Probably the biggest advantage that fossil fuels have over renewable energy resources is that they are easy to store. Over the last 150 years, we have spent massive amount of money building out that storage capacity and the related infrastructure. Renewables resources, on the other hand, such as solar and wind, are usually difficult and costly to store. The good news is that this situation is changing and it may change very fast because of the electrification of transport, which will cause an increase not only in renewables and energy storage penetration but ultimately a decrease in fossil fuel consumption.
The infrastructure to store fossil fuels is truly colossal. Most houses, for a start, have sheds or cellars where oil or coal can be stored. We also have tanks in our cars where diesel and gasoline can be kept. Then we have a massive infrastructure of pipes, rail carriages and tankers designed to bring gas, coal and oil from large storage areas into our homes and workplaces. And this infrastructure has taken over a century to build up in places like Europe, the US and Japan.
Renewables resources on the other hand, be it wind, solar or hydro tend to generate electricity, which is difficult to store. Electricity cannot be directly stored; it needs to be converted into another form of energy such as chemical energy, in a battery, or kinetic energy, through pumped hydropower. However, this costs money. The alternative, when there is too much renewable power in the system is to switch down or even off fossil fuel generation, and/or to flexibilise demand. These are the cheapest way to store renewables but they do have their limits. In fact, no matter how flexible a power system becomes, at some point storage will be needed if we want to move away from fossil fuels. The good news is that a solution may be close at hand in the form of the electric car.
The coming of the electric cars brings with it a new electricity storage infrastructure at zero incremental cost. Every new EV will probably mean one extra charging station and a battery, which in the case of a Tesla S would be enough power for the average home for three days! And if cars have intelligent charging and vehicle to grid (V2G) and vehicle to home (V2H) capabilities then the cars could be used as resources to balance intermittent renewables and increase the share of renewables without needing expensive grid reinforcements.
To put this potential into perspective, if only one tenth of Europe’s car fleet were Nissan Leafs, the most sold electric vehicle, with a standard battery capacity of 30kW, there would be close to 24 million batteries, or 720GWh of storage capacity, linked to the European grid every day. This is more than five times the existing pumped hydro storage capacity and what is more, it would cost the energy customer and the taxpayer zero! And the grid could tap into this energy if and when it’s needed. So, for example, instead of switching on a coal power station, electricity could simply be downloaded from some stationery vehicles that don’t need the energy at that moment. While this might sound highly futuristic to many, this scenario isn’t very far away and the digital technology to do so is already here.
