette platform for setting up local energy markets based on blockchain technology. The first phase of the project is taking place at De Ceuvel, an Amsterdam community which has become a globally visible showcase for sustainable urban development. De Ceuvel features its own private microgrid, in which Spectral, together with Dutch DSO Alliander, are piloting new approaches for enabling local (peer-to-peer) energy trading via a local alternative token called the “Jouliette.”


The project aims to become a landmark example of how to harness the capabilities of blockchain technology to create greater social value and to support a bottom-up transition towards a more distributed, robust and transparent economy, underpinned by 100% renewable energy. In the current energy market, energy suppliers receive data from a (smart) meter, a bill is issued to the customer, and then the bill is paid via a monetary transaction from one bank to another.

With the Jouliette token, the De Ceuvel community members are able to make secure (peer-to-peer) transactions directly between their own virtual currency ‘wallets’. The blockchain, the technology behind Bitcoin, ensures that these transactions are secure and decentralized, with the history of transactions being shared with all the community members, so they can be (automatically) verified without needing the intervention of a “trusted” bank.


As a system integration specialist, Spectral is responsible for the development of the blockchain-based software solution, as well as delivery of customized hardware solutions for smart-metering and data collection. The software side of the project consisted of configuring an open-source blockchain technology (MultiChain) to facilitate local transactions within the community microgrid, and an online user portal which features historical data visualizations, forecasts, real-time energy billing, and an automated trading interface.

Each building at the pilot site was equipped with its own “block box,” which includes a single-board computer running the blockchain software and three smart-meters for measuring (real-time) data from the PV system, heat pump, and total building consumption. The initial hardware prototype has been further enhanced since the pilot launch at De Ceuvel and transformed into a low-cost, high-performance, and tamper-proof embedded device.



This implementation enables the community to exchange renewable energy (independent of the national electricity grid) produced by their photovoltaic panels, without any restrictions, and therefore avoid existing market barriers.

With the Jouliette platform, the De Ceuvel community can easily manage their own micro-economy, and unlike purely speculative currencies, the Jouliette tokens are backed up by physical energy production. Beyond enabling energy exchange, the community are exploring further applications for the Jouliette, such as using it to trade for goods at the De Ceuvel Cafe, to facilitate a local time-banking system, and to integrate other intra-community services, such as a car-sharing program.

Partners, duration, link

The main partners in the project are the Dutch DSO Alliander and the community members at De Ceuvel.

The first phase went live in September 2017, followed by an updated version in April 2018 that incorporated new energy billing features, implementation of automated trading agents, and a secondary token for the further exchange of goods and services at De Ceuvel.