How flexibility can solve green energy's greatest challenge

'What about when the wind's not blowing and the sun's not shining?'

We're asked this age-old question all the time in our quest for a 100% green energy system. The answer? We need an energy grid fit for the future. The old system: "burn stuff when people need to use power", isn't smart enough anymore – a lot of things in our world have got more complex since the industrial revolution, and energy is no exception. The full potential of renewables will be unlocked through a smart, dynamic, interconnected power system that works a bit like the internet.

The eternal challenge of every energy system is how to keep the grid in balance: matching energy supply (the power from the generators) and energy demand (the power people and businesses are using) to ensure they're equal at any given moment. The energy grid needs to have the wiggle room (flexibility) to adapt easily when either supply or demand changes unexpectedly.

This is really quite important: if things become unbalanced, there can be power cuts or system overloads which can damage grid infrastructure.

In systems designed for huge coal power plants, flexibility has been fairly simple. Whenever people need more power, we've just burned more dirty fossil fuels, and that's the system we've all been comfortable with for hundreds of years. With renewables, things aren't so simple. You can't just switch on the sun to meet energy demand whenever we need it.

At the same time, our energy needs have become more complicated, with electric cars, heat pumps, batteries and more becoming the norm.

A system fit for today's world is vastly more complex: a smart, dynamic, interconnected grid that works almost like the internet.

Flexibility in the age of renewable energy

Yet wind and solar energy is also ‘intermittent.’ We can’t say for sure when the wind will blow or the sun will shine - we can’t just ‘turn on’ renewables whenever we want. On some especially windy days we already generate far more wind power than we need, and actually have to pay wind generators to ‘turn off’ their turbines in order to protect the electrical grid. It’s an utter waste of low-carbon power, especially given that when energy demand peaks (usually between 4-7pm in the evening, when the sun is low) the grid often has to ask generators to burn more fossil fuels to keep up.

So there’s the central challenge of the energy transition: if we can no longer rely on turning large, dirty generators on and off to match our ever-changing energy demand, then ‘flexibility’ is going to have to come from somewhere else. Only then can we smooth the sun and wind's spiky, erratic power into a stable, controllable, 24/7 supply. Fortunately, we’ve got some clever solutions.

So where will energy flexibility come from?

People-powered flexibility

In a world powered by renewables, we need to flip flexibility on its head. We can unlock huge amounts of flexibility by encouraging (and rewarding) people for changing the times they use power in a way that matches when the greenest power is available.

In the past, it was assumed that individual people's flexibility wouldn't have much of an impact on the wider grid. Yet research suggests that our collective energy use can make a MASSIVE difference.

Here are a few of our projects encouraging people to use power flexibly.

Smart tariffs:

Smart tariffs like Intelligent Octopus, Octopus Go, and Agile Octopus are designed to reward customers for using energy in a way that unlocks flexibility - consuming more energy when the grid is chock full of green, renewable generated electrons, and using less when the grid is in demand and at its dirtiest (usually between 4-7pm on weekdays).

Just like that, customers are rewarded for being a bit more flexible with their energy usage. In other words, there’s an incentive for travelling “off peak” - shifting your energy consumption by a couple of hours (running washing machines and charging laptops a little earlier in the day, or later in the evening).

In the process, smart tariff customers are unlocking unprecedented flexibility - taking loads of stress off the grid at times when renewables are often a little harder to come by, and using up green energy when it would otherwise go to waste.

Smart Trials:

For the last few years, Octopus Energy has been running smart trials with various operators of different parts of the UK’s energy system. These valuable trials, including The Big Switch On, The Big Dirty Turn Down, The Windy Day Fund, Equinox, and Crowdflex, have been designed to test the potential for consumer-based flexibility (and take some strain off the grid in the process).

Supply-based flexibility

As we leave fossil fuels behind, another path to energy ‘flexibility’ involves finding new ways to adjust energy supply – turning on spare clean sources of power when we need a bit more to cover demand.

Here are a few of our projects in energy storage, vehicle-to-grid and green hydrogen.

Energy Storage:

What it sounds like, really – finding ways to hold large amounts of renewable-generated power to use at a later time when the wind isn’t blowing. Storage devices, from large commercial batteries to smaller in-home batteries, can charge up when renewables are abundant (and so energy is at its very cheapest and greenest). We can then use up this energy later on, rather than having to turn on dirty fossil fuel generators.

Here then, we’ve managed to find another way to unlock flexibility. By storing renewably generated electrons when they’re available for use later on, we have one way to call on green energy when we need it.

Kraken Flex:

Home-energy storage:

Thousands of Octopus Energy customers are already living in futuristic flexible homes thanks to home batteries and EVs, storing and discharging energy in much the same way that larger batteries do. In doing so, they’re laying the blueprint for a second massive, decentralised network of smaller, smarter in-home batteries.

Vehicle to grid charging:

On a similar note, Electric cars have a massive storage potential – they’re basically giant batteries on wheels, and more and more of them are being built with the ability to export power rather than just taking it in. Octopus’ Powerloop scheme helps turn electric vehicles into a vast network of decentralised batteries – rewarding drivers for storing cheap, green energy overnight, driving around all day, and then once home, discharging any spare energy back into the grid to help address the 4-7pm daily peak.

Early analysis suggests that if the UK’s EV’s were all plugged in at the right times, they could store renewables with enough capacity to meet a whopping half of the UK’s energy needs.

Finding flexibility with green hydrogen:

Flexibility: unlocking a cheaper and greener energy system

Customers already stand to save serious £££ in exchange for helping out with consumer-based flexibility via smart tariffs, home-energy storage, EVs, and smart trials. And that’s on top of the £8bn a year the UK stands to save by making the most of cheaper, greener renewable energy, and reducing the need for expensive infrastructure updates (according to the National Infrastructure Commission)!

So what are you waiting for? Get involved with a smart-trial, sign up for a smart tariff, or look into smart-home batteries - and you too could start flexing on the fossil fuel industry today.