There’s a popular belief that the looming presence of batteries in people’s homes will lead to the widespread defection of those customers from the power grid.
In this view, living the dream means grid-independence where you harvest your own energy, one-finger salute the power companies and, when grid power fails for others in the street, your battery keeps the party going at your house.
While cutting the power cord sounds good in theory, in practice consumers gain many more advantages from staying connected to the grid.
Likewise, rather than fear or obstruct the connection of batteries, energy utilities need to see distributed energy storage as a powerful resource that can add to the stability, sustainability and profitability of the power grid.
The short term motivation for consumers staying connected to the grid is the hip pocket.
Staying connected allows them to use the grid to dynamically resolve any shortfall between the energy they generate on their roof and the energy they need in their home.
The obvious scenario is to smoothly handle the times when your battery runs out of energy capacity overnight. Staying on the grid lets you keep things running until the sun comes up again. If you find that this is happening a lot, then you can consider buying more batteries later.
Another scenario is the handling of periods when the instantaneous energy needs of your house exceed the peak energy output rate that the batteries can supply. If your home is standalone, the house power will fail in these situations. However, when you’re still connected, the grid acts as an enormous on-demand, pay-as-you-go backup battery to meet any of these transient demand peaks that your battery can’t supply.
Without the grid, your only options are to buy an awful lot more batteries just to handle a week of rainy days or to maintain a backup generator on site. Otherwise, you may well suffer the somewhat ironic experience of sitting in the dark, surrounded by a suburb full of people whose lights are still on!
While in the medium term, you may progressively add more batteries to your home as you become familiar with your own energy usage patterns, those “peak power” demand periods still present a very valid reason for staying connected to the grid as an affordable on-demand backup source of energy.
The long term reasons for staying connected are much more interesting because they involve battery-equipped customers becoming part of the solution to the problem of supplying “peak power” back to the grid.
In Australia and globally, alert grid operators recognise that the proliferation of batteries presents them with some enormous technical advantages, which may include paying to use their customers’ batteries to help the grid work better.
Currently, the grid is a tree-like structure where energy emerges from distant generators, then flows through the trunk and along the branches to the ‘leaves’ of each house.
That hierarchical system can run into many problems. While the obvious one is a major power outage, the most common issue in grids is with maintaining grid stability in terms of frequency and voltage, especially at the extreme endpoints of the energy delivery path to customers.
The proliferation of residential solar panel systems (without batteries) actually makes management of grid stability much harder for grid operators.
When residential batteries are added, everything changes. These batteries can then be called upon in aggregate as a distributed ‘virtual generator’, embedded deeply throughout the grid’s customer base. In the future, then, a grid operator can call upon this virtual generator to dynamically and precisely balance frequency and voltage, and to do it exactly where and when that balancing is needed most.
Grid stabilisation of this sort is a service that customers can expect to be paid to provide back to the grid operator when needed.
Overall, then, widespread and integrated battery storage provides three clear benefits for the grid operator:
- They can inject energy back into the grid to help meet peak demand periods (without running up expensive gas-fired generators)
- They can help stabilise the frequency or the voltage of energy supplies
- They can help the grid operator diagnose problems throughout their coverage areas by offering precise diagnostics of what’s happening where to grid-supplied energy – this is where the rubber hits the road for the much-touted “Internet of things”.
In a nutshell, batteries attached to Internet-enabled control electronics in homes will create the key technology that enables the truly “smart” grid.
Grid operators need not only depend on the batteries installed by their customers: They can install their own large-scale batteries at power substations and country towns to at first supplement and ultimately replace expensive fossil-fuel powered energy generation.
The end game, if grid operators are smart enough to play it, is that the energy grid winds up much more like the Internet in that it becomes a trading platform on which energy is produced and consumed at lots of places instead of being a top-down network.
We could live in a world where you could build a community micro-grid without ever getting off the macro-grid, allowing useful energy commerce between you and your neighbours, and also between neighbouring micro-grids, while also delivering a more resilient energy future to all consumers.
The bottom line is that this much greater interconnectivity will drive down the price of electricity because consumers will be able to ‘roll their own’ while batteries will shave the demand peaks that currently bedevil our electricity generators.
Once that happens, then we will see consumers choosing electricity over fossil sources such as gas and petrol to meet their energy needs because it is both cheaper and more convenient.
Grid customers are already voting with their wallets and installing battery systems to complement their solar panel installations. Meantime, grid operators need not fear the battery revolution – they can, and they should, welcome it with open arms.
If you’re interested in more information about this topic, you might enjoy watching this conversation about the future of energy grids (recorded in October 2015 at the Future In Review conference in the USA).
This post is based upon a presentation delivered on February 15, 2016 at the Solar Supercharge conference in Brisbane http://www.solarcitizens.org.au/solar_supercharge.