Real-World Pilot Rollout
On a very rainy day last week, we installed the final batteries in real homes for our pilot. It’s an exciting step and we’re already learning lots about how we can make the Windfall Battery the best possible battery aimed at renters and people living in flats.
What and why
Our initial first working prototype wasn’t pretty. It was a jumble of disparate components wired together - definitely not something we’d want to install in someone’s home, but it did the job in proving that we could use a small home battery to shift energy consumption and save money.
We’ve also shared the design process that’s getting us towards our own beautiful battery for flats. Our pilot is somewhere in between. To get things moving, we’re using off-the-shelf batteries controlled by our own software and app.
Choosing the battery to use for these pilot users wasn’t trivial, and frankly, was a painful process. This is perhaps not surprising because the whole reason for Windfall Energy is that the product we’re developing doesn’t exist. So there were necessary compromises with our pilot setup, but the hardware is good enough for our first real-world pilot.
The reason for this pilot is to further validate our hypothesis in the real world. Our key goals are:
Test the installation process in a range of home types: from renters, shared-ownership flats, to small homes.
Ensure we can control the charge and discharge of the batteries effectively with our software.
Gather data from batteries to measure performance.
Validate our software model for calculating savings from smart meter data, which we’re using to develop propositions in collaboration with our energy supplier partners.
Confirm the appetite from customers for our product, and understand how they interact with it.
Installation
When setting up in people’s homes, the environments are all different, especially in smaller homes where space is at a premium. Our pilot installations all went smoothly though and we were pleased to see that our assumptions about battery size and positioning played out more or less as expected.
A small cul-de-sac landing was the perfect spot for one of the batteries
Installation is a very important part of the overall value proposition of the Windfall Battery. It needs to be quick and easy in order to open up the benefits of a small home battery to as many people as possible, and to make sure the ROI is optimised.
We’ll continue to evolve the process as we develop our production system. Ultimately, our batteries need to be installed as simply as setting up a new laptop, not like plumbing in a new washing machine.
However, for the battery we’ve chosen for the pilots, electrical wiring regulations recommend a hard-wired power connection with an isolator switch, as shown below.
We’ve managed to make this a short, simple job for an electrician, which costs around £100, rather than the vastly more expensive, lengthy and complicated installation process required for a large home battery such as a Tesla Powerwall.
When the production Windfall Battery is ready it will be as simple as plugging the battery into a regular mains socket.
A lot of modern flats have a large utility cupboard which is a great spot for a small battery
The physical installation of the battery is just part of the process. If you’ve ever set up an IoT device like a smart plug or a connected doorbell you’ll know that it can be quite a fiddly process. Connecting a device to Wi-Fi and getting all the settings sorted on the app often involves way more effort than it should.
The batteries we’re using for these pilots come with an app, but it’s not great, particularly when trying to set up the battery to charge and discharge at certain times. You’d think that would be a relatively simple feature in an app that’s designed to control a battery, but sadly that’s not the case.
To make the experience for our pilot users better, and more like it will be with our production app, we’ve disaggregated the battery control so that they can use the Windfall App to do all they need to. This meant a lot more work on our side to reverse-engineer the API, pre-configure the batteries and set everything else up, but the result is a smooth experience for our users.
Data
Initial results from a data point of view have also been good. The batteries are all consistently sending data and operating as we expected. In the example below you can see the battery charging (the peak in the black line) during the night when electricity was cheapest (the green line). Overlaid on that is the yellow line showing the carbon intensity of the grid. It clearly shows the correlation between price and emissions, which highlights the win-win of our approach.
Battery data flowing from one of our pilot batteries
Unknown unknowns
One of the most important reasons for a real-world trial is for us to learn things we don’t even know we don’t know. It’s all very well having theoretical software models, and even hardware running in a lab, but we need to get out of those safe environments to fully understand the problem space.
Thankfully we haven’t hit any real roadblocks, but there were certainly some minor bumps. For example, a couple of the trial batteries had older versions of firmware straight out the box, which pretty much meant they didn’t work at all! Thankfully a firmware update easily got things moving again, but that kind of scenario could be missed in a sterile test environment.
And if software can be unpredictable, try adding humans into the mix. When we wondered why nothing was connecting at one install, we realised that our trial user had accidentally unplugged his router when getting the Wi-Fi credentials for us!
Over the coming months we’ll continue to monitor the data coming from the trial batteries, and we’ll keep an eye on how patterns might change as we get into the colder months of the year. We’ll also be ready for the unexpected.
From data and technical performance through to user experience feedback, this trial will deepen our understanding of the problem and, where necessary, direct us to build improvements and resilience into the solution.
Stay tuned for more updates as we get closer to bringing the final Windfall Battery to your home.
