Renewable Energy Storage (And How BEVs Present a Solution)

Renewable Energy Storage (And How BEVs Present a Solution)

Renewable Energy Demand

The two main drivers of the ever-increasing demand for renewable energy are: the globally accepted need to respond to climate change and information technology. These drivers enable the surprisingly complex management of renewable technology to be packaged as a commodity. But as usage is scaled, it becomes progressively difficult to reach demand.

Image: UK Renewable Energy Duck Curve | Image Source: Energy.gov

Renewable Energy Duck Curve In the UK

Renewable energy capacity can be easily scaled until it reaches our minimum energy requirements at any given time. However, as energy delivery starts to exceed demand, the grid experiences what has been coined: The Duck Curve. In other words, the naive use of renewable energy offers diminishing returns (making it more expensive), while the cost to customers can reach zero or below in a given situation [1].

For the UK, the Duck Curve is most likely to happen during the night when wind energy can often exceed usage (about 19GW).

Image Source: Author

SOLVING THE DUCK CURVE PROBLEM WITH IT

Supply & Demand

The main solutions for the energy imbalance are to apply information technology to time-shift energy usage where possible, to where it’s needed - for example, by running machinery at night or by managing the demand to the amount of supply.

Thus, electricity usage shifts to a supply-driven model.

Energy Storage

Another option, which has the most potential, is to store the energy. Storing energy allows us to overcommit renewable energy generation up to the point where it is equally cost-effective.

We have a number of energy storage options in the UK:

• Hydro (which is limited by geography and is currently about 4700 MWh [2]);
• Novel or arcane mechanisms such as liquid air (actually N2 extracted from air)
• Flywheels (which, although may sound comical, has practical applications in the order of MWh of stored energy).

All these energy storage options are inevitably distributed, due to either geography; because they are best placed near renewable energy sources themselves; or because they can be bought by private individuals, or communities.

However, by far the most versatile form of energy storage is certainly batteries and the most common form is Battery Electric Vehicles (BEV).

BEVs & Energy Storage

Last year, 190,000 full battery electric vehicles (BEVs) were added to the UK’s road network. On average they will have added over 9 GWh of potential energy storage (50kWh x 190,000 = 9 GWh) [3]. In this calculation, we should also consider the additional 200,000 BEVs already on the road, with a likely average of 40kWh, giving a potential 18 GWh of energy storage.

But by 2030 it’s possible (on lower than current trends) that an astounding 50% of vehicles on the road will be full EVs - perhaps 15 million - with a storage capacity of 750 GWh of energy storage.

That in itself is enough to substitute for current average gas power electricity generation, for a solid 62.5 hours.?By 2030, however, due to an increase in renewable energy, it will be considerably longer.

In comparison, utility scale battery storage solutions have a total capacity of 1.3GW [4], which according to their figures is equivalent to 52,000 BEVs. Residential battery storage in the UK can be estimated as about 200 MWh today [5].

In essence, the demand for electric vehicles places the potential for the bulk of renewable energy backup in the hands of millions of UK citizens.

Replicating Energy Storage in Popular Devices

It’s important to grasp that it’s not mere coincidence that the majority of battery storage is and will be embedded in EVs.?It’s happening because EVs - like the smartphones, tablets and laptops that previously used the majority of our high energy density batteries - are mobile and therefore the most versatile.

This means that battery EVs have the side-effect of driving us towards a more sustainable energy platform into the 2030s.

The demand for battery power is pushing battery R&D like never before in human history. For example, it means that utility and additional domestic storage will be forced to use less competitive chemistries such as Sodium-ion [2], where energy density isn’t quite as critical, and use depleted BEV batteries as they become available.

In either case, it’s the full battery EV market that’s disrupting existing transport and energy, while opening up energy generation and storage to many more people than was possible in the 20th century.

Conclusion

Battery EVs and charging systems are central to renewable energy demand.?They already provide by far the largest source of electrical storage.

In already playing a role, EV battery technology development is also advancing all battery technology; which, in itself, will further open markets for the storage of renewable energy.