The path to a sustainable electricity system: decentralised control


Matthew Williams, founder and CTO of Faraday Grid, believes we need a new platform for electricity, transforming our old assets into a highly flexible system with the autonomy to manage disturbances real-time.

Imagine it is August 2039, 20 years from today. The air conditioning is running full tilt in the northern hemisphere, and the heaters are on in the south.

This article was originally published in Smart Energy International 4-2019. Read the full digimag here or subscribe to receive a print copy here.

Autonomous electric vehicles chauffeur us from here to there, electric trains and trucks move our goods.

A generation has never been cleaner, or cheaper. By 2039, our energy generation is almost emission-free and distributed throughout modernised electric grids which are fully integrated with the design of our cities. The system is more reliable, and electricity is more accessible than ever before.

This is not just a daydream. Over one hundred US cities with 100% renewable generation mandates have committed to this future. The UN’s IPCC report requires us to achieve this energy system, to keep climate change below 2 degrees Celsius.

How did we get here?

The path to this future is not simple. The power grid of today was designed over a hundred years ago to deliver power from a few massive thermal generators to houses and businesses scattered around them.

Over the last decade, points of generation have been proliferating throughout the grid – where about 80 generation points served all of the United Kingdom in the early 2000s, now over one million different nodes generate electricity.

The system operator traditionally balanced the system by controlling the large generators from a central point to match consumption. But the ongoing evolution means that operators are losing not just control, but even visibility over the many new types of generation points contributing to power flows.

The grid is suddenly expected to deal with distributed, variable input in a rigid, centralised setting.

Evolving generation, changing loads When it comes to renewable generation, the challenges of whether the wind stops blowing or the sun stops shining are easily understood. But there are other constant, highly technical issues that come with evolving electric generation and demand.

Renewable and distributed generation, as opposed to synchronised, centralised fossil generation, destabilises the alternating current (AC) sine waves of electricity that are delivered to our homes and devices. This destabilisation comes in many forms, including voltage dips and swells, and phase imbalances.

Electric loads are designed with limited tolerance for disturbances in the waveform, and beyond that tolerance the system shuts down protectively. Big electric loads, like EV chargers, also come with issues: the inverters they use introduce harmonics to the AC sine wave, turning a smooth wave into a choppy one.

To date, these issues affecting electricity in the wires have been treated piecemeal. New technology is stuck onto the grid-like Band-Aid, treating individual symptoms but not causes.

This increases complexity, which in any system design leads to higher fragility and costs.

Without a fundamental change to the underlying system, our options for innovation will be limited – a system that is no longer fit for purpose can only be improved so much.

This is not the only reason why our electricity bills are getting higher Aside from cost increases due to mitigating technologies, renewable generation also has to be supplemented and curtailed in order to maintain the balance of real-time supply and demand, which is not free: “ancillary-” or “balancing services” take up a growing chunk within the system costs everybody pays in their electricity bill. And there’s no economy of scale; as renewables proportionally grow in the energy mix, the balancing costs will rise almost exponentially.

This is due to the centralised set-up. In many cases, the system operator’s best solution is to keep nuclear and fossil fuel plants running while curtailing solar and wind at times. Thermal plants use the inertia in their massive flywheels to compensate for changes in frequency or voltage due to renewable volatility.

Variable and distributed renewables cannot be reliably and affordably delivered with the same design that was put in place for synchronous, responsive thermal generation.

To achieve the fully electrified, decarbonised energy future we aspire for, a transformation of our electric grid is needed.

A system-wide solution

The electric grid has not changed in its fundamental design in over a hundred years, and the opportunities of the digital age are largely untapped. Small steps towards modernisation are visible in a proliferation of sensors and smart meters throughout the grid, which send information to the central control points.

But rather than attempting to balance the system through its ever-changing endpoints and compensating for its shortcomings with external solutions, I propose that it is time to bring the locus of control to the grid itself and making it decentralised.

This is not without analogues – the internet, a network of similar complexity, does not need a master controller and is able to serve as a platform for innovation of unprecedented speed.

Decentralised control enables the grid to support distributed renewables, batteries, smart software, microgrids, and technology still to come. The grid can become agnostic to how we generate and use energy. The system should not be a limiting factor in our options for future innovation, nor should it limit our lives right now.

This is what we have been working on at Faraday Grid: a new platform for electricity, transforming our old assets into a highly flexible system with the autonomy to manage disturbances real-time.

The Faraday Grid is underpinned by power flow control devices, called Faraday Exchangers.

Each Faraday Exchanger device manages a local area, but they also collaborate to form the highly stable network that can flexibly respond to changes in power flows.

This is a radical new way of thinking about the grid. Instead of passive wires carrying flowing power, the grid can be a self-regulating network. Instead of a fragile and rigid system, it can become a flexible and responsive asset.

The impact of reimagining the electricity system

This tectonic shift can also impact the economics of energy. A decentralised transactive layer could be added to the control points to couple the physics closely to the economics of energy. This brings efficiencies that will lead to cost reductions, but also open up entirely new market designs. People with rooftop solar installations would be able to sell to the market, rather than the utility, and therefore see demand-responsive pricing for their generation rather than flat fees.

Perhaps the biggest challenge to reach a decentralised grid is to do it with an achievable rollout pathway – we cannot shut down the electricity grid to start over.

To maintain reliability and keep costs in check, the transformation will have to be undertaken without disrupting continuous grid operation. The Faraday Grid was designed to be rolled out incrementally: Exchangers replace transformers that reach the end of their lives for a similar cost, one at a time.

Working towards the future we want

The electricity grid as we know it today was not designed for the future we aspire for. We must bring our grid into the digital age to enable a decarbonised energy mix.

We’re looking at a transformation on a par with taking telephones from switchboards to cellphones or taking the internet from dial-up to 5G: the end-user experience is still a conversation, or an internet search, or a switch turning on, but behind the scenes there’s a whole new approach.

Our electricity grid can be a technology platform that enables any kind of productive contribution. Collaboration and interoperability will be key, between technologies and across jurisdictions.

Ultimately, our society needs reliable, affordable, and sustainable energy, and we can only have it if we have a system that is fit for purpose now, and for the future. SEI